LOSSES IN GRAIN YIELD CAUSED BY RUSSIAN WHEAT APHID Diuraphis noxia (Mordvilko)

A field experiment was conducted to evaluate the response of different wheat genotypes to Russian wheat aphid (RWA) Diuraphis noxia (Mordvilko). For this purpose, seven wheat cultivars were sown in a randomized complete block design with three replications at Regional Agricultural Research Institute Bahawalpur. A significant genotypic variability existed with respect to aphid infestation and yield losses. Aphid infestation resulted in 7.9 to 34.2% yield losses. The wheat genotype V-4012 was found to be the least infested with aphid giving a maximum grain yield (3754 kg ha^-1) with 1.57 aphids per tiller. The strain V-2237 was second best with 1.72 aphids per tiller and a grain yield of 3458 kg ha^-1. The commercial wheat variety Punjnad-1 was heavily infested (2.85 aphids per tiller) with a grain yield of 2470 kg ha^-1. Aphid population increased up to 4th week of March and then started declining. The genotype V-4012 was later on released for general cultivation based on its better performance as Fareed-06.