Laboratory life fertility table and field biology of millet in nigerhead miner

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Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE

December 1999

Major Subject: Entomology



LaboratoryLife-Fertility Table Assessment and Field Biology of Millet Head Miner (Lepidoptera: Noctuidae) in Niger. (December 1999) Hame Abdou Kadi Kadi, B.S., Texas A&M University; Co-chair of Advisory Committee: Dr. Frank E. Gilstrap Co-chair of Advisory Committee: Dr. George L. Teetes

Life tables were used to study millet head miner, Heliocheilus albipunctella de Joannis, under controlled conditions in alaboratory. 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 2ºC increase. Millet head miner females and males survived in exclusioncages in the field for 3.1-4.0 and 3.23.8 d. Oviposition period was significantly longer at 28 (3.2 d) than 24ºC (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 oviposited more eggs at warmer than cooler temperatures. In the field, each female oviposited 29.6 and 44.9 eggs in 1996 and 1997.Cool and warmtemperatures 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 30ºC. Developmental times from eggs to adults were

iv longest (51.1-55.4 d) when millet head miners were fed Bio-Serv® diet and shortest(40.2-50.2 d) when fed soft-dough millet diet. The best temperature to rear millet head miners fed soft-dough millet diet could be 24ºC. Highest net reproductive rate was 5.84 females per female when millet head miners were fed Bio-Serv® diet at 30ºC. Cohort generation time was shortest (16.98 d) on middle-flowered millet diet at 28ºC. Based on survivorship curves, millet head miners could best bereared 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 bemanipulated to reduce survival and damage by millet head miner in the Sahel.



I dedicate this work:

To my parents Abdou Kadi Kadi Malam Saley and Absatou Mato who have given me their constant support and encouragement throughout my education.

In memory of my late uncle, Laouali Malam Saley, who passed away in 1991 after a long illness. May his soul rest in peace. Amen.In memory of my late father-in-law, Elhadji Souley Dan Naroua, who passed away on 20 August 1997 while I was conducting my 2nd year of research in Niger. May his soul rest in peace. Amen.



Above all, I thank ‘Allah’ for giving me the strength to start and complete this work. I am grateful to Dr. Frank E. Gilstrap, Professor and chairman of my advisory committee, formaking it possible for me to come to Texas A&M University and work on this project. He was fully committed in arranging for my research to be conducted at ICRISAT (International Crops Research Institute for the Semi-Arid Tropics) in Niger. He provided leadership and full support and was anxious to see this work completed. Special thanks are due to Dr. George L. Teetes, Professor and co-chairman...