FUNGAL SPORES AND POLLEN AS POTENTIAL NUTRITIONAL ADDITIVES FOR THE CROSS SPIDER Araneus diadematus Clerck (ARANEAE, ARANEIDAE).

Prior to make a new cobweb, the Araneus
diadematus Clerck cross spider eats its old web regulary
everyday. In this paper we issue a quantitative and
qualitative analysis of pollen grains and fungal spores
present in the cob web, which might contribute to the
diet of this arachnide. Cob webs were collected at the
Natural Park of Ticino (Pavia, northern Italy). Fungal
spores and pollen grains were taxonomically counted
and identified for each sample. Quantitative analysis
showed that both spores and pollen present in the cob
webs exhibited some seasonal variation as regards
quantity, whereas the qualitative analysis revealed that
spores and pollen grains belong to 14 and 7 taxa,
respectively. Alternaria, Cladosporium, Fusarum were
the most frequent fungal taxa while Urticaceae,
Betulaceae and Poaceae became the most representative
plant families. About 5700 fungal spores and 2000 pollen
grains were found to be present in the cob web of this
spider everyday. Based on this information, it is possible
to think that the aeroplancton stuck to the cob web can
become a nutritional additive for the diet of this
arachnide