Search results for "lepidoptera"
showing 10 items of 191 documents
Vip3C, a novel class of vegetative insectidal proteins from Bacillus thuringiensis
2012
Three vip3 genes were identified in two Bacillus thuringiensis Spanish collections. Sequence analysis revealed a novel Vip3 protein class (Vip3C). Preliminary bioassays of larvae from 10 different lepidopteran species indicated that Vip3Ca3 caused more than 70% mortality in four species after 10 days at 4 οg/cm 2. © 2012, American Society for Microbiology.
Use of Bacillus thuringiensis toxins for control of the cotton pest earias insulana (Boisd.) (Lepidoptera: Noctuidae)
2006
ABSTRACT Thirteen of the most common lepidopteran-specific Cry proteins of Bacillus thuringiensis have been tested for their efficacy against newly hatched larvae of two populations of the spiny bollworm, Earias insulana . At a concentration of 100 μg of toxin per milliliter of artificial diet, six Cry toxins (Cry1Ca, Cry1Ea, Cry1Fa, Cry1Ja, Cry2Aa, and Cry2Ab) were not toxic at all. Cry1Aa, Cry1Ja, and Cry2Aa did not cause mortality but caused significant inhibition of growth. The other Cry toxins (Cry1Ab, Cry1Ac, Cry1Ba, Cry1Da, Cry1Ia, and Cry9Ca) were toxic to E. insulana larvae. The 50% lethal concentration values of these toxins ranged from 0.39 to 21.13 μg/ml (for Cry9Ca and Cry1Ia, …
The onset of metamorphosis in Tenebrio molitor larvae (Insecta, Coleoptera) under grouped, isolated and starved conditions
1991
Abstract The post-embryonic development of the beetle Tenebrio molitor presents a variable number of larval instars. Several parameters (instar length, time of apolysis and cuticle deposition) were compared during the larval-larval and larval-pupal cycles of mealworms over 50 mg, reared in grouped or isolated conditions. In grouped conditions comparable to mass breeding, larval-larval and larval-pupal apolyses were found to occur at the same time, but instar duration was longer in the case of prepupae. However, isolation was found to accelerate larval-pupal (but not larval-larval) apolyses and to reduce the number of larval instars, whereas starvation inhibited larval-larval (but not larval…
Global phylogeography and geographical variation in warning coloration of the wood tiger moth (Parasemia plantaginis)
2015
Aim To investigate the phylogeography of the aposematic wood tiger moth (Parasemia plantaginis) across its Holarctic distribution and to explore how its genetic structure relates to geographical differences in hindwing warning coloration of males and females. Males have polymorphic hindwing coloration, while female hindwing coloration varies continuously, but no geographical analyses of coloration or genetic structure exist. Location The Holarctic. Methods We sequenced a fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) from 587 specimens. We also examined more current population structure by genotyping 569 specimens at 10 nuclear microsatellite loci. Species distribut…
Investigating the origin of parthenogenesis and ploidy level in Dahlica fennicella (Lepidoptera: Psychidae)
2013
The theories for the predominance of sexual reproduction predict that parthenogens should have no long-term evolutionary potential due to the lack of genetic recombination, despite short term advantages. Although parthenogenesis is rare among high order animals, true parthenogens can be found in various taxa. The intriguing question of the proliferation and persistence of parthenogenetic species needs investigation. An ideal species for such research is a parthenogenetic mont Dahlica fennicella that appears to be as equally successful as other coexisting sexual species. We investigated whether high ploidy level of D. fennnicella is due to hybridization between closely related sexual species…
Ovicide-induced serosa degeneration and its impact on embryonic development in Manduca sexta (Insecta: Lepidoptera)
2003
Abstract Eggs of Manduca sexta treated with the ovicide Ov. 165049 turn orange, and the embryos later die. The orange pigmentation is at first confined to the serosa, and is accompanied by pathological changes of serosal cells. Lipid vesicles aggregate and spindle-shaped electron-lucent vesicles—normally forming a single layer below the apical cell surface—greatly accumulate. The mitochondria swell considerably, and their matrices become electron-lucent. Subsequently, the serosal cells develop additional features of necrosis. They form many autophagic vacuoles which contain mostly degradating mitochondria, but also segregated rough endoplasmic reticulum (rER) and glycogen granules. The whol…
Quantitative genetic analysis of Cry1Ab tolerance in Ostrinia nubilalis Spanish populations
2013
30 p.-2 fig.-3 tab.
Seasonal changes in predator community switch the direction of selection for prey defences
2014
Insect communities consist of aposematic species with efficient warning colours against predation, as well as abundant examples of crypsis. To understand such coexistence, we here report results from a field experiment where relative survival of artificial larvae, varying in conspicuousness, was estimated in natural bird communities over an entire season. This takes advantage of natural variation in the proportion of naive predators: naivety peaks when young birds have just fledged. We show that the relative benefit of warning signals and crypsis changes accordingly. When naive birds are rare (early and late in the season), conspicuous warning signals improve survival, but conspicuousness b…
New records of gall-inducer and inquiline insects in a few mediterranean countries, with biological notes
2014
An annotated list of some gall-inducing and inquiline insects found on herbaceous plants and trees in Italy and in other few Mediterranean countries is reported. Among the gall-inducer species, Phanacis phoenixopodos (Mayr, 1882) is new for the Italian peninsula, Callirhytis rufescens (Mayr, 1882), Andricus quercusramuli (L., 1761) and Plagiotrochus amenti Kieffer, 1901 (Cynipidae: Hymenoptera) are new for Sicily; the latter was previously cited from Italy without collecting data. Oecocecis guyonella Guenée, 1870 was found in Libya and Amblypalpis olivierella Ragonot, 1886 (Gelechiidae: Lepidoptera) in Jordan, Libya, Northern Yemen, and the United Arab Emirates. In addition, Saphonecrus gal…
Horizontally transmitted parasitoid killing factor shapes insect defense to parasitoids
2021
Protection from parasitism by a virus Parasitoid wasps have developed myriad systems to overcome the defense mechanisms of their hosts as they lay their eggs in the bodies and eggs of targeted species. Gasmi et al . report how the host can fight back when infected by a virus that expresses a protein conferring resistance to the parasitoid. When members of the butterfly and moth family are targeted by wasps, a protein family has evolved that is horizontally carried by viruses—and sometimes is incorporated into the host genome—and impairs the ability of parasitoid offspring to fully develop and emerge. Characterizing the ability of this protein to protect hosts against specific parasites, the…