Intraspecific hybridization of two karyotypic forms of Anopheles vagus (Diptera: Culicidae) and the related egg surface topography.

Hybridization tests of the two karyotypic forms (Form A and B) of laboratory-raised, isolines of Anopheles vagus, were conducted by induced copulation. The results of reciprocal- and back-crosses indicated that they were genetically compatible, providing viable progeny. Comparative egg morphometry and morphology, aided by scanning electron microscopy (SEM), revealed that the eggs of the two karyotypic forms were morphometrically and morphologically similar.

Intraspecific hybridization of Anopheles minimus (Diptera: Culicidae) species A and C in Thailand.

Hybridization tests of laboratory-raised, isolines of Anopheles minimus, species A and C were conducted by induced copulation. The three isolines were established based on three morphological variants of wild-caught, fully engorged females and two distinct types of metaphase chromosomes. They were An. minimus species A: V form (X1,Y1), M form (X2,Y1); species C: P form (X3,Y2). The results of reciprocal and back crosses indicated that the two morphologically variant forms of species A were genetically compatible, providing viable progeny and completely synaptic salivary gland polytene chromosomes, whereas they were genetically incompatible with species C and/or the P form. Hybrid progeny was only obtained from both forms of species A females x species C males, but asynaptic salivary gland polytene chromosomes on 3L and partial development of ovarian follicles in females were seen. Back crosses of F1 hybrid males with parental species A females provided viable progeny, while back crosses of F1 hybrid females with parental species C males provided progeny of low viability and adult males with abnormal spermatozoa, suggesting the partial reproductive isolation of An. minimus species A and C.