Search results for "Dictyoptera"
showing 10 items of 23 documents
Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transfe…
2006
0048-3575 doi: DOI: 10.1016/j.pestbp.2005.05.002; Oral toxicity of boric acid, an inorganic insecticide, was evaluated on German cockroach, Blattella germanica L. (Dictyoptera, Blattellidae). Newly emerged adults were exposed to various concentrations of boric acid incorporated into the diet. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. Histological study of midgut revealed alterations in the epithelial cells and a signiWcant increase in the epithelium thickness. In a second series of experiments, the compound was investigated on the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs). Data showed that the compound…
Isolation and identification of 4,6,8-trimethyl-7,9-undecadien-5-ol, a female-specific compound, in tergal gland secretion ofCryptocercus punctulatus…
1991
International audience; The secretion of the tergal glands of Cryptocercus punctulatus consists of a complex mixture of 27 compounds. Of this mixture, only one compound (compound B) is specific for females. By dissecting 200 tergal glands, 50 µg of pure compound B was collected by preparative GC; it was identified as (Z, E-4,6,8-trimethyl-7,9-undecadien-5-oI. Its functions as well as its absolute configuration still have to be determined.
Male sex pheromone of cockroach Eurycotis floridana (Walker) (Blattidae, Polyzosteriinae): role and composition of tergites 2 and 8 secretions
1994
0098-0331; In Eurycotis floridana, the male calling behavior is associated with the exposition of epidermal glands located under tergites 2, 7, and 8. 4-Hydroxy-5-methyl-3(2H)-furanone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were recently identified as the specific components of tergite 7 secretion. Methylene chloride extracts of tergite 7 and its major compound 4-hydroxy-5-methyl-3(2H)-furanone attract the conspecific females at a distance. Methylene chloride extracts of tergite 8 are also attractive at a distance to the females, whereas extracts of tergite 2 had no effect on males and females. Our GC investigations showed the absence of specific compounds in tergite 2 secretions. The GC…
Tergal glands of male and femaleCryptocercus punctulatus scudder (Dictyoptera: Cryptocercidae): Composition, sexual dimorphism, and geographic variat…
1991
International audience; Males and females of Cryptocercus punctulatus possess tergal glands, but they differ in position, size, morphology, and secretion chemistry. Compound A (linalyl acetate) is the most abundant of the 21 compounds found only in the secretion of these glands. Compound B, 4,6,8-trimethyl-7,9-undecadien-5-ol, is specific to the tergal secretion of females.C. punctulatus lives only in the United States; its distribution is disjunct. Compound A is found in samples from the eastern population but is absent in samples from the western population. The amount of compound B per gland in samples from the western population is at least twice as high as in the samples from the easte…
The defensive secretion of Eurycotis floridana (Dictyoptera, Blattidae, Polyzosteriinae): chemical identification and evidence of an alarm function
1997
0965-1748 doi: DOI: 10.1016/S0965-1748(97)00033-7; The defensive secretion of the cockroach Eurycotis floridana was believed to contain only (E)-2-hexenal. However, we have shown it consists of 40 components, of which 30 were tentatively identified. (E)-2-Hexenal, (E)-2-hexenol and (E)-2-hexenoic acid represented approximately 98% of the organic phase. The other 2% included 10 aldehydes, 10 alcohols, four acids, two lactones and one ether. Four compounds are novel insect exudates: 3-ethoxyhexanal, 3-hydroxyhexanal, [(E)-1-pentenyl]-4-propyl-1,3-dioxane and 3-[(E)-2-hexenoxyl-hexanal. In addition to its well-known allomonal function, we have demonstrated that the defensive secretion also act…
2-methylthiazolidine and 4-ethylguaiacol, male sex pheromone components of the cockroach Nauphoeta cinerea (Dictyoptera, Bladeridae) : A reinvestigat…
1992
49 ref.; International audience; In Nauphoeta cinerea, male calling behavior is associated with sex pheromone release by the sternal glands. The male pheromone that attracts females from a distance is a mixture of 2-methylthiazolidine and 4-ethylguaiacol. It is active at very low concentrations, 0.05 and 0.01 ng, respectively. Two other compounds, 3-hydroxy-2-butanone and 2-methyl-2thiazoline, act at close range, keeping the female in the vicinity of the male. The function of the volatile pheromone and those of previously described contact pheromones are discussed in regard to their possible involvement in the establishment of male dominant-subordinate relationships.
Could male tergal secretions be considered as a nuptial gift in the Madeira cockroach?
2008
International audience; Many male insects provide somatic nuptial gifts that may strongly influence reproductive fitness, ensuring effective copulation or mediating paternal resource benefits in offspring. Although the courtship feeding behaviour on tergal gland secretions has been described in numerous cockroaches, studies on the function of these so-called nuptial gifts are lacking in this group. In this study, we examined, in the Madeira cockroach, Leucophaea maderae, the functional significance of tergal secretions by manipulating their availability on the back of males. We tested whether male tergal secretions function as a form of mating effort, and/or as a form of paternal investment…
Calling behaviour of female Periplaneta americana: Behavioural analysis and identification of the pheromone source
1993
Abstract The site for the production of Periplanone B, one of the components of the female sex pheromone of Periplaneta americana , was localized in glands situated in the genital atrium, and we have called these structures atrial glands. While emitting the sex pheromone, females adopt a characteristic calling posture during which time the atrial glands are exposed. Behavioural assays of males utilizing pentane extracts of various female body parts revealed that atrial gland extracts are highly attractive, and induced more wing-raising behaviour, than any other female body part. GC-MS analyses support these results by revealing that Periplanone B is only present in the atrial glands. We est…
Diet shapes the gut microbiota of the omnivorous cockroach Blattella germanica
2015
The gut microbiota of insects contributes positively to the physiology of its host mainly by participating in food digestion, protecting against pathogens, or provisioning vitamins or amino acids, but the dynamics of this complex ecosystem is not well understood so far. In this study, we have characterized the gut microbiota of the omnivorous cockroach Blattella germanica by pyrosequencing the hypervariable regions V1-V3 of the 16S rRNA gene of the whole bacterial community. Three diets differing in the protein content (0, 24 and 50%) were tested at two time points in lab-reared individuals. In addition, the gut microbiota of wild adult cockroaches was also analyzed. In contrast to the high…
Changes of species specific cuticular hydrocarbon profiles in the cockroaches Nauphoeta cinerea and Leucophaea maderae reared in heterospecific groups
1997
0013-8703 (Print) 1570-7458 (Online); The cuticular hydrocarbon profiles of the cockroaches Nauphoeta cinerea and Leucophaea maderae are species-specific when maintained in homospecific rearings. When individuals were reared in mixed species colonies, they initially remained in homospecific groups under different shelters. However, after 14 days they formed one heterospecific group with cuticular profiles showing characteristics of both species. When individuals were returned in monospecific rearings, their cuticular hydrocarbon profiles returned to species-specific ones within 3 weeks.