Jassids on Eggplant
Initial symptoms appear as chewing patterns on the lower leaf side. The infested leaves turn yellowish and later show burnt patches, curling upward along the margins as the disease progresses. Plants generally show a stunted growth and bushy appearance, with shorter internodes, large number of branches and buds. Smaller, deformed leaves also have shorter petioles, thereby the common name "little leaf disease". An infestation of the field can lead to a symptom called "hopper-burn” (whole leaves turn brown), defoliation, sterile flowers and reduced fruit stands. This is followed by heavy yield loss.
The adults are small, longish, slim and bright green to yellow-green with shimmering wings, depending on the species. The female lays about 50 tiny, greenish and banana-shaped eggs into the large leaf veins or the petioles. After about 6-10 days the larvae hatches. There are different larval stages, the older one is about 2 mm, yellowish-green and looks pretty much like the adult insect but smaller and without wings. Usually they are located on the lower leaf side. The larval stage lasts for about 14-18 days. Through warm and wet weather periods the population growth is high and there can be several generations within a season. Jassids are also vectors for virus and bacteria, and therefore an infestation may be very damaging.
Parasitoid wasps species such as Anagrus flaveolus and Stethynium tridavatum can be used to control the populations of jassids. Leaf extracts of neem, tobacco and eucalyptus can be sprayed onto the foliage.
Whenever possible, opt for an integrated approach. If insecticides are necessary, products containing malathion and dichlorvos can be used as foliar spray applications. Bear in mind that dichlorvos is toxic and has a negative impact on human health as well as on animals such as bees, fish and birds.