- Repository URL:
- entomology.; Major entomology.
thesis / dissertation description
Life tables were used to study millet head miner, Heliocheilus albipunctella de Joannis, under controlled conditions in a laboratory. Population reproductive statistics were estimated and survivorship curves described. Survival, oviposition period, fecundity, and cohort development were assessed on pearl millet in a field. Longevity of females was longer and more affected by temperature than that of males. Longevity of females declined 0.2 d for each 2C̊ increase. Millet head miner females and males survived in exclusion cages in the field for 3.1-4.0 and 3.2-3.8 d. Oviposition period was significantly longer at 28 ̊(3.2 d) than 24C̊ (2.3 d). Days of oviposition in the laboratory were similar to those in the field, 2.4 and 3.1 d in 1996 and 1997. Females in the laboratory ovipositor more eggs at warmer than cooler temperatures. In the field, females oviposited an average of 29.6 and 44.9 eggs in 1996 and 1997. Cool and warm temperatures tended to increase and decrease, respectively, survival and developmental rate. More millet head miners survived better when fed Bio-Serv® than any of the millet-based diets. Fed Bio-Serv® diet, survival from eggs to adults was greatest (5.4%) at 30C̊. Developmental times from eggs to adults were longest (51.1-55.4 d) when millet head miners were fed Bio-Serv® diet and shortest (40.2-50.2 d) when fed sob-dough millet diet. The best temperature to rear millet head miners fed soft-dough millet diet could be 24C̊. Highest net reproductive rate was 5.84 females per female when millet head miners were fed Bio-Serv® diet at 30C̊. Cohort generation time was shortest (16.98 d) on middle-flowered millet diet at 28C̊. Based on survivorship curves, millet head miners could best be reared on soft-dough millet diet because cohort survival overlapped the cumulative curve. Time pearl millet was available in the field influenced millet head miner survival and developmental time. More prepupae and pupae developed on pearl millet planted in June than later. More days (3-4.5) were required to develop from eggs to pupae on early- than on late-planted pearl millet. Planting date might be manipulated to reduce survival and damage by millet head miner in the Sahel.