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Lifecycle of the bruchid beetle Bruchidius uberatus and its predation of Acacia nilotica seeds in a tree savanna in Botswana

Ernst, W.H.O., Decelle, J.E., Tolsma, D.J., Verweij, R.A.
Entomologia experimentalis et applicata 1990 v.57 no.2 pp. 177-190
Bruchidius, Vachellia nilotica, adults, females, hatching, host specificity, larvae, longevity, multivoltine habit, pollen, predation, rearing, savannas, seeds, spring, summer, temperature, trees, univoltine habit, Botswana, Sudan
The life cycle of the bruchid beetle Bruchidius uberatus in seeds of Acacia nilotica has been investigated under field and laboratory condition. In contrast to the multivoltine populations in the Sudan, in Botswana most beetles of B. uberatus are univoltine. They emerge from the seed and pod in early spring (October to November). Only a small part of the population, which emerge in late summer (February to March) is multivoltine, as confirmed by rearing experiments. The reproductive activity of females is not stimulated by pollen, as found in feeding experiments. Minimum life-span of adult beetles varies between 4 and 40 days, but it did not differ between univoltine and multivoltine beetles. Other data on life-history are 22 days for hatching of the fist-instar larva at a temperature regime of 20/15 °C (day/night) and 15 days at a temperature regime of 32/15 °C and 3 to 11 months for development from larvae to beetle. During dry storage of seeds B. uberatus can destroy the total amount of stored seeds within a few years. In stored seed pool, host-specificity of larva is low. The life cycles of the Botswana population have been discussed in relation to that of the species in the Sudan.