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PubMed2004

Biological characteristics of Trichogramma maxacalii (Hymenoptera: Trichogrammatidae) on eggs of Anagasta kuehniella (Lepidoptera: Pyralidae).

Individuals of two populations of Trichogramma maxacalii (Hymenoptera: Trichogrammatidae) were collected from eggs of Euselasia apisaon (Lepidoptera: Riodinidae), a lepidopteran defoliator of Eucalyptus, in plantations in the states of São Paulo and Minas Gerais, Brazil. This study investigated the sex ratio, number of parasitoids per egg, and longevity of individuals of these two populations of T. maxacalii, when this parasitoid was reared receiving eggs of the factitious host Anagasta kuehniella (Lepidoptera: Pyralidae) in different periods after emergence, and with or without honey. Sex ratio of T. maxacalii varied from 0.44 to 0.60, and was affected by the interaction between populations, availability of food (honey), and length of time in which the parasitoid stayed without host eggs after their emergence. The population of T. maxacalii collected in São Paulo produced a larger number of individuals per egg of the host A. kuehniella and lived longer when fed.

Animals↗
PubMed1996

Intracytoplasmic Bacteria in Male Germ Cells of Philudoria potatoria L. (Lasiocampidae, Lepidoptera, Insecta)

The fine structure of bacteria, detected in the cytoplasm of spermatogonia, spermatocytes, and spermatids of a Lepidoptera species, Philudoria potatoria L. (Lasiocampidae), was described using transmission electron microscopy of ultrathin sections through testes. The effects of the bacteria on the germ cells were studied in semithin sections using light microscopy and in ultrathin sections using transmission electron microscopy. Larvae of the animal were collected in the field at the same location in two subsequent summers and the picture was very similar in both preparations. We examined a total of five animals and all were infected. The intracytoplasmic bacteria were usually rod-shaped, up to 1.7 μm long, and about 0.5 μm thick. They lay in intracellular cavities of the germ cells and were separated from the host cell by a membrane. The envelope of the bacteria consisted of two thin electron-dense layers interspersed by a transparent zone which represent the plasma membrane and the cell wall, respectively. Thus, the bacteria are most probably gram-negative. When the cells contained a small number of intracytoplasmic bacteria, pachytene spermatocytes and the development and structure of the meiotic spindles appeared regular. A prominent layer of perispindle membranes that is typical of male meiosis in the Lepidoptera (Wolf, 1994) was, however, missing in the infected animals. A low number of bacteria apparently does not interfere with the onset of spermiogenesis and it is possible that the microorganisms are transmitted into the next generation via the male germ line. In contrast, high numbers of intracytoplasmic bacteria result in cell degeneration in late prophase I of meiosis. Under these circumstances, electron-dense bodies formed within the nuclei and the nucleoplasm became transparent. The most prominent event in the cytoplasm was the aggregation of the mitochondria into large clusters. Finally, the nuclear envelope dissolved and the germ cells degenerated. The intracytoplasmic bacteria of P. potatoria are interpreted as parasites.

Journal Article↗
PubMed2006

Genetic relatedness of six North-Indian butterfly species (Lepidoptera :Pieridae) based on 16S rRNA sequence analysis.

The present work involves the assessment of level of genetic relatedness or divergence amongst the six North-Indian species of Lepidoptera belonging to family Pieridae and sub family Pierinae on the basis of sequence variation of 16S ribosomal RNA. The PCR amplified products of these species were directly sequenced using ABI Prism BigDye Terminator Sequencing Kits (Applied Biosystems). The multiple nucleotide sequence alignment analysis has revealed several differences across these species. Significantly high percentage of A + T base composition content ranging between 73.13% (Ixias pyrene ) and 79.20 % (Pieris brassica) was observed in studied species. The percentage divergence in the investigated species of Pieridae family varied from 5.5% to 21.7%. The two species of Catopsilia revealed minimum sequence divergence of only 5.5%, whereas the other two groups of Ixias and Pieris revealed 15.5% and 8.6% sequence divergence, respectively. Pieris canidia and Ixias pyrene are genetically most divergent (21.7%) amongst the studied lepidopteran species. Phylogenetic analysis based on 16S rRNA nucleotide sequence revealed grouping of six species of Lepidoptera in the form of two different clusters, each cluster being represented by two species from the same genera. The separate taxonomic grouping of these Indian species has been observed when compared with several species of Piernae and Coliadinae subfamilies from other country isolates.

