Distribution and ecological aspects of Rhodnius pallescens in Costa Rica and Nicaragua and their epidemiological implications

In light of the Central American Initiative for the control of Chagas disease, efforts were made on the part of Costa Rican and Nicaraguan teams, working separately, to determine the present status of Rhodnius pallescens in areas close to the common border of the two countries, where the insect has appeared within the last few years. The opportunity was also used to establish whether R. prolixus, a vector present in some areas of Nicaragua, has been introduced in recent years into Costa Rica with Nicaraguan immigrants. It became evident that wild adults of R. pallescens are common visitors to houses in different towns of a wide area characterized as a humid, warm lowland, on both sides of the frontier. Up to the present, this bug has been able to colonize a small proportion of human dwellings only on the Nicaraguan side. There was strong evidence that the visitation of the adult bug to houses is related to the attraction of this species to electric lights. There were no indications of the presence of R. prolixus either in Nicaragua or in Costa Rica in this area of the Caribbean basin. Triatoma dimidiata, a widespread domestic species in both countries, was totally absent in the explored areas of Costa Rica but occasionally occurs on the Nicaraguan side. Serological surveys in children of both areas showed that transmission of Chagas disease takes place in a rather small degree in Costa Rica and more commonly in Nicaragua, indicating that R. pallescens could be a potential threat as a vector in this particular region.

Valoración de la capacidad depredadora de hydrophilus insularis y thermoneutes circunscripta coleoptera: hydrophilidae y dytiscidae en condiciones de laboratorio / Valoration of the capacity depredator of hydrophilus insularis and thermoneutes circunscripta coleoptera: hydrophilidae and dysticidae in condition of laboratory

En el presente trabajo se hizo una valoración de la capacidad depredadora de Hydrophilus insularis (Coleoptera Hydrophilidae) y Thermoneutes circunscripta (Coleoptera: Dysticidae). El orden Coleoptera representa uno de los grupos de mayor importancia, tanto las formas larvales como adultas depredan poblaciones larvales de mosquitos. Los resultados indicaron que Hydrophilus insularis en estadio larval es un buen biorregulador de larvas de mosquitos consumiendo un promedio de 36 larvas por, día, sin vegetación, y 31 larvas por día, con vegetación, mientras que Thermoneutes circunscripta manifiesta menor capacidad depredadora con un promedio de 12 larvas por día, sin vegetación, y 4 larvas por día, con vegetación.