Mustard Aphid (Lipaphis erysimi)
Description
Aphids are small, soft-bodied, pearl-shaped insects that have a pair of cornicles (honey tubes) projecting out from the fifth or sixth abdominal segment. There are four nymphal stages (instars). Wingless, female, aphids are yellowish green, gray green or olive green with a white waxy bloom covering the body. . The winged, female, adult aphids have a dusky green abdomen with dark lateral stripes separating the body segments and dusky wing veins. Male aphids are olive-green to brown in color. The aphid attacks generally during December and continues till March. The most favourable temperature is 200C or below. Cloudy and cold weather help in accelerating the growth of insects. About 45 generations are completed in a year.
Nature of Damage
Plants are infested at all the stages. Both nymph and adults suck the sap from leaves, inflorescence or the developing pods. Curling may occur for infested leaves and at advanced stage plants may wither and die.
Control Measures Cultural Control
Use tolerant varieties like JM-1 and RK-9501. The crop sown before 20th October escape the damage. Apply recommended dose of fertilizers.
Mechanical Control
Destroy the affected parts along with aphid population in the initial stage.
Biological Control
Ladybird beetles viz., Cocciniella septempunctata, , Hippodamia variegata and cheilomones vicina are most effcient pradators of the mustard aphid. Adult beetle may feed an average of 10 to 15 adults/day. Several species of syrphid fly i.e., Sphaerophoria spp., Eristallis spp., Metasyrphis spp., Xanthogramma spp and Syrphus spp. are predating on aphids. The lacewing, Chrysoperla carnea predates on the mustard aphid colony.
Chemical Control
Spraying should be done at ETL level. Spraying should be done in evening time. Spray the crop with one of the following insecticides in the aphid appearance; Imidacloprid 17.8% @ 0.25 ml/l,Thiamethoxam 25 WG @ o.2g/l, Dimethoate 30EC @ 1 ml/l of water.