LIFE-HISTORY AND MASS-REARING OF MUSSIDIA-NIGRIVENELLA RAGONOT (LEPIDOPTERA, PYRALIDAE) ON ARTIFICIAL DIETS IN THE LABORATORY

The life history of Mussidia nigrivenella Ragonot was studied at 26 +/ - 2 degrees C, 65 +/- 5 % RH in the laboratory. When reared on artific ial diet, the larval stage lasted 18.4 days, the pupal stage 10.2 days , and total development time (one-day-old larvae to adult) 28.7 days. On average, pupae of males weighed 80.7 mg and those of females 111.2 mg; adult males weighed 44.0 mg and females 65.2 mg. Mated females lai d an average of 268 eggs, while unmated ones laid 155. Females had a l onger mean life span (6.1 days) than males (5.3 days). Individuals rea red in batches of 30 larvae had significantly shorter larval periods a nd total developmental times than those reared in batches of 60, 90 or 120. Pupal and adult weights decreased significantly as the populatio n size increased. Development period was significantly shorter and wei ghts of pupae significantly higher on a soyflour + wheatgerm-based die t and a soyflour + maize flour + wheatgerm-based diet than on most oth er diets. Seven oviposition substrates, including plastic mesh, wire m esh, brass screen, wax paper and paper towel were compared for prefere nce by M. nigrivenella. In both multiple and no-choice tests, paper to wel folded diagonally and 21 x 21 units (meshes/cm(2)) plastic mesh ha d significantly more eggs laid on them than other substrates.