Comparative larvicidal toxicities of three ecdysone agonists on the mosquitoes <i>Aedes aegypti, Culex quinquefasciatus</i>, and <i>Anopheles gambiae</i>

Beckage, Nancy E.; Marion, Ken M.; Walton, William E.; Wirth, Margaret C.; Tan, Frances F.

doi:10.1002/arch.20021

Cited by 46 publications

(40 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, concerns over nontarget effects and target insect resistance have led to a shift in control towards more biorational approaches, such as the bacterium Bacillus thuringiensis israelensis (Bti), and insect growth regulators (IGRs), such as JH mimics (methoprene) and ecdysone agonists. The normal larval physiology of metamorphosis is disrupted by IGRs (Beckage et al, 2004; …”

Section: Discussionmentioning

confidence: 99%

Larval feeding duration affects ecdysteroid levels and nutritional reserves regulating pupal commitment in the yellow fever mosquitoAedes aegypti(Diptera: Culicidae)

Telang

Frame

Brown

2007

Journal of Experimental Biology

111

View full text Add to dashboard Cite

SUMMARY What little is known about the endocrine regulation of mosquito development suggests that models based on Lepidoptera and Drosophila may not apply. We report on basic parameters of larval development and the commitment to metamorphosis in the yellow fever mosquito Aedes aegypti that are affected by varying the length of feeding time for last instar larvae. A critical mass for pupal commitment was achieved after 24 h of feeding by last instars, also the age at which tissue production and hemolymph titers of ecdysteroids are increasing. A greater proportion of last instars successfully pupated and eclosed as adults as the length of their feeding time increased. Less than 24 h of feeding time resulted in last instars that were developmentally arrested; these larvae tolerated starvation conditions for up to 2 weeks and retained the capacity to pupate if re-fed. Starvation tolerance may be a common trait among container-inhabiting species, and this period is an important factor to be considered for vectorial capacity and control measures. To distinguish cues for metamorphosis related to a larva's nutritional status versus its age, newly molted last instars were fed for different periods of time but sampled at the same age; ecdysteroid levels,body mass and nutrient reserves were then measured for each group. Our data suggest that metamorphic capacity is dependent on a larva's nutritional condition and not just the age at which ecdysteroid titers increase. Last instars that have fed for a particular length of time may initiate their metamorphic molt when both threshold levels of nutrient reserves and ecdysteroid titer have been met. Future studies will lead to a conceptual model specific for the nutritional and hormonal regulation of mosquito post-embryonic development. This model should facilitate the exploitation of current and novel insect growth regulators that are among favored strategies for vector population suppression.

show abstract

Section: Discussionmentioning

confidence: 99%

Larval feeding duration affects ecdysteroid levels and nutritional reserves regulating pupal commitment in the yellow fever mosquitoAedes aegypti(Diptera: Culicidae)

Telang

Frame

Brown

2007

Journal of Experimental Biology

111

View full text Add to dashboard Cite

show abstract

“…These results are typical effects of an ecdysteroid activity at the cellular level (Wing 1988;Trisyono et al 2000). Beckage et al (2004) tested the potency of three ecdysteroid agonists on larvae of three mosquito species, Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus. A. gambiae was the most susceptible species and Ae.…”

Section: Purposely Synthesized Endocrine Disruptersmentioning

confidence: 89%

“…Mosquitoes have been investigated intensively, because some of them are important vectors of disease, and there is a variety of methods for testing the efficacy of insecticides targeted against the aquatic larval stages (Beckage et al 2004;Boudjelida et al 2005).…”

Section: Brief Description Of the Insect Hormone Systemmentioning

confidence: 99%

Endocrine disruption in aquatic insects: a review

Soin

Smagghe

2007

Ecotoxicology

View full text Add to dashboard Cite

There is mounting evidence that a wide variety of compounds can have endocrine disrupting effects on humans and wildlife. However, investigations so far have focused primarily on exposure to human and other vertebrates, with invertebrate findings largely restricted to marine mollusks or to the ecdysteroid and juvenile hormone agonists as purposely synthesized endocrine disrupters for the pest management of insects. This article provides a brief description of the insect hormone system, a short sum-up of the relevant insect groups with aquatic life stages, and an overview of the additional evidence for endocrine disruption in aquatic insects from laboratory and field studies since 1999. In addition, the suitability of insects as sentinels for endocrine disrupting chemicals in aquatic ecosystems is discussed. Conclusions are drawn and research needs are defined.

show abstract

“…In this case the in vivo parameters could compensate for the lower activity against EcR/USP. It is also observed that commercial DAHs have toxic effects against larvae of mosquitoes and fl ies and that this toxicity is mediated through the induction of a premature molt (Smagghe et al 2002 ;Beckage et al 2004 ;Boudjelida et al 2005 ) . However, high concentrations are needed (EC 50 of ~20 m g/L to ~2 mg/L) which indicates that the use of DAHs to control mosquito and fl y larvae in their aquatic environment may not be very practical.…”

Section: Validation: Larval Toxicity Assaysmentioning

confidence: 94%