We identified species of copepods in natural mosquito breeding sites in the region of Soconusco, Chiapas, Mexico and compared their predatory ability on first instar larvae of Aedes aegypti and A. albopictus. Four sampling sites were selected: two in the coastal area and two in the bottom of the mountain. Copepods were cultured in the laboratory and identified. The species found were: Mesocyclops pehpeiensis (Hu, 1943), M. longisetus (Thiébaud, 1912), M. brasilianus (Kiefer, 1933), Macrocyclops albidus (Jurine, 1820), Eucyclops leptacanthus (Kiefer, 1956), and E. torresphilipi (Suárez-Morales, 2004). With the exception of E. leptacanthus, all collected species of copepods were successfully cultured in the laboratory. The predation potential was experimentally evaluated using a copepod female adult and 20 first-instar mosquito larvae. The copepod species showed varying percentages of predation, M. pehpeiensis being the one with the greatest predation potential (80% of A. aegypti and 67% A. albopictus per day). Eucyclops torresphilipi showed no differences with respect to the control, so it can be considered as a non-predatory species. Predation tests show that the copepods present in natural mosquito breeding sites have the potential to be used as agents of biological control of mosquito larvae and are a good alternative to be considered in integrated vector management strategies of dengue fever in the region of Soconusco, State of Chiapas, Mexico.

Se identificaron las especies de copépodos presentes en sitios de crianza de mosquitos en la región del Soconusco, Chiapas, México, y se evaluó su capacidad depredadora sobre larvas de primer estadio de mosquitos Aedes aegypti y A. albopictus. Se seleccionaron cuatro sitios de muestreo: dos en la zona costera y dos en una zona al pie de montaña. Los copépodos fueron cultivados en el laboratorio e identificados. Las especies encontradas fueron: Mesocyclops pehpeiensis (Hu, 1943), M. longisetus (Thiébaud, 1912), M. brasilianus (Kiefer, 1933), Macrocyclops albidus (Jurine, 1820), Eucyclops leptacanthus (Kiefer, 1956) y E. torresphilipi (Suárez-Morales, 2004). Con excepción de E. leptacathus, todas las especies de copépodos colectadas fueron cultivadas con éxito en el laboratorio. Experimentalmente se evaluó el potencial de depredación de las especies, usando un copépodo adulto hembra y 20 larvas de mosquitos de primer estadio. Las especies de copépodos presentaron porcentajes variables de depredación, siendo M. pehpeiensis la especie con mayor potencial de depredación (80% con A. aegypti y 67% con A. albopictus, por día). Eucyclops torresphilipi no mostró diferencias con respecto al control, por lo que puede considerarse como no depredadora. Las pruebas de depredación mostraron que los copépodos presentes en los sitios de crianza de larvas de mosquitos tienen potencial para usarse como agentes de control biológico, y que son una buena alternativa a considerar dentro de las estrategias de manejo integrado de vectores del dengue en la región del Soconusco, Chiapas, México.

Introduction The use of entomopathogenic fungi to control disease vectors has become relevant because traditional chemical control methods have caused damage to the environment and led to the development of resistance among vectors. Thus, this study assessed the pathogenicity of entomopathogenic fungi in Triatoma dimidiata. Methods Preparations of 108 conidia/ml of Gliocladium virens, Talaromyces flavus, Beauveria bassiana and Metarhizium anisopliae were applied topically on T. dimidiata nymphs and adults. Controls were treated with the 0.0001% Tween-80 vehicle. Mortality was evaluated and recorded daily for 30 days. The concentration required to kill 50% of T. dimidiata (LC50) was then calculated for the most pathogenic isolate. Results Pathogenicity in adults was similar among B. bassiana, G. virens and T. flavus (p>0.05) and differed from that in triatomine nymphs (p=0.009). The most entomopathogenic strains in adult triatomines were B. bassiana and G. virens, which both caused 100% mortality. In nymphs, the most entomopathogenic strain was B. bassiana, followed by G. virens. The native strain with the highest pathogenicity was G. virens, for which the LC50 for T. dimidiata nymphs was 1.98 x108 conidia/ml at 13 days after inoculation. Conclusions Beauveria bassiana and G. virens showed entomopathogenic potential in T. dimidiata nymphs and adults. However, the native G. virens strain presents a higher probability of success in the field, and G. virens should thus be considered a potential candidate for the biological control of triatomine Chagas disease vectors.