Ecological effect on the attack intensity of P. javana

Bogor, 21-22 October 2015 609

3.5 Ecological effect on the attack intensity of P. javana

The development of pests is influenced by various factor, one of this factor is ecology aspect. Two aspects of ecology used as parameter measured in this study are season and growth rate of H. macrophyllus represented by location. Based on analysis, influence of season and location of attack intensity show that season and location of each study significantly affect the intensity of attacks, while the interaction between season and location was not significant Table 3. Attack intensity of P. javana in dry season was higher 51.46 than rainy season 43.59. This condition showed that the influence of rainfall was significant to attack intensity of P. javana. This is similar to Fasunwon and Badjo 2010, that rainfall had significant effect on populations of Podagrica, while temperature and humidity had no significant effect. Moreover, based ANOVA test of regression models which presented in Tables 4 and 5, show that precipitation effect was significant linear with a reduction of rainfall as indicated by negative value constant or increasing rainfall then decreasing attack intensity of P.javana. The rain can directly affect the populations of pests, when large rain, many pest are dead, especially influential in the growth and activity of pests. The effect of rain on pest life can be directly mechanically or indirectly to air and soil condition. Mechanical influences intended as pounding of raindrops on insects or in habitat. Heavy rain can lead a lot of beetles fall and die, causing a significant reduction of pest population. Table 4: Further test results of location infleunce to attack intensity of P. javana Location Intensity of attack Tanjungjaya 43,1917a Sodonghilir 46,0000a Gunungtanjung 53,3333b Table 3: Analysis results of season and location influence to P. javana intensity attack Sum square df Mean square F Sig. Corrected Model 13175,125a 5 2635,025 12,491 ,000 Intercept 812535,025 1 812535,025 3851,658 ,000 Season 5577,469 1 5577,469 26,439 ,000 Location 6580,717 2 3290,358 15,597 ,000 Season Location 1016,939 2 508,469 2,410 ,091 Error 74678,850 354 210,957 Total 900389,000 360 Corrected Total 87853,975 359 Note: = significant significantly different Table 5: Analysis ANOVA results for linear regression Sum square df Mean square F Sig. Regresi 11748,674 2 5874,337 27,556 0,000 Residu 76105,301 357 213,180 Total 87853,975 359 Note: = significant significantly different Bogor, 21-22 October 2015 610 Effect of location represents the growth rate of H. macrophyllus. Table 4 shows that attack intensity in Gunungtanjung 53.3 was significantly different from attack intensity in Sodonghilir and Tanjungjaya. The growth rate of H. Macrophyllus in Gunungtanjung dominated with seedlings and saplings compared to Sodonghilir and Tanjungjaya that dominated with pole and tree. Larvae and imago P. javana prefer to attack young plants, so that pest attack on seedlings and saplings growth rate higher than pole and tree. Table 6: Value constants and coefficients for linear regression B KB t Sig. Constant 49,175 3,078 15,976 0,000 Season -7,872 1,539 -5,115 0,000 Location 5,071 ,942 5,380 0,000 Note: = significant significantly different Regression models obtained are as follows: Y = 49,175 - 7,872X 1 + 0,571X 2 Description: Y = attack intensity X1 = season X2 = location Similarly, the results of the regression analysis showed that the constant of location is positive or higher composition of seedlings and saplings of H. Macrophyllus make higher the attack intensity of P. javana. Food abundant of pest affect pest population increase that cause an increase attack intensity.

3.6 Pest control