Tropidacris collaris (Orthoptera: Romaleidae) expands its damage in orchards of the dwarf cashew,Anacardium occidentale (Anacardiaceae)

The giant grasshopper Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae) is a Neotropical species that causes economic damage to diverse and unrelated crops. We report herein the occurrence of this grasshopper in orchards of dwarf cashew Anacardium occidentale L. (Anacardiaceae) located in the state of Ceará, one of the main cashew‐producing areas of Brazil. Nymphs and adults were observed feeding on cashew leaves during June and July 2016, causing partial or total defoliation of some plants. This report updates the feeding plants of T. collaris and its distribution in Brazil and serves as an early warning of possible future attacks by the pest on cashew orchards in the northeastern region of the country.     

Ultrastructure of the ovarioles of Tropidacris collaris (Stoll) (Orthoptera: Romaleidae) submitted to three photoperiods

The research evaluated the ultrastructure of the ovarioles of Tropidacris collaris (Stoll), submitted to photoperiods 10L:14D, 12L:12D and 14L:10D. Sixty nymphs (30 males and 30 females) in the last stage of development were paired in ten couples in each treatment. Thirty days after adult emergence, the females were immobilized with ethylic ether and dissected under stereomicroscope. The ovarioles were transferred to Karnovsky fixative (2.5% glutaraldehyde, 4% paraformaldehyde and 0.1 M sodium cacodylate buffer) and analyzed in transmission and scanning electron microscopes. The different photoperiods had no effect on the ovarioles' ultrastructure. Each ovariole is covered by a thick sheath constituted by a homogeneous and filamentous material. In the terminal filament, there are cells with large nuclei, some with scarce cytoplasm and projections cytoplasmatic, besides filamentous structures assuming characteristic of conjunctive tissue. In the germarium, the germ cells are big with large nuclei, scarce cytoplasm and plasma membrane containing interdigitations. The follicular cells are small with a small nucleus, yet presenting cytoplasmatic projections. In the vitellarium the follicular cells suffer modifications in their morphology varying from cubic to flat.     

A Comparative Cytogenetic Analysis between the Grasshopper Species Chromacris nuptialis and C. speciosa (Romaleidae): Constitutive Heterochromatin Variability and rDNA Sites

The chromosomes of Chromacris nuptialis and C. speciosa were comparatively analyzed using different cytogenetic techniques, in order to determine the level of karyotypic similarities and differences between the species. The results show similarities in chromosome number (2n = 23,X0) and acrocentric morphology. In some C. nuptialis individuals meiotic irregularities were detected involving the L₂ bivalent. This bivalent was delayed and presented anaphasic bridges and other aberrations. Differences in constitutive heterochromatin (CH) patterns and composition were observed through C-banding and fluorochromes staining. Silver nitrate staining revealed a single medium nucleolar organizer regions (NORs) pair, per species. Differences were also observed in NORs location, which was pericentromeric in C. nuptialis and proximal in C. speciosa. FISH using an rDNA probe confirmed the existence of ribosomal sites coinciding with active regions visualized by silver nitrate. The possible implications of the karyotype differences observed between both species are discussed.     

Evolution of diploid chromosome number,sex‐determining systems,and heterochromatin in Western Mediterranean and Canarian species of the genus Pimelia (Coleoptera: Tenebrionidae)

A compilation of the diploid chromosome numbers and karyotype formulae of 30 species of the genus Pimelia from Morocco, Iberian Peninsula, Balearic and Canary Islands is presented. All species show a conservation of diploid numbers and karyotype formulae 2n = 18 (8 + Xy_p) except for Pimelia cribra, Pimelia elevata, and Pimelia interjecta 2n = 20 (9 + Xy_p) and Pimelia sparsa sparsa 2n = 18 (8 + neoXY). The ancestral state for the genus Pimelia is suggested to be 2n = 18 (8 + Xy_p) in accordance with a previously described phylogeny of these species based on mitochondrial and nuclear DNA. The derived state 2n = 20 (9 + Xy_p) is present in a monophyletic clade, which originated about 2.5–5 Mya. The male meiotic formula 8 + neoXY found in P. sparsa sparsa seems to have originated by the reorganization of the Xy_p pair resulting in two homomorphic sexual chromosomes and the lost of most of the heterochromatin from the former X chromosome. In all chromosomes C‐banding revealed conspicuous pericentromeric heterochromatic blocks, except in the Y chromosome in most of the species, and in situ hybridization of satellite DNA probes revealed the correspondence between heterochromatin and satellite DNA. Finally, the possible role of heterochromatin and satellite DNA is discussed in relation to the uniformity of the Tenebrionidae α‐karyology.     

