134 INSTITUTO DE MEDICINA TROPICAL “FELIX PIFANO”, UNIVERSIDAD CENTRAL DE VENEZUELA HIROSAKI UNIVERSITY SCHOOL OF MEDICINE, JAPAN A preliminary study of haemolymph from four Venezuelan populations of Panstrongylus geniculatus Latreille, 1811 (Hemiptera: Reduviidae) and its epidemiological significance Lic. Matías Reyes-Lugo, 1 MC. María E Girón, 2 Dr. Haruo Kamiya 3 y Dr. Alexis Rodríguez-Acosta 4 SUMMARY SDS-PAGE profiles of both sexes of the haemolymphs of Panstrongylus geniculatus from different Venezuelan regions (savannas, piedmont, tropical forest and urban areas) were compared. It was determined that the haemolymphs showed a different electrophoretic profile, with proteins that ranged from 14 to 164 kDa. The most representative protein band in the profile of females was observed in two sectors: between 164 and 46 kDa and between 33 and 30 kDa. The main illustrative protein band in males was observed in one region: from 46 to 35 kDa. The Haemolymph composition of P. geniculatus from populations evaluated in this work expressed high homogeneity of this species with a clear difference between males and females. This similarity may be useful for control of these insects, taking into account that the genetic stability may be very important, since the use of an insecticide in a population with these characteristics is always more successful. According to the bibliographic review, this is the first study of haemolymph from Panstrongylus geniculatus. Key words : Epidemiology, haemolymph, Panstrongylus geniculatus, Reduviidae, Venezuela. Panstrongylus geniculatus Latreille 1811 1 is probably the species of triatomine, which has the high geographical distribution in the Americas. Its presence in Argentina, Uruguay, Paraguay, Perú, Bolivia, Brazil, Ecuador, Colombia, Guyana, French Guiana, Surinam, Venezuela, Trinidad, Panamá, Costa Rica and Nicaragua 2-3 has been established. In Venezuela, in nearly all federal dependencies has been described. 4 It is one of the most important vectors in the wild cycle of Schizotrypanum cruzi and occasional visitor of the housings arriving in directional flight attracted by the light. 4,5 1 Profesor Asistente en Medicina Tropical. Instituto de Medicina Tropical de la Universidad Central de Venezuela. 2 Máster en Ciencias. Investigador Asistente en Medicina Tropical. Instituto de Medicina Tropical de la Universidad Central de Venezuela. 3 Full Professor in Parasitology. Hirosaki University, Japan. 4 Profesor Titular en Medicina Tropical. Instituto de Medicina Tropical de la Universidad Central de Venezuela. The blood of the insects is called haemolymph, which may be a clear colourless fluid. The electrophoretic (SDS-PAGE) profiles of triatomine haemolymph demonstrate a complicated composition of proteins, permitting the separation of species. 1,6 Nevertheless, it is unknown whether the composition of haemolymph varies within either species or different populations. With these considerations, the main aim of this study was to compare the haemolymph electrophoretic profiles from four Venezuelan populations of P. geniculatus and try to search the similarity or difference genetic among specimens from different geographical locations. REV CUBANA MED TROP 2006;58(2):134-8