Entomologia Croatica, Vol. 13 No. 2, 2009.
Original scientific paper
BIOLOGY, BEHAVIOUR AND FUNCTIONAL RESPONSE OF Sphedanolestes variabilis Distant (Insecta: Hemiptera: Reduviidae: Harpactorinae), A POTENTIAL PREDATOR OF LEPIDOPTERAN PESTS
Dunston P. AMBROSE
; Entomology Research Unit, India
X. Justin SEBASTI RAJAN
; Entomology Research Unit, India
Kalimuthu NAGARAJAN
; Entomology Research Unit, India
V. JEBA SINGH
; Entomology Research Unit, India
S. Sivarama KRISHNAN
; Entomology Research Unit, India
Abstract
Sphedanolestes variabilis Distant laid light brown colour eggs singly as well as in small clusters of 5 to 10 eggs. The incubation period was 6.92±0.29 days. The stadial durations of I,II,III,IV and V instar nymphs were 6.83±0.58, 6.83±0.94, 6.58±1.56, 8.42±2.68 and 8.67±2.23 and 19.67±3.44 days respectively. Adult males and females lived for 93.83±13.04 and 102.83±12.69 days and their sex ratio was 1: 1 (male and female). The sequential acts of predation as well as that of mating conform to these of other harpactorine reduviids. S. variabilis exhibited Holling's type II functional response as indicated by the positive correlation obtained between the prey density and the number of prey killed by the predator. The attack ratio decreased as the prey density was increased. A negative correlation was obtained between the searching time and the prey density.
Keywords
Sphedanolestes variabilis; assassin bug; biology; behaviour; functional response
Hrčak ID:
48344
URI
Publication date:
18.11.2009.
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