The life cycle of Amblyomma neumanni Ribaga, 1902 (Acari: Ixodidae) in the laboratory.

A colony of Amblyomma neumanni was started with engorged females collected from cattle in the province of Salta (24 degrees 51'S, 65 degrees 33'W), Argentina. The larvae and nymphs were fed on rabbits and the adults on calves. The non-parasitic stages were maintained in darkness at 27 +/- 1 degrees C and 83-86% RH. The life cycle (pre-feeding period not tested) had a mean duration of 205.7 days. The mean time (days) for the different phases of the cycle were as follows: feeding of females 8.8, pre-oviposition 23.8, oviposition 41.4, minimum egg incubation 76.1, feeding of larvae 8.5, pre-moult to nymphs 16.4, feeding of nymphs 7.9 and pre-moult to adults 22.8. The mean recovery rates of larvae, nymphs and females were 83.8, 85.6 and 89.3%, respectively. The nymphs moulting to females were heavier (8.1 +/- 2.34 mg) than those moulting to males (6.0 +/- 2.34 mg; p < 0.01), but their range of engorgement weight showed overlap (2.3-16.2 versus 2.2-12.8 mg, respectively). Two gynandromorphs were detected between the nymphs. A comparison of biological parameters of A. neumanni with other American Amblyomma species from mammals is presented.