• Busseola fusca;
  • maize stem borer;
  • artificial diet;
  • mass rearing


Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is a major pest of maize and sorghum in many countries of tropical Africa. Hitherto, research on this important pest has been hampered by the occurrence of a six-month long diapause in the last larval stage and the lack of an artificial diet for rearing the insect in the laboratory. Incorporating 4 to 8-week-old sorghum powder in a nutritionally adequate diet and rearing larvae individually in vials at ambient laboratory conditions (25–30 °C, 50–80% r.h., and L12: D12) have made it possible to rear 15 successive non-diapausing generations of B. fusca capable of producing between 35 to 40 healthy pupae/litre of diet and upto 70% pupation without loss of vigour or reproductive capacity. Five to six generations were completed per year and the overall mean developmental period (egg-egg) was 68 days (egg 6, larval 45, pre-pupal 1, pupal 14 and pre-oviposition 2 days). Larval period lasted 70 days in the first generation compared to 32.3 days in the fifteenth generation. Average fecundity increased from 158.0 to 394.6 eggs per female with a concomitant increase of egg hatch from 44.8 to 79.6% in the first and fifteenth generation, respectively.