Bickerton Matthew, McSorley Kathryn, Toledo Alvaro
Department of Entomology, Rutgers University, United States; Bergen County Department of Health Services, United States; Center for Vector Biology, Rutgers University, United States.
Bergen County Department of Health Services, United States.
Ticks Tick Borne Dis. 2021 Jan;12(1):101581. doi: 10.1016/j.ttbdis.2020.101581. Epub 2020 Oct 1.
Haemaphysalis longicornis Neumann is an invasive tick species that has recently been detected in the eastern United States. We designed field studies to monitor the population dynamics of H. longicornis over a year (2019) in New Jersey, and to assess the efficacy of a pyrethroid acaricide (lambda-cyhalothrin) in controlling this tick using a stage-treatment approach. Nymphs were the most abundant life stage found host-seeking from May through early July, followed by a brief period of high adult activity in mid-July, and a very high larval peak extending from late July through October. Overall, 542 adults, 1910 nymphs, and 69,238 larvae were recorded during the sampling. In the present study, the efficacy of acaricide treatments to suppress host-seeking ticks was assessed by applying lambda-cyhalothrin once during each of the three periods of activity for nymphs (June), adults (July), and larvae (August), or sequentially during all three months. Control plots were left untreated and used for phenology studies. Applications in June and July provided 100 % control of all life stages, including the dominant nymphal and adult stages for 42 and 35 d, respectively. Ticks re-established at normal or reduced levels following applications in June or July, respectively, compared to untreated controls. The application in August provided 100 % control for 49 d, and a high level of suppression (>99 % control) remained through the end of the tick season in October. This study therefore supports that single pyrethroid applications can provide 100 % control of H. longicornis for up to 7 wk, and a single late-summer application towards the end of host-seeking adult activity can provide near complete control of the larval population. An evaluation of single applications over the course of the season revealed that treatments in July or August did not lead to significant reductions in the nymphal population. However, multiple sequential treatments targeting all life stages provided 66 %, 97 %, and >99 % control of adults, nymphs, and larvae, respectively through the season of H. longicornis activity.
长角血蜱是一种入侵性蜱虫物种，最近在美国东部被发现。我们设计了实地研究，以监测2019年新泽西州长角血蜱一年中的种群动态，并采用分阶段处理方法评估拟除虫菊酯杀螨剂（高效氯氟氰菊酯）对这种蜱虫的防治效果。若虫是5月至7月初寻找宿主时最常见的虫态，其次是7月中旬成虫短暂的高活动期，以及从7月底持续到10月的非常高的幼虫高峰期。总体而言，采样期间共记录到542只成虫、1910只若虫和69238只幼虫。在本研究中，通过在若虫（6月）、成虫（7月）和幼虫（8月）的三个活动期分别施用一次高效氯氟氰菊酯，或在所有三个月内依次施用，来评估杀螨剂处理对寻找宿主的蜱虫的防治效果。对照地块未进行处理，用于物候学研究。6月和7月的施药分别对所有虫态提供了100%的防治效果，包括对占主导地位的若虫和成虫阶段分别持续42天和35天。与未处理的对照相比，6月或7月施药后蜱虫分别以正常或降低的水平重新出现。8月的施药提供了49天的100%防治效果，并且在10月蜱虫季节结束时仍保持高水平的抑制（>99%的防治效果）。因此，本研究支持单次施用拟除虫菊酯可对长角血蜱提供长达7周的100%防治效果，而在寻找宿主的成虫活动末期进行单次夏末施药可对幼虫种群提供近乎完全的防治效果。对整个季节单次施药的评估表明，7月或8月的处理并未导致若虫种群显著减少。然而，针对所有虫态进行多次连续处理，在长角血蜱活动季节期间分别对成虫、若虫和幼虫提供了66%、97%和>99%的防治效果。
