Sacosternum

Fikáček, Martin & Short, Andrew E. Z., 2010, A revision of the Neotropical genus Sacosternum Hansen (Hydrophilidae: Sphaeridiinae: Megasternini), Zootaxa 2538, pp. 1-37 : 29

Sacosternum sp.

Except of the material mentioned above, we have examined the following female specimens belonging to the “ S. cruciphallus complex”. Most of the specimens below are females and are very similar to each other and we therefore did no attempt to identify them up to the species level until the males will be available from these localities. The only male from Mexico almost certainly belongs to an undescribed species standing possibly close to S. emissarium and S. cruciphallus based on the morphology of its aedeagus (but it lacks the lateral sclerites of the median lobe in contast to these species). The genitalia of this specimen was unfortunatelly lost during the preparation of the temporary slide and the species cannot be therefore described. Two females (one from Mexico, collected at the same locality as the mentioned male specimen, the second collected at the Guatemalan locality listed below) share extremely enlarged teeth on the posterior margin of abdominal ventrite 4 (Fig. 35). The precise shape of these teeth vary slightly even between the two specimens. Both specimens were collected together with those having simply denticulate posterior margin of the ventrite. For this reason, we are not able to decide whether the enlarged teeth represent a character of taxonomic importance, an infrequently occurring abberation or sexually dimorphic character.

Material examined. MEXICO: 1 male, 1 female (possibly not conspecific) ( FMNH): “ MEXICO: Veracruz / Canyon SW Rio Metlac / 3200 feet, VII.31.1973 / A. Newton // berl., vacated Eciton / burchelli bivouac / 24 hrs. vacant”. GUATEMALA: 3 females (possibly not conspecific) ( FSCA): “ GUATEMALA: Dept. of / Guatemala, Puerta Parada / 5-VIII-1999 / J. C. Schuster”. COSTA RICA: 1 female ( KSEM): “ COSTA RICA: Puntarenas / Monte Verde, 1400m / 23 May 1989, J. Ashe / R. Brooks, R. Leschen / ex: black light // Costa Rica Exped. #400 / Snow Entomol. Mus.”; 1 female ( KSEM): “ COSTA RICA: Heredia Province / 16km SSE La Virgen, 1070m / 10°16'N 84°05'W / 11–20.ii.2001; 11/TN/16/006 / INBio-OET- ALAS transect”. PANAMA: 1 female ( CUIC): “ PANAMA: Chiri. / Fortuna, 28.ix. / 1976, H. Wolda”; 1 female ( UCDC): “ Fortuna PAN / Chirique Prov. / VIII-10-1977 / Henk Wolda”; 1 female ( UCDC): “ Fortuna PAN / Chirique Prov. / V-8-1979 / Henk Wolda”; 1 female ( UCDC): “ Fortuna PAN / Chirique Prov. / V-2- 1979 / Henk Wolda”. VENEZUELA: 1 female ( CMN): “ VENEZUELA: Merida / Tabay, La Mucuy Valley / 1900M, 15.VI.–30.VII. / 1989, S. & J. Peck / agric. Zone, UV, 89-214”.