title: Response of the common cutworm Spodoptera litura to lead stress: changes in sex ratio, Pb accumulations, midgut cell ultrastructure.
abstract: When cutworm Spodoptera litura larvae were fed on the diets with different lead (Pb) concentrations for one or five generations, changes in growth and food utilization were recorded; Pb accumulations were detected by Atomic Absorption Spectrophotometer; changes in midgut cell ultrastructure were observed by Transmission Electron Microscopy (TEM). The effects of Pb stress on S. litura growth and food utilization differed significantly between insects of the 1st and 5th generation. The male-female rate of 200mgkg(-1) Pb treatment from the 1st generation and 50mgkg(-1) Pb treatment from the 5th generation was significantly higher than control. No significant difference of Pb accumulations was found in larvae, pupae and adults between the 1st and 5th generation. No significant difference of Pb accumulations in corresponding tissues of larvae was found between male and female. Compared to fat body, hemolymph, head, foregut and hindgut, the highest Pb accumulation was found in migut of larvae exposed to 200mgkg(-1) Pb. TEM showed that expanded intercellular spaces were observed in Pb-treated midgut cells. The nuclei were strongly destroyed by Pb stress, evidenced by chromatin condensation and destroyed nuclear envelope. Mitochondria became swollen with some broken cristae after exposure to Pb. Therefore, neither gender nor progeny difference was present in Pb accumulations of S. litura, although effects of Pb stress on S. litura growth and food utilization differed from different generations and genders. Pb accumulations in midgut caused pathological changes in cells ultrastructure, possibly reflected the growth and food utilization of S. litura.
authors.affiliation: Key Laboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions, Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture, Department of Crop Science and Technology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China; State Key Laboratory of Biological Control and Institute of Entomology, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Shu
authors.affiliation: State Key Laboratory of Biological Control and Institute of Entomology, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Jialiang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Biological Control and Institute of Entomology, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Lu
authors.affiliation: Key Laboratory of Agroecology and Rural Environment of Guangdong Regular Higher Education Institutions, Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture, Department of Crop Science and Technology, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Keqing
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biological Control and Institute of Entomology, Sun Yat-sen University, Guangzhou 510275, China. Electronic address: lsszhou@mail.sysu.edu.cn.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000378:metabolism / Q000633:toxicity; D005260:Female; D007422:Intestines / Q000187:drug effects / Q000196:embryology / Q000648:ultrastructure*; D007814:Larva / Q000187:drug effects; D007854:Lead / Q000378:metabolism* / Q000633:toxicity*; D008297:Male; D046529:Microscopy, Electron, Transmission; D009928:Organ Specificity; D011679:Pupa / Q000187:drug effects; D012744:Sex Ratio; D013054:Spectrophotometry, Atomic; D018411:Spodoptera / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism* / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D004785:Environmental Pollutants; D007854:Lead
keywords: Cell ultrastructure; Food utilization; Growth; Midgut; Pb accumulations; Sex ratio