Many farmers house livestock in open pens or sheds that offer no physical protection against biting flies, with protection relying heavily on the use of residual or on-animal insecticides. Insecticidal barriers can offer an alternative or additional option to managing pestiferous biting flies near livestock but they need to be evaluated in the field. We assessed the efficacy of a deltamethrin-incorporated net to reduce contact of Culicoides and mosquitoes with livestock. On cervid farms, reduction of biting-midges in light traps was assessed for traps surrounded by deltamethrin-treated nets, untreated nets, or no-net controls. Significantly fewer Culicoides were collected in pens surrounded by untreated nets compared to no-net, and further significant reductions were achieved with deltamethrin-treated nets. Similar results were observed on a subsistence poultry and swine farm. Total Culicoides and mosquito abundance and abundance of blood-fed females was significantly reduced in light-trap collections after surrounding livestock units with a deltamethrin-treated net. These results suggest the use of insecticidal nets at a 2 m height can reduce contact between livestock and some biting flies in open areas or sheds.
Lutzia vorax Theobald (Diptera: Culicidae) is a ferocious predator of small container habitats in the forests and rural areas of the eastern Palearctic and Oriental regions. Owing to its consumption of various invertebrates, including mosquito larvae, it is considered a potential biological control agent of vector species. However, studies on the general biology of Lt. vorax are scarce; thus, our understanding of its role in natural habitats is limited. To elucidate its ecological role with regard to its interaction with vector species populations, we conducted field monitoring surveys in two different deciduous forests in South Korea, using tire traps for larvae in 2023. Community samples of mosquito larvae were collected every three weeks (July to September, 2023) from each trap, which replicated the natural container environment in forest areas. Then, community structures were compared based on the presence or absence of Lt. vorax. Communities with Lt. vorax larvae exhibited distinct structures characterized by lower species richness, diversity, and vector species density. Furthermore, non-metric multidimensional scaling results showed that the group structure differed depending on the presence of Lt. vorax larvae. Gut content analysis of the predaceous larvae supported the evidence of top-down regulation of Lt. vorax with considerable predation rates on other mosquito larvae in each habitat: 63.92 ± 30.72% in Site A and 72.85 ± 18.03% in Site B (mean ± SD). Thus, we suggest that Lt. vorax serves as both a significant natural enemy and key predator species in container habitats in the forested areas of Korea.
In Peru, since the beginning of the 20th century, 18 mosquito species (Diptera: Culicidae) and three forms have been discovered by previous authors: Anopheles acanthotorynus, An. calderoni, An. peruvianus, Chagasia ablusa, Ae. (Howardina) Iquitos form, Aedes epinolus, Haemagogus obscurescens, Hg. (Conopostegus) Peruvian highland form, Hg. (Con.) Peruvian lowland form, Culex archegus, Cx. debilis, Cx. diplophyllum, Cx. escomeli, Cx. raymondii, Onirion aenigma, On. celatum, Sabethes idiogenes, Trichoprosopon hyperlecum, Tr. subsplendens, Wyeomyia baltae, and Wy. paucartamboensis. Of these, seven species were later synonymized under the name of other species, the rest remain as valid species, one of them is placed in Nomen dubium, and the forms continue retained without specific status. With the intention of updating the checklist of mosquito species in Peru, historical and recent species-records were reviewed and mosquito collections were conducted in specific sites of Peru, resulting in the confirmation of the presence of Hg. anastasionis, Hg. capricornii, Psorophora dimidiata, Ps. cilipes, Cx. usquatissimus, Cx. dunni, Mansonia wilsoni, Johnbelkinia leucopus, Limatus pseudomethysticus, Tr. compressum, and Uranotaenia socialis. Additionally, Ae. aurivittatus, Ae. terrens/zavortinki, Cx. acharistus, Cx. dolosus, and Cx. surinamensis are reported for the first time in Peru, while An. apicimacula, An. mediopunctatus, Ae. condolescens, Cx. bihaicolus, and Sa. tarsopus are removed from the Peruvian mosquito fauna. An updated list of 198 nominal species and four forms of mosquitoes from Peru is presented.
Tick-borne pathogens pose an ongoing threat to human health in the southeastern United States, where tick and host abundances are high. In North Carolina, several medically important tick species are present, but in the Piedmont region, Amblyomma americanum is particularly abundant and associated with multiple human pathogens, including Rickettsia amblyommatis, a hypothesized human pathogen. In this study, we build on recent tick surveillance efforts across several North Carolina counties by screening A. americanum for Ehrlichia ewingii, Ehrlichia chaffeensis, and R. amblyommatis while also analyzing tick abundance, pathogen prevalence, and county-level human disease case data from the North Carolina Department of Health to assess potential correlations. Our results reveal variation in pathogen prevalence across counties, with Chatham County consistently emerging as a high-risk area due to high tick abundance and elevated infection rates. However, we did not observe a strong correlation between tick abundance or pathogen prevalence and reported human disease cases at the county level. These findings highlight counties of elevated risk in a region experiencing an increasing burden of tick-borne disease and contribute to our understanding of ongoing public health trends.
The subtropical coastal plain of Deep South Texas provides a wildlife corridor for hosts of disease-transmitting ixodid species, including the southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini). Wind tides and storm surges push hypersaline Lower Laguna Madre water inland on occasion, creating substantial areas of saline soil dominated by sea ox-eye daisy, Borrichia frutescens (L.) DC, and inhabited by numerous mud flat fiddler crabs, Uca rapax (Smith). Ixodid populations, especially larvae, in the saline areas are mostly negligible because of saltwater toxicity to eggs, desiccation, and predators. Soil salinity, U. rapax populations, and ant foraging activity were determined for areas dominated by B. frutescens, areas with intermediate stands, and areas without the plant. Borrichia frutescens density and U. rapax populations were moderately correlated with soil salinity, but predatory ant foraging was not correlated with soil salinity, B. frutescens density, and U. rapax abundance. Borrichia frutescens stand density, however, was strongly correlated with numbers of U. rapax holes, hence, the plant is an indicator of negligible ixodid activity. GIS mapping of high-Borrichia habitats might be useful for refining surveillance of ixodid populations, particularly one-host ixodids, such as R. (B.) microplus.
