SPECIFICITY TESTING OF THE NUCLEAR POLYHEDROSIS-VIRUS OF THE GYPSY-MOTH, LYMANTRIA-DISPAR (L) (LEPIDOPTERA, LYMANTRIIDAE)

An aqueous suspension of the nuclear polyhedrosis virus of Lymantria d ispar (L.), LdNPV, was fed to third-instar caterpillars of L. dispar a nd 46 species of nontarget Lepidoptera in four successive, 24- to 48-h doses of 3 x 10(4) polyhedral inclusion bodies (PIBs) in 2 mu L appli ed to small pellets of artificial diet or isolated surfaces of foliage . Adults of the fly Cyrtophleba coquilletti Aldr., and adult males of the bee Megachile rotundata (Fabr.), were assayed with a single dose o f 1.2 x 10(5) PIBs in 2 mu L Of 30% sucrose solution. Only those speci mens that completely consumed the dose(s) were transferred to appropri ate maintenance conditions for 7-10 days whereupon they were frozen. S amples of macerates of experimental specimens were dot-blotted onto ny lon membranes on which whole genomic LdNPV DNA-probing and chemilumine scence techniques were used to show presence of LdNPV DNA. With refere nce to positive and negative controls, the 48 nontarget species were d iagnosed as nonpermissive of LdNPV but the target species was clearly infected. This study demonstrates a high degree of host-specificity of LdNPV.