Insecticidal Control of SHB Ebook Free Download
Insecticidal Control of
Small Hive Beetle
Developing a ready-to-use product
by Dr Garry Levot
September 2007
RIRDC Publication No 07/146
RIRDC Project No DAN 216A
© 2007 Rural Industries Research and Development Corporation.
All rights reserved.
ISBN 1 74151 542 4
ISSN 1440-6845
Insecticidal Control of Small Hive Beetle: Developing a ready-to-use product
Publication No. 07/146
Project No. DAN216A Pt II
The information contained in this publication is intended for general use to assist public knowledge and discussion
and to help improve the development of sustainable regions. You must not rely on any information contained in
this publication without taking specialist advice relevant to your particular circumstances.
While reasonable care has been taken in preparing this publication to ensure that information is true and correct,
the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication.
The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the
authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to
any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or
omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the
part of the Commonwealth of Australia, RIRDC, the authors or contributors.
The Commonwealth of Australia does not necessarily endorse the views in this publication.
This publication is copyright. Apart from any use as permitted under the Copyright Act 1968, all other rights are
reserved. However, wide dissemination is encouraged. Requests and inquiries concerning reproduction and rights
should be addressed to the RIRDC Publications Manager on phone 02 6271 4165.
Researcher Contact Details
Garry Levot
Elizabeth Macarthur Agricultural Institute (NSW DPI)
Woodbridge Road Menangle, NSW 2568
Phone:
Fax:
Email:
02 4640 6376
02 4640 6300
garry.levot@dpi.nsw.gov.au
In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form.
RIRDC Contact Details
Rural Industries Research and Development Corporation
Level 2, 15 National Circuit
BARTON ACT 2600
PO Box 4776
KINGSTON ACT 2604
Phone:
Fax:
Email:
Web:
02 6271 4100
02 6271 4199
rirdc@rirdc.gov.au.
http://www.rirdc.gov.au
Published in September 2007
Printed by Union Offset
ii
Foreword
This project aimed to refine the prototype refuge trap developed in DAN 216A Part I into a safe and
effective insecticide-based device that beekeepers could use for the control of Small Hive Beetles in
hives. The Small Hive Beetle Harbourage created comprises a fipronil-treated fluted cardboard insert
permanently sandwiched between a pair of custom-designed plastic mouldings that once assembled,
allow beetles to enter but exclude bees. The harbourage was shown to be compatible with existing
hive structure and bee keeping habits, easy to use, highly effective in reducing beetle infestations and
safe to users, bees and honey. There are patents pending for the invention not only in Australia but
also in the United States of America, Canada and New Zealand. However, a lack of commercial
interest in registering the product and restricted access to fipronil for this purpose may delay the
commercial availability of the device until the fipronil patents lapse. The commercialisation of the
device is essential so that beekeepers have an effective means for control of Small Hive Beetles in
hives and to discourage the use of 'home remedies' that could lead to contamination of honey and place
the industry at risk.
This project was funded from industry revenue which is matched by funds provided by the Australian
Government.
This report, an addition to RIRDC’s diverse range of over 1600 research publications, forms part of
our Honeybee R&D program, which aims to improve understanding and management of bee diseases
and pests and reduce production losses caused by pests and diseases.
Most of our publications are available for viewing, downloading or purchasing online through our
website:
•
•
downloads at www.rirdc.gov.au/fullreports/index.html
purchases at www.rirdc.gov.au/eshop
Peter O’Brien
Managing Director
Rural Industries Research and Development Corporation
iii
Acknowledgments
My thanks go to Mr Steve Goray, Mrs Lyn White and Mr Pat Carroll for allowing use of their hives in
the field trials and especially to Mr Nicholas Annand and Mr Bruce White for their willing
participation with the conduct of the field trials. The contribution of Dr Michael Hornitzky to this
project is gratefully acknowledged and I thank Mr John Ryan, NSW DPI Manager Commercialisation
for advice on the production of the commercialisation dossier and patent applications.
Abbreviations
APVMA - Australian Pesticides and Veterinary Medicines Authority (the regulatory authority
responsible for the registration of pesticides in Australia).
NSW - New South Wales
NSW DPI - New South Wales Department of Primary Industries
LC50 - Lethal Concentration to 50% of individuals tested
iv
Contents
Foreword ..................................................................................................................................iii
Acknowledgments.................................................................................................................... iv
Abbreviations........................................................................................................................... iv
Executive Summary ................................................................................................................ vi
Introduction .............................................................................................................................. 1
Objective................................................................................................................................. 3
Materials and Methods ............................................................................................................ 4
Refining the harbourage ......................................................................................................... 4
Residue trial with the End-Use-Product ................................................................................. 4
Honey.................................................................................................................................. 4
Cardboard inserts ................................................................................................................ 4
Commercialisation.................................................................................................................. 5
Field trials with the End-Use-Product .................................................................................... 5
Residual efficacy of the harbourages...................................................................................... 5
Refining the harbourage ......................................................................................................... 6
Residue trial with the End-Use-Product ............................................................................... 11
Commercialisation................................................................................................................ 14
Field trials with the End-Use-Product .................................................................................. 14
Trial 1. Wilberforce .......................................................................................................... 17
Trial 2. South Maroota...................................................................................................... 20
Trial 3. North Richmond................................................................................................... 22
Residual efficacy of the harbourages.................................................................................... 24
Discussion................................................................................................................................ 25
References ............................................................................................................................... 27
v
Executive Summary
What the report is about
This report details the development, safety and effectiveness of an insecticide-treated refuge trap for
the control of adult Small Hive Beetles in the hive.
