Derallus rudis Sharp, 1887

Short, Andrew Edward Z. & Torres, Phillip J., 2006, Review of the Hemiosus Sharp and Derallus Sharp of North America, Central America, and the Caribbean (Coleoptera: Hydrophilidae: Berosini), Zootaxa 1369, pp. 1-17 : 14

Derallus rudis Sharp, 1887

( Figs. 8 , 10 )

Derallus rudis Sharp, 1887: 765 ; Oliva, 1982: 156 (lectotype designation).

Type material examined. Lectotype (male): “ Derallus ru-/dis Type D.S./ Vera Cruz,/ Mex. Hoge”, “Sharp Coll./ 1095.- 313.”, “Vera Cruz,/ Mexico,/ Hoge”, “B.C.A. Col. I. 2. / Derallus / rudis ,/ Sharp.”, “ LECTOTYPUS ”, “Lecto-type [purple disc]” ( BMNH).

Additional material examined (94). MEXICO: Campeche: 21 mi. E of Campeche, 27.vii. 1964, P.J. Spangler leg. (44: USNM, AEZS); Haltunchen, 5.viii. 1964, P.J. Spangler, leg. (3: USNM); 19 mi. S Champoton, 26.vii. 1964, P.J. Spangler leg. (2: USNM); Jalisco: 15 mi. N Chapala, 2.viii. 1963, P.J. Spangler leg (2: USNM); Morelos: near Cuautla, 28.viii. 1962, J.R. Zimmerman leg. (4: USNM); Sinaloa: Mazatlan, 17–23.vii. 1963, P.J. Spangler leg. (2: USNM); Tabasco: Villahermosa, 6.viii. 1964, P.J. Spangler leg. (1: USNM); Villahermosa, 13 mi. SE, 13.vi. 1971, J.R. Zimmerman leg., 627 (4: USNM); Veracruz: 25 mi. S Acayucan, 4.vii. 1965, P.J. Spangler leg. (19: AEZS, USNM); Alvarado, 10.viii. 1964, P.J. Spangler leg. (5: AEZS, USNM); Alvarado, 6.viii. 1957, small pond, D. Lauck leg. (1: USNM); Near La Tinaja, 25.viii. 1962, J.R. Zimmerman leg., 406, (1: USNM); Paso del Toro, 15 km W, 8.ix. 1964, J.R. Zimmerman leg., 566 (2: USNM); Santiago Tuxtla, 10 km S, 8.ix. 1964, J.R. Zimmerman leg., 564 (1: USNM); Coatzocoalcosl, 15 km E, 26.viii. 1962, J.R. Zimmerman leg., 411 (2: USNM). GUATEMALA: Izabel, 2 km SW of Montufar, 15.vii. 2001, 360 ft., stream, W.D. Shepard leg. (1: AEZS). Representative material deposited in MALUZ, MIZA, MFPC and NMW.

Diagnosis. Total length: 2.3–3.4 mm. This species can be distinguished by two to three rows of ground punctures in interstria X, the two teeth of the mesoventrite projection being uneven in height, and the very diagnostic aedeagus, which has long lateral extensions of the basal piece and parameres which are quadrate at the apex.

Distribution. Cuba, Guadeloupe, Mexico, Guatemala (new record).

Remarks. This is the only species of the genus that does not also occur in continental South America. Oliva (1982) designated the lectotype and provided a redescription and illustration of the species. The larva and habitat were described by Spangler (1966).

Figures

FIGURES 6 – 9. Lateral view of left elytron of Derallus. Arrows indicate the tenth elytral interstria. 6: D. altus (LeConte); 7: D. terraenovae Oliva; 8: D. rudis Sharp; 9: D. angustus Sharp. Scale bars 1.0 mm.

FIGURES 10 – 11. Ventral view of the metasternum of Derallus. 10: D. rudis Sharp; 11: D. angustus Sharp. Scale bar 0.2 mm.