Pest Status, Feeding Preferences and Control of Termites of Pakistan

Abstract

1. In wheat fields, six species of termites were recorded damaging the crop in Punjab. Population density of termites increased from December to March. 2. As regards vertical distribution in wheat fields, termites were more abundant in upper 20cm layer of the soil. 3. Correlation coefficient between atmospheric temperature and population/m2 was positive (.8836) at Lahore. At Rawat, however, negative correlation (0. 903), between atmospheric temperature and population/m2 was recorded. 4. Damage to wheat was highest, when the crop was approaching harvesting stage. 5. Of the six species of termites recorded damaging wheat crop in Punjab, microphagous was found to be the most abundant during 1986-1987. 6. During 1987-1988, obesity was more abundant in wheat fields in Punjab and constituted 76. 7% of the total population. 7. Seven species of termites were recorded from cotton fields in Punjab. 8. In cotton fields at Qadir Pur, Multan, unicolor and paradoxids were found only in upper 15cm layer of soil, whereas, microphagous and obesity were equally abundant at 15cm, 30cm, and 45cm depths. 9. Maximum termite activity in cotton fields in Punjab was recorded when the plants were very young i.e., in August. During December, termite’s population was poor in cotton fields. 10. In sugarcane fields, five species of termites were recorded damaging the crop. 11. Among the termite species collected from sugarcane fields, obesity and microphagous were abundant at 30cm depth, whereas, paradoxids was abundant at 15cm depth. 12. Maximum population density (253.1/m2) in sugarcane field at Manga Mandi was recorded in the month of July at 27°C atmospheric temperature and 89% relative humidity. 13. Sugarcane plants reaching maturity are damaged more by termites than the younger plants. Significant correlation was found between height of plant and percent damage. 14. As regards the wood preferences of fungus growing termite, nine wood species were tested. Mangifera indica was found most palatable wood to termites. 15. Studies on the effect of volume and position of stakes on feeding by subterranean termites revealed that more feeding was done on larger stakes and stakes resting on soil surface than stakes 50% buried or completely buried in soil. 16. As Cedrus deodara was found highly resistant wood to subterranean termites, effect of different temperatures on its natural resistance was also studied. Blocks of Cedrus deodara dried at 100°C or 12°C were consumed more than those dried at 50°C or 75°C indicating that the timber loses its resistance quality with increase in temperature. 17. Studies on feeding preferences of a Carton nest building termite, i.e., Microcerotermes championi revealed that a Azadirachta indica is highly susceptible to attack of this termite. The same wood, however, was resistance to subterranean fungus growing termites, indicating that different species have different feeding preferences. 18. Size of container also affected feeding of championi. Maximum feeding was recorded in a container having a volume of 57. 7 cm, but survival ·Was maximum in a container whose volume was 157.0 cm3. 19. Studies on nest population density of some pest species were undertaken. Population of the workers, which are responsible for doing damage to human property was higher from January to March. As regards the proportions of Castes (workers, soldiers and nymphs), they changed throughout the study period. Soldiers’ proportions were higher when nymphs were not present and when alates were ready to swarm in. 20. Diurnal and seasonal fluctuation, activity was also studied. Maximum population of termites was recorded at Noon time. 21. Swarming pattern of fungus growing subterranean termites was observed. Odontotermes obesus was recorded as the most abundant species. 22. Studies on several aspects of population ecology of Microcerotermes championi were carried out. Maximum population (137,038) was recorded in a nest which was opened in February. 23. As regards the laboratory screening of insecticides, various insecticides showed wide differences in toxicity. Heptachlor showed greater toxicity against obesus than Lorsban or Dieldrin. However, Tenekil was not found effective at any concentration. After 6 months storage Lorsban treated soil lost its toxicity. 24. The LD5ovalues (per termite) of Dieldrin, Heptachlor and Lorsban for obesus were 28.18 ppm, 28.85 ppm and 19.94 ppm after 6.5, 1.5. and 2.5 hours respectively. 25. Repellency tests with Lorsban, Heptachlor, Dieldrin and Tenekil revealed that Lorsban and Heptachlor were repellent at all concentrations tested (12.5, 25, 50, and 100 ppm). Dieldrin behaved as repellent at 100 ppm only and not at lower concentration. Tenekil was not repellent at any infested concentration. 26. Efficacy of insecticides in field tests was also studied. Soil was treated with 1% of Lorsban and Tenekil at rate of 140 ml per 200 cm area. Lorsban was found more effective in protecting 1,1100 than Tenekil during 30 months observations. 27. Efficacy of insecticides applied directly to wood was also studied. In this study, 1% Dieldrin and 2% Lorsban were found 100% effective in protecting the wood from termite attack during the 21 months. The experiment is still 11 progresses for long term results. 28. Efficacy of Lorsban and Dieldrin in protecting cotton crop from termite was also compared. Three concentrations i.e., 400 GAI/Acre, 800 GAI/Acre and 1600 GAI/Acre of the two insecticides were used. Lorsban at rate of 1600 GAI Acre was nearly as effective in protecting cotton crop from termite attack as Dieldrin applied at rate of 400 GAI/Acre.