title: An acquired distaste: sugar discrimination by the larval parasitoid Microplitis croceipes (Hymenoptera: Braconidae) is affected by prior sugar exposure.
abstract: We examined gustatory responses of the larval parasitoid Microplitis croceipes to determine whether the adults discriminate among common sugars, including fructose, glucose, maltose and sucrose, found in plants. When given single sugar solutions of sucrose, glucose, fructose and maltose at concentrations of 0.008-2.0 mol l(-1), the estimated concentrations at which 50% of wasps initiated feeding ranged between 0.054 and 0.085 mol l(-1) for sucrose, glucose and fructose, which was significantly lower than for maltose. Wasps showed a strong decrease in feeding time for maltose or fructose following a brief exposure to other sugars, suggesting that wasps can distinguish maltose and fructose from the other sugars tested. The higher acceptance threshold and short feeding time in the case of maltose appears adaptive in light of the relatively poor nutritional quality of the sugar in the longevity trial. The pronounced feeding inhibition seen for fructose following exposure to other sugars is not linked with lower nutritional performance. This feeding inhibition was even seen in wasps that had fed on glucose at the lowest acceptance threshold (0.031 mol l(-1)) and persisted for 24 h. This study is the first to show feeding inhibition of otherwise phagostimulant sugars such as maltose and fructose after gustatory stimulation on other sugars.
authors: Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors: J K
authors: JK
authors: Makatiani
authors: Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors: H K
authors: HK
authors: Le
authors: Crop Protection and Management Unit, USDA-ARS, Tifton, GA 31793-0748, USA.
authors: D M
authors: DM
authors: Olson
authors: Centre for Sustainable Agriculture, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK.
authors: F L
authors: FL
authors: Wäckers
authors: Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan takasu@brs.kyushu-u.ac.jp.
authors: K
authors: K
authors: Takasu
mesh_terms: D000818:Animals; D005247:Feeding Behavior; D005260:Female; D005632:Fructose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007814:Larva / Q000469:parasitology; D007915:Lepidoptera / Q000469:parasitology; D008297:Male; D008320:Maltose / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism; D013649:Taste; D014863:Wasps / Q000254:growth & development / Q000502:physiology*
chemical_list: D005632:Fructose; D013395:Sucrose; D008320:Maltose; D005947:Glucose
keywords: Feeding inhibition; Gustatory responses; Sugar feeding