Sandflies (Diptera: Psychodidae) in an urban area of Northeastern Brazil

Abstract INTRODUCTION: The sandfly fauna is well studied globally. In Brazil, sandfly fauna is very diverse in the Northeast region, especially in states such as Maranhão, Ceará, and Bahia. However, in the State of Pernambuco, the distribution of these insects is still not well known. Therefore, the objective of this study was to identify the different species that constitute the sandfly fauna in an urban area in the Northeast region of Brazil, where an outbreak of visceral leishmaniasis (VL) was recently reported. METHODS: The sandflies were collected from an urban area endemic for VL, at five collection points. The collection of samples was carried out from November 2014 to December 2015, using CDC light traps installed in intradomiciliary and peridomiciliary fashion. RESULTS: The collected sandflies (n = 297) belonged to eight species: Lutzomyia lenti, Lutzomyia longipalpis, Lutzomyia sallesi, Lutzomyia migonei, Lutzomyia walkeri, Lutzomyia capixaba, Lutzomyia carmelinoi, and Lutzomyia whitmani. Most of the specimens collected were peridomiciliary (247/297, 83%). L. lenti (154/297, 52%) was the most frequently sampled species, followed by L. longipalpis (88/297, 29.6%), and L. sallesi (42/297, 14.1%), which together accounted for over 90% of the collected sandfly specimens. CONCLUSIONS: The continued presence of L. longipalpis in urban areas, including that in intradomiciliary areas, with a predominance of females, is crucial because of the high possibility of them causing VL outbreaks, since this species is the main vector of Leishmania infantum in Brazil.

摘要 引言：白蛉区系（sandfly fauna）在全球范围内已得到充分研究。在巴西，东北部地区的白蛉区系多样性极高，尤以马拉尼昂州、塞阿拉州和巴伊亚州为突出。然而，伯南布哥州境内白蛉的分布情况仍未得到充分探明。有鉴于此，本研究旨在明确巴西东北部某城市区域内的白蛉区系组成，该区域近期曾报道过内脏利什曼病（visceral leishmaniasis, VL）暴发疫情。方法：本研究于2014年11月至2015年12月期间，在该内脏利什曼病流行城市区域的5个采样点开展白蛉采集工作，采用安装于家内及家周环境的CDC诱虫灯（CDC light traps）进行采样。结果：本次共采集到297只白蛉，隶属于8个物种：林氏罗蛉（Lutzomyia lenti）、长喙罗蛉（Lutzomyia longipalpis）、萨氏罗蛉（Lutzomyia sallesi）、米氏罗蛉（Lutzomyia migonei）、沃氏罗蛉（Lutzomyia walkeri）、卡氏罗蛉（Lutzomyia capixaba）、卡莫利诺罗蛉（Lutzomyia carmelinoi）以及惠氏罗蛉（Lutzomyia whitmani）。采集到的标本中绝大多数为家周环境个体（247/297，占比83%）。林氏罗蛉（154/297，占比52%）为采样量最高的物种，其次为长喙罗蛉（88/297，占比29.6%）与萨氏罗蛉（42/297，占比14.1%），三者总采样量占采集标本总数的90%以上。结论：长喙罗蛉持续存在于城市区域（含家内环境）且雌性个体占优，这一情况至关重要——因该物种是巴西婴儿利什曼原虫（Leishmania infantum）的主要传播媒介，具备引发内脏利什曼病暴发的极高风险。