Effect of insecticides on some parasitoids of insect pests of sugarcane
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Date
2005
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Publisher
CCSHAU
Abstract
Studies on the effect of 6 insecticides on the mortality,
parasitization and adult emergence of sugarcane bioagents viz.,
Trichogramma chilonis Ishii, Trichogramma japonicum Ashmead,
Ooencyrtus papilionis Ashmead and Epiricania melanoleuca Fletcher
using Corcyra cephalonica Stnt. and Pyrilla perpusilla, respectively as
host were carried out at 27±2oC temperature and 75-80 per cent
relative humidity in the Central Biological Control Laboratory, Sonipat
with assistance of Department of Entomology, CCS Haryana
Agricultural University, Hisar.
Dimethoate (56.66%) and monocrotophos (63.33%) recorded
lowest per cent adult mortality of T.chilonis, hence they are relatively
safe and are harmful when applied immediately after spraying. No
insecticide is safer to T.japonicum at initial toxicity hence, all found harmful to use. Chlorpyriphos and monocrotophos gave 100 per cent
mortality followed by endosulfan and profenphos (93.33%) so regarded
as highly toxic to O.papilionis. There was 100 per cent mortality of
E.melanoleuca when treated with chlorpyriphos and profenphos.
Endosulfan, dimethoate, monocrotophos and oxy-demetan methyl
treated eggs yielded high parasitization and are rated as comparatively
safe insecticides and chlorpyriphos and profenphos severely inhibited
the parasitization. The eggs treated with oxy-demetan methyl gave
maximum adult emergence followed by dimethoate and monocrotophos
where as endosulfan, chlorpyriphos and profenphos recorded very less
per cent adult emergence.
Based upon the residual toxicity to the parasitoids, dimethoate
and oxydemeton methyl were considered as slightly persistent and
endosulfan, chlorpyriphos, monocrotophos, profenphos were considered
as moderately persistent with respect to adult mortality, parasitization
and adult emergence as per IOBC guidelines. Chlorpyriphos and
profenophos gave 13.33 and 23.33 per cent pupation and 40.0 and 30.0
per cent moth emergence found harmful at recommended doses of
insecticides whereas in sublethal doses of insecticides, all found
relatively safer to Epiricania melanoleuca.