Search results for "pupa"
showing 10 items of 72 documents
The Drosophila ACP65A cuticle gene: deletion scanning analysis of cis-regulatory sequences and regulation by DHR38.
2005
The regulatory sequences of the Drosophila ACP65A cuticle gene were analyzed in vivo in transgenic flies, using both fusion genes constructs and transposase-mediated deletions within a P element containing ACP65A regulatory sequences fused to the lacZ gene (deletion scanning). The sequences located between −594 and +161 are sufficient to confer both temporal and spatial expression specificities, indicating the presence of tissue-specific enhancers and response elements to hormone-induced factors. In addition, timing of expression and tissue-specificity appear to be controlled by distinct cis-regulatory elements, which suggests the existence of independent hormonal and tissue-specific signal…
Environment-mediated morph-linked immune and life-history responses in the aposematic wood tiger moth
2012
1. Warning signals are expected to evolve towards conspicuousness and monomorphism, and thereby hamper the evolution of multiple colour morphs. Here, we test fitness responses to different rearing densities to explain colour polymorphism in aposematic wood tiger moth (Parasemia plantaginis) males. 2. We used larval lines sired by white or yellow adult males selected for small or large melanization patterns of coloration. We reared these selected lines either solitarily (favourable conditions) or in aggregations (challenged conditions), and followed their performance to adult stage. We tested whether differences in larval density affected life-history traits, adult melanin expression, adult …
Wingless ant males adjust mate-guarding behaviour to the competitive situation in the nest
2011
We investigated whether wingless sexuals of the ant Hypoponera opacior adjust mate-guarding behaviour to the level of competition in the nest. Males mate with young nestmate females shortly before these emerge from the cocoon. Aggressive interactions among adult males have never been observed, but males embrace and guard the cocoons of their mating partners for up to 2 days. In laboratory experiments, the duration of pupal guarding increased with the number of adult males in the nest, but decreased with an increasing number of mating partners per male. These findings demonstrate that males are aware of the competitive situation in the nest and adjust their mating behaviour in an adaptive ma…
Morphogenesis of the wing Anlagen in the mealworm beetle tenebrio molitor during the last larval instar.
1990
The wing Anlagen of Tenebrio develop from epidermal cells located on the lateral margins of meso- and metathoraces. Three to four days after larval ecdysis, these cells start to proliferate slowly, continuing to do so until day 13 which corresponds to the period of the pupal commitment of the remaining epidermis. The wing Anlagen cells then proliferate rapidly until day 18.5. Three days before pupal ecdysis, the mitotic index falls suddenly while 40% of the Anlagen cells disappear owing to cell degeneration. The sudden changes observed in the mitotic index are correlated with two hemolymphatic peaks in ecdysteroid levels. Anlagen of the forewings and hindwings show similar development excep…
Cloning of Two Putative Ecdysteroid Receptor Isoforms from Tenebrio Molitor and their Developmental Expression in the Epidermis during Metamorphosis
1997
Using the Drosophila EcR-B1 cDNA as a probe, we have cloned the putative ecdysteroid receptor from the mealworm Tenebrio molitor. We have isolated two cDNAs with different 5' termini that contain a complete open reading frame. These two cDNAs encode two proteins with distinct N-terminal regions corresponding to two isoforms. The coleopteran receptor is obviously related to the ecdysteroid receptor of other insects, but shares only 89% and 61% amino acid identities with the DNA-binding and ligand-binding domains of the Drosophila receptor, respectively. Its expression pattern has been examined in the epidermis during the last larval instar and pupal stage of T. molitor, in correlation with t…
The roles of foraging environment, host species, and host diet for a generalist pupal parasitoid
2018
Even for parasitoids with a wide host range, not all host species are equally suitable, and host qualityoften depends on the plant the host feeds on. We compared oviposition choice and offspring perfor-mance of a generalist pupal parasitoid,Pteromalus apum(Retzius) (Hymenoptera: Pteromalidae), ontwo congeneric hosts reared on two plant species under field and laboratory conditions. The plantscontain defensive iridoid glycosides that are sequestered by the hosts. Sequestration at the pupal stagediffered little between host species and, although the concentrations of iridoid glycosides in the twoplant species differ, there was no effect of diet on the sequestration by host pupae. The rate of …
Integration of complex larval chemosensory organs into the adult nervous system ofDrosophila
2003
The sense organs of adult Drosophila, and holometabolous insects in general, derive essentially from imaginal discs and hence are adult specific. Experimental evidence presented here, however, suggests a different developmental design for the three largely gustatory sense organs located along the pharynx. In a comprehensive cellular analysis, we show that the posteriormost of the three organs derives directly from a similar larval organ and that the two other organs arise by splitting of a second larval organ. Interestingly, these two larval organs persist despite extensive reorganization of the pharynx. Thus, most of the neurons of the three adult organs are surviving larval neurons. Howev…
Candidate target mechanisms of the growth inhibitor cyromazine: Studies of phenylalanine hydroxylase, puparial amino acids, and dihydrofolate reducta…
2000
Cyromazine, an insect growth regulator, affects larval and pupal cuticles in dipterans and some other insects. The mode of action of this aminotriazine is not known yet, though it has been shown not to inhibit the synthesis of chitin and cuticular proteins. Cyromazine may, however, act on some step(s) of sclerotization of the cuticle. In the present study, we have analyzed the key enzyme for the production of sclerotization agents, phenylalanine hydroxylase (PAH), using the enzyme from Drosophila, a cyromazine-sensitive insect. PAH was studied in vitro with cyromazine and three biologically less active derivatives at concentrations ranging from 1 μM to 1 mM. None of the compounds did signif…
Formation of melanin-based wing patterns is influenced by condition and immune challenge in Pieris brassicae
2005
According to life-history theory, trade-offs emerge because organisms possess a limited amount of resources that they have to allocate between different bodily functions. Here, we tested whether there is a trade-off between melanin-based immune response and dark melanized wing patterning in the large white butterfly, Pieris brassicae L. (Lepidoptera: Pieridae), by activating the immune system of pupae and measuring the wing pigmentation of freshly emerged adults. In contrast to expectations, we did not find any negative associations between immune challenge and wing patterning. Furthermore, implanted and punctured male pupae tended to have larger and darker forewing tips as adults compared …
Dacnusa cicerina (Hymenoptera: Braconidae: Alysiinae), A New Species of Endoparasitoid of Liriomyza cicerina (Diptera: Agromyzidae)
2008
Abstract The larvae, pupa, adults, and venom apparatus of Dacnusa cicerina sp. n., an endoparasitoid of Liriomyza cicerina (Rondani), found on Cicer arietinum Linnaeus in Spain, are described, illustrated, and compared with those of allied species. The mature larva of Eurytoma sp., possibly a hyperparasitoid of D. cicerina, also is described, illustrated, and compared with those of allied species. Keys to discriminate adults are provided and morphological structures of phylogenetic value are discussed. The adults of D. cicerina are similar to those of Dacnusa rodriguezi Docavo & Tormos (1997). The immature larvae are similar to those of Dacnusa areolaris (Nees) and Dacnusa dryas (Nixon), an…