Organisation of wing cuticle in Locusta migratoria linnaeus,Tropidacris cristata linnaeus and Romalea microptera beauvais (Orthoptera : Acrididae)

The composite fibrous architectures of the wing cuticles of Locusta migratoria, Tropidacris (= Eutropidacris) cristata and Romalea microptera (Orthoptera : Acrididae) have been established. The wing cuticle in all the 3 species consists of: (i) an exocuticle, which is either pigmented or birefringent, and which under an electron microscope shows constantly helicoidal architecture of chitin microfibrils; (ii) endocuticle, which shows alternately birefringent and isotropic layers when sectioned transversely across the wing veins; these layers show helicoidal and unidirectional architecture, respectively of chitin microfibrils under the electron microscope. In transverse section, the chitin microfibrils appear as clear rods (2.8 nm in diameter) in a darkly stained matrix. However, in the hinge called the “claval furrow”, these microfibrils are considerably larger, being 25 nm in diameter. This presumably gives sufficient hardness to the claval hinge, which is the most vulnerable area for wear and tear during flight. The pore canals follow the parabolic pattern of microfibrils in the helicoidal layer, but remain straight in the unidirectional layers. The thickness of wing cuticle increases up to about 10–12 days, the time at which the acridids most probably attain the optimum flight ability. It is suggested that changes in the wing cuticle are related to increased wing beat frequency and speed of flight with age, and may help in resisting the simultaneous increase in the bending and twisting forces on the wing.     

W-heterochromatin of chicken; its unusual DNA components,late replication,and chromatin structure

About 65% of DNA in the chicken W chromosome has been shown to consist ofXhoI andEcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature on a polyacrylamide gel. Three dimensional structures of the 0.7-kbXhoI and the 1.2-kbEcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the 16 dinucleotide steps. Fluorescencein situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about 1 h later than the peak of S phase. The chromatin structure formed alongXhoI andEcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the β-actin gene sequence in that the linker DNA lengths of the former were significantly longer. Fractionation of theHaeIII-digested MSB-1 nuclei yielded a chromatin fraction in whichXhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for theXhoI family sequence were present in this fraction.     

Histological description of the midgut and the pyloric valve of Tropidacris collaris (Stoll, 1813) (Orthopetera: Romaleidae).

The present research describes the histology of the midgut, gastric caeca, and pyloric valve of Tropidacris collaris (Stoll, 1813), (Orthopetera: Romaleidae). We used light microscopy, staining (Gomori's trichrome and periodic acid-Schiff (PAS)), and a routine histological analysis method (hematoxilin-eosin). The insects were obtained from, and also bred in, the Laboratory of Entomology, Department of Biology, of the Rural Federal University of Pernambuco (UFRPE). The collected material was fixed in alcoholic Botüin and embedded in paraplast. The results demonstrated that the midgut wall is composed of an inner epithelial layer and two outer layers of striate muscles: one internal (circular) and the other external (longitudinal), with connective tissue between the muscle fibers. The epithelium is single-layered, with two cell types: regenerative and elongated columnar. The gastric caeca presents muscle layers similar to those of the midgut. Simple columnar epithelium lines the gastric caeca, which presents villi and projects towards the lumen. The pyloric valve is of striate muscle tissue, covered by a single epithelial-cell layer.     

Qualitative and quantitative analysis of the genomes and chromosomes of spider monkeys (Primates: Atelidae)

Heterochromatin distribution and chromosomal rearrangements have been proposed as the main sources of karyotype differences among species of Neotropical primates. This variability suggests that there could be differences at other smaller‐scale levels of DNA organization as well. In particular, quantitative differences between genomes result from gains and losses of individual DNA segments, and may result in varying genome sizes (C‐values) among species. In this work, we studied the genomes of 23 individuals from four species in the genus Ateles (Primates: Platyrrhini): A. chamek, A. paniscus, A. belzebuth, and A. geoffroyi. We analyzed genome size and its relationship with the presence of chromosomal rearrangements and patterns of heterochromatin distribution. The C‐value presented in this work for Ateles chamek is the first estimate for this species (3.09 ± 0.23 pg), whereas our estimates for A. belzebuth (2.88 ± 0.06 pg) and A. geoffroyi (3.19 ± 0.24 pg) differed from those previously published. Fluorescent in situ hybridization (FISH) and interspecies comparativegenomic hybridization (iCGH) analyses revealed that differences in genome size among species relate to localized blocks in both heterochromatic and euchromatic regions, the latter of which appear to be genetically unstable. There were also quantitative differences in Y chromosome content. It remains to be seen whether the chromosomal characteristics of Ateles here discussed are common to platyrrhine monkeys, but it is clear that these monkeys exhibit some intriguing genomic features worthy of additional exploration.     

