Smithistruma fridericimuelleri (Forel 1886)

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu

4 March 1997

Identification
worker lateral view
worker face view

Color red-brown; 6-segmented antennae; face not shiny; posterolateral mesosoma shiny; clypeus broadly curved (not v-shaped) anteriorly; anteromedian section of promesonotum smooth and shining; free posterodorsal face of petiolar node approximately as long as broad and as long as the free postpetiolar disc. Compare with Smithistruma nigrescens.

Carara specimens (see below) are larger, darker, and with longer propodeal spines than Atlantic slope specimens. I predict this will be a consistent difference between Pacific slope and Atlantic slope material, following a trend of diagnostically distinct forms on the two sides of Costa Rica (pers. obs.).

Geography

Previously known from southern Brazil (type locality), and one collection from Panama that W. L. Brown identified as this species. In Costa Rica, I have two collections. One is from the Pacific slope (Carara Biological Reserve, 500m); the other is from the Atlantic slope ("Zona Protectora" portion of Braulio Carrillo National Park, 500m).

Natural History

Presumably a member of the "cryptobiotic" leaf litter fauna found on the forest floor. I have observed one nest: in a small chamber in a rotten stump (the Atlantic slope collection above). Presumed predaceous.

How to collect

This is apparently a rare and/or difficult to collect species. Based on two collections, the species may be more common in or restricted to mid-elevation wet forest (around 500m) on either slope. The collection from Carara came from Winkler bag extraction from sifted forest floor leaf litter. This is the only occurrence among dozens of sifted litter samples that I have examined from throughout Costa Rica. The colony collection from a rotten stump is one collection among many person-hours of searching in rotten stumps throughout Costa Rica.

Page author: John T. Longino longinoj@evergreen.edu

Last modified: 03/04/1997