Loss estimation and economic threshold level for aphids (Acyrthosiphon pisum Harris) in lucerne

摘要

Lucerne (Medicago sativa Linn.) is cultivated globally as a feed resource for all classes of livestock. In addition to its versatility as a feed resource, M. sativa is well known for-its ability to enrich soil and an effective source of biological nitrogen. Over 1000 species of Arthropods have been reported to occur in lucerne fields. Of these about 20 are injurious and few serious pests lead to economic injury. Pea aphid, Acyrthosiphon pisum Harris is a sap sucking insect of family Aphididae and a major pest species. It feeds on several species of legumes (Family: Fabaceae) worldwide including forage crops. These aphids are responsible to reduce yield and also palatability of lucerne fodder to livestock due to the secondary growth of black sooty mould. In the present studies estimation of losses and economic threshold level (ETL) for A. pisum was carried out. ETL for A. pisum was calculated to be 85 aphids/stem.