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Viscuso, R., Brundo, M.V., Marletta, A. and Vitale, D.G.M. 2015. Fine structure of male genital tracts of some Acrididae and Tettigoniidae (Insecta: Orthoptera).-Acta Zoologica (Stockholm) 96: 418-427.A morphological, histological and ultrastructural study was carried out on the spermiducts and seminal vesicles of some species of Acrididae and Tettigoniidae. In all the species examined, the spermiducts and seminal vesicles have a monolayered secretory epithelium. Only the species of Acrididae have the sac with a flattened epithelium. Furthermore, in the most distal tubule region of the seminal vesicles of Eyprepocnemis plorans plorans, a rather characteristic secretory mechanism was found: the cytoplasm of the epithelial cells contained a large vesicle delimited by tightly packed microvilli. Numerous small vesicles open into this large vesicle which gradually dilates to merge with the apical plasma membrane releasing its contents into the lumen. Spermiophagic activity was found in all the species investigated. In the Tettigoniidae, this activity was found only in some epithelial cells of the seminal vesicle wall; in the species of the Acrididae the spermiophagic activity was carried out in the spermiduct lumen by an epithelial-type cellular group. Spermiophagic activity is discussed as well as its role in the reproduction of these insects.

The last immature stage and the mature larva of Anteon flavicorne (Dalman) and Lonchodryinus ruficornis (Dalman) (Dryinidae, Anteoninae) are described. Figures and descriptions of some characters of the exuvia of the mature larva of Deinodryinus hispanicus (Olmi) are added. The immature larvae of the studied species are characterized by a layer (“mask”) covering the frontal region, the absence of cephalic vesicles, the body with its posterior region strongly bent ventrally, and the position on the host always on the thorax or between metathorax and abdomen. Main features of the mature larvae are the very long setae on the body and head, the labrum with few long sensory bristles and two sensory pits and with an apical row of sensory bristles, the epipharynx with two sensilla, the subtriangular labium with narrow subquadrate spinneret, and the bulb-shaped spiracles of approximately equal size in thorax and abdomen. The cocoon is built in the ground and covered by soil particles.

This paper is the first to describe the silk produced by Segestriidae spiders. Field and specimen data together with webs secreted by Namibian arid-adapted Ariadna spiders were collected from different research work stations. The silks were solubilized with hexafluoroisopropanol and characterized by Fourier transform infrared (FT-IR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and differential scanning calorimetry (DSC) techniques, in order to get data on the silk composition. FT-IR analysis confirms that proteins are the main component of the extracted materials. MALDI-TOF mass spectra of silks of three different sites (R, M and K, with three varied environmental conditions: coastal foggy area, hot central desert area and savannah) reveal the presence of low-molecularweight (< 10,000 g/mol) proteins mostly based on glycine and alanine amino acids. Besides many peptides with identical or similar composition, other low-molar mass proteins with different compositions were also revealed in these silks. The DSC curves show that the studied silks have different melting temperature ranges. This behaviour may be due to the proteins having different molecular weight and/or different amino acid composition. The presence of small peptides with different amino acid composition could be correlated to the different habitats where the spiders live. Hypotheses linking different amino acid compositions with environmental features are suggested.

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