Managing mosquitoes and ticks in a rapidly changing world - Facts and trends

Abstract

Vector-borne diseases transmitted by mosquitoes and ticks are on the rise. The effective and sustainable control of these arthropod vectors is a puzzling challenge for public health worldwide. In the present review, I attempted to provide a concise and updated overview of the current mosquito and tick research scenario. The wide array of control tools recently developed has been considered, with special reference to those approved by the World Health Organization Vector Control Advisory Group (WHO VCAG), as well as novel ones with an extremely promising potential to be exploited in vector control programs. Concerning mosquitoes, a major focus has been given on genetically modified vectors, eave tubes, attractive toxic sugar baits (ATSB) and biocontrol agents. Regarding ticks, the recent development of highly effective repellents and acaricides (including nanoformulated ones) as well as behavior-based control tools, has been highlighted. In the second part of the review, key research questions about biology and control of mosquitoes and ticks have been critically formulated. A timely research agenda outlining hot issues to be addressed in mosquito and tick research is provided. Overall, it is expected that the present review will contribute to boost research and applications on successful mosquito and tick control strategies, along with an improved knowledge of their biology and ecology.

Keywords: Acaricides; Dengue; Integrated Vector Management; Lyme disease; Malaria; Nanoparticles; Repellents; Zika virus.

Fig. 1

Several Anopheles species acting as malaria vectors: (a) Anopheles albimanus, (b) Anopheles arabiensis (c) Anopheles atroparvus, (d) Anopheles farauti, (e) Anopheles funestus, (f) Anopheles gambiae, (g) Anopheles merus, (h) Anopheles minimus, (i) Anopheles plumbeus, (l) Anopheles quadriannulatus, (m) Anopheles sinensis, and (n) Anopheles stephensi (photo credit: A. plumbeus: ECDC; A. stephensi: Dr. W. Collins; others: Dr. J. Gathany, CDC-PHIL).

Fig. 2

Ticks act as major vectors of medical and veterinary importance. Among soft ticks, is worthy of mention (a) Ornithodoros hermsi, vectoring a bacterial disease called tick-borne relapsing fever. Hard ticks play a major role as pathogen vectors, including – among others – (b) the Gulf Coast tick, Amblyomma maculatum (female here), (c) the cayenne tick, Amblyomma cajennense (male here), (d) Amblyomma triste (female here), (e) the Rocky Mountain wood tick, Dermacentor andersoni (female here), and (f) the blacklegged deer tick, Ixodes scapularis (engorged female here) (photo credit: courtesy of Dr. J. Gathany, CDC-PHIL, except for I. scapularis, Dr. G. Alpert).

Fig. 3

A research agenda for next future mosquito research: key questions to address about mosquito biology and ecology are given in dark grey, while crucial issues about control tool development and validation are given in light grey.

Fig. 4

A research agenda for next future tick research: key questions to address about tick biology and ecology are given in dark grey, while main issues about control tool development and validation are given in light grey.