Who is the report targeted at?
The report is written for beekeepers, advisors to the honeybee industry and the agrochemical industry.
Background
The Small Hive Beetle is an introduced pest of bee hives causing hive losses and reduced productivity
for beekeepers on Australia's eastern seaboard. Beekeepers may use oil traps to kill beetles in hives or
permethrin soil drenches to control larvae in the soil. Both are laborious, need regular attention and are
of limited effectiveness.
Aims/Objectives
This project aimed to refine the insecticidal harbourage developed during DAN 216A Part I into a
ready-to-use product for beekeepers. It was hoped that the device could be registered with the
Australian Pesticides and Veterinary Medicines Authority (APVMA) and marketed commercially by a
manufacturer.
Methods used
The design of the harbourage evolved from discussions between the Principal Investigator, specialist
plastics fabricators, cardboard manufacturers and beekeepers. Safety of the device was tested in a
honey residue trial conducted in accordance with APVMA Guideline No. 28 Residues in Honey. Field
trials conducted under APVMA Permit PER9732 in co-operation with commercial beekeepers in
western Sydney were used to demonstrate effectiveness in naturally-infested hives.
Results/Key findings
A device that excluded bees but which was actively sought out by adult beetles was developed. The
design: ensured that the insecticide-treated fluted cardboard insert was inaccessible to bees; is suitable
for use in current hive boxes; is user-friendly; and safe for beekeepers, their bees and honey.
Compared to 'control' hives, beetle infestations in hives at three western Sydney apiaries were reduced
by 90-99% over six weeks with no detrimental effects on hive productivity or bee health.
Implications for relevant stakeholders
These results demonstrate that use of this device in well-managed commercial hives provides
effective, safe and economical insecticidal control of Small Hive Beetle. The favourable results of the
honey residue trial demonstrated that use of the device did not compromise the safety of honey to
consumers by leaving unacceptable insecticide residues. There is no other control strategy with
comparable efficacy to the Small Hive Beetle Harbourage but currently no company or other body has
shown any interest in registering and commercialising the device in Australia or elsewhere in the
world where patent protection exists. An essential element of the device is the use of the insecticide
fipronil. Existing formulations of fipronil combine outstanding contact efficacy against Small Hive
Beetle with favourable physicochemical characteristics such as extremely low vapour pressure but
until patents expire BASF holds exclusive rights over all uses of fipronil. At the time of writing BASF
has stated that the use of fipronil as proposed is inconsistent with its product stewardship position.
Recommendations
That effort continues to ensure this product becomes commercially available for beekeepers. It may be
necessary to identify a sufficiently attractive overseas market to make registration of such a specialist
device an economically attractive proposition.
vi
Introduction
The Small Hive Beetle, Aethina tumida Murray was detected at Richmond in western Sydney hives late
in 2002 (Fletcher and Cook 2002). A. tumida is a native of southern Africa where it causes little concern to
apiarists. Primary damage caused by Small Hive Beetle is through the activity of the larvae that feed on
brood, pollen and honey causing it to ferment. Stored supers of honey or extracted comb are also
susceptible to damage by larvae and adult beetles (Elzen et al. 1999). Small Hive Beetle has
established in eastern Australia although initial foci were around Richmond in Sydney's west, Cowra
and Stroud (Gillespie et al. 2003).
The Consultative Committee on Emergency Animal Diseases concluded that the incursion of Small
Hive Beetle into NSW and Queensland could not be eradicated or contained. With the assistance of its
expert steering committee comprising representatives of the Commonwealth and affected State
governments, the Rural Industries Research and Development Corporation and the Australian
Honeybee Industry Council, Animal Health Australia developed a National Small Hive Beetle
Management Plan (2003) that had as one of its aims to "reduce the impact on productivity, slow the
spread of the Small Hive Beetle in Australia and minimise the damage in infested apiaries by
identifying and implementing measures (chemical, non-chemical and management) that minimise the
risk of harmful chemical residues" …... to control Small Hive Beetle.
Insecticide use was considered one of the strategies that could be used against adult and larval beetles.
In particular, insecticidal control of beetles inside the hive was the ambitious primary aim. In DAN
216A Part I we identified fipronil as being superior to several alternative insecticides by having the
desirable physicochemical characteristics of extremely low vapour pressure (Colliot et al. 1992) and
low water solubility as well as excellent contact efficacy against adult Small Hive Beetles (Levot and
Haque 2006) and no repellent effects. The behaviour of the beetles in laboratory culture (Haque and
Levot 2005) suggested that a refuge trap incorporating core-fluted cardboard might be devised for inhive use. Harbourages comprised of fipronil-treated core-fluted cardboard covered with adhesivebacked 50 µm thick aluminium foil were tested in the laboratory (Levot and Haque 2006) and in a
small number of NSW DPI research hives. The laboratory experiments demonstrated that over 98% of
beetles placed inside sealed hive boxes of stored comb were killed by the harbourages (Levot and
Haque 2006) but the trials in the research hives suggested that unless the open ends of the cardboard
were protected by several layers of foil bees could attack the cardboard (Figure 1) and hives would be
lost. Moreover, small residues of fipronil were detected in the honey produced by hives in which the
prototype harbourage was present.
