The imago of Baetodes traverae Mayo, 1972 (Ephemeroptera: Baetidae), with a redescription of the nymph

Male imago of Baetodes traverae is described and its nymph is redescribed. The male imago is distinguished from the other known species of the genus by (1) abdominal tubercles absent, (2) turbinate eyes moderately large and not contiguous apically, (3) segment II of forceps without constriction, (4) coxal gills absent, and (5) abdominal tubercles absent. Baetodes traverae nymph is redescribed, with new illustrations aiming to improve the original description done by Mayo (1972). Its nymph has the following characters: (1) terminal filament very short, less than half the length of abdominal segment X, (2) labium with glossae very short, less than half the length of paraglossae, (3) labrum expanded laterally, with submarginal row of four setae, (4) coxal gills absent and (5) abdominal tubercles absent.

Ovary Structure and Oogenesis of Trypophloeus klimeschi (Coleoptera: Curculionidae: Scolytinae)

The female reproductive system, ovary structure and ultrastructure of Trypophloeus klimeschi (Coleoptera: Curculionidae: Scolytinae) were investigated using light microscopy, scanning electron microscopy, and transmission electron microscopy. Its female reproductive system is comprised of two ovaries (each ovary has two ovarioles), lateral oviducts, common oviduct, spermathecal sac, spermathecal pump, two accessory glands and bursa copulatrix. Well-developed endoplasmic reticulum can be clearly seen in the secretory cells of spermathecal sac. This species has telotrophic meroistic ovarioles that are comprised of terminal filament, tropharium, vitellarium and pedicel. The terminal filaments are simple; each is comprised of cellular peritoneal sheath. The presence of several clusters of nurse cells in the tropharium is indicative that its ovarioles conform to the transition stage. This indicates that there are at least two different types (transition stage and secondary stage) of ovarioles in Curculionidae.

Distinct gene expression dynamics in germ line and somatic tissue during ovariole morphogenesis in Drosophila melanogaster

The survival and evolution of a species is a function of the number of offspring it can produce. In insects the number of eggs that an ovary can produce is a major determinant of reproductive capacity. Insect ovaries are made up of tubular egg-producing subunits called ovarioles, whose number largely determines the number of eggs that can be potentially laid. Ovariole number is directly determined by the number of cellular structures called terminal filaments, which are stacks of cells that assemble in the larval ovary. Elucidating the developmental and regulatory mechanisms of terminal filament formation is thus key to understanding the regulation of insect reproduction through ovariole number regulation. We systematically measured mRNA expression of all cells in the larval ovary at the beginning, middle and end of terminal filament formation. We also separated somatic and germ line cells during these stages and assessed their tissue-specific gene expression during larval ovary development. We found that the number of differentially expressed somatic genes is highest during late stages of terminal filament formation and includes many signaling pathways that govern ovary development. We also show that germ line tissue, in contrast, shows greater differential expression during early stages of terminal filament formation, and highly expressed germ line genes at these stages largely control cell division and DNA repair. We provide a tissue-specific and temporal transcriptomic dataset of gene expression in the developing larval ovary as a resource to study insect reproduction.

Distinct gene expression dynamics in germ line and somatic tissue during ovariole morphogenesis in Drosophila melanogaster

The survival and evolution of a species is a function of the number of offspring it can produce. In insects the number of eggs that an ovary can produce is a major determinant of reproductive capacity. Insect ovaries are made up of tubular egg-producing subunits called ovarioles, whose number largely determines the number of eggs that can be potentially laid. Ovariole number is directly determined by the number of cellular structures called terminal filaments, which are stacks of cells that assemble in the larval ovary. Elucidating the developmental and regulatory mechanisms of terminal filament formation is thus key to understanding the regulation of insect reproduction through ovariole number regulation. We systematically measured mRNA expression of all cells in the larval ovary at the beginning, middle and end of terminal filament formation. We also separated somatic and germ line cells during these stages and assessed their tissue-specific gene expression during larval ovary development. We found that the number of differentially expressed somatic genes is highest during late stages of terminal filament formation and includes many signaling pathways that govern ovary development. We also show that germ line tissue, in contrast, shows greater differential expression during early stages of terminal filament formation, and highly expressed germ line genes at these stages largely control cell division and DNA repair. We provide a tissue-specific and temporal transcriptomic dataset of gene expression in the developing larval ovary as a resource to study insect reproduction.

A structure-derived mechanism reveals how capping protein promotes nucleation in branched actin networks

Heterodimeric capping protein (CP/CapZ) is an essential factor for the assembly of branched actin networks, which push against cellular membranes to drive a large variety of cellular processes. Aside from terminating filament growth, CP stimulates the nucleation of actin filaments by the Arp2/3 complex in branched actin networks through an unclear mechanism. Here, we report the structure of capped actin filament barbed ends, which reveals how CP not only prevents filament elongation, but also controls access to both terminal filament subunits. In addition to its primary binding site that blocks the penultimate subunit, we find that the CP sterically occludes the central interaction site of the terminal actin protomer through one of its C-terminal tentacle extensions. Deletion of this β tentacle only modestly impairs capping. However in the context of a growing branched actin network, its removal potently inhibits nucleation promoting factors (NPFs) by tethering them to capped filament ends. End tethering of NPFs prevents their loading with actin monomers required for activation of the Arp2/3 complex and thus strongly inhibits branched network assembly both in cells and reconstituted motility assays. Our results mechanistically explain how CP couples two opposed processes -capping and nucleation- in branched actin network assembly.

