The Subgenus Persicargas (Ixodoidea, Argasidae, Argas ). 14. Biological studies on the adult stage of A. (P.) arboreus Kaiser, Hoogstraal & Kohls in Egypt12

Abstract

The feeding and oviposition of adult Argas (Persicargas) arboreus Kaiser, Hoogstraal & Kohls were investigated at different constant temperature and RH levels and with 6 host bird species. Females ingested less blood in the first and final meals than in other meals; males ingested 1/3–1/2 as much blood as females. The coxal fluid to bloodmeal ratio was constant despite sex or age, but reduced in partly engorged females and those held at high temperature or low RH levels. The bird species did not influence prefeeding and feeding periods, except adult herons, the hosts in nature, for which the periods were longer, probably owing to acquired host immunity to tickbite. Females that fed on rabbits died soon or survived without oviposition. Females deposited 4–6 viable egg batches following a single mating; repeated mating increased the frequency of oviposition. The optimum oviposition temperature was ca 34°C. The minimum engorged weight for oviposition was 20.1 mg, above which a mean of 3.3 eggs was deposited for each mg increase in body weight. The bird host species, temperature (23–34°C), and RH (20–85%) did not affect female fertility. Females lost ca 50% of their weight between engorgement and ending oviposition. Unfed adult survival periods were inversly related to temperature, not to RH except at 21°C. These periods ensure the survival of the tick colony in nature even if herons do not return to their rookery for 1 year. The sex ratio was 1: 1. Males molted from earlier nymphal instars than females. The emergence, mating, and oviposition processes are described.