Another prototype (Figure 2) with strengthened, overhanging foil edges was tested in twenty
commercial hives at two locations under APVMA Permit PER8167. After one month, with the use of
the treated harbourages at a Wilberforce apiary, the numbers of live adult beetles seen on the bottom
boards and elsewhere in the hives indicated a mean reduction of 93% compared to pre-treatment
counts. At an apiary located at Cranebrook the mean reduction in live beetle counts was 87%
compared with untreated control hives. However, at the Cranebrook site one hive was killed when
bees damaged the harbourage.
1
Figure 1. Damage to cardboard done by bees that forced entry into an early prototype
harbourage.
Figure 2. Early prototype cardboard harbourage used in the preliminary field trials (2005).
2
Two conclusions were drawn from the limited field work: the harbourages worked in that beetle
numbers in the hives were drastically and rapidly reduced, and; a more robust covering for the
fipronil-treated cardboard insert was required to protect bees and minimize the possibility of honey
contamination. This became the focus of the current project.
Objective
The project had a single objective:
•
To refine the insecticidal harbourage developed during DAN 216A Part I into a ready-to-use
product for use by beekeepers that could be registered with the Australian Pesticides and
Veterinary Medicines Authority and developed commercially by a manufacturer.
3
Materials and Methods
Refining the harbourage
Technical drawings of a two-piece rigid plastic harbourage shell thought to contain all the features
deemed important to the safety of bees and to the efficient operation of the device were made by the
Principal Investigator in August 2005. Important design features of the harbourage were:
•
A two-piece rigid plastic design
•
Tamperproof after assembly (no user access)
•
Made such that there are precisely sized openings that allow beetles in but exclude bees
•
Protective of C flute cardboard insert
•
Designed such that the cardboard insert is positioned 8 mm in from openings
•
Black
•
Compatible with silicone adhesives
•
Inexpensive
•
Disposable in household garbage.
Discussions were held with two potential manufacturers. The cardboard insert material ('C' flute
corrugated cardboard (Australian Corrugated Box Pty. Ltd., Wetherill Park, NSW; Product Code no.
CO3 RL150,) was deemed to be ideal in terms of a refuge for the beetles and as a matrix for the
insecticide.
As a check that the plastic harbourage was as attractive to the beetles as the foil-covered versions, a
piece of untreated cardboard was placed inside a final version of the harbourage as soon as it was
delivered. The assembled harbourage was, in turn, placed inside a plastic box containing over 100
adult Small Hive Beetles. The box was inspected four hours later.
Residue trial with the End-Use-Product
Honey
Five research hives located at Belgenny Farm, Camden were used in a honey residue trial that
commenced on 12 September 2006 when ambient temperatures and flowering favoured bee activity.
In accordance with APVMA Guideline 28 Residues in honey (APVMA 2001) two central frames
from the middle super of each hive were removed and brought to the laboratory. The cells on each
frame were uncapped and the honey extracted using a manual bench-top extractor. Honey from each
hive was bulked into a 10 L plastic drum and sub-samples were poured into labelled clean glass jars
prior to being placed into frozen storage. Drawing pins were pushed into the frames so that they could
be easily identified later and the frames were then placed back into the hives. One month later the
same frames were again removed. In accordance with the Guidelines the honey extracted from the ten
frames was bulked together. Five sub-samples of this post-treatment honey were transferred into
labelled clean glass jars which were then placed into a freezer. The frozen sample jars were sent to
AgriSolutions Australia Pty. Ltd. in Queensland as coded samples (i.e. the laboratory was blind to the
sample history).
Cardboard inserts
To quantify the amount of fipronil present in the cardboard used in the harbourages eight 5 x 5 cm
samples (identified as Cardboard samples CS, CT, CU, CV, CW, CX, CY and CZ) were sent to
AgriSolutions for individual analysis. CZ was an untreated 'control' piece of cardboard. Samples CS,
CT, CU, CV and CW were pieces cut from the cardboard that had been inside the harbourages used
for one month in the honey residue trial whereas CX and CY were recently treated cardboard.
4
Commercialisation
Until fipronil comes off-patent, BASF holds exclusive rights to its use. In anticipation of a change of
circumstance a commercialisation dossier was produced in collaboration with Mr John Ryan,
Commercialisation Manager (NSW DPI). This dossier was advertised in a call for Expressions of
Interest in the national newspapers in February 2007. The Executive Summary and the covering letter
calling for Expressions of Interest were also directly mailed to fifteen agrochemical companies. The
dossier contained a thorough description of the features, safety and effectiveness of the harbourage.
The closing date for applications was 13 March 2007.
Field trials with the End-Use-Product
A Category 23 (Application for a Research Permit) permit application was dispatched to the APVMA
in November 2006 as soon as the results of the honey residue trial with the plastic harbourage were
received. The application was based on the efficacy data collected during the 2005 field trials with the
prototype harbourage and on the favourable insecticide residue data collected during the spring 2006
trials with the plastic harbourage. The application contained supplementary information under the
headings Residues and Trade Considerations, Occupational Health and Safety and Target
Species Efficacy and Safety. A draft label with Directions for Use was also provided.
Field trials began shortly after the issue of the permit. On 1 March, previously purchased knife-cut
cardboard inserts were treated with Regent® 200SC Insecticide (1.5 mL per litre of water). When the
cards were dry and flat one hundred harbourages were assembled and sealed shut with 'plumbers'
plastic pressure pipe cement (Type P Plumbers Mate PVC-U Pipe Cement). Co-operators in South
Maroota, Wilberforce and North Richmond were enlisted into the trials.
