Search results for "Lepidoptera genitalia"

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…

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…

Quantitative genetic analysis of Cry1Ab tolerance in Ostrinia nubilalis Spanish populations

2013

30 p.-2 fig.-3 tab.

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…

2005

Background Despite the two-fold cost of sex, most of the higher animals reproduce sexually. The advantage of sex has been suggested to be its ability, through recombination, to generate greater genetic diversity than asexuality, thus enhancing adaptation in a changing environment. We studied the genetic diversity and the population structure of three closely related species of bag worm moths: two strictly sexual (Dahlica charlottae and Siederia rupicolella) and one strictly asexual (D. fennicella). These species compete for the same resources and share the same parasitoids.

2015

Bracoviruses are symbiotic viruses associated with tens of thousands of species of parasitic wasps that develop within the body of lepidopteran hosts and that collectively parasitize caterpillars of virtually every lepidopteran species. Viral particles are produced in the wasp ovaries and injected into host larvae with the wasp eggs. Once in the host body, the viral DNA circles enclosed in the particles integrate into lepidopteran host cell DNA. Here we show that bracovirus DNA sequences have been inserted repeatedly into lepidopteran genomes, indicating this viral DNA can also enter germline cells. The original mode of Horizontal Gene Transfer (HGT) unveiled here is based on the integrativ…

Mitochondrial Dna Sequence Variation among Geographic Strains of Diamondback Moth (Lepidoptera: Plutellidae)

1997

We examined genetic variation among 6 geographic strains of diamondback moth, Plutella xylostella (L.), using 365 base pairs of the mitochondrial gene encoding cytochrome oxidase I (COI). No sequence variation was detected within 5 of the 6 strains; 1 strain contained 2 haplotypes that differed by a single base substitution (0.27%). Sequence differences between strains of diamondback moth from Hawaii, the Philippines, and Pennsylvania ranged from 0 to 0.82%. With one exception, base pair substitutions among strains resulted in synonymous codons and did not alter amino acid sequence. Genetic divergence between strains of diamondback moth was not correlated with geographic distances between t…

Headspace Volatile Composition of the Flowers of Caralluma europaea N.E.Br. (Apocynaceae)

2009

The volatile constituents of the flowers of Caralluma (Apteranthes) europaea (Guss.) N.E. Br. (Apocynaceae - Asclepiadoideae) from Lampedusa Island were analyzed by headspace method. The analyses allowed the identification and quantification of 41 compounds. The main components were, among the monoterpenoids, terpinolene (23.3%), a-terpinene (19.1%) and linalool (18.4%), whereas, among the carbonylic compounds the major constituents were heptanal (2.0%), octanoic acid (2.4%) and hexanoic acid (1.7%). It is worth to mention the presence of a nitrogen containing compound, indole (0.8%) and of a sulphur containing compound, dimethylsulphide (t). The compounds found in the flowers of C. europea…

Synergism and Antagonism between Bacillus thuringiensis Vip3A and Cry1 Proteins in Heliothis virescens, Diatraea saccharalis and Spodoptera frugiperda

2014

Made available in DSpace on 2015-03-18T15:56:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-10-02Bitstream added on 2015-03-18T16:28:28Z : No. of bitstreams: 1 WOS000342591500006.pdf: 270331 bytes, checksum: c280e3f5bc5e3bb0b92bf74d046135f0 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Spanish Ministry of Economy and Competivity FEDER Second generation Bt crops (insect resistant crops carrying Bacillus thuringiensis genes) combine more than one gene that codes for insecticidal proteins in the same plant to provide better control of agricultural pests. Some of the new combinations involve co-expression of cry and vip genes. Because Cry and Vip proteins …

Binding of individual Bacillus thuringiensis Cry proteins to the olive moth Prays oleae (Lepidoptera: Yponomeutidae)

2009

The microlepidopteran Prays oleae is one of the main insect pests causing significant crop losses in the Mediterranean olive groves. Bacillus thuringiensis based insecticides are being successfully used to minimize the impact of the second and third generations of this pest. However, because of its very small size and difficulty of rearing, very few studies have been carried out to determine the potency and mode of action of B. thuringiensis Cry proteins in this insect. In this study, Cry1Ac, Cry1Ca, and Cry1Fa proteins were shown to be toxic to third instar larvae of P. oleae. Furthermore, binding assays with (125)I-Cry1Ac and brush border membrane vesicles from midguts of last-instar larv…