A hybridization model forRhipicephalus appendiculatus andR. zambeziensis (Acarina: Ixodidae) using glucose-6-phosphate-isomerase isoenzymes

In the Eastern Province of Zambia,Rhipicephalus appendiculatus (Neumann) andR. zambeziensis (Walker) are sympatric. Intermediate forms as well as typical specimens are found. No morphological criteria could detect cross-breeding between these species in the field.Hybrids betweenR. appendiculatus andR. zambeziensis were produced and glucose-phosphate-isomerase (EC 5.3.1.9.; GPI) isoenzymes resolved by agarose electrophoresis. Phenotyping hybrids in the F1 and F2 generations was explained by the autosomal transmission of two loci of GPI-genes. Identification of some hybrid phenotypes offers the possibility of showing presently undetected hybridization in the field. A genetic model is proposed to explain the patterns.