Pre-treatment hive inspections were conducted at each apiary (14-21 March 2007). At each site ten
(usually) hives with suitable numbers of beetles were selected and Small Hive Beetle counts recorded
during disassembly of the hives. A single harbourage was placed on the bottom board of each 'trial
hive' in the apiary and, where possible, into each other hive at the apiary. At the South Maroota and
North Richmond sites two hives acted as 'controls'. At the smaller apiary at Wilberforce a single hive
acted as a control. In these hives a harbourage containing an untreated cardboard insert was placed on
the bottom board. Four and six weeks after placement the numbers of live and dead beetles were
recorded and all dead beetles removed. At each time point the percentage reduction in beetle numbers
was calculated with, and without correction for changes in beetle numbers in the 'control' hives.
Hence, for each site the absolute reduction in beetle numbers compared to the pre-treatment number
was calculated and also, the reduction in beetle numbers relative to the 'controls'. Here the % reduction
in live beetles was calculated using the Henderson and Tilton (1955) formula: 100 x (1 - (Ta/Tb x
Cb/Tb) where Ta and Tb were the mean number of beetles seen in the treated hives post- and pretreatment respectively and Ca and Cb were the mean number of beetles seen in the untreated hives
post- and pre-treatment.
After the six weeks post-treatment inspections the harbourages were removed, placed into individual
labelled sealable plastic bags and brought back to the laboratory where they were de-constructed and
the number of dead beetles inside recorded. With these numbers added, the total number of dead
beetles found in each hive during the trial interval was calculated. Of course, this number did not
include any dead beetles removed from the hives by the bees.
Residual efficacy of the harbourages
A trial was undertaken to assess the shelf-life of the fipronil treated cardboard. Cardboard inserts were
removed from four assembled harbourages that had been stored at ambient temperatures for 14 weeks.
The harbourages were from the same treatment batch used in the field trials (see below). The
cardboard had been treated on 1 March and the inserts were removed on 4 June 2007. Pieces of the
cardboard (9 x 9 cm) were wrapped in 50 µm thick adhesive backed aluminium foil and placed inside
the plastic containers (18 x 12 x 4 cm) with approximately 20 laboratory reared (Haque and Levot
2005) adult beetles. The containers were kept in an illuminated incubator run at 28oC. Mortality was
assessed after 48 hours and LC50s calculated according to the probit method of Finney (1970).
5
Results
Refining the harbourage
The technical drawings and the project in general were discussed with Low Volume Plastics Pty. Ltd.
Villawood, NSW on 6 September 2005 when a quotation for producing a prototype was requested.
Despite repeated contact, Low Volume Plastics failed to respond and were abandoned as potential
fabricators/manufacturers. Discussions with an alternative supplier were initiated immediately and
subsequently an order was placed with ProPlas Pty. Ltd. (19 October 2005) to provide a milled sample
of the two-piece prototype as originally drawn. A plastic prototype was delivered in early December
2005 (Figure 3) but the dimensions of the beetle entrance were larger than specification and another
prototype was ordered. This was not delivered until 27 April 2006 but again was unacceptable (Figure
4). In this version the gap entrance was too small for beetles to enter. On 20 June yet another revised
prototype was delivered but again was not as per specification. Although the entrance gap was the
correct size in this version, the height of the internal 'atrium' into which this gap opens was less than
the height of the cardboard insert. This effectively prevented beetles from gaining access to half of the
tunnels in the corrugated cardboard. At this point the issue of making the assembled harbourage
'tamperproof' was resolved when the designer suggested that the proposed clip locking device would
be too brittle for an acrylic plastic device and that the only way of permanently closing the device
would be to ultrasonically weld the halves together or to use a plastics' glue. The final design was
delivered in mid-July 2006 (Figure 5). At the recommendation of Mr. Bruce White, a very experienced
apiarist, small holes that could accept thin wire retrieval lanyards were added to the design (Figures 6,
7). Inclusion of a wire lanyard allows easy retrieval of the harbourage without the need to dismantle
the hive. Details of the internal structure of the harbourage, including the locking tabs that hold the
two halves firmly together, are shown in Figures 8-10. The acrylic plastic harbourage is rigid so that
there is little distortion of the assembled device and yet very resistant to breakage. It satisfies all of the
criteria set out in the specifications.
The plastic harbourage was eagerly sought out by the adult beetles in the laboratory experiment. When
checked four hours after placement all the beetles were inside the trap.
6
Figure 3. The first plastic prototype harbourage.
Figure 4. The second plastic prototype harbourage.
7
Figure 5. The final product assembled.
8
Figure 6. Assembled harbourage with retrieval wire attached.
Figure 7. Assembled harbourage showing detail of retrieval wire attachment.
9
Figure 8. Open harbourage showing location of cardboard insert.
Figure 9. Open harbourage showing location of cardboard insert and locking tabs.
10
Figure 10. Open harbourage showing locking tabs.
Residue trial with the End-Use-Product
The residue trial was conducted under ideal conditions for hive activity. This is reflected in the fact
that the bees stored approximately 9.4 kg of honey in the ten 'trial frames' during the month that the
harbourages were in the hives. AgriSolutions Australia Pty. Ltd. provided a Certificate of Analysis
(Figure 11). As expected, the total fiprole content (i.e. the sum of fipronil and its three toxic
metabolites MB 46513, MB 45950 and MB 46136) in each of the pre-treatment samples (Honey
samples #1, #2, #3, #4 and #5) was below the Limit of Quantification (
Small Hive Beetle
Developing a ready-to-use product
by Dr Garry Levot
September 2007
RIRDC Publication No 07/146
RIRDC Project No DAN 216A
© 2007 Rural Industries Research and Development Corporation.
