Effects of Plant Substrate, Insecticide, and Blood Meal Status on the Efficacy of Barrier Treatments Against Aedes albopictus

Abstract

The effects of 3 plant species (Cornus florida [dogwood], rhododendron X ‘Chionoides' [rhododendron], and Ilex opaca [American holly]), 4 insecticide treatments (Demand® CS [lambda-cyhalothrin] at 6.25 ml[AI]/liter; Talstar® Professional [bifenthrin] at 7.81 ml[AI]/liter, and Suspend® Polyzone® [deltamethrin] at 11.72 ml[AI]/liter, and water), and 2 physiological states (blood-fed and unfed) were evaluated for knockdown (1 h) and mortality (24 h) against female Aedes albopictus over an 8-wk sampling period. Analyses determined that there was a significant interaction between the tested plant species and the insecticides evaluated. Significant differences were likewise observed between the insecticide treatments for unfed Ae. albopictus females, with Demand CS demonstrating the highest knockdown and mortality rates (from >90% to >10% at wk 8 and >95% to ∼50% at wk 8, respectively), followed by Talstar Professional (from >75% to <10% at wk 2 and >90% to <10% at wk 2, respectively) and Suspend Polyzone (from >20% to <10% at wk 8 and >25% to >50% at wk 8, respectively). All treatments were no longer significant for knockdown or mortality at the end of the 8-wk timeframe. Significant differences were also observed between insecticide treatments for blood-fed Ae. albopictus females; Demand CS showed high knockdown and mortality rates (from 100% to ∼50% at wk 8 and 100% to >60% at wk 8, respectively), Suspend Polyzone rates were similar to Demand CS (from >80% to ∼50% at wk 8 and ∼90% to >65% at wk 8, respectively), and both were followed by Talstar Professional (from 100% to <10% at wk 4 and 100% to <20% at wk 4, respectively). All tested pyrethroid sprays showed a significant increase in effectiveness against recently blood-fed Ae. albopictus females, as compared to the unfed females. These results suggest that Demand CS can be used as an effective barrier spray against Ae. albopictus adults due to the limited impact of target foliage, its long-term efficacy under environmental conditions, and its continued effectiveness regardless of the blood meal status of the target mosquito.

Assessing transfluthrin mortality against Aedes aegypti and Culex quinquefasciatus inside and outside US military tents in a northern Florida environment

“…Data on the vapor toxicity of transfluthrin from the diffusers against the three sentinel mosquito species consisted of mean mosquito mortality after Abbottʼs correction. Sentinel mortality frequencies were analyzed using a linear mixed model for repeated measures ANOVA ( Littell et al., 2000 ; Feazel-Orr et al., 2016 ; McMillan et al., 2021 ). The model examined sampling week (0, 1, 2, 3, 4, 5, 6, 7 and 8), sentinel cage location (inside tent, tent doorway or outside tent), treatment (transfluthrin diffuser or control), mosquito strain ( Ae.…”

Baseline Survey on the Insecticide Resistance Profile of Anopheles Gambiae (Diptera: Culicidae) to Selected Insecticides in Igbokoda, Southwestern-Nigeria

“…Mosquito control involving insecticide spraying of houses and insecticide treated nets are losing their effectiveness (Kelly-Hope et al 2008;Tungu et al 2021;McMillan et al 2021), which have played a dominant role in reducing the transmission of malaria in the past (NMEP 2016) and six classes of insecticides have been classified for use (WHOPES 2007). Since the introduction of long-lasting insecticide treated nets (LLINs) in Nigeria in 2011, the total estimated ISSN: 2708-7182 (Print); ISSN: 2708-7190 (Online)…”