PCR-RFLP assay to differentiate Liriomyza huidobrensis from L. bryoniae, L. trifolii and Chromatomyia horticola in lettuce crops
In northern Italy, Liriomyza huidobrensis (EPPO A2 list) is a serious pest of lettuce crops grown in open fields. In lettuce crops, it coexists with other agromyzid species, in particular Liriomyza bryoniae (EU Annexes), Liriomyza trifolii (EPPO A2 list) and Chromatomyia horticola but these species have never been reported to cause yield losses. The rapid detection of L. huidobrensis is crucial for effective management strategies. Studies have been made in Italy to develop a PCR-RFLP assay to differentiate L. huidobrensis from other species commonly present in lettuce crops (L. bryoniae, L. trifolii, C. horticola). The possible effect of the presence of DNA belonging to the parasitic wasp Dacnusa spp. was also investigated. A region (approximately 1,031-bp) of the mitochondrial genome was amplified by PCR and digested by the enzymes PvuII and SnaBI separately. Both endonucleases cut the amplicons of L. huidobrensis in two fragments, whereas the original band was not cleaved in the other analyzed species. The presence of parasitic wasp did not bias the assay. This PCR-RFLP assay was found rapid and reliable in separating L. huidobrensis (adults, pupae or larvae) from L. bryoniae, L. trifolii and C. horticola.
Sources
Maseti A, Luchetti A, Mantovani B, Burgio G (2006) Polymerase Chain Reaction-restriction fragment length polymorphism assays to distinguish Liriomyza huidobrensis (Diptera: Agromyzidae) from associated species lettuce cropping systems in Italy. Journal of Economic Entomology 99(4), 1268-1272.