All rights reserved.
ISBN 1 74151 542 4
ISSN 1440-6845
Insecticidal Control of Small Hive Beetle: Developing a ready-to-use product
Publication No. 07/146
Project No. DAN216A Pt II
The information contained in this publication is intended for general use to assist public knowledge and discussion
and to help improve the development of sustainable regions. You must not rely on any information contained in
this publication without taking specialist advice relevant to your particular circumstances.
While reasonable care has been taken in preparing this publication to ensure that information is true and correct,
the Commonwealth of Australia gives no assurance as to the accuracy of any information in this publication.
The Commonwealth of Australia, the Rural Industries Research and Development Corporation (RIRDC), the
authors or contributors expressly disclaim, to the maximum extent permitted by law, all responsibility and liability to
any person, arising directly or indirectly from any act or omission, or for any consequences of any such act or
omission, made in reliance on the contents of this publication, whether or not caused by any negligence on the
part of the Commonwealth of Australia, RIRDC, the authors or contributors.
The Commonwealth of Australia does not necessarily endorse the views in this publication.
This publication is copyright. Apart from any use as permitted under the Copyright Act 1968, all other rights are
reserved. However, wide dissemination is encouraged. Requests and inquiries concerning reproduction and rights
should be addressed to the RIRDC Publications Manager on phone 02 6271 4165.
Researcher Contact Details
Garry Levot
Elizabeth Macarthur Agricultural Institute (NSW DPI)
Woodbridge Road Menangle, NSW 2568
Phone:
Fax:
Email:
02 4640 6376
02 4640 6300
garry.levot@dpi.nsw.gov.au
In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form.
RIRDC Contact Details
Rural Industries Research and Development Corporation
Level 2, 15 National Circuit
BARTON ACT 2600
PO Box 4776
KINGSTON ACT 2604
Phone:
Fax:
Email:
Web:
02 6271 4100
02 6271 4199
rirdc@rirdc.gov.au.
http://www.rirdc.gov.au
Published in September 2007
Printed by Union Offset
ii
Foreword
This project aimed to refine the prototype refuge trap developed in DAN 216A Part I into a safe and
effective insecticide-based device that beekeepers could use for the control of Small Hive Beetles in
hives. The Small Hive Beetle Harbourage created comprises a fipronil-treated fluted cardboard insert
permanently sandwiched between a pair of custom-designed plastic mouldings that once assembled,
allow beetles to enter but exclude bees. The harbourage was shown to be compatible with existing
hive structure and bee keeping habits, easy to use, highly effective in reducing beetle infestations and
safe to users, bees and honey. There are patents pending for the invention not only in Australia but
also in the United States of America, Canada and New Zealand. However, a lack of commercial
interest in registering the product and restricted access to fipronil for this purpose may delay the
commercial availability of the device until the fipronil patents lapse. The commercialisation of the
device is essential so that beekeepers have an effective means for control of Small Hive Beetles in
hives and to discourage the use of 'home remedies' that could lead to contamination of honey and place
the industry at risk.
This project was funded from industry revenue which is matched by funds provided by the Australian
Government.
This report, an addition to RIRDC’s diverse range of over 1600 research publications, forms part of
our Honeybee R&D program, which aims to improve understanding and management of bee diseases
and pests and reduce production losses caused by pests and diseases.
Most of our publications are available for viewing, downloading or purchasing online through our
website:
•
•
downloads at www.rirdc.gov.au/fullreports/index.html
purchases at www.rirdc.gov.au/eshop
Peter O’Brien
Managing Director
Rural Industries Research and Development Corporation
iii
Acknowledgments
My thanks go to Mr Steve Goray, Mrs Lyn White and Mr Pat Carroll for allowing use of their hives in
the field trials and especially to Mr Nicholas Annand and Mr Bruce White for their willing
participation with the conduct of the field trials. The contribution of Dr Michael Hornitzky to this
project is gratefully acknowledged and I thank Mr John Ryan, NSW DPI Manager Commercialisation
for advice on the production of the commercialisation dossier and patent applications.
Abbreviations
APVMA - Australian Pesticides and Veterinary Medicines Authority (the regulatory authority
responsible for the registration of pesticides in Australia).
NSW - New South Wales
NSW DPI - New South Wales Department of Primary Industries
LC50 - Lethal Concentration to 50% of individuals tested
iv
Contents
Foreword ..................................................................................................................................iii
Acknowledgments.................................................................................................................... iv
Abbreviations........................................................................................................................... iv
Executive Summary ................................................................................................................ vi
Introduction .............................................................................................................................. 1
Objective................................................................................................................................. 3
Materials and Methods ............................................................................................................ 4
Refining the harbourage ......................................................................................................... 4
Residue trial with the End-Use-Product ................................................................................. 4
Honey.................................................................................................................................. 4
Cardboard inserts ................................................................................................................ 4
Commercialisation.................................................................................................................. 5
Field trials with the End-Use-Product .................................................................................... 5
Residual efficacy of the harbourages...................................................................................... 5
Refining the harbourage ......................................................................................................... 6
Residue trial with the End-Use-Product ............................................................................... 11
Commercialisation................................................................................................................ 14
Field trials with the End-Use-Product .................................................................................. 14
Trial 1. Wilberforce .......................................................................................................... 17
Trial 2. South Maroota...................................................................................................... 20
Trial 3. North Richmond................................................................................................... 22
Residual efficacy of the harbourages.................................................................................... 24
Discussion................................................................................................................................ 25
References ............................................................................................................................... 27
v
Executive Summary
What the report is about
This report details the development, safety and effectiveness of an insecticide-treated refuge trap for
the control of adult Small Hive Beetles in the hive.