A new species of Isonychia Eaton, 1871 (Ephemeroptera: Isonychiidae) from Kapila River, Central Western Ghats, India

Isonychia (Isonychia) radhae n. sp. is described based on larvae and imagoes from Kapila River, Dakshina Kannada, Karnataka State, India. The imagoes of I. radhae n. sp. can be distinguished from the other known Oriental species by the following combination of characters: (i) absence of rusty brown maculae in the costal, subcostal, and median areas of forewing; (ii) forelegs dark brown except coxae; (iii) Scattered barbs present in penis; (iv) Second segment of gonostylus long and slender; and (v) sterna of abdominal segment X in female not deeply cleft. Isonychia radhae n. sp. can be distinguished in the larval stage from other known Oriental species by the following combination of characters: (i) tergites II–IV without distinct stripe medially, tergites V–X with a pair vague oblique stripe; (ii) abdominal terga II–IX with median dark brown maculae progressively larger with dark brown slanting streaks in lateral margins; (iii) gills I and II small, tracheae of abdominal gills I–VII unbranched; (iv) postero-lateral projection on anterior segments of abdomen blunt and small, acute on segments VIII–IX and large at on segment IX; (v) median terminal filament slightly shorter than 1/3 length of cerci; (vi) distal segments of cerci dark, basal ¾ of mesal margin of cerci and lateral margin of terminal filament with long thin setae. Revised keys to the known larvae and male imagoes of Oriental species of Isonychia are also provided.

Description of the final stadium larva of Bayadera serrata Davies & Yang, 1996 (Odonata: Euphaeidae) from Thailand

The damselfly genus Bayadera Selys, 1853 comprises 17 species, but the larvae of only four species have been described. Here we describe the final stadium larva of another species—Bayadera serrata Davies & Yang, 1996. Larvae were collected from a headwater stream at Nam Nao National Park, Phetchabun Province, Thailand. The larva of B. serrata is distinguished from congener species following the presence of one to three distinct spines on the genae, two pairs of setae on the ligula, one pair of setae on the ventral side of prementum, the presence of three teeth of the distal end of the labial palp, the presence of a plate-like spine on the gonapophyses, the presence of a row of rod-like setae on the distal end of the tibial comb, the presence of a cluster of long simple setae on the abdominal terga S3–9, and the presence of short terminal filament of the caudal gills. The larvae of genus Bayadera have been compared with other known larvae from family Euphaidae. Key is provided to the genera with known Southeast Asian euphaeid larvae: Anisopleura, Bayadera, and Euphaea.

Anatomy of male and female reproductive organs of stink bugs pests (Pentatomidae: Heteroptera) from soybean and rice crops

Pentatomidae comprises a diverse group of stink bugs widely distributed in the Neotropical region. Many species are phytophagous and cause injuries to plants, and can thus be defined as agricultural pests. In this study, the anatomy of the female and male reproductive tracts of three important agricultural pests in Colombia is described: Piezodorus guildinii Westwood, 1837 and Chinavia ubicaRolston 1983, found on soybeans, and Oebalus insularis Stål, 1872, found in rice crops. For that, light microscopy techniques were used. The anatomy of the reproductive tract of sexually mature males of the three species studied consisted of a pair of testes, vas deferens, seminal vesicles, ejaculatory bulb, an ejaculatory duct that opens into an aedeagus, and paired accessory glands. The reproductive tract of females consisted of a pair of ovaries, each with seven telotrophic-meroistic ovarioles, a pair of lateral oviducts, common oviduct, spermatheca, and a genital chamber. Telotrophic ovarioles were comprised of terminal filament, tropharium, vitellarium, and pedicel. Differences in size, color, and position of structures along the reproductive tract were observed between the species examined. Reproductive biology of insects provides informative characters for behavioral and evolutionary studies, as well as useful data for pest control strategies.

A new species of Camelobaetidius Demoulin, 1966 (Ephemeroptera: Baetidae), from the Colombian Orinoco River basin

Three species of Camelobaetidius Demoulin, 1966 have been reported from Colombia until now, based on nymphs. We describe a fourth species based on nymphs from the Colombian Orinoco river basin. The new species can be recognized by: 1) labrum narrowly rounded anteriorly; 2) segment II of labial palp with a short rounded distomedial projection; 3) incisors of right mandible with eleven denticles; 4) gills absent from the bases of coxae; 5) tarsal claws with ten denticles; 6) outer margin of forefemur with a row of about 23 long, spine-like setae; 7) posterior margin of tergum IV with truncate spines, and 8) terminal filament almost as long as cerci. [Zoobank URL: urn:lsid:zoobank.org:act:500CF998-8EF3-43E3-BA8B-F062B92768F3]

New species and new records of Camelobaetidius Demoulin, 1966 (Ephemeroptera: Baetidae) from Southeastern Brazil

The genus Camelobaetidius Demoulin, 1966 has 37 species distributed throughout the Nearctic and Neotropical Regions, being one of the most studied genera of the family Baetidae. The nymphs are common in lotic habitats, can often be found on top of rocks, and can be easily recognized by the presence of the spatulate tarsal claws. Based on material from Southeastern Brazil, the aim of the present paper is to describe two new species with the terminal filament as long as the cerci (C. juparana sp. nov. and C. spinosus sp. nov.), to describe the female of C. anubis (Traver & Edmunds, 1968), to describe new characters for the male of this species, and to present new records for the genus in southeastern Brazil.