Potential for insecticide resistance in populations of Bactrocera dorsalis in Hawaii: spinosad susceptibility and molecular characterization of a gene associated with organophosphate resistance

Abstract

The potential for populations to become resistant to a particular insecticide treatment regimen is a major issue for all insect pest species. In Hawaii, for example, organophosphate (OP)‐based cover sprays have been the chemical treatment most commonly applied against oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), populations since the 1950s. Moreover, bait spray treatments using spinosad were adopted as a major control tactic in the Hawaii area‐wide fruit fly pest management program beginning in the year 2000. To determine the current level of spinosad and OP tolerance of wild B. dorsalis populations, bioassays were conducted on flies collected from a range of geographic localities within the Hawaiian islands. Adult B. dorsalis flies were tested (1) for the level of susceptibility to spinosad using LC50 diagnostic criteria, and (2) for the presence of alleles of the ace gene previously shown to be associated with OP resistance. Regarding spinosad tolerance, only flies from Puna, the one area lacking prior exposure to spinosad, showed any significant difference compared to controls, and here the difference was only in terms of non‐overlap of 95% fiducial limit values. With respect to OP tolerance, specific mutations in the ace gene associated with resistance to these insecticides were found in only two populations, and in both cases, these alleles occurred at relatively low frequencies. These results suggest that at the present time, populations of B. dorsalis in Hawaii show no evidence for having acquired resistance to the insecticides widely used in control programs.

Virology, Epidemiology and Pathology of Glossina Hytrosavirus, and Its Control Prospects in Laboratory Colonies of the Tsetse Fly, Glossina pallidipes (Diptera; Glossinidae)

“…Inferring from other insect-viral systems, this discovery of the virus in the wasp may be significant. B. dorsalis is distributed throughout Southeast Asia and the Pacific, and is considered to be one of the most prominent agricultural pests in this part of the globe [ 107 ]. D. longicuadata is known to introduce D. longicuadata entomopoxvirus (DlEPV) into Caribbean fruit fly Anastrepha suspensa (Diptera: Tephritidae) during oviposition [ 108 ].…”

Suppression of female melon fly, Zeugodacus cucurbitae, with cue‐lure and fipronil bait stations through horizontal insecticide transfer

“…Cover sprays provide temporary control of fruit flies, but control is short‐lived. Repeated applications are not only costly and labor intensive, but also pose significant risks to non‐target beneficial species in the environment and increase the risk of development of pesticide resistance (Leblanc et al., ; Chou et al., ). In recent years, the concept of an area‐wide management approach has gradually shifted grower practices from a single tactic cover spray to multiple tactics in an integrated pest management (IPM) program (Vargas et al., ).…”

Overexpression of two α-esterase genes mediates metabolic resistance to malathion in the oriental fruit fly,Bactrocera dorsalis(Hendel)

“…The oriental fruit fly, Bactrocera dorsalis (Hendel), is considered to be one of the most economically damaging and widespread pests in the world. It is able to attack over 250 host plants, including many commercial fruits, such as carabola, citrus, mandarin and mango, as well as a large variety of agricultural products such as coffee and chilli pepper (Christenson & Foote, 1960;Chou et al, 2010;Jin et al, 2011;Hsu et al, 2014). Much of the damage that this pest inflicts occurs through oviposition punctures and subsequent larval development (Hsu et al, 2014), which can easily destroy the marketable qualities of fruits and cause huge economical losses.…”

“…Owing to the high economic importance and particular method of damage, for more than 50 years, the control of the oriental fruit fly has mostly relied on the use of bait spray with organophosphate (OP)-based insecticides, such as malathion and trichlorphon (Bateman, 1972;Chou et al, 2010;Jin et al, 2011). However, the effectiveness of insecticides is decreasing and resistance to OPs in B. dorsalis has evolved and has been documented in many areas.…”

“…However, the effectiveness of insecticides is decreasing and resistance to OPs in B. dorsalis has evolved and has been documented in many areas. For example, in Taiwan and Hawaii, resistance to OPs was found in field populations of B. dorsalis (Chou et al ., ; Hsu et al ., ). Resistance monitoring of this pest in southern areas of mainland China also suggested that at least 10 geographic populations of B. dorsalis have developed resistance to OPs (Jin et al ., ).…”