Who is the report targeted at?
The report is written for beekeepers, advisors to the honeybee industry and the agrochemical industry.
Background
The Small Hive Beetle is an introduced pest of bee hives causing hive losses and reduced productivity
for beekeepers on Australia's eastern seaboard. Beekeepers may use oil traps to kill beetles in hives or
permethrin soil drenches to control larvae in the soil. Both are laborious, need regular attention and are
of limited effectiveness.
Aims/Objectives
This project aimed to refine the insecticidal harbourage developed during DAN 216A Part I into a
ready-to-use product for beekeepers. It was hoped that the device could be registered with the
Australian Pesticides and Veterinary Medicines Authority (APVMA) and marketed commercially by a
manufacturer.
Methods used
The design of the harbourage evolved from discussions between the Principal Investigator, specialist
plastics fabricators, cardboard manufacturers and beekeepers. Safety of the device was tested in a
honey residue trial conducted in accordance with APVMA Guideline No. 28 Residues in Honey. Field
trials conducted under APVMA Permit PER9732 in co-operation with commercial beekeepers in
western Sydney were used to demonstrate effectiveness in naturally-infested hives.
Results/Key findings
A device that excluded bees but which was actively sought out by adult beetles was developed. The
design: ensured that the insecticide-treated fluted cardboard insert was inaccessible to bees; is suitable
for use in current hive boxes; is user-friendly; and safe for beekeepers, their bees and honey.
Compared to 'control' hives, beetle infestations in hives at three western Sydney apiaries were reduced
by 90-99% over six weeks with no detrimental effects on hive productivity or bee health.
Implications for relevant stakeholders
These results demonstrate that use of this device in well-managed commercial hives provides
effective, safe and economical insecticidal control of Small Hive Beetle. The favourable results of the
honey residue trial demonstrated that use of the device did not compromise the safety of honey to
consumers by leaving unacceptable insecticide residues. There is no other control strategy with
comparable efficacy to the Small Hive Beetle Harbourage but currently no company or other body has
shown any interest in registering and commercialising the device in Australia or elsewhere in the
world where patent protection exists. An essential element of the device is the use of the insecticide
fipronil. Existing formulations of fipronil combine outstanding contact efficacy against Small Hive
Beetle with favourable physicochemical characteristics such as extremely low vapour pressure but
until patents expire BASF holds exclusive rights over all uses of fipronil. At the time of writing BASF
has stated that the use of fipronil as proposed is inconsistent with its product stewardship position.
Recommendations
That effort continues to ensure this product becomes commercially available for beekeepers. It may be
necessary to identify a sufficiently attractive overseas market to make registration of such a specialist
device an economically attractive proposition.
vi
Introduction
The Small Hive Beetle, Aethina tumida Murray was detected at Richmond in western Sydney hives late
in 2002 (Fletcher and Cook 2002). A. tumida is a native of southern Africa where it causes little concern to
apiarists. Primary damage caused by Small Hive Beetle is through the activity of the larvae that feed on
brood, pollen and honey causing it to ferment. Stored supers of honey or extracted comb are also
susceptible to damage by larvae and adult beetles (Elzen et al. 1999). Small Hive Beetle has
established in eastern Australia although initial foci were around Richmond in Sydney's west, Cowra
and Stroud (Gillespie et al. 2003).
The Consultative Committee on Emergency Animal Diseases concluded that the incursion of Small
Hive Beetle into NSW and Queensland could not be eradicated or contained. With the assistance of its
expert steering committee comprising representatives of the Commonwealth and affected State
governments, the Rural Industries Research and Development Corporation and the Australian
Honeybee Industry Council, Animal Health Australia developed a National Small Hive Beetle
Management Plan (2003) that had as one of its aims to "reduce the impact on productivity, slow the
spread of the Small Hive Beetle in Australia and minimise the damage in infested apiaries by
identifying and implementing measures (chemical, non-chemical and management) that minimise the
risk of harmful chemical residues" …... to control Small Hive Beetle.
Insecticide use was considered one of the strategies that could be used against adult and larval beetles.
In particular, insecticidal control of beetles inside the hive was the ambitious primary aim. In DAN
216A Part I we identified fipronil as being superior to several alternative insecticides by having the
desirable physicochemical characteristics of extremely low vapour pressure (Colliot et al. 1992) and
low water solubility as well as excellent contact efficacy against adult Small Hive Beetles (Levot and
Haque 2006) and no repellent effects. The behaviour of the beetles in laboratory culture (Haque and
Levot 2005) suggested that a refuge trap incorporating core-fluted cardboard might be devised for inhive use. Harbourages comprised of fipronil-treated core-fluted cardboard covered with adhesivebacked 50 µm thick aluminium foil were tested in the laboratory (Levot and Haque 2006) and in a
small number of NSW DPI research hives. The laboratory experiments demonstrated that over 98% of
beetles placed inside sealed hive boxes of stored comb were killed by the harbourages (Levot and
Haque 2006) but the trials in the research hives suggested that unless the open ends of the cardboard
were protected by several layers of foil bees could attack the cardboard (Figure 1) and hives would be
lost. Moreover, small residues of fipronil were detected in the honey produced by hives in which the
prototype harbourage was present.
