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•？ Hawk moth showed foraging preference to P. vittata fronds with low As concentation. •？ Hawk moth can not exclude As by excretion. •？ The main As speciation of hawk moth is As(III)-SH.
The development of an effective and green bioinsecticide is a research hotspot. This study demonstrated the possibility of using an arsenic (As) hyperaccumulator as a bioinsecticide. When the As concentration in the Pteris vittata fronds exceeded 138 mg kg−1, the larva of the hawk moth (Theretra clotho) displayed apparent preference to lower-As-concentration P. vittata fronds. The As concentration in the larva body was as high as 850 mg kg–1 Such high concentration of As in the larva body might have been the case that T. clotho lacks a process to exclude As. The larval frass showed an As concentration of only 1%–4% of that in the larva body. The predominant As species in the larva body and frass was As(III)-SH. The percentage of As(III)-SH was slightly higher in the frass than that in the larval body. Chelation with thiols may be a universal detoxification mechanism for As in both plants and insects. In general, the adoption of P. vittata as a bioinsecticide should be feasible. However, the exact processes to achieve this goal still need further study. The mechanism of different animals to detoxify As is another interesting research topic. |
