The filamentous spermatozoa of scale insects (Hemiptera) are highly modified compared with those of typical insects. Here, we investigate the morphology of the testes, sperm bundles, spermatozoa, and spermatogenesis of the winglessKerria chinensis(Mahdihassan) (Hemiptera: Kerriidae), a shellac-producing scale insect. Each testis contains two antiparallel groups of several hundred syncytial sperm bundles. In each spermatocyte cyst, 16 primary spermatocytes divide via inverted meiosis, resulting in 16 quadrinucleated spermatids, each having two euchromatic and two heterochromatic nuclei. During spermiogenesis, each spermatid produces two spermatozoa protruding out of the spermatid close to the two euchromatic nuclei and their tails then grow in opposite directions. In each cyst, the 32 spermatozoa form two sperm bundles lying in an antiparallel direction oriented to different ends of the testis. Each spermatozoon has three distinct regions, an apex, a filamentous region and a tail. The spermatozoa have long thread-like nuclear cores that occupy about one-fourth of the sperm body length, located primarily in the posterior half. At the anterior end of the spermatozoon is a translucent, swollen vesicle and a distal, densely-stained structure; a putative acrosome of a type not previously reported in the spermatozoa of scale insects.

The giant water bug, Lethocerus indicus (Lepeletier and Serville) (Heteroptera: Belostomatidae), a native species of Southeast Asia, is one of the largest insects belonging to suborder Heteroptera. In this study, the meiotic chromosome of L. indicus was studied in insect samples collected from Thailand, Myanmar, Loas, and Cambodia. Testicular cells stained with lacto-acetic orcein, Giemsa, DAPI, and silver nitrate were analyzed. The results revealed that the chromosome complement of L. indicus was 2n = 22A + neo-XY + 2m, which differed from that of previous reports. Each individual male contained testicular cells with three univalent patterns. The frequency of cells containing neo-XY chromosome univalent (∼5%) was a bit higher than that of cells with autosomal univalents (∼3%). Some cells (∼0.5%) had both sex chromosome univalents and a pair of autosomal univalents. None of the m-chromosome univalents were observed during prophase I. In addition, this report presents clear evidence about the existence of m-chromosomes in Belostomatidae.

Ngernsiri, L., Piyajaraprasert ,W., Wisoram,W. and Merritt, D.J. 2014. Structure of the female reproductive system of the lac insect, Kerria chinensis (Sternorrhyncha, Coccoidea: Kerridae). -Acta Zoologica (Stockholm) 00: 000-000.The ovaries of female lac insects, Kerria chinensis Mahd (Sternorrhyncha: Coccoidea: Kerridae), at the last nymphal stage are composed of several balloon-like clusters of cystocytes with different sizes. Each cluster consists of several clusters of cystocytes arranging in rosette forms. At the adult stage, the pair of ovaries consists of about 600 ovarioles of the telotrophic-meroistic type. An unusual feature when considering most scale insects is that the lateral oviducts are highly branched, each with a number of short ovarioles. Each ovariole is subdivided into an anterior trophic chamber (tropharium) containing six or seven large trophocytes and a posterior vitellarium harbouring one oocyte which is connected with the trophic chamber via a nutritive cord. No terminal filament is present. Late-stage adult females show synchronized development of the ovarioles, while in undernourished females, a small proportion of ovarioles proceed to maturity.