Another prototype (Figure 2) with strengthened, overhanging foil edges was tested in twenty
commercial hives at two locations under APVMA Permit PER8167. After one month, with the use of
the treated harbourages at a Wilberforce apiary, the numbers of live adult beetles seen on the bottom
boards and elsewhere in the hives indicated a mean reduction of 93% compared to pre-treatment
counts. At an apiary located at Cranebrook the mean reduction in live beetle counts was 87%
compared with untreated control hives. However, at the Cranebrook site one hive was killed when
bees damaged the harbourage.
1
Figure 1. Damage to cardboard done by bees that forced entry into an early prototype
harbourage.
Figure 2. Early prototype cardboard harbourage used in the preliminary field trials (2005).
2
Two conclusions were drawn from the limited field work: the harbourages worked in that beetle
numbers in the hives were drastically and rapidly reduced, and; a more robust covering for the
fipronil-treated cardboard insert was required to protect bees and minimize the possibility of honey
contamination. This became the focus of the current project.
Objective
The project had a single objective:
•
To refine the insecticidal harbourage developed during DAN 216A Part I into a ready-to-use
product for use by beekeepers that could be registered with the Australian Pesticides and
Veterinary Medicines Authority and developed commercially by a manufacturer.
3
Materials and Methods
Refining the harbourage
Technical drawings of a two-piece rigid plastic harbourage shell thought to contain all the features
deemed important to the safety of bees and to the efficient operation of the device were made by the
Principal Investigator in August 2005. Important design features of the harbourage were:
•
A two-piece rigid plastic design
•
Tamperproof after assembly (no user access)
•
Made such that there are precisely sized openings that allow beetles in but exclude bees
•
Protective of C flute cardboard insert
•
Designed such that the cardboard insert is positioned 8 mm in from openings
•
Black
•
Compatible with silicone adhesives
•
Inexpensive
•
Disposable in household garbage.
Discussions were held with two potential manufacturers. The cardboard insert material ('C' flute
corrugated cardboard (Australian Corrugated Box Pty. Ltd., Wetherill Park, NSW; Product Code no.
CO3 RL150,) was deemed to be ideal in terms of a refuge for the beetles and as a matrix for the
insecticide.
As a check that the plastic harbourage was as attractive to the beetles as the foil-covered versions, a
piece of untreated cardboard was placed inside a final version of the harbourage as soon as it was
delivered. The assembled harbourage was, in turn, placed inside a plastic box containing over 100
adult Small Hive Beetles. The box was inspected four hours later.
Residue trial with the End-Use-Product
Honey
Five research hives located at Belgenny Farm, Camden were used in a honey residue trial that
commenced on 12 September 2006 when ambient temperatures and flowering favoured bee activity.
In accordance with APVMA Guideline 28 Residues in honey (APVMA 2001) two central frames
from the middle super of each hive were removed and brought to the laboratory. The cells on each
frame were uncapped and the honey extracted using a manual bench-top extractor. Honey from each
hive was bulked into a 10 L plastic drum and sub-samples were poured into labelled clean glass jars
prior to being placed into frozen storage. Drawing pins were pushed into the frames so that they could
be easily identified later and the frames were then placed back into the hives. One month later the
same frames were again removed. In accordance with the Guidelines the honey extracted from the ten
frames was bulked together. Five sub-samples of this post-treatment honey were transferred into
labelled clean glass jars which were then placed into a freezer. The frozen sample jars were sent to
AgriSolutions Australia Pty. Ltd. in Queensland as coded samples (i.e. the laboratory was blind to the
sample history).
Cardboard inserts
To quantify the amount of fipronil present in the cardboard used in the harbourages eight 5 x 5 cm
samples (identified as Cardboard samples CS, CT, CU, CV, CW, CX, CY and CZ) were sent to
AgriSolutions for individual analysis. CZ was an untreated 'control' piece of cardboard. Samples CS,
CT, CU, CV and CW were pieces cut from the cardboard that had been inside the harbourages used
for one month in the honey residue trial whereas CX and CY were recently treated cardboard.
4
Commercialisation
Until fipronil comes off-patent, BASF holds exclusive rights to its use. In anticipation of a change of
circumstance a commercialisation dossier was produced in collaboration with Mr John Ryan,
Commercialisation Manager (NSW DPI). This dossier was advertised in a call for Expressions of
Interest in the national newspapers in February 2007. The Executive Summary and the covering letter
calling for Expressions of Interest were also directly mailed to fifteen agrochemical companies. The
dossier contained a thorough description of the features, safety and effectiveness of the harbourage.
The closing date for applications was 13 March 2007.
Field trials with the End-Use-Product
A Category 23 (Application for a Research Permit) permit application was dispatched to the APVMA
in November 2006 as soon as the results of the honey residue trial with the plastic harbourage were
received. The application was based on the efficacy data collected during the 2005 field trials with the
prototype harbourage and on the favourable insecticide residue data collected during the spring 2006
trials with the plastic harbourage. The application contained supplementary information under the
headings Residues and Trade Considerations, Occupational Health and Safety and Target
Species Efficacy and Safety. A draft label with Directions for Use was also provided.
Field trials began shortly after the issue of the permit. On 1 March, previously purchased knife-cut
cardboard inserts were treated with Regent® 200SC Insecticide (1.5 mL per litre of water). When the
cards were dry and flat one hundred harbourages were assembled and sealed shut with 'plumbers'
plastic pressure pipe cement (Type P Plumbers Mate PVC-U Pipe Cement). Co-operators in South
Maroota, Wilberforce and North Richmond were enlisted into the trials.
