Eggplant Integrated Pest Management AN ECOLOGICAL GUIDE

_____________________________________________________________________Ecology of insect pests and natural enemiesNet houses may also be higher: about 2 - 3 meters. These can be used for both nurseries and productionfields. For good insect prevention, they need to be fully closed!Although initial investment for preparing the net houses is high, savings from reduced sprayings canmake it attractive. When properly prepared and maintained, net houses can be used more than once.Inside a net house, the temperature may be a bit lower due to shading effect of the net and the humiditymay be a bit higher than outside. This may result in a quicker growth of the crop but it may also result inmore disease problems.Related exercises from CABI Bioscience/FAO Vegetable IPM Exercise Manual:2-B.9. Roofing and screening of seed beds4.11.2 Use of trapsThere are several types of traps to catch insects. Most traps will catch adult insects. These traps areoften used for monitoring of populations rather than actual control. However, since some traps catchlarge quantities of insects they are often considered as control measures in addition to monitoring.If traps are used in isolation, information from them can be misleading. A low number catch will notindicate the timing of a pest attack, let alone its severity. Similarly, the number of insects caught in onecrop cannot be used to predict the number that will occur in other crops, not even when the crops are inadjacent fields.The most common types of traps used in the field are shortly described below.Pheromone traps: these are traps that contain a sticky plate and a small tube with a chemical solutioncalled a pheromone. Pheromones are chemicals produced by insects that cause strong behavioralreactions in the same species at very small amounts. They are usually produced by females to attractmales of the same species for mating. Such chemical is called ‘sex pheromone’.The males will fly to the pheromone trap and are trapped on the sticky plate. Pheromones have beendeveloped for several vegetable pests including fruit and shoot borer (Leucinodes orbonalis).Pheromones are mainly used for detecting and monitoring pests, to a lesser extent for control of pestpopulations. One of the reasons is the high cost of pheromones, which have to be synthesized in alaboratory.A pheromone trap attracts male adultsPitfall traps: are plastic or glass jars, half-filled with water and a detergent like soap, buried into the soilup to the rim of the jar. These traps are good for catching ground-dwelling insects like ground beetles.Purpose of these traps is purely for monitoring as many ground beetles are active during the night andyou may miss them when monitoring the field during the day. Pitfall traps may also be used without waterand detergent, to catch living insects for insect zoos. However, good climbers will escape.A pitfall trapjar withwater+detergent,buried at soil level59Eggplant Ecological Guide