USE OF MALIC ENZYME TO DETECT HYBRIDS BET WEEN TORYMUS-SINENSIS AND T-BENEFICUS (HYMENOPTERA, TORYMIDAE) ATTACKING DRYOCOSMUS-KURIPHILUS (HYMENOPTERA, CYNIPIDAE) AND POSSIBILITY OF NATURAL HYBRIDIZATION

Hybrids between the early-season strain of Torymus beneficus and T. si nensis, in which the malic enzyme (ME) is fixed at the F and S alleles , respectively, can be discriminated from their parents by the enzyme banding pattern using PAG electrophoresis. The ME locus of hybrids bet ween the late-season strains of T. beneficus and T. sinensis is fixed at the S allele. Females of Torymus spp. collected in the field at Tsu kuba had various ratios of ovipositor sheath length to thorax length a nd three ME genotypes: SS, FS and FF. Detection of FS in this populati on indicates that natural hybridization occurs between early-season st rains of T. beneficus and T. sinensis.