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R. K. Saini - One of the best experts on this subject based on the ideXlab platform.
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Identification of major components of larviposition pheromone from larvae of tsetse fliesGlossina morsitans morsitans Westwood andGlossina morsitans centralis Machado
Journal of Chemical Ecology, 1996Co-Authors: R. K. Saini, J. Andoke, Peter Ahuya, Ahmed Hassanali, W. P. OumaAbstract:The presence of pheromones produced by larvae of Glossina morsitans morsitans and G. m. centralis , respectively, which attract Gravid Females and result in aggregation of pupae, is confirmed. Behavioral experiments indicated that Females preferred to larviposit over moist sand conditioned by previously allowing larvae to pupariate in it. Similar results were obtained with filter papers contaminated with the prepupariation excretions of larvae and with volatiles collected from larvae prior to pupariation. n -Pentadecane and n -dodecane were identified as the dominant electrophysiologically active components of the larviposition pheromones of G. m. morsitans and G. m. centralis , respectively, by GC-EAD and GC-MS analysis of the trapped larval volatiles. Both identified compounds were shown to significantly attract Gravid Females to larviposition sites in laboratory behavioral assays.
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Semiochemicals from froth of egg pods attract ovipositing female Schistocerca gregaria.
Journal of Insect Physiology, 1995Co-Authors: R. K. Saini, Ahmed Hassanali, J. Wawiye, H. OdongoAbstract:Abstract A chemical signal, originating from the froth of egg pods attracts Gravid female Schistocerca gregaria (Orthoptera: Acrididae) to common egg laying sites. Behavioural experiments indicated that Females preferred to oviposit in moist sand contaminated with froth (60% egg laying vs 34% in sterilized sand). Extracts and volatiles collected from froth were also attractive to Gravid Females. In fact, froth volatiles elicited the strongest egg laying response (80% egg laying). Results with froth extracts obtained by sequential extraction with solvents of increasing polarity suggest that both non-polar and polar compounds are involved in the attraction of Gravid Females. Electroantennogram recordings with extracts and volatiles collected from froth confirmed the presence of olfactory receptors on the antennae that are responsive to compounds in the extracts and the volatile collections.
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semiochemicals from anal exudate of larvae of tsetse fliesglossina morsitans morsitans westwood andg morsitans centralis machado attract Gravid Females
Journal of Chemical Ecology, 1993Co-Authors: David E Leonard, R. K. SainiAbstract:Tsetse flies (Diptera: Glossinidae:Glossina) mature their offspring in utero, giving birth to mature larvae that burrow into soil and pupariate. During the hot dry seasons, puparia of some species of tsetse are aggregated in areas of deep shade in dense thickets. We have confirmed the presence of a semiochemical from the prepupariation excretions of larvae ofGlossina morsitans morsitans Westwood and report a similar semiochemical inGlossina morsitans centralis Machado. These semiochemicals are attractive to Gravid Females and result in the aggregation of puparia. Behavioral studies withG. m. centralis showed that a higher percentage of Females larviposited over moist sand conditioned by the anal exudate of larvae. Electroantennogram analyses of extracts of sand conditioned byG. m. centralis andG. m. morsitans confirmed the presence of olfactory receptors on the antennae for the semiochemicals. Both subspecies responded to extracts of the semiochemicals of the other, withG. m. morsitans more responsive to lower concentrations of extract ofG. m. centralis than the converse.
W. P. Ouma - One of the best experts on this subject based on the ideXlab platform.
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Identification of major components of larviposition pheromone from larvae of tsetse fliesGlossina morsitans morsitans Westwood andGlossina morsitans centralis Machado
Journal of Chemical Ecology, 1996Co-Authors: R. K. Saini, J. Andoke, Peter Ahuya, Ahmed Hassanali, W. P. OumaAbstract:The presence of pheromones produced by larvae of Glossina morsitans morsitans and G. m. centralis , respectively, which attract Gravid Females and result in aggregation of pupae, is confirmed. Behavioral experiments indicated that Females preferred to larviposit over moist sand conditioned by previously allowing larvae to pupariate in it. Similar results were obtained with filter papers contaminated with the prepupariation excretions of larvae and with volatiles collected from larvae prior to pupariation. n -Pentadecane and n -dodecane were identified as the dominant electrophysiologically active components of the larviposition pheromones of G. m. morsitans and G. m. centralis , respectively, by GC-EAD and GC-MS analysis of the trapped larval volatiles. Both identified compounds were shown to significantly attract Gravid Females to larviposition sites in laboratory behavioral assays.
David E Leonard - One of the best experts on this subject based on the ideXlab platform.
