First report of Linognathus africanus (Phthiraptera: Anoplura) on goats in Bulgaria

The current study was conducted in 28 farms from 11 administrative districts in Bulgaria and included 4132 goats from six breeds, naturally infested with ectoparasitic insects. The visit to the farms was paid after the owners alarmed for signs of strong discomfort and itching among the animals. From the 28 studied herds, 14 (50%) turned out to be infested with the African sucking louse of goats: Linognathus africanus (Kellog & Paine, 1911) belonging to the family Linognathidae, suborder Anoplura, order Phthiraptera. All documented cases were of mixed infestation with other ectoparasitic species. The ectoparasites were collected and preserved in 70o ethanol for laboratory identification, morphological observation and for preparing photographic material. The full morphological description of the species showed that the total body length (TBL) of the male individuals varied between 0.912-1.556 mm, and that of the females: from 1.159 to 1.784 mm. A morphological identificationof the phylogenetically close species Linognathus africanus (Kellog & Paine, 1911) and Linognathus stenopsis (Burmeister, 1838) was conducted in laboratory conditions. The population structure of the species was presented through the sex identification of Linognathus africanus which demonstrated a numerical ratio of F:M = 2.2:1.