Wandering and web spiders feeding on the nectar from extrafloral nectaries in neotropical savanna

Despite their essentially carnivorous habits, spiders can supplement their diets with other food sources, such as extrafloral nectar. The extrafloral nectar can constitute an excellent complementary energy source for spiders because it is rich in mono and disaccharides besides other compounds. We investigate the presence of fructose and its concentration in the bodies of wandering and web weaver spiders collected on extrafloral nectary-bearing plants from a neotropical savanna area by means of cold anthrone test. The tested spiders belonged to seven families: Anyphaenidae, Araneidae, Oxyopidae, Pisauridae, Salticidae, Theridiidae and Thomisidae. A total of 265 (88.04%) of all tested individuals were fructose intake positive. In general, there was no difference in the percentage of positive spiders between wandering and web weaver spider species or between adult and immature individuals. Results found in this study corroborate those from other studies that suggest that nectar feeding is a common activity among spiders and it includes a new family (Theridiidae) in the nectivory spiders list.