Extreme degree of chromosome number variability in species of the spider genus Scytodes (Araneae, Haplogynae, Scytodidae)

Genus Scytodes includes most species of the spider family Scytodidae. Until now, 187 species of the genus have been described. In spite of this great diversity, only three Scytodes species were karyotyped so far. The present paper provides for the first time karyotype analysis of two synanthropic species, Scytodes fusca and Scytodes itapevi. Furthermore, new data on karyotype of Scytodes globula are also provided using conventional and differential cytogenetical procedures. The diploid number in the genus Scytodes varied considerably, namely from 2n = 13 to 2n = 31. The diploid number found in S. globula (2n♂ = 13) is the lowest in haplogyne spiders with monocentric chromosomes. Except S. globula, this number has been found only in one haplogyne spider with monocentric chromosomes, namely Ochyrocera sp. (Ochyroceratidae). On the contrary, the diploid number of S. fusca (2n♂ = 31) is one of the highest diploid numbers recorded in haplogyne spiders. The degree of intrageneric variation found in the genus Scytodes is the highest recorded in araneomorph spiders with monocentric chromosomes so far. Some karyotype characteristics (diploid number, chromosome morphology, total chromosome length, and distribution of constitutive heterochromatin) allowed us to postulate a close relationship between S. globula and S. itapevi. According to the karyotype data, S. fusca is not closely related to these two species. This conclusion corroborates a recent taxonomic work that grouped S. globula, S. itapevi, and other four Scytodes species in the ‘globula group’.     

Chromosomal diversification of diploid number,heterochromatin and rDNAs in two species of Phanaeus beetles (Scarabaeidae,Scarabaeinae)

The genus Phanaeus is included in the tribe Phanaeini, one of the most diverse tribes within the subfamily Scarabaeinae in terms of chromosomal characteristics. However, so far the species of this genus were not studied with differential cytogenetic techniques, limiting any inference of the probable mechanisms responsible for this diversity. In this work, several techniques were applied with the aim of cytogenetically characterizing two Phanaeus species. The karyotype found for Phanaeus (Notiophanaeus) chalcomelas was 2n = 12, neo-XY, and that of P. (N.) splendidulus was 2n = 20, Xy_p, considered primitive for the family Scarabaeidae. The chromosomes of both species showed a high amount of constitutive heterochromatin (CH), with blocks rich in base pairs GC (CMA₃⁺). Moreover, in P. (N.) chalcomelas the marks revealed by C-banding and fluorochrome staining were different in size, showing CH variability. Sites of 18S ribosomal DNA (rDNA) were identified in one autosomal pair of P. (N.) chalcomelas and in five autosomal pairs of P. (N.) splendidulus. On the other hand, only one autosomal pair exhibited 5S rDNA sequences in these species. The results suggest that the karyotype differentiation of the Phanaeus species studied here involved pericentric inversions and centric fusions, as well as mechanisms related to amplification and dispersion of CH and rDNA sequences.     

印氏卵翅蝗的一例间性体(直翅目:卵翅蝗亚科)

首次报道印氏卵翅蝗Caryanda yini Mao et Ren,2006的一例偏雄性间性体.该个体总体特征为雄性,特别是雄性外生殖器发育完全,雄性下生殖板锥形,但出现了一些典型的雌性特征:前翅棕色、腹部两侧棕色、第十腹节背板后缘无尾片、肛上板三角形、尾须顶端直;腹内有一条线形动物寄生,未见性腺.推测该间性体的形成可能与线形动物的寄生有关.     

利用RAPD对稻蝗属昆虫亲缘关系的研究

通过20个随机引物的PCR扩增,得到了日本主要稻蝗的随机扩增多态性DNA（RAPD）图谱,根据扩增结果,计算了种间相似系数和遗传距离,建立了UPGMA系统树。结果表明,分布没有重叠、种间容易交配、能产生杂种的中华稻蝗台湾亚种与小翅稻蝗的亲缘关系最近;分布重叠的日本稻蝗与中华稻蝗台湾亚种、日本稻蝗和小翅稻蝗的亲缘关系较近。小稻蝗与其它3种稻蝗的亲缘关系较远。     

我国蝗虫二新种记述 (直翅目：蝗总科)

报道了采自安徽及内蒙古地区的蝗虫二新种：黑翅负蝗Atractomorpha nigripennis sp.nov.及黄足小车蝗Oedaleus cnecososodius sp.nov.。模式标本保存于陕西师范大学动物研究所。     

Microsatellite DNA markers for a grasshopper: Prionotropis hystrix rhodanica (Orthoptera,Pamphagidae)

Microsatellite loci were isolated from Prionotropis hystrix rhodanica, an endangered grasshopper species, endemic to a steppic area southeast of France. Six polymorphic loci were obtained from an enriched partial genomic libray. A high genetic diversity was observed at all loci, with an observed number of alleles ranging from seven to 29, and an observed heterozygosity between 0.71 and 0.90. Test of cross‐amplifications on two closely related taxa are presented.     