Animals↗
PubMed1992

Phylogenetic studies of ribosomal RNA variation in higher moths and butterflies (Lepidoptera: Ditrysia).

The selection of exemplars has been shown both theoretically and empirically to affect tree topology, but the importance of the number and nature of taxa used to represent higher taxonomic lineages in molecular studies is rarely stressed. In our rRNA study of higher moths and butterflies (Lepidoptera: Ditrysia), the selection of different exemplars and outgroups caused major tree rearrangements. We also examined the effectiveness with which conserved rRNA regions track the diversification of Lepidoptera. Homoplasy is as prevalent at the few variable sites of conserved regions (18E, 18J, 28F) as at the many variable sites of a more rapidly evolving region (28B). Finally, 28B sequence variation differs qualitatively among lepidopteran superfamilies of presumed comparable age, the Papilionoidea (true butterflies) and Noctuoidea (cutworm moths and relatives).

Animals↗
PubMed2004

Juvenile hormone regulation of the E75 nuclear receptor is conserved in Diptera and Lepidoptera.

Despite longstanding efforts, the juvenile hormone (JH) signaling pathway remains unknown. In Drosophila melanogaster (Diptera), JH activates expression of the E75A nuclear receptor. The E75 gene encodes a family of related proteins. A homologue of Drosophila E75 was previously identified and two isoforms, mE75A and mE75B, were reported in Manduca sexta (Lepidoptera). Here, we describe the identification of two additional isoforms, mE75C and mE75D, and the hormonal regulation of mE75 gene expression in Manduca CH1 cultured cells. mE75A and mE75B isoforms are specifically induced by ecdysone in CH1 cells. One isoform, mE75C, shows constitutive expression. The mE75D isoform exhibits dual hormonal regulation; it can be activated by either ecdysone or the JH analog, methoprene. E75-encoded proteins represent the first example of transcription factors directly induced by JH. E75 activation by JH, in both Diptera and Lepidoptera, suggests a conserved function in the JH signaling pathway.

Amino Acid Sequence↗
PubMed2002

Plant odour processing in the antennal lobe of male and female grapevine moths, Lobesia botrana (Lepidoptera: Tortricidae).

Moths of Lobesia botrana (Lepidoptera: Tortricidae) are confronted with different volatiles emitted from the host plant during the different seasons. To test the hypothesis of plasticity of central plant odour processing in moths of different generations in the future, we first investigated the responses of antennal lobe (AL) interneurons of laboratory-reared virgin and mated males and females. We used intracellular recording and staining techniques while stimulating the antenna with a range of host and non-host plant odours. The AL structure of L. botrana is similar to that found in other Lepidoptera species studied. The most frequent physiological responses for all types of moths were obtained with (E)-2-hexenal, and with thujyl alcohol and beta-thujone, components of tansy, a behaviourally attractive non-host plant. Some broadly responding neurons were capable of distinguishing between different compounds through different response patterns (excitation/inhibition) and/or different dose-response characteristics. Response characteristics (response spectra, threshold and specificity) of neurons were similar, independent of sex or mating status of the moths. Significant differences between the groups were, however, found in the proportion of responding neurons for a few tested components.

Journal Article↗
PubMed2002

Pheromone binding proteins of Epiphyas postvittana (Lepidoptera: Tortricidae) are encoded at a single locus.

