Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

__________________________________________________________________Major Natural Enemies of Eggplant Insect PestsConservationAs for almost all natural enemies, hoverflies are easily killed by broad-spectrum insecticides. Avoid useof these pesticides when possible.Adult hoverflies need flowering plants to feed on. They are attracted to weedy borders and gardenplantings. Flowers have an important function in attracting hoverfly adults. See also section 4.9 onconservation of natural enemies.6.1.5 Spiders - AraneaePrimary prey: aphids, mites, moths, flies and beetles, depending on the species ofspider. They may also attack other natural enemies.Predatory stages: nymphs and adults.Description and life cycleSpiders are not insects but belong to the order of Araneae which have 8 rather than 6legs. There are many species of spiders and they can be roughly divided into two maingroups: spiders that hunt in search of prey and spiders that make webs and wait forprey to be caught in the web. Both types are very common predators in a vegetablefield and they can be very voracious. Most hunting spiders are very mobile and spend alot of time searching for prey. Web-makers are important predators of flying insects like moths.Like many other predators, the more prey spiders can consume, the more eggs will be laid by the female.This allows these predators to increase their numbers when the pest population increases.The number of eggs spiders can lay varies from a few to several hundreds, depending on the species.Some spiders carry the eggs in a little sac until the young spiders hatch from the eggs (e.g. wolf spiders– Lycosidae). Others guard the location where the eggs are deposited (e.g. lynx spiders) or place theegg mass in the web or on leaves, covered with fluffy silk. Spiders may live up to 4 months, dependingon the species.EffectivenessSpiders are voracious predators: it depends on the species how many prey it can eat on a day. Somespiders can eat as many as 5 large insects per day!ConservationMulching, especially organic mulch, can increase the number of spiders in vegetable crops becausespiders can hide in the layer of mulch and they find protection from sun and rain.Spiders are easily killed by broad-spectrum insecticides. Avoid using pesticides as much as possible.6.1.6 Praying mantids - MantodeaAlso called praying mantis. Several species of mantids are found invegetables.Primary prey: flies, bees, moths and small spiders.Predatory stages: nymphs and adults are predators.Description and life cycleBoth adult and nymphs have large front legs which they hold in a “praying”position. The nymphs look like small adults. The swaying motion allows themantid to judge how far away its prey is.Adult praying mantid102Eggplant Ecological Guide