Effects of five temperatures on the free living stages of Amblyomma parvum (Aragão, 1908) (Acari: Ixodidae) / Influência de Cinco Temperaturas na Fase de Vida Livre de Amblyomma parvum (Aragão, 1908) (Acari: Ixodidae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Amblyomma parvum is a tick of wide geographical distribution which parasite wild and domestic animals. In Brazil, the literature records only data on their geographical distribution and hosts. There is no record on the action of different temperatures in Brazilian populations of this species. The objective of this work was to evaluate the effects of five different temperatures on the free living stages on the life cycle of A. parvum. The experiment was conducted under 18, 21, 24, 27 and 321C and relative humidity of 8010%. For the eggs stage, 15 animals were used for infestation in the back after previous trichotomy. The females that dropped were randomly detach at different temperatures. The eggs were packed in glass jars after the fifth day of posture and observed daily for analysis of the average pre-hatching, average hatching and mean percentage of hatching. For others stages, three rabbits were used for each temperature, totaling 15 animals for each stage. The engorged ticks that dropped were collected daily. In the laboratory, they were cleaned, weighed and observed daily. The average of pre-ecdysis of the larvae and nymphs varied inversely proportional to the temperature. The average percentage of ecdysis for the larvae was statistically similar for the five treatments. The average moulting period had the same change that the average of preecdysis period for larvae and nymphs, where longer periods corresponds to lower temperatures. The average period of larval survival was similar statistically for the treatments 18, 21 and 241C and was lower in the temperatures of 27 and 321C. The average ecdysis period of the nymphs were statistically different only in the treatments of 18 and 321C and was much longer in the temperature of 181C (19.1 days). Similar to larvae, the average percentage of ecdysis for the nymphs was statistically similar to the five treatments. The lowest average period of survival of nymphs, with average of 117.5 days, was observed at 32 C. The average of pre-oviposition and oviposition periods were similar. Both were inversely proportional to the increase of temperature, however, only had significant difference in the three lower temperatures. Regarding the average weight of oviposition, the heavier weight was found at 271C (average of 10748.3 mg). The average production of eggs index and the average nutritional efficiency index had the highest average at 271C. The average of pre-hatching period differed significantly in five treatments, and was inversely proportional to the increase of temperature. The average hatching period and the average percentage of hatching were longer and lower in the temperature of 181C. The temperature of 18C can be used for delaying the life cycle, however, it may be deleterious to the ticks.

ASSUNTO(S)

experimental amblyomma parvum temperatura experimental. medicina veterinaria temperature

ACESSO AO ARTIGO

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