Articles
INSECT-PLANT INTERACTIONS IN PEST MANAGEMENT: A CASE STUDY OF LIPAPHIS ERYSIMI (KALT.) AND ITS CRUCIFEROUS HOSTS
-farnesene (EBF) along with extracts of host plants including 3-butenylisothiocyanate in ether caused aphid Lipaphis erysimi to move away from feeding sites.Ether extracts of Brassica juncea and B. napus along with EBF and that of the aphid cloning B. juncea and B. napus were equal in eliciting an alarm response in the aphid.
Extracts from B. juncea elicited a higher alarm response than stimuli from other host plants and 3-butenylisothiocyanate.
The effects were observed to last only 2–5 min.
However, when acetone and cyclohexanone were used as propellants through a slow release cartridge, the effects lasted up to 12 h in an inverted funnel, although at lesser magnitude.
In another set of experiments, Eruca sativa, which is not a preferred host of the aphid, was grown in the field in alternating rows with B.juncea in 1:1 to 1:4 row combinations.
The number of colonizing aphids/plant of B.juncea varied between 3.5 to 8.5 on the 1st to 4th row away from that of E. sativa while there were 15.8 aphids/plant in the pure stand of B.juncea. The maximum infestation varied between 25 and 77.5 (1:1 to 1:4) to 95 per cent in the pure stand.
In a third set of experiments, L. eryszmi was found to colonize all the growth stages of susceptible cultivars viz.
BSH-1 (B.campestris) and RLM 619 (B.junceal while comparatively resistant cultivars YSRL-9 and PBR-91 (B.juncea) and GSL-1 and-GSL-2 (B. napus) attracted colonizing aphids only at the bud and flowering stages.