The diet of the black widow spider Latrodectus mirabilis (Theridiidae) in two cereal crops of central Argentina

POMPOZZI GABRIEL; FERRETTI NELSON; SCHWERDT LEONELA; COPPERI SOFÍA; FERRERO ADRIANA; SIMÓ MIGUEL

IHERINGIA. SéRIE ZOOLOGIA

FUNDACAO ZOOBOTANICA RIO GRANDE SUL

Lugar: Porto Alegre; Año: 2013 vol. 103 p. 388 - 392

0073-4721

The spider Latrodectus mirabilis (Theridiidae) is commonly found in cereals crops of central Argentina. We studied its diet composition at the field and capture rate on leaf-cutting ants based on laboratory experiments. This study comprises the first approach that documents the diet of L. mirabilis in wheat and oat fields of central Argentina. We identified 1004 prey items collected from its webs during the last phenological stages of both cereal crops. The prey composition was variable but the spiders prey mainly on ants (Formicidae, Hymenoptera), who represented more than 86% of the total. Meanwhile, in the capture rate experiences we registered a high proportion of ants captured by spiders at the beginning of experiences, capturing the half of the ants from total in the first four hours. Summarizing, we reported a polyphagous diet of this spider species in wheat and oat fields. Ants were the most important prey item of this spider, as found in other Latrodectus spiders around the world.