Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

__________________________________________________________________________________Major Eggplant Insect PestsRed ant is considered a “pest” because it can remove seeds from the seedbed, damage newly emergingseedlings, or cause injury to the shoots of eggplant.Description and life cycleAnts are social insects, living in colonies of variable size. There are at least threemorphologically different forms: queens (fertile females), males and workers. The malesare short-lived and die after the nuptial flight. Females, or queens, are also winged butlose their wings after the nuptial flight. Their reproductive organs are well-developed,and all females are able to lay eggs. The number of queens per colony may varybetween a single queen and several queens. Workers are wingless female progeny,which are generally smaller than the queen. In contrast to the queens, whose solefunction is to produce eggs, workers are responsible for brood care, foraging and colony defense.Eggs are usually laid in specific egg chambers, where workers care for them. Larvae are maggotswithout legs and eyes. Larval development is usually completed within four instars. Adults are long-lived,with queens often reaching an age of >10 years.Host rangeBesides eggplant, the ant also attacks potato, cauliflower, cabbage, radish, turnip, groundnut and beans.Plant damage and plant compensationRed ant is a serious problem in some parts of India, in Mymensingh (Bangladesh) and especially inNepal. It attacks mainly young plants. During a TOT in Mymensingh, Bangladesh (1999), participantsfound that ants made small holes on growing tips of eggplant shoots and fed on the sap emerging fromthe wound.Red ants can also remove or damage seeds in the seedbeds.Eggplant can probably compensate for shoot damage by ants, depending on the amount of damage andthe growth stage.Natural enemiesUnknown.Management and control practicesIn Bangladesh, traditional methods of control include:• Use of turmeric powder. Turmeric, a perennial plant, has excellent pest repellent properties.• Use of wood ash.• Use of wheat flour: this distracts ants from feeding on plants or seeds in the nursery. Other scatteringfood pieces such as rice grains, breadcrumbs etc. can also be used. Some farmers found that thesmaller the pieces of food, e.g. wheat flour, the longer it took the ants to remove them.• Baiting the ants with paper soaked in vegetable oil.(pers.comm. Dr. Lim Guan Soon, 2001; CAB International, Crop Protection Compendium, 2000).Related exercises from CABI Bioscience/FAO Vegetable IPM Exercise Manual4-A.3. Plant compensation study95Eggplant Ecological Guide