title: Egg Hatch and Survival and Development of Beet Webworm (Lepidoptera: Crambidae) Larvae at Different Combinations of Temperature and Relative Humidity.
abstract: To understand the role that temperature and humidity play in the population dynamics of the beet webworm, Loxostege sticticalis L. (Lepidoptera: Crambidae), egg hatch, survival of first-fifth instars, survival of the full larval stage, survival curves, and larval development rates were investigated at combinations of four temperatures (18, 22, 26, and 30°C) and five relative humidities (RH; 20%, 40%, 60%, 80%, and 100%). We found that greatest egg hatch rate, survival rates of the first and second instars, and survival rate of the complete larval stage occurred at 22°C and 60-80% RH; the lowest values for these parameters were observed at 30°C and 20% RH. Survival of first instars was significantly affected by the interaction of temperature and relative humidity. However, survival of third and fourth instars was neither affected by temperature nor relative humidity, and that of fifth instars was significantly affected only by relative humidity level. The survival curve for larvae was well described by a type III Weibull distribution. Duration of larval stage decreased as temperature increased, but was not affected by relative humidity. We therefore conclude that eggs and early instars are the most critical stages for survival to the pupal stage, and 22-26°C and 60-80% RH are the optimum conditions for their survival and development. These findings confirm that temperature and relative humidity are the critical environmental factors affecting the population growth of L. sticticalis, with temperature being more important.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, CAAS, Beijing 100193, China (jihong_23@163.com; yxcheng@ippcaas.cn; xfjiang@ippcaas.cn; leizhang@ippcaas.cn; lzluo@ippcaas.cn), lzluo@ippcaas.cn.
authors.forename: Jihong
authors.initials: J
authors.lastname: Tang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, CAAS, Beijing 100193, China (jihong_23@163.com; yxcheng@ippcaas.cn; xfjiang@ippcaas.cn; leizhang@ippcaas.cn; lzluo@ippcaas.cn).
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: USDA-Agricultural Research Service, Corn Insects & Crop Genetics Research Unit, Genetics Laboratory, Iowa State University, Ames, IA 50011 (Tom.Sappington@ars.usda.gov), and.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Sappington
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, CAAS, Beijing 100193, China (jihong_23@163.com; yxcheng@ippcaas.cn; xfjiang@ippcaas.cn; leizhang@ippcaas.cn; lzluo@ippcaas.cn).
authors.forename: Xingfu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, CAAS, Beijing 100193, China (jihong_23@163.com; yxcheng@ippcaas.cn; xfjiang@ippcaas.cn; leizhang@ippcaas.cn; lzluo@ippcaas.cn).
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, CAAS, Beijing 100193, China (jihong_23@163.com; yxcheng@ippcaas.cn; xfjiang@ippcaas.cn; leizhang@ippcaas.cn; lzluo@ippcaas.cn), lzluo@ippcaas.cn.
authors.forename: Lizhi
authors.initials: L
authors.lastname: Luo
mesh_terms: D000818:Animals; D006813:Humidity; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008136:Longevity; D009036:Moths / Q000254:growth & development / Q000502:physiology*; D010063:Ovum / Q000254:growth & development / Q000502:physiology; D013696:Temperature
keywords: Loxostege sticticalis; development; relative humidity; survival rate; temperature