Mitochondrial genome deletions and minicircles are common in lice (Insecta: Phthiraptera)

Background The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome. Results Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia). Conclusions Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the loss of this gene lead to the formation of minicircles in lice.

A comparative analysis of Mitochondrial genomes in Coleoptera (Arthropoda: Insecta) and genome descriptions of six new beetles

Coleoptera is the most diverse group of insects with over 360,000 described species divided into four suborders: Adephaga, Archostemata, Myxophaga, and Polyphaga. In this study, we present six new complete mitochondrial genome (mtgenome) descriptions, including a representative of each suborder, and analyze the evolution of mtgenomes from a comparative framework using all available coleopteran mtgenomes. We propose a modification of atypical cox1 start codons based on sequence alignment to better reflect the conservation observed across species as well as findings of TTG start codons in other genes. We also analyze tRNA-Ser(AGN) anticodons, usually GCU in arthropods, and report a conserved UCU anticodon as a possible synapomorphy across Polyphaga. We further analyze the secondary structure of tRNA-Ser(AGN) and present a consensus structure and an updated covariance model that allows tRNAscan-SE (via the COVE software package) to locate and fold these atypical tRNAs with much greater consistency. We also report secondary structure predictions for both rRNA genes based on conserved stems. All six species of beetle have the same gene order as the ancestral insect. We report noncoding DNA regions, including a small gap region of about 20 bp between tRNA-Ser(UCN) and nad1 that is present in all six genomes, and present results of a base composition analysis.

Leichhardt's vanishing thrips: A remarkable new genus and species of Insecta, Thysanoptera, Phlaeothripinae

Leichhardtithrips evanidus gen. et sp. nov., a wingless, fungus-feeding species of Phlaeothripidae, is described from a single female taken in D'Aguilar National Park, Brisbane. This species has exceptionally reduced sclerotisation rendering systematic comparisons of the new genus difficult. The cylindrical form of the eighth antennal segment is unique in the family, and the compound eyes are not developed on the ventral surface of the head. © The State of Queensland, Queensland Museum 2013.

Biological management of the invasive Vachellia nilotica ssp. indica (Benth.) Kyal. & Boatwr. (Fabales: Mimosoideae) in tropical Australia: stress-inducing potential of Anomalococcus indicus Ramakrishna (Insecta: Hemiptera: Coccoidea: Lecanodiaspididae), an agent of promise

Vachellia nilotica ssp. indica (hereafter, V. n. indica) is an important tree weed in Australia. Its dense populations induce undesirable changes in the vast areas of northern Australia. Because chemical and mechanical management options appear unviable for various reasons, biological management of this tree is considered a better option. Among the many trialled arthropods in Australian context, Anomalococcus indicus, a lecanodiaspid native to India, has been identified as a potent-candidate, since in India, its native terrain, it is the most widespread and occurs throughout the year. Severe infestations of A. indicus cause defoliation, wilting and death of branches, and occasionally the tree. Populations of A. indicus have been brought into Australia and are being tested for its host specificity under quarantine conditions. This article reports the physiological damage and stress it inflicts in the shoots of V. n. indica. Younger-nymphal instars of A. indicus feed on cortical-parenchyma cells of young stems, whereas the older instars and adults feed from the phloem of old stems. Two conspicuous responses of V. n. indica arising in response to the feeding action of A. indicus are changes in the cell-wall dynamics and irregular cell divisions. The feeding action of A. indicus elicits a sequence of reactions in the stem tissues of V. n. indica such as differentiation of thick-walled elements in the outer cortical parenchyma, differential thickening of cells with supernumerary layers of either suberin or lignin, proliferations of parenchyma and phloem, wall thickening and obliteration of inner lumen of phloem cells, and the sieve plates plugged with callosic deposits. The responses are the culminations of interaction between the virulence factor (one or more of the salivary proteins?) from A. indicus and the resistance factor in V. n. indica. We have analysed structural changes in the context of their functions, by comparing the feeding action of A. indicus with that of other hemipteroids. From the level of stress it induces, this study confirms that A. indicus has the potential to be an effective biological management of V. n. indica in Australia. © 2014 © 2014 Taylor & Francis and Aboricultural Association.

