We compared the mating systems and genital morphology of three Orius species dominant in Japan: Orius sauteri (Poppius), Orius minutus (L.), and Orius strigicollis (Poppius) (Heteroptera: Anthocoridae). In all three species, the males were polygamous and could inseminate at least three females at a rate of one female per day. Compared to the other two species, the O. minutus males had a lower rate of success in three consecutive mating orders. The mated females laid the same number of eggs irrespective of mating sequence. Orius minutus and O. strigicollis females were found to be monandrous, and they re-mated with another male only when the 1st mating failed. In contrast, O. sauteri females were polyandrous and accepted a 2nd male even when the 1st mating was successful. Multiple mating with a single male did not increase their fecundity, and it decreased the hatching success of eggs. Mating with multiple males did not affect the fecundity or hatching success. Our scanning electron microscopy observation suggested that the genitalia of O. minutus and O. strigicollis were more similar in shape. The similarities in mating system and morphology between O. minutus and O. strigicollis support a close phylogenetic relationship.

Traumatic insemination (TI) is an extraordinary style of mating behavior wherein the female integument is pierced by the male extragenital structure to transfer the spermatozoa into the female's body through wounding. Flower bugs of the genus Orius belong to the family Anthocoridae (Heteroptera), which is referred to as the "TI family". Males possess sharp shaped extragenitalia, and females receive the extragenitalia using the copulatory tubes, which are specialized extragenital structures in Orius species. Since TI is not well studied in insects possessing the copulatory tube, we examined the genital structures and copulatory processes of three species, Orius strigicollis, O. sauteri, and O. minutus. Scanning electron microscopic observations revealed the positions of male extragenital structures during copulation. A needle-like flagellum was deeply inserted into the female intersegment between the abdominal VII and VIII segments, while the curved part of a sickle-like cone forced the intersegment to expand. No scars were detected around the copulation region after copulation. The copulatory tube adhered to the interior of segment VII, and the interior integument around the copulatory tube remained intact after copulation. On the basis of these results, TI does not occur in these Orius species. A pair of seminal conceptacles, which exists in typical TI insects, was found at the base of the oviducts in O. strigicollis. The distal end of the copulatory tube connected to a closed bag with a double-membrane, termed the sperm pouch. The sperm pouch was filled with filamentous structures after copulation and structures with equivalent forms were observed in adult male testis. These structures, considered to be spermatozoa, persisted in the pouch for at least two weeks after copulation, suggesting that the pouch is a long-term spermatozoa storage organ.

In host-parasitoid interactions, the venom fluid of a female wasp (Cotesia glomerata) is considered to play a role in regulation of the host immune response to protect her offspring. In this study, we detected a rapid increase in protein content in the female C. glomerata venom reservoir just after eclosion, at which time the venom gland cell exhibited fine structures typical of secretory function. We isolated a protein from the venom, termed C. glomerata venom protein 1 (CgVP1). After N-terminal amino acid sequencing analysis of CgVP1, the complementary DNA (cDNA) encoding this protein was cloned and sequenced. Two cDNAs (CgVP1-a and CgVP1-b) were obtained whose nucleotide sequences differed at two positions, resulting in putative substitutions of amino acid residues at two positions in the mature protein. The following features were indicated by cDNA sequence analysis and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry analysis: (1) CgVP1 consists of 81 amino acid residues, eight of which are cysteine; (2) CgVP1 is preceded by a putative secretory signal consisting of 18 amino acids; (3) the molecular masses of mature CgVP1-a and CgVP1-b are 9316.2 and 9302.0, respectively; (4) the eight cysteines of CgVP1 form four pairs of intramolecular disulfide bonds; and (5) BLAST searching indicated that CgVP1 has no similarity to previously reported proteins.