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semiochemicals from anal exudate of larvae of tsetse fliesglossina morsitans morsitans westwood andg morsitans centralis machado attract Gravid Females
Journal of Chemical Ecology, 1993Co-Authors: David E Leonard, R. K. SainiAbstract:Tsetse flies (Diptera: Glossinidae:Glossina) mature their offspring in utero, giving birth to mature larvae that burrow into soil and pupariate. During the hot dry seasons, puparia of some species of tsetse are aggregated in areas of deep shade in dense thickets. We have confirmed the presence of a semiochemical from the prepupariation excretions of larvae ofGlossina morsitans morsitans Westwood and report a similar semiochemical inGlossina morsitans centralis Machado. These semiochemicals are attractive to Gravid Females and result in the aggregation of puparia. Behavioral studies withG. m. centralis showed that a higher percentage of Females larviposited over moist sand conditioned by the anal exudate of larvae. Electroantennogram analyses of extracts of sand conditioned byG. m. centralis andG. m. morsitans confirmed the presence of olfactory receptors on the antennae for the semiochemicals. Both subspecies responded to extracts of the semiochemicals of the other, withG. m. morsitans more responsive to lower concentrations of extract ofG. m. centralis than the converse.
Oriel M M Thekisoe - One of the best experts on this subject based on the ideXlab platform.
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evaluation of larviposition site selection of glossina brevipalpis
Veterinary Parasitology, 2016Co-Authors: S Renda, C J De Beer, Gert J Venter, Oriel M M ThekisoeAbstract:Abstract Tsetse species (Diptera: Glossinidae) are vectors of trypanosome parasites which cause disease in both humans and livestock. In South Africa Glossina austeni Newstead, 1912 and G. brevipalpis Newstead, 1911 are responsible for the cyclical transmission of animal trypanosomes causing African animal trypanosomiasis also referred to as nagana. Gravid tsetse Females deposit a single larva in specific sites but little information is available on biotic and abiotic factors that govern site selection. This study therefore aimed to characterize some of the substrate conditions that may influence selection of larviposition sites. Colonised, Gravid female G. brevipalpis were presented with a choice of four larviposition sites. Sites differed in qualities of pH (5, 7, 9), salinity (0, 1.3, 4 g/L) and the presence of other tsetse pupae ( G. brevipalpis or G. austeni ). These trials indicated no significant selection by Gravid Females with regard to pH and salinity. Females selected significantly more often for sites with pupae ( P P G. brevipalpis. This may imply that G. brevipalpis larvae produce a pheromone during pupation as seen in G. morsitans morsitans . Isolation of such semio-chemicals would allow the development of larviposition traps to attract Gravid Females.
Richard Shine - One of the best experts on this subject based on the ideXlab platform.
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Costs of reproduction in lizards: escape tactics and susceptibility to predation
Behavioral Ecology and Sociobiology, 1992Co-Authors: Lin Schwarzkopf, Richard ShineAbstract:Increased basking and reduced agility in Gravid female southern water skinks (Eulamprus tympanum) suggest that they will be more vulnerable to predators. However, Gravid Females shift their anti-predator tactics towards crypsis, by allowing potential predators (such as a human observer) to approach more closely than do males and non-Gravid Females. Gravid Females were taken no more frequently than were non-Gravid Females or males when exposed to two types of natural predators, birds (kookaburra, Dacelo gigas) or snakes (common blacksnakes, Pseudechis porphyriacus) in field enclosures. Both these results suggest that the vulnerability of potential prey in this system is determined by the predator's probability of detecting a potential prey item, not its probability of capturing the prey item after detection. Hence, laboratory-based measures of performance demonstrating reduced escape speed may sometimes have little relevance to actual fitness under field conditions, if the probability that an animal will be taken by a predator depends primarily on whether or not it is seen, rather than on how quickly it can escape.
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thermal biology of reproduction in viviparous skinks eulamprus tympanum why do Gravid Females bask more
Oecologia, 1991Co-Authors: Lin Schwarzkopf, Richard ShineAbstract:In some reptiles, Gravid Females bask more, and/or maintain higher body temperatures than do males or non-Gravid Females. This phenomenon is usually explained in terms of the female or her offspring benefitting from accelerated embryogenesis and early birth, but the effect of increased basking on gestation period has not been studied. In a laboratory experiment, gestation periods of Gravid female skinks (Eulamprus tympanum) decreased with the duration of access to radiant heat. Embryonic development was more rapid in the laboratory than in the field, and there were no apparent adverse effects of this accelerated gestation on Females or offspring. Number and mass of offspring, survival rates of embryos, relative clutch mass and female mass before and after parturition were not influenced by the decrease in gestation period caused by increased basking. Females selected similar temperatures in the laboratory and field (32° C), despite the availability of higher temperatures in the laboratory. Thus, gestation in the laboratory was accelerated by spending longer periods at usual basking temperatures, rather than by selecting higher temperatures. In the field, mean and modal body temperatures of active animals were similar in Gravid Females, males and non-Gravid Females, but Gravid Females appear to bask more of the time, even in cloudy weather when other members of the population do not bask. Hence, an apparent similarity in thermal regimes of Gravid and non-Gravid animals may mask significant underlying differences in thermoregulatory strategies.