The presence in the Marche of Sericostoma siculum McL. (Insecta-Trichoptera). Translation from: Boll.Soc.eustachiana 43(2), 47-50, 1950]

The caddisfly (Trichoptera) Sericostoma siculum was found in the Marche region in Italy. The article summarises biology and ecology of the caddisfly, focusing on the larvae stage.

The distribution, conservation, and larval food plant of Epiplema becki Hayes (Insecta: Lepidoptera: Uraniidae) on the Galapagos Islands

Two new populations and the host plant of the rarely encountered Galapagos endemic moth Epiplema becki were found on Isabela Island, on Wolf and Sierra Negra volcanoes, with a sighting on Darwin Volcano. The host plant is the native Duranta dombeyana (Verbenaceae). The habitats where all known specimens were collected were Scalesia forest with Duranta bushes. To ensure the conservation of E. becki, we recommend control of introduced species in its habitat. CDF Contribution Number 1010.

Results of the Austrian-Ceylonese hydrobiological mission 1970 of the 1st Zoological Institute of the University of Vienna (Austria) and the Department of Zoology of the Vidyalankara University of Ceylon, Kelaniya. Pt. 6. A new Drepanosticta from Ceylon (Order: Odonata; insecta)

The author describe a new species of Drepanosticta from Sri Lanka. This new species is named in honour of the collector, Professor Dr. F. Starmühlner.

Mitochondrial genomes of two luminous beetles, Rhagophthalmus lufengensis and R-ohbai (Arthropoda, Insecta, Coleoptera)

We determined the mitochondrial MA (mtDNA) sequences of two luminous beetles (Arthropoda, Insecta, Coleoptera), Rhagophthalmus lufengensis from Yunnan, China and Rhagophthalmus ohbai from Yaeyama Island, Japan. We identified all the 37 mtDNA genes of R. l

Diversity Variation of Ground-dwelling Beetle(Insecta:Coleoptera) Communities in Jiaozi Mountain, Yunnan, China

对云南轿子雪山自然保护区地表甲虫物的种组成及生物多样性季节变化进行了连续跟踪调查.调查结果如下:(1)通过对4种典型微环境样地(草地、灌丛、林地以及农田生态系统)连续3次跟踪连续调查,共获得标本2451头,分别隶属于24科.其中步甲科(Carabidae)为优势类群,占总数的62.10%;隐翅虫科(Staphylinidae)其次,占12.77%.可能由于海拔、气温等因素影响,该地区昆虫活动高峰期较短.(2)通过对4种典型微生态环境中地表甲虫的生物多样性的比较,表明不同生境内甲虫的多样性指数存在动态变化,在不同生境片区内甲虫存在迁移活动,甲虫多在灌丛中越冬,并随季节及食物源迁移.

Stegana (Oxyphortica) nigripennis species-group, with descriptions of four new species from southeast Asia (Insecta : Diptera : Drosophilidae)

The nigripennis species-group is established within the subgenus Stegana (Oxyphortica), consisting of five species distributed in the Oriental Region, Stegana (O.) nigripennis (Hendel) from southern Japan, S. (O.) aotsukai, new species and S. (O.) prigenti, new species from southern China and Thailand, and S. (O.) trisetosa, new species and S. (O.) yapingi, new species, from eastern Malaysia. A key to all the species in this group is provided.

Identificação dos principais Coleoptera (Insecta) associados a produtos armazenados.

2006

Presencia de Anagrus flaveolus en la Argentina parasitoide de un insecto dañino del trigo y maíz (Insecta - Hymenoptera - Mymaridae)

p.19-23

Detección de trypanosoma cruzi (Protozoa kinetoplastida) en triatominos (Reduvidae, insecta) por el ensayo inmunoabsorbente ligado a enzimas y amplificación de minicírculos del kADN [por] Zinnia Judith Molina Garza

Tesis (Maestría en Ciencias Biológicas con Especialidad en Entomología Médica) U.A.N.L.