No abstract

Abstract. The natural prey of the jumping spider Menemerus taeniatus (L. Koch, 1867) was studied on the Absheron Peninsula, Azerbaijan. The percentage of specimens of M. taeniatus found feeding was low (10.7%). This investigation showed that M. taeniatus is a polyphagous predator feeding on a wide range of arthropods, including representatives of eight arthropod orders. The primary food of M. taeniatus was Diptera and Lepidoptera, which collectively made up about two thirds of total prey. The length of prey killed by M. taeniatus ranged between 1.10 and 13.00 mm (mean 6.14 mm), which is between 15.2 and 216.7% (mean 90.3%) of the length of their captors. Most frequently taken prey (50%) were medium-sized arthropods varying between 50-100% of the spiders' body length.

The distinctions between a predator's diet, its prey-choice behaviour and its preferences are illustrated in a study of Aelurillus muganicus, a salticid spider from the Apsheron Peninsula in Azerbaijan. Laboratory experiments showed that A. muganicus has an innate predisposition to choose ants as prey. The natural diet of this species was determined by sampling individuals seen feeding in the field (n = 64). Ten arthropod orders were represented. Seven were from the class Insecta (Coleoptera, Collembola, Diptera, Heteroptera, Homoptera, Hymenoptera, Lepidoptera) and three from the class Arachnida (Acari, Araneae, Pseudoscorpiones). Collectively, four orders accounted for > 70% of the prey records: Hymenoptera (20%), Lepidoptera (19%), Acari (19%) and Homoptera (14%). No other order accounted for > 10% of the prey records. Of the 45 insects among the prey, 13 (29%) were Hymenoptera, with ants (family Formicidae) alone accounting for 24% of the prey records. Although ants were the preferred prey of A. muganicus, as revealed by laboratory testing, and also the most common single category of prey from the field prey records, records of A. muganicus feeding on prey other than ants were actually more common than records of it feeding on ants, suggesting that, besides prey choice, other factors have a strong influence on the diet of this species.

The prey of the lynx spider, Oxyopes globifer Simon 1876, occurring on Salsola nodulosa (Moq.) plants, was analyzed. In common with other cursorial spiders, the percentage of feeding specimens in the population of O. globifer was low (5.5%). Males were observed feeding significantly less frequently than females and immatures of both sexes. After oviposition, however, the records of prey capture in eggguarding females also declined considerably. Oxyopes globifer is a polyphagous predator feeding on a wide range of arthropods: insects of the orders Hymenoptera, Diptera, Lepidoptera and Homoptera, as well as on several spider species. The primary food was worker ants, which accounted for 62.7% of total prey. No other prey taxon was present in any considerable percentage. O. globifer captured prey ranging between 22.7 and 243.8% (mean 88.8%) of its own body length. Most frequently taken were mediumsized arthropods varying from 50-110% of spiders' body lengths.

The natural prey of the lynx spider Oxyopes lineatus Latreille, 1806 was studied in a meadow in the subtropical zone of Azerbaijan. The percentage of specimens of O. lineatus found while feeding was low (4.3%). Spiders were observed feeding both day and night. The investigation has shown that O. lineatus is a polyphagous predator feeding on a wide range of arthropods, with representatives of nine arthropod orders found in its diet. The primary food of O. lineatus was Diptera, Hymenoptera, and Homoptera, which collectively made up about three quarters of all prey. Worker ants constituted about 20% of the diet suggesting that O. lineatus is a myrmecophagic spider. The length of prey killed by O. lineatus ranged between 0.50 and 8.50 mm (mean 2.72 mm), varying from 12.1 to 171.4% (mean 61.4%) of the length of their captors. The most frequently captured prey were arthropods not exceeding the length of the spiders (87.5%).