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Abstract

The response to pirimiphos-methyl, in one strain of Acarus farris and two strains of Acarus siro, was assessed using an impregnated filter paper bioassay and by the selection of adults following exposure to pirimiphos-methyl. It was concluded that one of the strains of A. siro was resistant to pirimiphos-methyl and that a major resistance mechanism was involved. The second strain of A. siro gave a response similar to that of a laboratory strain unexposed to organophosphates and was considered to be susceptible. The A. farris strain responded to selection at the ED50 but not at the ED99, and it was concluded that a minor resistance mechanism is present in this strain. Assays of esterase activity were used to attempt to identify the biochemical mechanisms involved in the resistance detected by the bioassays. The A. farris and susceptible A. siro strains showed similar levels of esterase activity but the esterase activity of the resistant A. siro strain was significantly greater. An increase in esterase activity followed selection of both the A. farris strain and the resistant A. siro strain. An acetylcholinesterase assay showed no significant difference between the susceptible and pirimiphos-methyl selected strains of A. siro. The results suggest that esterases are involved in the resistance to pirimiphos-methyl found in A. siro and A. farris but that in A. siro, at least, other mechanisms may also be present.

Food Protective Effects of 3-Methylbenzaldehyde Derived from Myosotis arvensis and Its Analogues against Tyrophagus putrescentiae

“…Therefore, the control of stored food mites is mainly accomplished by the use of organophosphates (lindane, malathion, and pirimiphos-methyl) and pyrethroid insecticides 12 . However, some organophosphates have been banned, because of their toxicity in human 13 and the development of resistant mite population 14–16 . In addition, stored food mites have been reported to be significantly tolerant to pyrethroids 11, 17, 18 .…”

Pesticide residue exposure provides different responses of the microbiomes of distinct cultures of the stored product pest mite Acarus siro

“…The impregnated filter paper test [ 12 , 13 , 46 , 49 , 50 ] was modified as described previously [ 49 ]. The test was run in glass weighing bottles (cat.…”

“…However, the pesticide is expected to control stored product mites [ 8 , 11 ]. In the last 80 years, massive pesticide applications in cheese-producing factories have led to the development of resistance to the organophosphate insecticides etrimfos [ 12 ] and pirimiphos-methyl [ 13 ] and the chlorinated hydrocarbon lindane [ 14 ] in A. siro . Resistance to pesticides in A. siro likely occurred via metabolic detoxification caused by high esterase activity, but it is probable that other mechanisms were also involved [ 13 ].…”

“…In the last 80 years, massive pesticide applications in cheese-producing factories have led to the development of resistance to the organophosphate insecticides etrimfos [ 12 ] and pirimiphos-methyl [ 13 ] and the chlorinated hydrocarbon lindane [ 14 ] in A. siro . Resistance to pesticides in A. siro likely occurred via metabolic detoxification caused by high esterase activity, but it is probable that other mechanisms were also involved [ 13 ]. However, previous studies did not determine the origin of such enzymes regarding whether they are endogenous, produced by mites, or possibly originate from their associated gut microflora [ 15 , 16 ].…”

Acaricidal Activity of DHEMH, Derived from Patchouli Oil, against House Dust Mite, Dermatophagoides farinae

“…[6][7][8] However, the repeated use of chemicals has undesirable effects on non-target organisms, raises environmental and human health concerns, and can result in the development of acaricide resistance due to the mite's high reproductive potential and short life cycle. 6,9,10) Hence, the discovery of plantderived acaricides that are selective, biodegradable and safer for non-target organisms and the environment is desirable.…”