Insect cuticle: a critical determinant of insecticide resistance

Abstract

Intense use of insecticides has resulted in the selection of extreme levels of resistance in insect populations. Therefore understanding the molecular basis of insecticide resistance mechanisms becomes critical. Penetration resistance refers to modifications in the cuticle that will eventually slow down the penetration of insecticide molecules within insects' body. So far, two mechanisms of penetration resistance have been described, the cuticle thickening and the altering of cuticle composition. Cuticular modifications are attributed to the over-expression of diversified genes or proteins, which belong to structural components (cuticular proteins mainly), enzymes that catalyze enzymatic reactions (CYP4G16 and laccase 2) or ABC transporters that promote cuticular translocation. In the present review we summarize recent studies and discuss future perspectives.

Involvement of integument‐rich CYP4G19 in hydrocarbon biosynthesis and cuticular penetration resistance in Blattella germanica (L.)

“…It is possible that the egg case is much more impermeable to insecticide penetration than other body parts. Cuticle modification in resistant insects is mostly associated with thickening of the cuticle or composition alteration . Because the Res cockroachs presented a CHC profile qualitatively similar to that of the Sus strain, and both of the strains showed highly consistent relative proportions of individual CHC components (Table S2), we consider that the higher amount of CHCs in the Res strain, and possible thickening of the epicuticular layer are major differences between the Res and Sus strains as shown in A. gambiae and Triatoma infestans .…”

“…Cuticular penetration resistance, which usually involves cuticle thickening, and alteration of cuticular components and the physical structure of cuticle layers, is the least studied mechanism. This slow‐down mechanism has been hypothesized to delay insecticide molecules from reaching their target proteins …”

Climate change and the genetics of insecticide resistance

“…Other genetic changes to the thickness or composition of the cuticle may affect insecticide penetration as well. A survey of insecticide resistance in different mosquito species as well as the agricultural pests Heliothis virescens and Myzus persicae showed that many genes related to cuticular functions are up‐regulated in resistant strains of these species . Although these mechanisms have not been functionally tested, it should be mentioned that these different mechanisms could also drive the evolution of insecticide resistance via decreased cuticular penetration and could co‐evolve with adaptation to desiccation stress.…”

Extraction optimization, antioxidant activity, and tyrosinase inhibitory capacity of polyphenols from Lonicera japonica

“…Tyrosinases catalyze the ortho‐hydroxylation of tyrosine to dihydroxy‐phenyl‐alanine (DOPA) and the subsequent two‐electron oxidation to dopaquinone (Rolff et al, ). They are also related to enzymatic browning in fruit and vegetables, pigmentation, and insect physiological processes (Balabanidou, Grigoraki, & Vontas, ; Olmedo et al, ; Xue et al, ).…”