Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

_____________________________________________________________________Ecology of insect pests and natural enemiesNeem, derived from the neem tree (Azadiracta indica) of arid tropicalregions, contains many active compounds that act as feeding deterrentsand as growth regulators. The main active ingredient is azadiractin,which is said to be effective on 200 types of insects, mites andnematodes. These include caterpillars, thrips and whiteflies. It has lowtoxicity to mammals.Both seeds and leaves are used to extract the oil or juices. A neemsolution looses its effectiveness when exposed to direct sunlight and iseffective for only eight hours after preparation. It is most effective underhumid conditions or when the plants and insects are damp.High concentrations can cause burning of plant leaves! Also, naturalenemies can be affected by neem applications (Loke, 1992).neemNicotine, derived from tobacco, is extremely toxic and fast acting on mostanimals, including livestock such as cows and chicken. It can kill people. Thenicotine of half a cigarette is enough to kill a full-grown person! After anapplication, food plants should not be eaten for 3-4 days. This time is requiredfor the nicotine to decompose. In parts of West Africa, the tobacco plant isintercropped with maize because it is said to lower numbers of borer insects onthe maize. Nicotine kills insects by contact, or if inhaled or eaten. The mostcommon use is to control soft-bodied insects such as aphids, mites andcaterpillars.An additional danger of using tobacco leaf extract is that this extract maycontain a virus disease called Tobacco Mosaic Virus, or TMV. This virusdisease affects a wide range of plants, mainly solanaceous crops. Whenspraying tobacco extract, chances are that you actually apply TMV!Rotenone is extracted from the roots of bean legumes, especially Derris sp.Rotenone is a contact and stomach poison. It is also toxic to fish, pigs and honeybees! It irritates the human skin and may cause numb feelings in mouth and throat ifinhaled. Derris roots must be stored in cool, dry and dark places otherwise therotenone breaks down. Rotenone has very low persistence so once a spray isprepared it must be used at once.Pyrethrum is a daisy-like Chrysanthemum. In the tropics, pyrethrum is grown inmountain areas because it needs cool temperatures to develop its flowers.Pyrethrins are insecticidal chemicals extracted from the dried pyrethrum flower.Pyrethrins are nerve poisons that cause immediate paralysis to most insects. Lowdoses do not kill but have a “knock down” effect. Stronger doses kill. Humanallergic reactions are common. It can cause rash and breathing the dust cancause headaches and sickness.Both highly alkaline and highly acid conditions speed up degradation so pyrethrinsshould not be mixed with lime or soap solutions. Liquid formulations are stable instorage but powders may lose up to 20 percent of their effectiveness in one year.Pyrethrins break down very quickly in sunlight so they should be stored indarkness.62Eggplant Ecological Guide