Entomologia Croatica, Vol. 8 No. 1-2, 2004.
Original scientific paper
INSECTICIDAL IMPACT ON THE LIFE TABLE PARAMETERS OF A HARPACTORINE REDUVIID PREDATOR Rhynocoris marginatus (Fabricius), HETEROPTERA
PJ Edward George
; Entomology Research Unit, St. Xavier's College, Tamil Nadu, India
Dunston P. Ambrose
; Entomology Research Unit, St. Xavier's College, Tamil Nadu, India
Abstract
The effects of sublethal concentrations of three insecticides namely monocrotophos, dimethoate and quinalphos on the life table parameters were studied in a harpactorine reduviid predator Rhynocoris marginatus (Fabricius) in the laboratory (temp. 32 ± 2°C, Rh 75 - 80%, photoperiod 11-13 hrs). Normal R. marginatus were multiplied 59.20 times per generation in a mean generation time of 110.37 days. The insecticides reduced the capacity of multiplication and enhanced the mean generation time. The intrinsic rate of natural increase (rm) and finite rate of increase in control R. marginatus were 0.043 and 1.044, respectively, which decreased to 0.031 and 1.03, 0.035 and 1.036 and 0.038 and 1.038 in monocrotophos, dimethoate and quinalphos treated categories. Maximum reductions of weekly multiplications rate and annual rate of increase were observed in monocrotophos treated R. marginatus.
Keywords
Heteroptera; Reduviidae; Rhynocoris marginatus; monocrotophos; dimethoate; quinalphos; life and fecundity table; India
Hrčak ID:
283670
URI
Publication date:
31.1.2005.
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