Parasitism by bat flies (Diptera: Streblidae) on neotropical bats: effects of host body size, distribution, and abundance

Abstract

We examined the correlations between prevalence (proportion of infested individuals), mean intensity (number of parasites per infested individual), and the number of bat fly species parasitizing bats in Venezuela with host body mass, distribution, and abundance. Of 133 bat species sampled, 53 species in six families were captured frequently enough to allow estimation of their parasite loads. Over all species and six families, prevalence and mean intensity were uncorrelated with these variables, but the number of fly species was correlated with host body mass. Correlations of parasitism with body mass were strengthened among the 44 species of Phyllostomidae. Earlier studies showed that bat roosting habits influence their parasitism by bat flies with more permanent, enclosed roosts being with heavier parasitism. Multiple regressions of all measures of parasitism showed that roosting habits and host body mass, respectively, were the first variables to enter stepwise regressions, together accounting for 20-43% of the variation in measures of parasitism. Lack of correlation between proxies of distribution and abundance with parasitism is taken to indicate that proximate factors such as host-as-habitat, social groupings, and roost microhabitat take precedence over species-wide attributes like commonness and ubiquity.

The chiggerflea Hectopsylla pulex (Siphonaptera: Tungidae) as an ectoparasite of free-tailed bats (Chiroptera: Molossidae)

“…Although usually attributed to a dispersal strategy due to the less frequent grooming activity performed by young bats, this effect may also be related to the smaller mass. Patterson et al (2008) did not find a relationship between prevalence and mean intensity with host body mass, distribution, or abundance, but the number of fly species was correlated with host body mass.…”

The specificity of host-bat fly interaction networks across vegetation and seasonal variation

“…The syntax for each GLM fitted model was as follows: glm (H 2 ′∼vegetation type × season, Berror^). All analyses were performed with the vegan, pvclust, ade4, bipartite, and stats packages of the R 2.12.2 software (Suzuki & Shimodaira 2006;Dormann et al 2008;R Core Team Development 2012;Oksanen et al 2013).…”

“…The Baverage^distance method was used for the construction of the dendrogram. Additionally, to test for statistically significant differences between the observed bat and fly species similarities between season and vegetation type, we performed an analysis of similarities (ANOSIM) based on 999 permutations (Oksanen et al 2013). The ANOSIM analysis calculates an R-value which is a relative measure of the species composition dissimilarity and ranges from zero to one.…”

“…Pupation takes place off the host in the bats' roost and takes a few weeks. Emergent flies generally need to find a particular bat species within a few hours of pupation to survive (Patterson et al 2007). Therefore, bat flies are highly host-specific, with most species parasitizing from one to three bat species (Pilosof et al 2012).…”

Reinfestation of Streblidae ectoparasites (Diptera) in Carollia perspicillata (Linnaeus, 1758) (Chiroptera)

“…For each species of ectoparasite, the prevalence, mean abundance of infestation and mean intensity of infestation at the times of capture and recapture were calculated, following the definitions of Bush et al (1997). Since body size is a factor that can influence the intensity of infestation (PRESLEY;WILLIG, 2008;PATTERSON et al, 2008a), possible differences in body mass between individuals at the times of capture and recapture were checked using the chi-square test. This test was also used to analyze the abundances of Streblidae found in individuals at the times of capture and recapture, and between the proportions of individuals that presented more than one species of Streblidae concurrently, at the times of capture and recapture.…”