Natural role of Phytomyza orobanchia Kalt., a beneficial fly against the parasitic weeds Orobanche spp. infesting legumes and carrots in Egypt.

摘要

Orobanche crenata spike samples were collected weekly in February-March, 1997 from fields of faba beans, peas, Lupinus termis [L. albus] and carrots cultivated in the Qaliobia, Minoufia, Fayoum and Beheire Governates of Egypt. Microscopic analysis of O. crenata capsules determined percentage infestation by P. orobanchia larvae and pupae. Infestation rates ranged between 24.2 and 100%. Mean infestation levels on O. crenata were 66.3% in faba beans, 82.6% in L. albus and 96.0% in pea crops. A level of 78.7% infestation was recorded for the single carrot crop investigated. Mean infestation was 25.3% in Fayoum, 66.7% in Qaliobia, 73.9% in Minoufia and 84.4% in Behiera Governates. One-hundred percent infestation was found in O. crenata from a pea fieldin Tahrir South (Behiera). It is concluded that P. orobanchia is a naturally important biological control agent of the parasitic weed O. crenata in a variety of crops in Egypt.