Myrmecophily and Myrmecophagy of Attacobius lavape (Araneae: Corinnidae) on Solenopsis saevissima (Hymenoptera: Myrmicinae)

Abstract

Attacobius lavape, a small spider from the Corinnidae family, has been recently described living inside a fire ant colony of Solenopsis saevissima species in the municipality of Morrinhos, south region of the Goiás State, Brazil. Yet several aspects of this spider relationship with the host ant remain unknown. In this way, we performed an extension study to determine its local (Morrinhos) and regional (latitudinal transect) occurrence. We also investigated if the spider uses the host ant as a feeding source. For this, we established arenas with a known number of young and adult ant individuals plus one spider and observed the feeding rate for some determined time. Regarding local distribution, differently from most socially parasitic myrmecophiles, A. lavape showed high local infestation, being found in 47% of the colonies in the sites where the spider occurred, and high transmission, being found in 42% of the 12 collection sites. Regionally, among the 11 study sites, this species only occurred in the municipality of Morrinhos, but its distribution still needs to be verified in the north region. Attacobius lavape consumed eggs, larvae and pupae, confirming that the myrmecophily was explained by myrmecophagy. The spiders consumed eggs (not estimated), 4.45 ± 2.14 larvae and/or 3 ± 0.87 pupae per day. Considering that the mean abundance was approximately seven spiders per colony (extent 1-23), we foresee an impact of 35 larvae and/or 21 pupae consumed per day in each hosting colony. The possibility of consuming sexual eggs, larvae and pupae classifies A. lavape as a potential agent of biological control of S. saevissima.

First records of Anagraphis ochracea (Araneae: Gnaphosidae) for continental Italy and Sicily with new observations on its myrmecophilous lifestyle

“…Although several authors have noted and studied this peculiar behaviour within the Araneae (Hölldobler & Wilson 1990, Cushing 1997, 2012, Witte et al 2008, Nelson & Jackson 2009, most have primarily focused on myrmecomorphy (mimcry of ants) and myrmecophagy (the consumption of ants). As of today, very few contributions have discussed myrmecophily and the social integration of spiders in ant colonies (Mendonça et al 2019). Several myrmecophile spider species not only resort to active, evasive manoeuvres to avoid direct interaction with the ant, but have also developed the ability to chemically hide.…”