Morphological characteristics of Dermanyssus gallinae (Mesostigmata, Dermanyssidae)

The red mite Dermanyssus gallinae (De Geer, 1778), a dangerous parasite of poultry which causes significant economic losses to poultry farming, is widespread, including in economically developed countries. These mites are transient blood-sucking parasites that can attack not only birds and other mammals, but also humans, causing itching and dermatitis. A deeper understanding of the morphology and identification of D. gallinae will allow us to avoid complications in their differentiation from similar dermanyssid parasites, which may share the host species and environment. The aim of the research was to describe the morphological features and metric parameters of gamasid mites of the species D. gallinae, isolated from chickens in Ukraine. Morphometric studies have identified 30 parameters in male and 40 indicators in female mites, which characterize the general structure of the body, species-specific morphological features, as well as characters of sexual dimorphism. In male and female mites, the structure and dimensions of the body, gnathosoma, idiosoma, tagmas, dorsal shield, specific arrangement of dorsal setae, length of adanal and postanal setae, as well as the distance between sternal setae st1–st1, st2–st2, st3–st3, st1–st2, st1–st3, metasternal setae mst–mst, ventral setae vl1–vl1, adanal setae ad–ad are described. A characteristic feature of females of D. gallinae is the presence of a stylet-like second cheliceral article, while in males there are no cheliceral articles of a stylet-like shape. In males, the dimensions of the sternogenital and ventroanal shields are additionally described and determined. In females, the dimensions of the sternal, genitoventral and anal shields, the genitoventral valve, the length of the setae st1, st2, st3, mst, and the distance between the setae st1–mst were additionally described and determined. For the first time, the dimensions of females with a formed egg in their body cavity were described and compared with the dimensions of female mites without eggs. The data obtained in this study expands existing data on the morphometric characteristics of male and female D. gallinae.