29 January 2007

Latrodectus geometricus....the Holy Grail


Saturday (27 Jan 07), Larry Allain and I braved the stormy conditions here in Acadiana to collect brown widows (L. geometricus) on Ambassador Caffery Pkwy. in Lafayette. The purpose of this excursion was to supply Jayme (Necaise) with specimens for a genetic anaylsis/scientific publication in a medical journal with three others. We first checked the brick columns in front of the Super Target, but did not find any webs. We were not to be disapponted however; for when we moved down in front of Stage, we hit the jackpot! In all, we collected 13 (12 females, 1 male) widows. I couldn't help but keep two females for myself naturally..... It is generally thought that the presence of these widows is due to importation on plants from either Florida or Texas; most likely the former. Genetic analyses of these specimens should yield the answer to this. I have yet to do any investigating at places such as Home Depot or Lowe's, which have plant nurseries, where the spiders could be brought in. I suspect however, that such research could produce the answer. Maybe I could wrangle Steven Barney out into the field next time....

Also of note were the presence of both Plexippus paykulli and Phidippus audax jumping spiders in "purse-like webs" located inside of the widows' webs! After talking this over with Zack last night, this seems typical in Latrodectus spiders. It is not yet fully understood what (if any) purpose(s) this serves. Impressively, we found one widow that had captured and apparently consumed a large female Rabidosa rabidosa wolf spider.

Included are a few pictures taken by Larry throughout the morning.

-James



1) cellar spider, Crossopriza lyoni 2) female Phidippus audax

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