The development of Aspavia armigera Fabricius (Hemiptera: Pentatomidae) and its status as a pest of cowpea and rice
1990
Ewete, F.K. | Olagbaju, R.A.
The development and pest status of Aspavia armigera on two cowpea varieties viz: Ife Brown and TVU 1890 and also on two upland rice varieties viz: ITA 128 and ITA 257 were studied under ambient conditions in the laboratory and at the roof-top garden, Department of Agricultural Biology, University of Ibadan, Nigeria. The oviposition periods on rice were 15.1 and 6.0 days respectively on ITA 257 and ITA 128; and on cowpea 10.6 and 8.5 days respectively on Ife Brown and TVU 1890. Fecundity was low. Mated females laid the highest number or eggs (24.6) on the cowpea Ife Brown and this was significantly higher than in the other cultivars. Mated and unmated males and females lived longer on Ife Brown and ITA 257 than on ITA 128 and TVU 1890. The developmental period (nymph to adult), was shorter on ITA 257 (23.3 days) and Ife Brown (22.9 days) than on ITA 128 (23.3 days) and TVU 1890 (25.3 days). There were five nymphal instars and the mean growth ratio of head capsule measurements was 1.32. Infestation at the level or two A. armigera per peduncle caused total seed losses in the two cowpea varieties whereas four and eight bugs per panicle caused 39.1 and 31.7% grain yield losses in ITA 257 and ITA 128 rice varieties respectively.
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