Biology of Clavigralla scutellaris (Hemiptera: Coreidae) in India

Abstract

The legume pest Clavigralla scutellaris (Westwood) is sympatric with C. gibbosa Spinola in southern India, and co-occurs with both C. orientalis Dolling and C. gibbosa farther north. Adults of C. scutellaris are easily distinguished from Indian congeners, but nymphal descriptions for this species have never been published. Nymphs of C. scutellaris were reared in the laboratory and the immature stages were described and illustrated. At 27 ± 2°C, the egg incubation period (mean ± S.D.) was 6.63 ± 0.74 days. Durations of the five stadia were 2.50 ± 0.51, 3.81 ± 0.77, 3.19 ± 0.68, 3.46 ± 0.40, and 5.96 ± 0.84 days, respectively. Total nymphal development period did not differ significantly between males and females. Adult life-history parameters (preoviposition period, premating interval, and longevity) were also determined. Nymphs of C. scutellaris can be reliably distinguished from those of C. orientalis and C. gibbosa on the basis of abdomen color (in early instars) and femur/tibia coloration pattern (in all instars). Eggs of C. scutellaris differ from those of the other two species in shape, surface sculpturing, and thickness of the chorion, and are distinctive both before and after hatching. Distribution of Clavigralla spp. in India is reviewed based on literature records, and the biology of C. scutellaris is compared with that of other South Asian species.