The light brown apple moth, Epiphyas postvittana (Tortricidae: Lepidoptera) uses a blend of (E)-11-tetradecenyl acetate and (E,E)-9,11-tetradecadienyl acetate as its sex pheromone. Odorant binding proteins, abundant in the antennae of male and female E. postvittana, were separated by native PAGE to reveal four major proteins with distinct mobilities. Microsequencing of their N-terminal residues showed that two were general odorant binding proteins (GOBPs) while two were pheromone binding proteins (PBPs). Full length cDNAs encoding these proteins were amplified using a combination of PCR and RACE-PCR. Sequence of the GOBPs revealed two genes (EposGOBP1, EposGOBP2), similar to orthologues in other species of Lepidoptera. Eleven cDNAs of the PBP gene were amplified, cloned and sequenced revealing two major phylogenetic clusters of PBP sequences differing by six amino acid substitutions. The position of the six amino acid differences on the protein was predicted by mapping onto the three-dimensional structure of PBP of Bombyx mori. All six substitutions were predicted to fall on the outside of the protein away from the inner pheromone binding pocket. One substitution does fall close to the putative dimerisation region of the protein (Ser63Thr). Expression of three of the cDNAs in a baculovirus expression system revealed that one class encodes an electrophoretically slow form (EposPBP1-12) while the other encodes a fast form (EposPBP1-2, EposPBP1-3). A native Western of these expressed proteins compared with antennal protein extracts demonstrated that PBP is also expressed in female antennae and that PBP may be present as a dimer as well as a monomer in E. postvittana. The fast and slow forms of EposPBP1 are allelic. Westerns on single antennal pair protein extracts and allele-specific PCR from genomic DNA both show a segregating pattern of inheritance in laboratory and wild populations. Radio labelled (E)-11-tetradecenyl acetate binds to both fast and slow PBP forms in gel assays. Taken together, the genetic and biochemical data do not support the hypothesis that these PBPs are specific for each component of the E. postvittana pheromone. However, duplication of this PBP locus in the future might allow such diversification to evolve, as observed in the other species.

Amino Acid Sequence↗
PubMed1996

A nuclear gene for higher level phylogenetics: phosphoenolpyruvate carboxykinase tracks mesozoic-age divergences within Lepidoptera (Insecta).

The sequence of phosphoenolpyruvate carboxykinase (PEPCK) has been previously identified as a promising candidate for reconstructing Mesozoic-age divergences (Friedlander, Regier, and Mitter 1992, 1994). To test this hypothesis more rigorously, 597 nucleotides of aligned PEPCK coding sequence (approximately 30% of the coding region) were generated from 18 species representing Mesozoic-age lineages of moths (Insecta: Lepidoptera) and outgroup taxa. Relationships among basal Lepidoptera are well established by morphological analysis, providing a strong test for the utility of a gene which has not previously been used in systematics. Parsimony and other phylogenetic analyses were conducted on nucleotides by codon positions (nt1, nt2, nt3) separately and in combination, and on amino acids, for comparison to the test phylogeny. The highest concordance was achieved with nt1 + nt2, for which one of two most-parsimonious trees was identical to the test phylogeny, and with all nucleotides when nt3 was down-weighted sevenfold or higher, for which a single most-parsimonious tree identical to the test phylogeny resulted. Substitutions in nt3 approached saturation in many, but not all, pairwise comparisons and their exclusion or severe downweighting greatly increased the degree of concordance with the test phylogeny. Neighbor-joining analysis confirms this finding. The utility of PEPCK for phylogenetics is demonstrated over a time span for which few other suitable genes are currently available.

Amino Acid Sequence↗
PubMed1999

Assessment of the application of baculoviruses for control of Lepidoptera.

