Common vampire bat (Desmodus rotundus) abundance and frequency of attacks to cattle in landscapes of Yucatan, Mexico.

Desmodus rotundus is one of the wild animal species that has benefitted by habitat alteration and its population has increased due to livestock activities. Common vampire bat population management has been implemented across Mexico due to the economic losses to livestock production, inflicted by vampire bat attacks and rabies transmission. Yucatan is one of the seven most impacted states in Mexico by the number of cattle rabies cases per year. However, there is little research on D. rotundus populations such as the frequency and attack patterns to cattle. This study's objective was to analyze the relationship between D. rotundus abundance and number of bovines attacked in livestock landscapes in Yucatan. The study used data gathered by the State Committee for Protection and Promotion of Livestock in Yucatan through the National Campaign for Common Vampire Bat Population Control. Data collected from January 2014 to December 2017 was analyzed using Pearson correlation. Distribution maps on Desmodus rotundus abundance and number of bovines attacked were also created. Higher abundance of Desmodus rotundus and number of cattle attacks were observed in the central region of Yucatan, particularly in Izamal municipality. Positive correlations were found between (1) abundance of Desmodus rotundus and number of cattle in the region, (2) total number of cattle and number of cattle attacked, and (3) abundance of Desmodus rotundus and number of cattle attacked. We can conclude that there is a relationship between Desmodus rotundus abundance and frequency of cattle attacks in most municipalities across Yucatan. Some outstanding exceptions were observed, which require further detailed investigations.

Entomological Efficacy of Aerial Ultra-Low Volume Insecticide Applications Against Aedes aegypti (Diptera: Culicidae) in Mexico.

A cluster-randomized controlled trial quantified the entomological efficacy of aerial ultra-low volume (AULV) applications of the insecticide chlorpyrifos against Aedes aegypti in Puerto Vallarta, México, during November-October 2017. The trial involved 16 large (1 × 1 km) clusters distributed between treatment-control arms. Primary endpoint was the abundance of Ae. aegypti indoors (total adults, females, and blood-fed females) collected using Prokopack aspirators. After four consecutive weekly cycles of AULV, all adult Ae. aegypti infestation indices were significantly lower in the treatment arm (OR and IRR ≤ 0.28). Efficacy in reducing indoor Ae. aegypti increased with each weekly application cycle from 30 to 73% (total adults), 33 to 76% (females), and 45.5 to 89% (blood-fed females). Entomological indices remained significantly lower in the treatment arm up to 2 wk after the fourth spraying round. Performing AULV spraying can have significant and lasting entomological impact on Ae. aegypti as long as multiple (ideally four) spray cycles are implemented using an effective insecticide.