Cytogenetics of Ticks (Acari: Ixodoidea) 18. Chromosomes and laboratory biology of Amblyomma dissimile1

Male Amblyomma dissimile possess 10 autosomal bivalents and 1 sex univalent chromosome. Anaphase I is the reductional division, and anaphase II is the equational division for the single sex chromosome. Chromosomal configurations indicate terminal centromeres on all chromosomes. Mitotic cells show 20 autosomes plus 1 sex chromosome. Individuals of all developmental stages of this species feed on reptiles, and only larvae also feed readily on rabbits. Developmental periods are more variable than those usually seen in mammalian tick parasites, and adults congregate in close proximity to one another while feeding. Individual females vary in their expression of parthenogenesis (thelytoky) from producing eggs with no embryonic development to fully embryonated eggs, some of which hatch.