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Host Body (host + body)
Selected AbstractsFlea species richness and parameters of host body, host geography and host ,milieu'JOURNAL OF ANIMAL ECOLOGY, Issue 6 2004BORIS R. KRASNOV Summary 1We have assessed how different host parameters affect species richness of flea assemblages using the independent contrasts method. Three groups of host parameters were examined. The first group included host body parameters (body size, basal and average daily metabolic rates), the second group included parameters of geographical range size and position of this range in relation to the equator (latitude) and the third group comprised parameters related to the number of sympatric closely related species. 2None of the host body parameters correlated with species richness of flea assemblages. 3Flea species richness increased with an increase in latitude of the geographical range centre of a host as well as with an increase in a composite variable that described the size of the geographical range. 4The number of sympatric closely related species both across the entire geographical range and locally was correlated positively with species richness of fleas. 5Our results show that species richness of ectoparasites is affected little by parameters of the host body and to a greater extent by parameters related to the host environment. [source] Effects of bio-pesticides on Eretmocerus warrae (Hym., Aphelinidae), a parasitoid of Bemisia tabaci (Hom., Aleyrodidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2008P. Kumar Abstract The sweet potato whitefly Bemisia tabaci (WF) can be controlled by two commercial neem products, NeemAzal-T/S® (1% azadirachtin) for foliar application, and NeemAzal-U (17% azadirachtin) for soil application, alongwith two biorational products of microbial origin, Abamectin (avermectin) and Success® (spinosad). Side effects of these products were tested in a laboratory bioassay against a native aphelinid, Eretmocerus warrae (EW). Eggs and early larval instars of the parasitoid, commonly found outside the host body, were highly susceptible to foliar spray of neem with only 8%, 18% and 55% emergences of adults from treated eggs. larval and pupal stages respectively at recommended dose-rates of 5 ml/l and 1%, 8% and 40% at twice recommend dose-rate (10 ml/l). Soil application with NeemAzal-U marginally affected EW. At highest tested dose-rate of 3.0 g/l, 46%, 64% and 81% emergence was recorded after treatement of plants harbouring WF parasitized by egg, larval and pupal stages of EW respectively. In contrast to neem application, Success® and Abamectin caused high mortality in development stages of the parasitoids. In particular, abamectin was highly toxic to the parasitoids with less than 1% emergence from either of the three development stages if treated with 1,2 ml/l. [source] Egg performance on an egg-carrying bug.OIKOS, Issue 2 2001Experiments in the field Selection of oviposition sites has direct influence on female fitness. Differences in offspring survival among sites should favour females to select oviposition sites with the highest survival. Golden egg bug females (Phyllomorpha laciniata; Coreidae, Heteroptera) use conspecifics as oviposition substrates. Most eggs are laid on the back of the bug but they can be found on all body parts. Females never carry their own eggs, and males commonly carry eggs received without copulation with the donor. We examined differences in egg survival relative to paternity to the egg, host sex and body size and attachment of an egg on a host's body in the field. We also studied which bugs received eggs. Egg loss was surprisingly common: 30,80% of recaptured individuals lost eggs during a six-day period. Unexpectedly, host's paternity to the eggs did not affect egg survival. Also, egg loss did not differ among hosts in respect to other parameters studied. Males received more eggs than females, but survival of the eggs was not better on a male's back than on a female's back. Since egg loss is common in the golden egg bug, we suggest that female oviposition strategy to lay eggs on conspecifics is not perfect. This is due to active behaviour of potential hosts (for example, rejected oviposition attempts) or lack of suitable oviposition substrates (conspecifics) in the field. Since eggs do not survive unless carried, females may be acting opportunistically, doing the best job possible by laying eggs on available conspecifics. [source] | ||||||||||