three threidiid spiders of the genus latrodectus occur in khorasan province: l.tredecimguttatus, l.pallidus, l.dahli. the three are described, their diagnostic features are illustrated, and taxonomic notes are given where possible. spider bites are very common in these regions, so, further notes about the medical importance of these species are given. a dichotomic key to the species of the genu...

The attention in the article is paid to key species research importance. Their classification was discussed our published “Studia Biologica” (Y. Tsaryk, O. Reshetylo, I. Biol. Stud. 2019: 13(1); 161–168). main emphasis made on ecological species, while other categories were analyzed as well (protective, social etc.). A row of potential different ecosystems proposed based original field research...