Comparison of efficiency and reproductive aptitude indexes between a reference and field strains of the cattle tickRhipicephalus (Boophilus) microplus, in Sinaloa, Mexico AbstractThe objective of this work was to study the reproductive behavior of two strains of R. (B.) microplus, one wild-caught (Native) and one reference strain (Media Joya) for two years, measuring the reproductive efficiency index (REI) and reproductive aptitude index (RAI). Engorged ticks from each strain were collected monthly from February 2002 to February 2004. These were weighed and kept in the laboratory until egg-laying. Oogenic masses were individually weighed and incubated until larvae emergence. REI and RAI were calculated from each sample, grouping ticks by weight in 100 mg range classes. An analysis of variance and Duncan's multiple rank tests were carried out on the data (P < 0.05). Pearson's correlation coefficients were estimated (P < 0.01) in order to determine the relationship between engorgement weight and the weight and number of laid and hatched eggs. The Native strain showed a higher engorgement weight than Media Joya strain. In both strains REI and RAI were similar in all weight classes; with a quadratic tendency in Media Joya and linear-quadratic in the Native strain (P < 0.05). Significant differences where observed when REI and RAI of both strains were compared along the duration of the study (P < 0.01) with the Native strain performing better in both indexes, including better performance during the dry season. All parameters studied showed highly significant correlation; eggs laid and eggs hatched were notably highly correlated, 0.94 and 0.91, for Media Joya strain and Native strain respectively. ResumoO objetivo deste trabalho foi estudar a conduta reprodutiva de duas cepas de R. (B.) microplus, uma coletada no campo (Nativa) e outra de referência (Média Jóia), por dois anos, calculando o índice de eficiência reprodutiva (REI) e o índice de aptidão reprodutiva (RAI). Foram coletados mensalmente carrapatos fêmeas engurgitadas de cada cepa no período de Fevereiro de 2002 a Fevereiro de 2004. Estas foram pesadas e conservadas no laboratório até ovipositar. As massas de ovos foram pesadas individualmente e incubadas até a eclosão das larvas. O REI e o RAI foram calculados para cada coleta, agrupando os carrapatos em classe de peso de 100 mg. Os dados foram submetidos a uma análise de variância e prova de classe múltipla de Duncan (P < 0,05). Foram calculados os coeficientes de correlação de Pearson (P < 0,01) para estimar a associação entre o peso dos carrapatos engurgitados e o peso e número de ovos postos e eclosionados. A cepa Nativa mostrou um peso ao engurgitamento mais alto do que a cepa Média Jóia. Os valores de REI e de RAI em ambas cepas foram similares em todos as classes de peso, mostrando tendência cuadrática na Média Jóia e linear-cuadrática na cepa Nativa (P < 0,05). Ambos os índices por classe de peso no engurgitamento foram sempre mais altos na cepa Nativa (P < 0,05). Os valores de REI e de RAI de amba...

Several biological parameters were evaluated to determine the capacity of Pimeliaphilus plumifer as biological control agent of Triatominae bugs. When P. plumifer and bugs of a variety of triatomine species were forced together in cages in the laboratory, the incidence of mite infestation was the following: Meccus pallidipennis > M. bassolsae > Triatoma rubida > M. longipennis > M. picturatus, and practically no mites were found on T. infestans and Rhodnius prolixus. Adults and hexapod larvae of P. plumifer were the only stages found to parasitize on M. pallidipennis. Fourth and fifth instar nymphs of this bug appeared most susceptible to mite infestation. P. plumifer mites located preferably on the coxae, ventral abdomen and pronotum of M. pallidipennis bugs. The number of blood meals, amount of ingested blood, and resistance to starvation of M. pallidipennis were similar in both the control and the mite infested groups. On the other hand, mite infection reduced molting rate in nymphs and longevity in adults, increased mortality in third-fifth instar nymphs, and fewer viable eggs were laid by females infected with P. plumifer. These effects could be related with nutritional deficiencies. Our results support the use of P. plumifer mites as control agents of host Triatominae species.

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