Ecological and biological studies on the green bug, Nezara viridula L. (Pentatomidae: Hemiptera)

Abstract

Nezara viridula L. is one of the most important pentatomid pests in the world. In the A.R. of Egypt, the insect, is widely spread all over the country attacking a wide variety of agricultural crops and many weed species. Recently, population size of the insect tended to be high causing a considerable damage to many host plants either directly by sucking plant juices or indirectly by transmitting pathogenic organisms. The present work was carried out during two successive seasons; 1999/2000 and 2000/2001 at Kafr El-Sheikh governorate to study some ecological and biological aspects of N. viridula. The obtained results could be summarized as follows:

1. Ecological studies:

1.1. The host range of Nezara viridula L.:

A total 36 plant species (12 field crops, 10 vegetable crops and 14 weed species) belonging to 10 botanical families were found to harbor N. viriaula. Both nymphs and adults were observed on 6 summer field crops (cotton, corn, rice, sunflower, soybean and mungbean) and 5 summer vegetable• crops (okra, egg-plant, pepper, tomato and cowpea) from mid­ March to December. The insect passed the winter as adults on six winter field crops (clover, faba bean, wheat, barley, flax and sugar-beet) and five winter vegetable crops (cabbage, cauliflower, potato, bean and peas) from December to early March. At the beginning of March, both adults and nymphal stages appeared on bean, potato, clover, faba bean, wheat, flax and sugar-beet. On the other hand, ten annual• and 4 perennial weeds were observed, harboring N. viridu/a. 7 annual• winter weeds (wild peas, wild mustard, wild chicory, milk thistle, grundsel, burrweed nettle goosefoot and chard) harbored N