Search results for "cuticular"
showing 7 items of 37 documents
Female-released sex pheromones mediating courtship behavior in Lysiphlebus testaceipes males
2013
Ethological aspects and chemical communication at close-range between the sexes of Lysiphlebus testaceipes Cresson (Hymenoptera: Braconidae) have been investigated through behavioral bioassays and chemical analysis. The attractiveness toward males of whole-body extracts of females and males in hexane and acetone was evaluated, adopting male fanning behavior as a key behavioral component. Also, the activity of polar and nonpolar fraction of female-body extract in hexane obtained using solid-phase extraction technique was investigated. In order to identify cuticular compounds, male and female whole-body extracts with hexane and acetone were analyzed by gas chromatography-mass spectrometry. Th…
Epicuticular changes and storage potential of cactus pear [Opuntia ficus-indica Miller (L.)] fruit following gibberellic acid preharvest sprays and p…
1999
Abstract Cactus pear [Opuntia ficus-indica Mill. (L.) cv. Gialla] fruit were treated 10 weeks after the second induced-bloom flush with 10 ppm gibberellic acid (GA3) or were heated at 37°C for 30 h under saturated humidity after harvest. The two treatments were also combined before storage at 6°C for 45 days plus 4 additional days at 20°C to simulate a marketing period (SMP). Fruit not treated with GA3 and unheated were used as controls. GA3 spray delayed fruit ripening as evaluated by peel colour change and scanning electron microscopic observations of epicuticular wax morphology, decreased ethanol levels in the flesh during storage and SMP, and reduced decay development during storage. Po…
Effects of halofenozide (RH-0345) on cuticular hydrocarbons of mosquito larvae of Culex pipiens
2011
Poster; Insect cuticular hydrocarbons are known to have a protection and a pheromonal role. Quantitative changes in the cuticular hydrocarbons of Diptera occur over time and were used in a preliminary attempt to age-grade of mosquitoes. Halofenozide (RH-0345) is an insect growth regulator belonging to the class of non-steroidal ecdysone agonists. In a previous study, halofenozide was found to be effective against larvae of Culex pipiens L. (Diptera: Culicidae) and exerted its toxicity primarily by the induction of a precocious lethal molting (Boudjelida et al., 2005). In this study, newly molted 4th instar larvae of C. pipiens were exposed to halofenozide (23% EC) for 24 h at LC50 (12.58 µg…
Interactions in the network of Usher syndrome type 1 proteins
2004
International audience; Defects in myosin VIIa, harmonin (a PDZ domain protein), cadherin 23, protocadherin 15 and sans (a putative scaffolding protein), underlie five forms of Usher syndrome type I (USH1). Mouse mutants for all these proteins exhibit disorganization of their hair bundle, which is the mechanotransduction receptive structure of the inner ear sensory cells, the cochlear and vestibular hair cells. We have previously demonstrated that harmonin interacts with cadherin 23 and myosin VIIa. Here we address the extent of interactions between the five known USH1 proteins. We establish the previously suggested sans-harmonin interaction and find that sans also binds to myosin VIIa. We …
Drosophila adult and larval pheromones modulate larval food choice
2014
Insects use chemosensory cues to feed and mate. In Drosophila , the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured their influence on larval food preference and puparation behaviour. We also tested compounds that varied between these species: (i) two larval volatile compounds: hydroxy-3-butanone-2 and phenol (predominant in D. simulans and D. buzzatii , respectively), and (ii) adult cuticular hydrocarbons (CHs). Dro…
Effect of an insect growth regulator (halofenozide) on the cuticular hydrocarbons of Culex pipiens larvae
2013
The cuticular hydrocarbons of the fourth-instar larvae of Culex pipiens aged one and six days were analysed by gas chromatography and gas chromatography-mass spectrometry. The effect of an insect growth regulator (halofenozide = RH-0345) on the cuticular hydrocarbons was evaluated using newly moulted fourth-instar larvae of C. pipiens, at the lethal concentrations (LC50 = 12.58 and LC90 = 28.58 mu g/l). A previous study revealed that RH-0345 is toxic to larvae of C. pipiens by induction of precocious larval moulting. Several cuticular hydrocarbons (CHCs) were identified and many of the other compounds remained unknown. Our data show that the CHC classes consisted of n-alkanes (C23-C29) and …
Sexual selection on song and cuticular hydrocarbons in two distinct populations of Drosophila montana
2011
Sexual selection has the potential to contribute to population divergence and speciation. Most studies of sexual selection in Drosophila have concentrated on a single signaling modality, usually either courtship song or cuticular hydrocarbons (CHCs), which can act as contact pheromones. We have examined the relationship between both signal types and reproductive success using F1–3 offspring of wild- collected flies, raised in the lab. We used two populations of the Holarctic species Drosophila montana that represent different phylogeographic clades that have been separate for ca. 0.5 million years (MY), and differ to some extent in both traits. Here, we characterize the nature and identify …