Penetration, Metabolism, and Elimination of Amitraz and N'-(2,4-Dimethylphenyl)-N-methylformamidine in Southwestern Corn Borer Larvae (Lepidoptera: Pyralidae)1

Knowles, Charles O.; Gayen, Apurba K.

doi:10.1093/jee/76.3.410

Cited by 10 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mode of action of amitraz against honey bees is unknown, however, amitraz has been shown to increase the frequency of cell death in larval midgut cells Bowen 2000, Gregorc andEllis 2011). In addition, unlike most insecticides that possess an ester bond, amitraz has been suggested to be bioactivated by hydrolysis (Schuntner andThompson 1978, Knowles andGayden 1983). As a consequence, differences in hydrolytic enzyme activity between queen and worker castes may contribute to differential sensitivity among the compounds tested.…”

Section: Discussionmentioning

confidence: 99%

Comparative Toxicity of Acaricides to Honey Bee (Hymenoptera: Apidae) Workers and Queens

et al. 2012

View full text Add to dashboard Cite

Acaricides are used to treat honey bee (Apis mellifera L.) colonies to control the varroa mite (Varroa destructor Anderson & Trueman), a worldwide threat to honey bee health. Although acaricides control a serious honey bee parasite and mitigate bee loss, they may cause harm to bees as well. We topically applied five acaricides, each with a different mode of action, to young adult queen and worker bees to generate dose-response curves and LD50. Twenty-four hours after treatment, queens were found to be three times more tolerant of tau-fluvalinate and six times more tolerant of thymol than workers when adjusted for body weight differences between workers (108 mg) and queens (180 mg). Queens survived the highest administered doses of fenpyroximate (1620 μg/g) and coumaphos (2700 μg/g) indicating that queens are at least 11-fold more tolerant of coumaphos and at least 54-fold more tolerant of fenpyroximate than workers. However, queens treated with as little as 54 μg/g of fenpyroximate exhibited reduced survival over 6 wk after treatment. Amitraz was the only acaricide tested for which queens were not more tolerant than workers. The striking difference in acaricide tolerance of queen and worker honey bees suggests physiological differences in how the two castes are affected by xenobiotics. D A H L G R E N E T A L . , J O U R N A L O F E C O N O M I C E N T O M O L O G Y1 0 5 (2 01 2 ) 2 Keywords: Varroa destructor, pesticide, Apis mellifera, miticide, queenThe eusocial honey bee lives in a colony in which a single mated queen is mother to thousands of semisterile female workers. Genetically identical female eggs may develop into either a queen or a worker depending only on their diet. Queen and worker larvae receive different diets (Beetsma 1979), with queen larvae receiving a blend of larval food that includes the protein royalactin that results in a faster growth rate, larger body size, and increased ovary development (Reginato and Cruz-Lamdim 2003, Kamakura 2011). Adult workers and queens differ physiologically in their energetic and metabolic requirements, their susceptibility to pathogens, and the circulating proteins found in the hemolymph (Chan et al. 2006). Despite pronounced differences between the castes, there is little information on how queens and workers differ in their tolerance of pesticides in general, or to the in-hive acaricides used by beekeepers to control the ectoparasitic mite Varroa destructor Anderson & Trueman.The widespread distribution of Varroa mites poses a global threat to honey bee colony health (Sammataro et al. 2000). Varroa mites weaken the hive by consuming hemolymph from pupal and adult bees and by transmitting viruses that may increase colony susceptibility to both abiotic and biotic environmental stressors (Shen et al. 2005). Many honey bee colonies infested with Varroa mites perish without beekeeper intervention (Kraus and Page 1995, National Acad. of Sciences [NAS] 2007). While labor-intensive alternatives to chemical control exist (Sammataro et al. 2000) many beekeep...

show abstract

Section: Discussionmentioning

confidence: 99%

Comparative Toxicity of Acaricides to Honey Bee (Hymenoptera: Apidae) Workers and Queens

et al. 2012

View full text Add to dashboard Cite

show abstract

“…It is metabolised to N 2 ‐(2,4‐dimethylphenyl)‐ N 1 ‐methyformamidine ( DPMF ) (Fig. A) and other compounds in ticks and insects . Both amitraz and DPMF have been shown to act on native octopamine receptors (OARs) in locust muscles, locust nervous tissues, cockroach nerve cords and mites .…”

Section: Introductionmentioning

confidence: 99%

Amitraz and its metabolite differentially activate α‐ and β‐adrenergic‐like octopamine receptors

Kita

Hayashi

Ohtani

et al. 2016

Pest Management Science

View full text Add to dashboard Cite

show abstract

“…The two OARs share 54.6% amino acid sequence identity. Amitraz is considered to be a pro‐acaricide/insecticide that is metabolized to DPMF, an active OAR agonist, in ticks and insects 26,27 . In contrast, both amitraz and DPMF have been shown to act on native OARs in locust muscles, locust nervous tissues, cockroach nerve cords and mites 28–33 .…”

Section: Discussionmentioning

confidence: 99%

A point mutation in the β‐adrenergic‐like octopamine receptor: possible association with amitraz resistance

Takata

Misato

Ozoe

et al. 2020

Pest Management Science

View full text Add to dashboard Cite

Background: Amitraz is a unique formamidine-class acaricide/insecticide that effectively controls ticks, mites, and insect pests. However, the recent emergence of amitraz-resistant cattle ticks is a serious problem that requires an urgent solution. A nonsynonymous single nucleotide polymorphism (A181T) leading to an amino acid substitution (I61F) in the ⊎-adrenergic-like (⊎-AL) octopamine receptor (OAR) of amitraz-resistant southern cattle ticks (Rhipicephalus microplus) (Rm⊎AOR) was proposed to be a cause of the amitraz resistance. However, it remains unclear whether this substitution exerts any functional effect on the action of amitraz. To make this clear, the functional role of this mutation was examined using an orthologous OAR (BmOAR2) from the silkworm (Bombyx mori). Results: Both amitraz and its metabolite N 2-(2,4-dimethylphenyl)-N 1-methyformamidine (DPMF) elevated intracellular cyclic AMP levels as orthosteric OAR agonists in HEK-293 cells stably expressing BmOAR2. The I45F mutant of BmOAR2 (equivalent to I61F in Rm⊎AOR) was generated and tested for its sensitivity to amitraz and DPMF. The assay result showed that the I45F mutation reduces the potency of DPMF to a level similar to that of the endogenous agonist (R)-OA in wild-type BmOAR2. Conclusion: The amino acid substitution found in the first transmembrane segment of Rm⊎AOR most likely causes target-site insensitivity to DPMF, which might contribute to the resistance of R. microplus to amitraz. This needs to be further confirmed using Rm⊎AOR.

show abstract

Penetration, Metabolism, and Elimination of Amitraz and N'-(2,4-Dimethylphenyl)-N-methylformamidine in Southwestern Corn Borer Larvae (Lepidoptera: Pyralidae)1

Cited by 10 publications

References 0 publications

Comparative Toxicity of Acaricides to Honey Bee (Hymenoptera: Apidae) Workers and Queens

Comparative Toxicity of Acaricides to Honey Bee (Hymenoptera: Apidae) Workers and Queens

Amitraz and its metabolite differentially activate α‐ and β‐adrenergic‐like octopamine receptors

A point mutation in the β‐adrenergic‐like octopamine receptor: possible association with amitraz resistance

Contact Info

Product

Resources

About