Evaluation of Novel Trapping Lures for Monitoring Exotic and Native Container-Inhabiting Aedes spp. (Diptera: Culicidae) Mosquitoes

Abstract

Surveillance for diurnal container-inhabiting mosquitoes such as Aedes albopictus (Skuse), Aedes japonicus japonicus (Theobald), and Aedes triseriatus (Say) have routinely relied on the deployment of multiple trap types, including CO2-baited light traps, gravid traps, oviposition traps, and BG-Sentinel. These trap configurations have met with varying degrees of effectiveness and in many instances likely under-sample these key mosquito vectors. Most recently, the BG-Sentinel trap used in conjunction with the human-scent lure has been largely accepted as the gold-standard for monitoring Ae. albopictus. However, its ability to attract other container-inhabiting Aedes species has not been fully evaluated. During 2018, we tested new scent lures, TrapTech Lure-A and Lure-H (Bedoukian Research, Inc.), using BG-Sentinel traps with CO2 in two regions of Connecticut, Stamford and Hamden, against the BG-Lure. Pooled mosquitoes were additionally screened for arbovirus infection. A total of 47,734 mosquitoes representing 8 genera and 32 species were captured during the study, with the Stamford site deriving on average three times as many mosquitoes per trap, adjusting for sampling effort. Lure-A and Lure-H outperformed the BG-Lure in terms of total numbers, diversity evenness, and the proportion of both Ae. j. japonicus and Ae. triseriatus. There were no significant differences among lures in capturing Ae. albopictus, and in terms of species richness. Fifty-seven isolates of virus (West Nile, Jamestown Canyon, and La Crosse viruses) were obtained during the study, with no significant difference between trap-lure. We highlight both novel lures as effective attractants for use in mosquito surveillance=, which either outperform, or equal, BG-Lure.

Local persistence of novel regional variants of La Crosse virus in the Northeast USA

“…(ii) A trapping-lure comparison study (reported by Eastwood et al [10]) was conducted in Stamford, CT In addition, as a pilot study of vertical transmission at those sites, six oviposition cups (black plastic casino cups, lined with seed germination paper), were placed in the eld and checked weekly to collect container-breeding mosquito eggs.…”

“…Adult mosquitoes were identi ed and screened for arbovirus as follows. Pools of up to 50 mosquitoes (grouped by species, location and capture date) are homogenized and inoculated on a Vero (African Green monkey kidney) cell line, for evidence of arboviral infection, as described Eastwood et al [10].…”

“…To identify viruses, RNA was extracted from isolates using a QIAampViral RNA mini kit (Qiagen, Germantown, MD, USA), eluted in a nal volume of 70 μl. A reverse transcription polymerase chain reaction (RT-PCR) was performed in a 25 μl reaction using a Titan onetube RT-PCR system (Roche Diagnostics, Indianapolis, IN, USA) with generic orthobunyavirus primers [10,12]. Ampli cation products of the appropriate size, were puri ed as per Eastwood et al [10], then commercially sequenced (Science Hill DNA Analysis Facility, Yale University, New Haven, CT, USA).…”

Local Persistence of Novel Regional Variants of La Crosse Virus in the Northeast United States

“…To identify viruses, RNA was extracted from isolates using a QIAampViral RNA mini kit (Qiagen, Germantown, MD), eluted in a nal volume of 70 µL. A reverse transcription polymerase chain reaction (RT-PCR) was performed in a 25 µL reaction using a Titan One-Tube RT-PCR system (Roche Diagnostics, Indianapolis, IN) with generic orthobunyavirus primers (10,12).…”

“…triseriatus, and thus enhanced chance of detecting LACV if it is present in an area (3); once commercially available, additional baits described Eastwood et al (2020) are even more effective than BG-Lure (10). Minimal eld infection rates reported elsewhere have ranged from 0.26 to 27 per 1,000 mosquitoes tested (15,28,30,31).…”