Baculoviruses, among other insect viruses, are regarded as safe and selective bioinsecticides, restricted to invertebrates. They have been used worldwide against many insect pests, mainly Lepidoptera. Their application as microbial pesticides, however, has not met their potential to control pests in crops, forests, and pastures, with the exception of the nuclear polyhedrosis virus of the soybean caterpillar (Anticarsia gemmatalis), which is used on approximately 1 million ha annually in Brazil. Problems that have limited expansion of baculovirus use include narrow host range, slow killing speed, technical and economical difficulties for in vitro commercial production, timing of application based on frequent host population monitoring, variability of field efficacy due to climatic conditions, and farmers' attitudes toward pest control, which have been based on application of fast-killing chemical insecticides. Farmer education regarding use of biological insecticides and their characteristics is considered one of the major actions necessary for increased use of baculoviruses. Strategies to counteract some of the limitations of baculoviruses, especially their slow killing activity, have been investigated and are promising. These include the use of chemical or biological substances added to virus formulations and genetic engineering of the viruses themselves to express insect toxins or hormones. Such strategies can enhance viral activity and increase speed of kill as well as reduce larval feeding activity. The use of baculoviruses against Lepidoptera is reviewed, with the utilization of the nuclear polyhedrosis virus of A. gemmatalis in Brazil serving as a case-study.

Journal Article↗
PubMed2005

Broadening the insecticidal spectrum of Lepidoptera-specific Bacillus thuringiensis strains by chromosomal integration of cry3A.

A TnpI-TnpIA-mediated and thermosensitive recombination system was developed to construct genetically modified Bacillus thuringiensis strains encoding a crystal protein particularly active against Coleopteran species. Based on B. thuringiensis transposon Tn4430, an integrative vector, pBMB-R14E, was constructed, by which the cry3A delta-endotoxin gene highly toxic to Lepidoptera was delivered into a wildtype B. thuringiensis subsp. kurstaki strain YBT1520. The cry3A gene was integrated into the chromosome of the host strain. Then the integrative vector was eliminated by moving recombinant cultures to 46 degrees C. Two recombinant B. thuringiensis strains, BMB1520-S and BMB1520-T, were obtained. In recombinant strains, the cry3A gene was stably expressed in measurable amounts and did not reduce the expression of endogenous crystal protein genes. Bioassay results showed that BMB1520-S and BMB1520-T, in addition to the activity against lepidopteran Plutella xylostella third-instar larvae present in the parental strains, exhibited a high level of activity against coleopteran Rhyllodecta vulgatissima third-instar larvae, absent from the parental strains.

Animals↗
PubMed1977

Histophysiological studies on the corpus allatum during prepupal diapause in Monema flavescens (Lepidoptera).

The appearance of the corpus allatum, the central endocrine gland of diapause, was examined histologically in the slug moth prepupae, Monema flavescens (Lepidoptera). Before beginning of diapause, the secretory cells of the corpus allatum increase in size with the enrichment of the cytoplasm in quantity and in number of orgenelles, while RNA synthesis also starts. As diapause progresses, the secretory cells have many large unstained vacuoles in the cytoplasm, which were demonstrated to contain some substances of lipoidal nature. It is not clear that the substance is juvenile hormone itself or a material related to juvenile hormone. Agranular ER is the most characteristic organelle connected with mitochondria and situated around the vacuoles during diapause. Electron micrographs show that agranular ER and mitochondria have an essential role for the production of juvenile hormone. The function of the corpus allatum during diapause and the relationship between juvenile hormone and diapause are discussed.

Animals↗
PubMed2000

Characterization of a single-nucleocapsid nucleopolyhedrovirus of Thysanoplusia orichalcea L. (Lepidoptera: Noctuidae) from Indonesia.

