Effect of Cocoa ( Theobroma cacao ) Plantation Types on the Distribution of Anuran Communities in Ore, Ondo State, Nigeria

Anuran species diversity and abundance were evaluated in different farming status of cocoa plantation in Ore, Ondo State, Nigeria. Applying the combination of visual encounter survey (VES) and acoustical survey (AES), the different farms surveyed were categorized as; 1) pure cocoa farms with pesticides applied (PCWP); 2) pure cocoa farms without pesticides application; 3) intercropped cocoa farms with pesticides applied (ICWP); and 4) intercropped cocoa farms without pesticides application (ICNP). The surrounding primary/secondary forest (PSFV) was sampled applying the transect method. A mean total of 690±2.6 anurans belonging to 28 species, 14 genera and 9 families were recorded during the study. Out of these, 10, 19, 17, 22 and 26 species were recorded respectively from PCWP, PCNP, ICWP, ICNP and PSFV. The anuran species richness was significantly different between the different cocoa plantation status and the forest sites (F4, 10 = 20.55, P< 0.01). The highest mean number of individuals (190±9.5) was observed at ICNP followed by PSFV (183±5.7), while the least was at PCWP (77±8.0). There was also significant difference (F4, 10 = 150.48, P< 0.01) between the abundance of anuran species at the various sites. Diversity indices (Shannon and Margalef) showed that the forest sites had the greatest (3.204 and 4.799) respectively while the pesticide using pure cocoa farms had the least (1.853 and 2.072). Generally, the result of the study clearly indicated that pesticide use cocoa farms were significantly lower compared to other sites. Farmers are encouraged to engage in intercropping (polyculture) especially with food and economic crops in a biodiversity friendly manner which could have similar characteristics of a natural ecosystem, thereby enhancing the biological diversity of agro-ecosystems.

Spatial distribution of triatomines in domiciles of an urban area of the Brazilian Southeast Region

Reports of triatomine infestation in urban areas have increased. We analysed the spatial distribution of infestation by triatomines in the urban area of Diamantina, in the state of Minas Gerais, Brazil. Triatomines were obtained by community-based entomological surveillance. Spatial patterns of infestation were analysed by Ripley’s K function and Kernel density estimator. Normalised difference vegetation index (NDVI) and land cover derived from satellite imagery were compared between infested and uninfested areas. A total of 140 adults of four species were captured (100 Triatoma vitticeps, 25 Panstrongylus geniculatus, 8 Panstrongylus megistus, and 7 Triatoma arthurneivai specimens). In total, 87.9% were captured within domiciles. Infection by trypanosomes was observed in 19.6% of 107 examined insects. The spatial distributions of T. vitticeps, P. geniculatus, T. arthurneivai, and trypanosome-positive triatomines were clustered, occurring mainly in peripheral areas. NDVI values were statistically higher in areas infested by T. vitticeps and P. geniculatus. Buildings infested by these species were located closer to open fields, whereas infestations of P. megistus and T. arthurneivai were closer to bare soil. Human occupation and modification of natural areas may be involved in triatomine invasion, exposing the population to these vectors.