Field studies on the biology and economic importance of Psalydolytta spp. (Coleoptera: Meloidae: Meloinae) in Mali, West Africa

Abstract

An account is given detailing some aspects of the biology and economic importance of Psalydolytta pilipes Maklin in pearl millet (Pennisetum glaucum) fields in north-west Mali. Descriptions of the triungulin larval stage, together with drawings of larval development from the first grub stage to the coarctate larval stage, are given for two Psalydolytta species, P. pilipes and P. vestita Dufour. First grub phase larvae were successfully reared through to coarctates from eggs obtained from field captured adult beetles, on egg-pods obtained from a selection of commonly occurring grasshopper species. Yield losses resulting from cage trial experiments showed that whole millet candles can be destroyed during one night's feeding at densities approaching 12 beetles per head.

Evaluation of host plant resistance, sowing date modification and intercropping as methods for the control ofMylabris and Coryna species (Coleoptera: Meloidae) infesting pearl millet in the Nigerian Sudan savanna

“…Meloid beetles began to appear in millet fields from 16 to 18 August in both trial years. The results, however, conform with reports on earlier studies in the West African region which suggest that meloid beetles begin feeding at the time of panicle emergence, with peak beetle activity occurring during flowering stage (Gahukar, 1984(Gahukar, , 1988Zethner & Laurense, 1988;Grunshaw et al, 1994;Jago, 1995).…”

“…Successful cultivation of pearl millet is, however, hampered by insect pests of which about 161 species are associated with millet in Nigeria alone (Ajayi, 1985). Species of Psalydolytta, Mylabris and Coryna (Coleoptera: Meloidae) are reported to be economic pests causing extensive damage to millet in the West African sub-region (Gahukar, 1984;Ajayi, 1985;Gahukar, 1988;Zethner & Laurense, 1988;Gahukar, 1991;Grunshaw, 1992;Grunshaw et al, 1994;Jago, 1995;Krall et al, 1995;Tanzubil & Yakubu, 1997). Mylabris and Coryna spp.…”

“…Psalydolytta spp. damage whole flowers and milky grains (Gahukar, 1984(Gahukar, , 1991Coop et al, 1993a;Grunshaw et al, 1994) causing sterilization (flower damage) or blanking (milky grain damage) in millet panicles (Coop et al, 1993a). In Nigeria, a yield loss of up to 70% caused by Coryna spp.…”

“…was sustained in millet grown under controlled conditions . The situation under field conditions may be different because their population dynamics and pest status are greatly influenced by the agroecology in which the millet is cultivated (Grunshaw et al, 1994). Consequently, this study was undertaken to assess the damage and grain losses caused by meloid beetles in different varieties of millet sown on different dates and in different millet-based cropping systems and cropping patterns.…”

Survival and mortality of grasshopper egg pods in semi-arid cereal cropping areas of northern Benin

“…In northwest Mali, Psalydolytta pilipes Maklin and P. vestita Dufour (Coleoptera: Meloidae) were reared from egg pods of several grasshopper species. The only exception was O. senegalensis whose smaller, more slender egg pods may have restricted larval development (Grunshaw et al, 1994). Psalydolytta fusca Olivier (Coleoptera: Meloidae) has been reared from C. fuscocoeruleipes egg pods in Gambia (Selander & Laurense, 1987).…”