A single-nucleocapsid nucleopolyhedrovirus (NPV) isolated from Thysanoplusia orichalcea L. (Lepidoptera:Noctuidae) (ThorNPV) in Indonesia has tetrahedral occlusion bodies (OBs) with a width of 1. 22 microm (range = 0.803-1.931 microm). The length of the virion with an envelope averaged 0.29 and 0.23 microm without an envelope. ThorNPV was propagated in Pseudoplusia includens (Walker) and its authenticity was confirmed by sequence analysis of the polyhedrin gene of the ThorNPV produced in T. orichalcea and P. includens. Polyhedrin amino acid sequence analysis revealed that ThorNPV belongs to Group II of baculoviruses and is closely related to Trichoplusia ni single nucleocapsid NPV, sharing 97.6% sequence identity. Infectivity of ThorNPV against third instar P. includens was low, with a LD(50) value of 65,636 OBs/larva. Electron microscopy of infected tissues showed many polyhedra without virions embedded, which might explain the low virulence against P. includens. Differences in virion occlusion rates between individual cells in the same tissue suggested that the inoculum consisted of at least two variants that differed in the gene(s) controlling virion occlusion. In a host range test using the LD(50) value to P. includens against Spodoptera exigua, S. frugiperda, S. eridania, Anticarsia gemmatalis, Helicoverpa zea, Trichoplusia ni, and P. includens, P. includens was the only species infected. The virus infected primarily the fat body, tracheal epithelium, and hypodermis. The genomic size of the ThorNPV is 135 kb.

Amino Acid Sequence↗
PubMed1986

An accessory olfactory pathway in Lepidoptera: the labial pit organ and its central projections in Manduca sexta and certain other sphinx moths and silk moths.

In the hawkmoth, Manduca sexta, the third segment of each labial palp contains a pit, which houses a densely packed array of sensilla. We have named this structure the labial pit organ (LPO). The sensilla within the pit are typical of olfactory receptors, characterized by a grooved surface, wall pores, and pore tubules. Axons arising from receptor cells that innervate these sensilla project bilaterally to a single glomerulus in each antennal lobe. We have compared this central projection with that in three other species of Manduca (M. quinquemaculata, M. dilucida, and M. lanuginosa) and in the silkmoths Antheraea polyphemus and Bombyx mori. A bilateral projection to a single glomerulus in each antennal lobe is present in all cases. We suggest that the LPO serves as an accessory olfactory organ in adult Lepidoptera.

Animals↗
PubMed1982

The regular divisions of the spermatocytes as related to a meiotic lysine-rich protein fraction. A study on the dichotomous male meiosis of Lepidoptera.

Lepidopteran primary spermatocytes are bipotential leading first to regular (eupyrene) and later to irregular (apyrene) meiotic divisions. The kinetics of the lysine-rich proteins during this dichotomous meiosis was studied using the fluorescent dye sulfoflavine. Throughout the spermatogonial divisions, the chromatin fluoresces while the cytoplasm remains unstained. Reversely, during the meiotic prophase, the cytoplasm fluoresces strongly while the nuclei show only a few weakly fluorescing structures. From premetaphase to telophase the meiotic chromosomes fluoresce strongly again. But during this period, only in the eupyrene cells the cytoplasm remains strongly fluorescent; the fluorescence vanishes in the cytoplasm of the apyrene spermatocytes. Thus, the regular (eupyrene) meiotic divisions and the presence of a lysine-rich protein fraction in the cytoplasm of the dividing spermatocytes of Lepidoptera, are probably related.

Animals↗
PubMed1980

Calcium content and distribution in egg vesicles of Galleria mellonella (Lepidoptera) as determined by X-ray microanalysis.

In egg vesicles of Galleria mellonella (Lepidoptera) electron microprobe analysis reveals calcium in concentrations of 9 and 3 mmoles per 1,000 g tissue wet weight in oocyters and accompanying trophic cells, respectively. This high average level of calcium characterizes both pre- and postvitellogenic oocytes, but the distribution of calcium is not uniform. In postvitellogenic vesicles the central area of the ooplasm shows a higher content of Ca than peripheral one, what may be correlated with the distribution of mature yolk platelets within the ooplasm.

Animals↗