An investigation of diversity and bioecology of araneofauna of Pathiramanal Island in Vembanad Lake, a Ramsar site, Kerala, India

A preliminary checklist of araneofauna of Pathiramanal Island is provided. A total of 147 species belonging to 26 families under 92 genera are documented. Tylorida ventralis (Thorell 1877) is considered to be the dominant species, and orb weavers are seen as the dominant guild. Araneidae, Salticidae, Theridiidae, Tetragnathidae and Thomisidae are five dominant families. The Shannon diversity, Simpson’s (1-D) diversity, evenness and Chao1 indices have been calculated. Seven species new to science such as Indopadilla insularis, Epeus triangulopalpis, Marengo sachintendulkar, Indomarengo chavarapater, Icius vikrambatrai, Piranthus planolancis (Salticidae) and Wolongia papafrancisi (Tetragnathidae) are documented as well as three genera and four species are added to the Indian spider taxonomy. The males of Meotipa picturara, Curubis tetrica and Pscellonus planus are described for the first time. Eight species are synonymized and redescribed. Mating plug formation in Argyrodes flavescens is reported for the first time. It is noted that spider species from Pathiramanl Island bear affinities with Oriental and Palearctic regions.

Mating-regulated atrial proteases control reinsemination rates in Anopheles gambiae females

Anopheles gambiae mosquitoes are the most important vectors of human malaria. The reproductive success of these mosquitoes relies on a single copulation event after which the majority of females become permanently refractory to further mating. This refractory behavior is at least partially mediated by the male-synthetized steroid hormone 20-hydroxyecdysone (20E), which is packaged together with other seminal secretions into a gelatinous mating plug and transferred to the female atrium during mating. In this study, we show that two 20E-regulated chymotrypsin-like serine proteases specifically expressed in the reproductive tract of An. gambiae females play an important role in modulating the female susceptibility to mating. Silencing these proteases by RNA interference impairs correct plug processing and slows down the release of the steroid hormone 20E from the mating plug. In turn, depleting one of these proteases, the Mating Regulated Atrial Protease 1 (MatRAP1), reduces female refractoriness to further copulation, so that a significant proportion of females mate again. Microscopy analysis reveals that MatRAP1 is localized on a previously undetected peritrophic matrix-like structure surrounding the mating plug. These data provide novel insight into the molecular mechanisms shaping the post-mating biology of these important malaria vectors.

The Effects of the sphragis on male and female genitalia in Acraea (Nymphalidae) butterflies

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.

On the identity of Trochosa hispanica (Araneae, Lycosidae), with notes on the synonymy of West Palaearctic “Trochosa” species

Specimens belonging to Trochosa hispanica Simon, 1870 collected in different parts of the range were compared to determine whether they belong to the same species or represent a series of cryptic species. No significant differences were found between different populations. Most of the females examined have a kind of mating plug blocking the pathway of embolus, but not the copulatory openings like in other spiders. A character previously unknown in the Lycosidae, a row of glabrous cuticular spots on male tibia I, is documented. The holotype female of Trochosa adjacens O. Pickard-Cambridge, 1885 from SW Xinjiang is illustrated for the first time. Three species described in three different genera in the same paper are synonymized with Trochosa hispanica: Arctosa nava Roewer, 1955 syn. n., Geolycosa flavichelis Roewer, 1955 syn. n., and Loculla austrocaspia Roewer, 1955 syn. n. Two species treated in Trochosa C.L. Koch, 1847 and Trochosula Roewer, 1960 are synonymized with Arctosa tbilisiensis Mcheidze, 1946: Trochosa impercussa Roewer, 1955 syn. n. and Trochosula afghana Roewer, 1960 syn. n. Three species are synonymized with Hogna ferox (Lucas, 1838): Geolycosa altera Roewer, 1955 syn. n., Geolycosa atroscopulata Roewer, 1955 syn. n., and Lycorma nigrichelis Roewer, 1955 syn. n. Lycosa (Trochosa) ochracea L. Koch, 1856 syn. n. from Spain, a species known by two taxonomic entries, is synonymized with Trochosa ruricola (De Geer, 1778). Trochosa hungarica Herman, 1879, a species known from a single publication, seems to belong to Geolycosa Montgomery, 1904 and is potentially a junior synonym of G. vultuosa (C.L. Koch, 1838). Pardosa persica (Roewer, 1955) comb. n., originally described in Dingosa Roewer, 1955, is transferred from Trochosa to Pardosa and belongs to the nebulosa-group. A new secondary homonym, Pardosa persica Marusik, Ballarin & Omelko, 2012, hom. n. is replaced with Pardosa persiana nom. n. in the monticola-group. Four species of Trochosa from Northern Africa are transferred to Alopecosa and Arctosa: Alopecosa garamantica (Caporiacco, 1936) comb. n., Alopecosa werneri (Roewer, 1960) comb. n., Arctosa annulipes (L. Koch, 1875) comb. n., and Arctosa tangerana (Roewer, 1960) comb. n. Trochosomma Roewer, 1960 syn. n. (type species Trochosa annulipes L. Koch, 1875) is removed from synonymy with Trochosa and synonymized with Arctosa C.L. Koch, 1847. Male lectotypes are designated for Arctosa nava Roewer, 1955, Geolycosa atroscopulata Roewer, 1955, and Trochosa rustica Thorell, 1875; female lectotype is designated for Geolycosa flavichelis Roewer, 1955.

Control of mating plug expelling and sperm storage in Drosophila: A gynandromorph- and mutation-based dissection

Introduction In this study, we analyzed gynandromorphs with female terminalia, to dissect mating-related female behaviors in Drosophila. Materials and methods We used gynandromorphs, experimentally modified wild-type (Oregon-R) females, and mutant females that lacked different components of the female reproductive apparatus. Results Many of the gynandromorphs mated but did not expel the mating plug (MP). Some of these – with thousands of sperm in the uterus – failed to take up sperm into the storage organs. There were gynandromorphs that stored plenty of sperm but failed to release them to fertilize eggs. Expelling the MP, sperm uptake into the storage organs, and the release of stored sperm along egg production are separate steps occurring during Drosophila female fertility. Cuticle landmarks of the gynandromorphs revealed that while the nerve foci that control MP expelling and also those that control sperm uptake reside in the abdominal, the sperm release foci derive from the thoracic region of the blastoderm. Discussion and conclusion The gynandromorph study is confirmed by analyses of (a) mutations that cause female sterility: Fs(3)Avar (preventing egg deposition), Tm2gs (removing germline cells), and iab-4DB (eliminating gonad formation) and (b) by experimentally manipulated wild-type females: decapitated or cut through ventral nerve cord.