云斑车蝗线粒体基因组全序列测定与分析

采用长距 PCR 扩增及保守引物步移法并结合克隆测序测定并注释了云斑车蝗 Gastrimargus marmoratus （Thunberg）的线粒体基因组全序列。结果表明：云斑车蝗线粒体基因组全序列为15 904 bp（GenBank登录号为EU527334）,A+T含量略高于非洲飞蝗Locusta migratoria,为76.04%,包括13个蛋白质编码基因,22个tRNA 基因,2个rRNA基因和一段1 057 bp的A+T富集区。蛋白质基因的起始密码子中,除COⅠ和ND5为TTG以外,均为昆虫典型的起始密码子ATN。ND5基因使用了不完全终止密码子T,其余基因均为典型的TAA或TAG。预测了22个tRNA基因的二级结构,发现tRNA^Ser（AGN）缺少DHU臂, tRNA^Ser（UGY）的反密码子环上有9个碱基。预测了云斑车蝗12S和16S rRNA二级结构,分别包括3个结构域30个茎环和6个结构域44个茎环。A+T富集区含有3个串联重复序列。     

High-resolution chromosome banding studies in Cebus apella,Cebus albifrons,and Lagothrix lagothricha: Comparison with the human karyotype

Karyotypes of three species of South American primates (Cebus apella, Cebus albifrons, and Lagothrix lagothricha) were studied using high-resolution banding techniques, and were compared to the human karyotype. The number of homologies was very high for the three species. Some of the breakpoints implicated in chromosome rearrangements corresponded with human fragile sites. The fragile sites in human chromosomes often correspond with the localization of latent centromeres in the platyrrhines or with large heterochromatic regions that may have been lost or newly added during evolution.     

Accumulation of Spock and Worf,two novel non-LTR retrotransposons,on the neo-Y chromosome of Drosophila miranda

Transposable elements constitute a major fraction of eukaryotic genomes. Here, I characterize two novel non-LTR retrotransposons, cloned from the neo-Y chromosome of Drosophila miranda. Worf is 4.1 kb in size and shows homology to the T1-2 non-LTR transposon characterized in Anopheles. Spock is 4.9 kb in size and shows similarity to the Doc element of D. melanogaster. Southern blot analysis of both elements yielded stronger signals for male DNA. In situ hybridization to polytene chromosomes revealed that both elements are accumulating on the neo-Y chromosome of D. miranda. PCR analysis was conducted to investigate the frequency of spock and worf and of the previously identified transposons, TRIM and TRAM, at individual chromosomal sites among 12 strains of D. miranda. Contrary to the observation that element frequencies are usually kept low at individual sites in Drosophila, the four transposons investigated are fixed at their genomic locations on the neo-Y chromosome. These results support the hypothesis that transposons accumulate in nonrecombining regions and may be one cause of the heteromorphism of sex chromosomes.     

PSR (paternal sex ratio) chromosomes: the ultimate selfish genetic elements

PSR (paternal sex ratio) chromosomes are a type of supernumerary (or B) chromosomes that occur in haplodiploid arthropods. They are transmitted through sperm but then cause loss of the paternal chromosomes (except themselves) early in development. As a result, PSR chromosomes convert diploid fertilized eggs (which would normally develop into females) into haploid males that carry a PSR chromosome. Because they act by completely eliminating the haploid genome of their hosts, PSR chromosomes are the most extreme form of selfish or parasitic DNA known. PSR was originally described in the parasitic wasp Nasonia vitripennis (Pteromalidae). A second PSR chromosome has been found in Trichogramma kaykai, an egg parasitoid from a different family of Hymenoptera (Trichogrammatidae). We argue that PSR chromosomes are likely to be widespread in haplodiploid organisms, but have so far gone under reported due to a paucity of population genetic studies in haplodiploids. We describe the two known PSR systems and related phenomena, and models indicating the conditions conducive to increase of PSR like chromosomes in haplodiploids.