Pre-treatment hive inspections were conducted at each apiary (14-21 March 2007). At each site ten
(usually) hives with suitable numbers of beetles were selected and Small Hive Beetle counts recorded
during disassembly of the hives. A single harbourage was placed on the bottom board of each 'trial
hive' in the apiary and, where possible, into each other hive at the apiary. At the South Maroota and
North Richmond sites two hives acted as 'controls'. At the smaller apiary at Wilberforce a single hive
acted as a control. In these hives a harbourage containing an untreated cardboard insert was placed on
the bottom board. Four and six weeks after placement the numbers of live and dead beetles were
recorded and all dead beetles removed. At each time point the percentage reduction in beetle numbers
was calculated with, and without correction for changes in beetle numbers in the 'control' hives.
Hence, for each site the absolute reduction in beetle numbers compared to the pre-treatment number
was calculated and also, the reduction in beetle numbers relative to the 'controls'. Here the % reduction
in live beetles was calculated using the Henderson and Tilton (1955) formula: 100 x (1 - (Ta/Tb x
Cb/Tb) where Ta and Tb were the mean number of beetles seen in the treated hives post- and pretreatment respectively and Ca and Cb were the mean number of beetles seen in the untreated hives
post- and pre-treatment.
After the six weeks post-treatment inspections the harbourages were removed, placed into individual
labelled sealable plastic bags and brought back to the laboratory where they were de-constructed and
the number of dead beetles inside recorded. With these numbers added, the total number of dead
beetles found in each hive during the trial interval was calculated. Of course, this number did not
include any dead beetles removed from the hives by the bees.
Residual efficacy of the harbourages
A trial was undertaken to assess the shelf-life of the fipronil treated cardboard. Cardboard inserts were
removed from four assembled harbourages that had been stored at ambient temperatures for 14 weeks.
The harbourages were from the same treatment batch used in the field trials (see below). The
cardboard had been treated on 1 March and the inserts were removed on 4 June 2007. Pieces of the
cardboard (9 x 9 cm) were wrapped in 50 µm thick adhesive backed aluminium foil and placed inside
the plastic containers (18 x 12 x 4 cm) with approximately 20 laboratory reared (Haque and Levot
2005) adult beetles. The containers were kept in an illuminated incubator run at 28oC. Mortality was
assessed after 48 hours and LC50s calculated according to the probit method of Finney (1970).
5
Results
Refining the harbourage
The technical drawings and the project in general were discussed with Low Volume Plastics Pty. Ltd.
Villawood, NSW on 6 September 2005 when a quotation for producing a prototype was requested.
Despite repeated contact, Low Volume Plastics failed to respond and were abandoned as potential
fabricators/manufacturers. Discussions with an alternative supplier were initiated immediately and
subsequently an order was placed with ProPlas Pty. Ltd. (19 October 2005) to provide a milled sample
of the two-piece prototype as originally drawn. A plastic prototype was delivered in early December
2005 (Figure 3) but the dimensions of the beetle entrance were larger than specification and another
prototype was ordered. This was not delivered until 27 April 2006 but again was unacceptable (Figure
4). In this version the gap entrance was too small for beetles to enter. On 20 June yet another revised
prototype was delivered but again was not as per specification. Although the entrance gap was the
correct size in this version, the height of the internal 'atrium' into which this gap opens was less than
the height of the cardboard insert. This effectively prevented beetles from gaining access to half of the
tunnels in the corrugated cardboard. At this point the issue of making the assembled harbourage
'tamperproof' was resolved when the designer suggested that the proposed clip locking device would
be too brittle for an acrylic plastic device and that the only way of permanently closing the device
would be to ultrasonically weld the halves together or to use a plastics' glue. The final design was
delivered in mid-July 2006 (Figure 5). At the recommendation of Mr. Bruce White, a very experienced
apiarist, small holes that could accept thin wire retrieval lanyards were added to the design (Figures 6,
7). Inclusion of a wire lanyard allows easy retrieval of the harbourage without the need to dismantle
the hive. Details of the internal structure of the harbourage, including the locking tabs that hold the
two halves firmly together, are shown in Figures 8-10. The acrylic plastic harbourage is rigid so that
there is little distortion of the assembled device and yet very resistant to breakage. It satisfies all of the
criteria set out in the specifications.
The plastic harbourage was eagerly sought out by the adult beetles in the laboratory experiment. When
checked four hours after placement all the beetles were inside the trap.
6
Figure 3. The first plastic prototype harbourage.
Figure 4. The second plastic prototype harbourage.
7
Figure 5. The final product assembled.
8
Figure 6. Assembled harbourage with retrieval wire attached.
Figure 7. Assembled harbourage showing detail of retrieval wire attachment.
9
Figure 8. Open harbourage showing location of cardboard insert.
Figure 9. Open harbourage showing location of cardboard insert and locking tabs.
10
Figure 10. Open harbourage showing locking tabs.
Residue trial with the End-Use-Product
The residue trial was conducted under ideal conditions for hive activity. This is reflected in the fact
that the bees stored approximately 9.4 kg of honey in the ten 'trial frames' during the month that the
harbourages were in the hives. AgriSolutions Australia Pty. Ltd. provided a Certificate of Analysis
(Figure 11). As expected, the total fiprole content (i.e. the sum of fipronil and its three toxic
metabolites MB 46513, MB 45950 and MB 46136) in each of the pre-treatment samples (Honey
samples #1, #2, #3, #4 and #5) was below the Limit of Quantification (