Nutritional quality of diet and fecundity in Lyctus africanus (Lesne)

摘要

In insect, host-finding is initiated by selectively laying eggs in particular site, which is known as oviposition. Host preference in lyctines is determined by some features like vessel size, moisture and starch content of the targeted host. Limited information is available on the significance of diet quality other than starch towards oviposition ability and fecundity of the lyctines. This study discusses the effects of nutritional quality of diets on oviposition of Lyctus africanus after feeding with cellulose-, cellulose powder (CP) and alpha cellulose (AC), and wood-based diets. Oviposition test was conducted on quantitative ashless filter papers which served as oviposition sites. The filter papers had been impregnated with nutritive solution and water to attract females laying their eggs. Those oviposition sites were put separately into a plastic jar with 10 pairs of lyctines adult. Then the eggs number and survived adults after two weeks were observed. The results showed that lyctine adults emerged from the cellulose-based diets ovipositing more eggs significantly on nutritive solution-than water-impregnated filter papers. This result may confirm that starch and sugar are the vital nutrients for L. africanus which could attract adult females to lay their eggs. The cellulose-based diets, both CP-and AC-based diet, are likely to affect adult stage of L. africanus to be more fecund by laying more eggs on filter papers. Also, CP-based diet generated the adults with higher survivals after ovipositing the eggs on both nutritive content and water-impregnated filter paper. The diet composition, in the case of cellulose content, is thus suggested to influence the fecundity of the adult insects of L. africanus