Effect of Insecticides on the Serpentine Leafminer, Liriomyza trifolii (BURGESS) (Diptera: Agromyzidae).

Abstract

An outbreak of the serpentine leafminer, Liriomyza trifolii (BURGESS) occurred on many ornamental crops and vegetables in the spring of 1990 in Shizuoka Prefecture, Japan. The fly proved impossible for growers to control with conventional insecticides. Insecticides were evaluated for control of the fly on a bean (Phaseolus vulgaris L.) in the laboratory.Among 54 insecticides tested by spraying on one-day-old larvae, isoxathion, thiocyclam, cartap, cyromazine, and flufenoxuron gave high mortality.The LC50 values three days after treatment were 33, 72, 236, 4.8, and 103ppm, respectively. Eight days after treatment, the LC50 values for the insect growth regulators (IGRs), cyromazine and flufenoxuron, were 3.0 and 2.8ppm, respectively. The granular systemic insecticides cartap and acephate gave good larval control. High pupal mortalities occurred with the prepupae were placed on a polyethylene film treated with isoxathion, cyromazine, cartap, and thiocyclam. Isoxathion, thiocyclam, and ethofenprox had high adulticidal activity and reduced the number of feeding and oviposition punctures. Cyromazine and flufenoxuron lacked adulticidal activity and the repellent effect on feeding and oviposition. However, adult females exposed for 2 days to the IGR-treated foliage had reduced eggs and larvae viability. Adult females that survived the IGR treatment as larvae had fewer progeny.

Insecticide susceptibility of the leafminer, Chromatomyia horticola (Goureau) (Diptera: Agromyzidae)

“…The effectiveness of dimethoate was high for the Kagoshima population, but low for the Shizuoka population. Flufenoxuron, which was effective on L. trifolii (Saito et al, 1992(Saito et al, , 1996, was less effective for the tested populations of C. horticola. It must be noted that emamectin-benzoate (Saito, 1997) and cyromazine (Parrella and Keil, 1984;Trumble, 1985;Saito et al, 1992), which are effective on L. trifolii, and fipronil, spinosad and chlorfenapyr, which are new insecticides, were highly effective on C. horticola.…”

“…Of the insecticides, however, only isoxathion showed a high effectiveness in the Shizuoka and Kagoshima populations with 31.2 ppm and 10.8 ppm of LC 50 , respectively, in the present assay. Saito et al (1992) found that isoxathion was a unique organophosphate with a high effectiveness (33 ppm of LC 50 ) to L. trifolii, which was resistant to organophosphates. However, the mechanism of high effectiveness of isoxathion on such leafminers remains unclear.…”

Comparison of thermal tolerance of seven native species of parasitoids (Hymenoptera: Eulophidae) as biological control agents against Liriomyza trifolii (Diptera: Agromyzidae) in Japan

“…Because L. trifolii had already acquired a high resistance to many insecticides (Parrella, 1987;Saito et al, 1992), chemical control often caused rapid growth of the pest population due to an adverse impact upon native natural enemies (Saito et al, , 1996. Two European species of parasitoid, Diglyphus isaea (Walker) and Dacnusa sibirica Telenga, have been introduced to Japan as an alternative control measure (Ozawa et al, 1993(Ozawa et al, , 1999Tatara et al, 1993;Saito et al, 1995;Ichikawa et al, 1996;Shibao et al, 1996;Matsumura et al, 2001).…”

Relative abundance of parasitoids reared during field exposure of sentinel larvae of the leafminers Liriomyza trifolii (Burgess), L. sativae Blanchard, and Chromatomyia horticola (Goureau) (Diptera: Agromyzidae)

“…All three leafminers have developed high levels of resistance to a range of chemical insecticides (e.g. Parrella and Keil, 1984;Saito et al, 1992;Saito, 2004;Ohta et al, 2005;Tokumaru et al, 2005), but insecticides do eliminate local parasitoids, leading to pest resurgence, suggesting that parasitoids may be important natural enemies of leafminers under insecticide-free conditions (e.g. Oatman and Kennedy, 1976;Schuster and Price, 1985;Saito et al, 1996;Saito, 2004).…”