Developmental biology of Aspavia armigera (Fabricius, 1775) (Hemiptera: Pentatomidae) on rice (Oryza sativa L.) (Poaceae) and three other hosts in Nigeria

Abstract The developmental biology of Aspavia armigera on four rice varieties ITA 301, ITA 305, ITA 307 and ITA 315 was studied under ambient conditions at the Plant Biology Laboratory, Olabisi Onabanjo University, Ago-Iwoye, Nigeria. Alternative host plants were also used in the experiment. The results showed that the development of A. armigera depended on its hosts. Oviposition periods were 41.7 days, 30.8 days, 22.6 days and 18.1 days on rice varieties ITA 301, ITA 305, ITA 307 and ITA 315, respectively. Fecundity ranged from 80.3 eggs on ITA 301, 79.6 eggs on ITA 307, 76.1 eggs on ITA 305 and 65.6 eggs on ITA 315. The differences in fecundity were not statistically significant. The eggs incubated for 4 to 6 days before hatching into nymphs on all the varieties. The longevity of mated and unmated males and mated females on the rice varieties were not statistically different, while unmated females lived significantly longer on ITA 305. There were five nymphal instars, which persisted for 16.8-19.5 days depending on the variety. The developmental period was significantly (p<0.05) delayed on ITA 315, and the mean growth ratio of head capsule measurements was 1.27. Oviposition periods ranged between 5 and 20 days on cowpea and 6 and 18 days on rice. A significantly higher number of eggs (fecundity) was laid by mated females of A. armigera fed on soybean than those fed on cowpea. Mean developmental periods were 25.7, 25.5, 21.4, and 20.3 days on soybean, amaranthus, rice and cowpea, respectively. Mated females lived for a significantly shorter period on cowpea (21.9 days) than on the other hosts.