Influence of aggregation on the molting process of Rhipicephalus sanguineus, (Latreille, 1806) (Acari: Ixodidae) under laboratory conditions

The objective of this experiment was to evaluate the influence of different aggregations on the molting process of Rhipicephalus sanguineus (Latreille, 1806). Tick-naive domestic rabbits (Oryctolagus cuniculus) were used as experimental hosts for the parasitic phase. A total of 10 rabbits were used on the experiment. All tick free-living phases were kept in incubator at 27 +/- 1 degrees C, 80 +/- 5% relative humidity and scotophase. The periods of pre-molt, molt, percentage of ecdisis and molt rhythm of larvae and nymphs were studied. A total of 1560 engorged larvae and 1560 nymphs of R. sanguineus were divided in six groups of aggregations: 1, 5, 10, 20, 40 and 80 ticks with ten repetitions each one. The ecdises of nymphs and adults were daily observed. The percentage of ecdysis was the only parameter with no aggregations effects. All others parameters were statistically different (p < 0.05). The results suggested that highest aggregations accelerate the molting process.