Susceptibility of a Mexican Field-Collected Wild Population of Diaphorina citri (Hemiptera: Liviidae) to Selected Insecticides

Abstract

The Asian citrus psyllid, Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), is a severe pest of citrus orchards worldwide. Its control is based mainly on the use of conventional insecticides, and resistance to many of those compounds is widespread. Phenotypic bioassays to detect resistance compare the response of a field-collected population with a laboratory-reared population that is susceptible to insecticides. This comparison usually does not involve a susceptible field-collected counterpart since its existence is currently rare. We found an isolated field population of D. citri living on a wild host, orange jasmine (Murraya paniculata [L.] Jack). Considering its lifetime fly capacity, gene flow with any insecticide-treated population was nonexistent or negligible. Thus, we determined the response in fourth-instar nymphs and unsexed 2- to 5-d-old adults in bioassays of commercial formulations of the commonly used insecticides chlorpyrifos, malathion, imidacloprid, and spinosad. In the bioassays, insects were placed on leaf discs previously immersed for 10 s in the respective insecticide concentrations. For adults, the lowest concentration–mortality response was with chlorpyrifos (lethal concentration 50 [LC50] of 0.72 mg L-1 and lethal concentration 95 [LC95] of 1.02 mg L-1). The highest toxicity response was with malathion (LC95 of 0.05 mg L-1). The highest toxicity response with fourth-instar nymphs was observed with spinosad (LC50 of 0.007, LC95 of 0.021 mg L-1). The estimated LC50 and LC95 values for chlorpyrifos, malathion, and spinosad were lower than those documented worldwide for these insecticides in susceptible populations of D. citri.

Thirty‐minute test to detect insecticide resistance under field conditions: the case of the Asian citrus psyllid

“…The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is found in all citrus‐growing areas of the world, 1 with devastating effects in Pakistan, 2 Malaysia, 3 China, 1 the United States of America, 4 Mexico 5 and Brazil 6 . This species feeds on important crops such as the Mexican lemon Citrus aurantifolia Swingle, 5 Valencia orange C. sinensis L Osbeck, 7 grapefruit C. paradisi MacFad 8 and mandarin C. reticulata Blanco 9 . Diaphorina citri causes both direct and indirect effects.…”

Rational Management of Insecticides in Monoculture Areas

“…The dispersal of these genes is influenced by the ability of individuals to move within the agroecosystem, which has implications for their management (Uesugi et al, 2021). Although nonchemical methods such as the use of biological control agents are available, farmers still resort to the use of a wide range of conventional insecticides (Pardo-Melgarejo et al, 2022). The use of agrochemicals is preferred due to their ease of use and ability to reduce the density of insect pests in a short period of time.…”