Use of pyriproxyfen in control of Aedes mosquitoes: A systematic review

Abstract

Background Dengue is the most rapidly spreading arboviral disease in the world. The current lack of fully protective vaccines and clinical therapeutics creates an urgent need to identify more effective means of controlling Aedes mosquitos, principally Aedes aegypti, as the main vector of dengue. Pyriproxyfen (PPF) is an increasingly used hormone analogue that prevents juvenile Aedes mosquitoes from becoming adults and being incapable of transmitting dengue. The objectives of the review were to (1) Determine the effect of PPF on endpoints including percentage inhibition of emergence to adulthood, larval mortality, and resistance ratios; and (2) Determine the different uses, strengths, and limitations of PPF in control of Aedes. A systematic search was applied to Pubmed, EMBASE, Web of Science, LILACS, Global Health, and the Cochrane database of Systematic Reviews. Out of 1,369 records, 90 studies met the inclusion criteria. Nearly all fit in one of the following four categories 1) Efficacy of granules, 2) Auto-dissemination/horizontal transfer, 3) use of ultra-low volume thermal fogging (ULV), thermal fogging (TF), or fumigant technologies, and 4) assessing mosquito resistance. PPF granules had consistently efficacious results of 90-100% inhibition of emergence for up to 90 days. The evidence is less robust but promising regarding PPF dust for auto-dissemination and the use of PPF in ULV, TF and fumigants. Several studies also found that while mosquito populations were still susceptible to PPF, the lethal concentrations increased among temephos-resistant mosquitoes compared to reference strains. The evidence is strong that PPF does increase immature mortality and adult inhibition in settings represented in the included studies, however future research should focus on areas where there is less evidence (e.g. auto-dissemination, sprays) and new use cases for PPF. A better understanding of the biological mechanisms of cross-resistance between PPF, temephos, and other insecticides will allow control programs to make better informed decisions.

The microbiome and mosquito vectorial capacity: rich potential for discovery and translation

“…This principle was the cornerstone of many of the earliest vector control strategies, where breeding sites were eliminated or diminished, or treated with larvicides to reduce the number of vectors in a population. It is also the rationale behind more contemporary strategies such as the dissemination of insect growth regulators like pyriproxyfen [ 57 ] or the release of Wolbachia -infected male mosquitoes [ 58 , 59 ]. Gut-associated microbes can influence vector density through the modulation of development, reproductive outputs, and resistance to abiotic stress.…”

Susceptibility of South Texas Aedes aegypti to Pyriproxyfen

“…aegypti in the LRGV. Pyriproxyfen is an insect growth regulator that targets immature stages of mosquitoes; it acts at very low doses and it persists for several months in larval habitats [ 20 , 21 ]. Therefore, autodissemination stations that rely on pyriproxyfen might have a meaningful impact as a control tool in areas were source reduction campaigns are unfeasible or cost prohibitive [ 22 ].…”

Stage-specific action of juvenile hormone analogs

“…23,[29][30][31] The use of JHA pyriproxyfen for controlling Aedes mosquitoes has increased dramatically during the past few years, 32,33) a recent review summarizes these applications. 34)…”

“…Methoprene is the most widely used JHA for controlling mosquito larvae. 22,23,[29][30][31][35][36][37][38][39][40][41][42][43][44][45] However, recent studies showed the efficacy of pyriproxyfen for larval control and adult sterilization of various mosquito species, 24,28,[32][33][34] which might increase the use of this chemical for vector control. In contrast, hydroprene was not used much for mosquito control.…”