Morphological and Morphometrical Study of the Stink Bug Mustha spinulosa (Lefebrve, 1831) (Hemiptera: Pentatomidae) from Erbil – Iraq

All life stages of the pentatomid stink bug Mustha spinulosa (Lefebrve, 1831) (Hemiptera: Pentatomidae) collected from several types of trees in Erbil Governorate, North Iraq, along with their morphometrical description, were illustrated. Eggs are barrel in shape, green in color when freshly laid, and usually deposited in clusters that contain 14 eggs each (sometimes 12). Nymphs complete their stage through 5 instars. Head, pronotum, and connexivum of the adults and instars are with pale pink and gray spines; female is slightly larger than male; female is 27.30 mm long and 12.80 mm wide, while male is 25.80 mm long and 11.98 mm wide. Labium proboscis is1.25 ± 0.01 cm long, with brown blackish color. A pair of scent glands are located on the underside of thorax between second and third leg base. All body parts, especially head, thorax, and abdomen are densely covered with setae.

Histomorphological perspectives of preputial and clitoral glands of soft-furred field rat Millardia meltada

The present study was an attempt to understand the sexual dimor-phism of the integumentary scent glands of soft-furred field rat Millardia meltada from the perspectives of anatomy, morphology and histology with view to correlate with the sex-specific pheromones they produce. The scent gland of male is known as preputial gland, and female, the clitoral gland. The rats, that are agricultural pests were field caught, the glands of males and females of almost identical size were dissected out, and subjected to gravimetric, morphometric and histological analyses. Both glands are yellowish-brown, pear-shaped, and dorsoventrally compressed. The mean weight, length and width of preputial glands are significantly (p < 0.05) larger than that of the clitoral glands. The preputial gland is composed of sebaceous glandular lobules and apocrine glandular lobules whereas the clitoral gland is formed only of sebaceous glandular lobules. The sebaceous glandular lobules of both preputial and clitoral glands are filled with a wax-like material. Thus, the scent glands of the soft-furred male field rats exhibit sexual dimorphism in respect histoarchitecture of the glands and the nature of the secretory material. This sexual dimorphism of the scent glands may reflect control by male and female sex hormones impinging on specific roles as sex attractant pheromones.

The hard task of a short-tailed mouse opossum (Monodelphis) to prey a harvestman (Arachnida: Opiliones)

ABSTRACT Despite the great diversity of small insectivorous mammals and the use of scent gland secretions as a defense mechanism by harvestmen, there is no observation about the effectiveness of scent glands against predators such as small mammals. We report a remarkable harvestman defense mechanism against a small-mammal attack. When a harvestman and a mouse opossum confronted each other inside a cage, the harvestman knocked out the mouse opossum two sequential times before it could attack the harvestman. Although it is a unique observation and there is no information about its frequency in nature, this report stimulates the study of agonistic behavior between small, cryptic species, which are difficult to observe in the field.

Benzoquinones in the defensive secretion of a bug (Pamillia behrensii): a common chemical trait retrieved in the Heteroptera

Benzoquinones are a phylogenetically widespread compound class within arthropods, appearing in harvestman, millipedes and insects. Whereas the function of benzoquinones as defensive compounds against potential predators and microbes has been well established, the full extent of benzoquinone usage across arthropods, and especially within Insecta, has yet to be established. Adding to the growing list of unique evolutionary origins of benzoquinone employment, we describe in this paper the metathoracic scent gland secretion of the mirid bug Pamillia behrensii, which is composed of heptan-2-one, 2-heptyl acetate, 2,3-dimethyl-1-4-benzoquinone, 2,3-dimethyl-1-4-hydroquinone as well as one unknown compound. Similarly, to many other arthropods that use benzoquinones, Pamillia releases the contents of its gland as a defensive mechanism in response to harassment by other arthropod predators. Morphological investigation of the gland showed that the benzoquinone-producing gland complex of P. behrensii follows a similar blueprint to metathoracic scent glands described in other Heteropterans. Overall, our data further underpins the widespread convergent evolution and use of benzoquinones for defense across the Arthropoda, now including the order Hemiptera.

Review of the genus Bubaces (Hemiptera: Heteroptera: Rhyparochromidae: Lethaeini) with descriptions of three new species, new distributional records, and key to species

The genus Bubaces Distant, 1893 is reviewed and three new species are described: B. gloriosus sp. nov., from Costa Rica (Puntarenas Province) and Mexico (Campeche, Chiapas, Guerrero, Oaxaca, and Veracruz), B. occidentalis sp. nov., from Mexico (Colima, Guerrero, Jalisco, and Michoacan) and B. rostralis sp. nov., from Mexico (Quintana Roo). Additional state faunistic records of the previously described species B. castaneus, B. convergens, B. enatus and B. uhleri are provided. Photographs of the dorsal habitus, the male genital capsule, and the parameres are included, as well as close up photos of the metathoracic scent glands of both sexes. A key to species of the genus is provided.

Scanning the Hyocephalidae: details of their external morphology with respect to phylogenetic relationships within Eutrichophora (Hemiptera: Heteroptera)

Hyocephalidae (Hemiptera: Heteroptera: Pentatomomorpha) is a small family of true bugs containing two genera and three species endemic to Australia. For the first time, we examine here selected structures of their external morphology using scanning electron microscopy – the external structures associated with the metathoracic and dorsoabdominal scent glands, the strainer organ on the sternite III, as well as the trichobothrial pattern and ultrastructure. The following character states are confirmed (i, ii, iii) or newly recognised (iv, v) as autapomorphies of Hyocephalidae: i) apically projected scimitar-shaped peritreme of the metathoracic scent glands; ii) presence of a strainer organ on sternite III in both sexes; iii) trichobothria on sternite V placed immediately ventrad of spiracle, iv) trichobothria on each of abdominal segments III–VII all grouped together within a common trichome, and v) presence of crocus-like structures within the trichome. Of particular interest is the presence of a shallow open bothrium (type B) surrounded by a trichome in Hyocephalidae, a probably derived character state shared with Pyrrhocoroidea and most Lygaeoidea, while Stenocephalidae (previously considered to be closely related to Hyocephalidae and used here for comparison) and the remaining Coreoidea possess a recessed bothrium of type A2, lacking the trichome. The morphology of trichobothria in Hyocephalidae may thus suggest either their closer relationship to Lygaeoidea + Pyrrhocoroidea than to Coreoidea, or a parallel evolution of the open bothrium with trichome in Eutrichophora. We highlight the importance of Hyocephalidae for a better understanding of the phylogeny of Eutrichophora and the urgent need to obtain phylogenomic data for future research. A taxonomic catalogue of Hyocephalidae is supplemented. The neotype designation for Hyocephalus aprugnus Bergroth, 1906 made by ŠTYS (1964) and supported by GRANT & ŠTYS (1970) is found invalid.