The relationship between web design and prey capture in orb-web spiders was examined by correlating the mean mesh height with the mean prey length per species taken from existing literature (15 species) and new data (Larinioides sclopetarius and Argiope keyserlingi). Pooling the data from all species, the results revealed no significant relationship. Analysing the data from L. sclopetarius and A. keyserlingi separately, no overall significant relationship was found. However, the analyses of the separate observation days showed that mesh height correlated significantly with prey length on one of the five observation days for A. keyserlingi, but not for L. sclopetarius. Consequently, the spacing of the sticky spiral in the orb-web can have a significant effect on the length of the captured prey under certain circumstances, which are discussed in the present paper.
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.