title: Effects of an organophosphorous insecticide on survival, fecundity, and development of Hylyphantes graminicola (Sundevall) (Araneae: Linyphiidae).
abstract: Abstract-The effects of an organophosphorous insecticide, methamidophos, on fecundity and development of the spider Hylyphantes graminicola (Sundevall) (Araneae: Linyphiidae) were assessed under laboratory conditions. Susceptibility of adults of both sexes to the insecticide and its influence on fecundity of females and development of offspring were investigated. At 48 h after topical application in adults, the median lethal dose (LD50) and 10% lethal dose (LD10) were 0.35 and 0.12 microg/spider, respectively, for males and 0.52 and 0.16 microg/spider, respectively, for females. Methamidophos had detrimental effects on fecundity of females; number of eggs per clutch, total egg mass, and clutch size decreased significantly. The hatching rate of eggs from LD10-treated females was slightly higher than the rate in the controls, but the hatching rate of eggs from LD50-treated females was lower than the rate in the controls. However, no significant differences were observed in hatching time and development time across treatments. Development time of spiderlings from LD50-treated females was significantly longer than the time in the controls, and body sizes of the first spiderlings from insecticide-treated females were larger than those in the controls. However, matured offspring were smaller than those in the controls. It was concluded that methamidophos has long-term effects on H. graminicola, and that this may affect the development of spider populations in the field.
authors.affiliation: Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Deng
authors.forename: Jiayin
authors.initials: J
authors.lastname: Dai
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
authors.forename: Muqi
authors.initials: M
authors.lastname: Xu
mesh_terms: D000818:Animals; D049628:Body Size / Q000187:drug effects; D005260:Female; D005298:Fertility / Q000187:drug effects; D007306:Insecticides / Q000633:toxicity*; D007928:Lethal Dose 50; D008297:Male; D009946:Organothiophosphorus Compounds / Q000633:toxicity*; D013112:Spiders / Q000187:drug effects* / Q000502:physiology
chemical_list: D007306:Insecticides; D009946:Organothiophosphorus Compounds; C014655:methamidophos