By Dr. Nicky Gallagher, technical services manager for Syngenta
The Asian tiger mosquito, Aedes albopictus, is one of the most invasive vector mosquito species. Its affinity for cryptic, man-made breeding sites, especially those in urban or suburban settings, has resulted in its prolific spread. As a container-breeding mosquito, it prefers containers in shaded areas that can hold water for approximately one week (enough time to develop from egg to adult).
Effective control should target breeding sites and adult resting sites. However, cryptic breeding sites pose difficulties in locating, removing or applying treatment. An insect growth regulator (IGR), combined with an adulticide, can help reach these cryptic sites, like tree holes or hidden containers under shrubs. Furthermore, mosquitoes can help disseminate an IGR to additional containers as females visit and lay eggs at several breeding sites.1
Syngenta recommends incorporating an IGR, such as Archer® IGR, with an adulticide, such as Demand® CS insecticide, when conducting mosquito barrier treatments. Both products are recommended as part of the SecureChoice℠ Mosquito Assurance Program, which offers 30- and 60-day assurances for guaranteed mosquito control. While the 30-day assurance relies on the power of Demand CS, the 60-day assurance adds Archer IGR for longer residual control.
Trial-proven mosquito control with Archer IGR
Containing the active ingredient pyriproxyfen, Archer IGR acts as a juvenile hormone mimic. Its mode of action doesn’t directly cause mortality, but instead induces inappropriate molting, resulting in deformed pupae and adults, which ultimately leads to death.
In a recent trial conducted by Virginia Tech researchers, the residual efficacy of Archer IGR under field conditions was measured on different substrates used in containers found in backyards. The objective was to evaluate the effect of substrate material (clay vs. plastic) on the residual performance of pyriproxyfen spray treatments against Asian tiger mosquitoes.
Plastic and clay plant saucers were treated to the point of runoff with either water or Archer IGR (0.01%). After drying, saucers were placed under a pine tree canopy to simulate cryptic field conditions (Figure 1). Saucers were held in the field for the following durations: Day 1 and Weeks 1, 2, 3, 4, 6 and 8. Saucers were brought into the lab and 50 mosquito first-instar larvae were added to each saucer. The number of new pupae and adults were tracked each day.
|Figure 1: clay saucers. Source: PPMU18503.|
Archer IGR treatments produced significantly fewer adults than the water controls throughout the eight-week study. The mean survival rate for the water-treated saucers was 93.8%, compared to 0% survival for the Archer IGR treatments. No adult mosquitoes were produced from a saucer treated with Archer IGR, regardless of substrate material or time after treatment (Figures 2 and 3).
Figure 2. Source: PPMU18503. Figure 3. Source: PPMU18503.
Remember: Mosquito control requires a multi-pronged approach, including breeding site removal, adulticide applications, and customer communication and education. Being properly prepared for mosquito season can help you provide effective barrier treatments for your customers. For more information, please visit SyngentaPMP.com/Mosquito.
1 B. Dell Chism and C. S. Apperson: Horizontal transfer of the insect growth regulator pyriproxyfen to larval microcosms by gravid Aedes albopictus and Ochlerotatus triseriatus mosquitoes in the laboratory. Med. Vet. Entomol. 17, 211–220 (2003).
Performance assessments are based upon results or analysis of public information, field observations and/or internal Syngenta evaluations. Trials reflect treatment rates commonly recommended in the marketplace.
All photos are either the property of Syngenta or are used with permission.
©2021 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. Archer®, Demand®, For Life Uninterrupted™, SecureChoice℠ and the Syngenta logo are trademarks or service marks of a Syngenta Group Company. Syngenta Customer Center: 1-866-SYNGENT(A) (796-4368).