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Host Colonies (host + colony)
Selected AbstractsLocal host ant specificity of Phengaris (Maculinea) teleius butterfly, an obligatory social parasite of Myrmica antsECOLOGICAL ENTOMOLOGY, Issue 5 2010MAGDALENA WITEK 1. Phengaris butterflies are obligatory social parasites of Myrmica ants. Early research suggested that there is a different Myrmica host species for each of the five European Phengaris social parasites, but more recent studies have shown that this was an oversimplification. 2. The pattern of host ant specificity within a Phengaris teleius metapopulation from southern Poland is reported. A combination of studying the frequency distribution of Phengaris occurrence and morphometrics on adult butterflies were used to test whether use of different host species is reflected in larval development. 3. Phengaris teleius larvae were found to survive in colonies of four Myrmica species: M. scabrinodis, M. rubra, M. ruginodis, and M. rugulosa. Myrmica scabrinodis was the most abundant species under the host plant but the percentage of infested nests was similar to other host ant species at two sites and lower in comparison to nests of M. rubra and M. ruginodis at the other two sites. Morphometric measurements of adult butterflies reared by wild colonies of M. scabrinodis and M. ruginodis showed that wing size and number of wing spots were slightly greater for adults eclosing from nests of M. ruginodis. 4. Our results suggest that P. teleius in the populations studied is less specialised than previously suggested. The results are consistent with the hypothesis that P. teleius is expected to be the least specific of the European Phengaris species, as it has the largest and best defended fourth-instar caterpillars and, as a predatory species, it spends less time in the central larval chambers of the host colonies. The fact that individuals reared by M. ruginodis had wider hind wings may suggest that P. teleius had better access to resources in M. ruginodis than in M. scabrinodis colonies. [source] Effects of resource availability and social parasite invasion on field colonies of Bombus terrestrisECOLOGICAL ENTOMOLOGY, Issue 3 2008CLAIRE CARVELL Abstract 1.,The survival, growth and fecundity of bumblebee colonies are affected by the availability of food resources and presence of natural enemies. Social parasites (cuckoo bumblebees and other bumblebees) can invade colonies and reduce or halt successful reproduction; however, little is known about the frequency of invasion or what environmental factors determine their success in the field. 2.,We used 48 experimental colonies of the bumblebee Bombus terrestris, and manipulated both resource availability at the landscape scale and date of colony founding, to explore invasion rates of social parasites and their effect on the performance of host colonies. 3.,Proximity to abundant forage resources (fields of flowering oilseed rape) and early colony founding significantly increased the probability of parasite invasion and thus offset the potential positive effects of these factors on bumblebee colony performance. 4.,The study concludes that optimal colony location may be among intermediate levels of resources and supports schemes designed to increase the heterogeneity of forage resources for bumblebees across agricultural landscapes. [source] Microsatellite analysis reveals strong but differential impact of a social parasite on its two host speciesMOLECULAR ECOLOGY, Issue 3 2006BIRGIT FISCHER-BLASS Abstract The speed and the dynamics of the co-evolutionary process strongly depend on the relative strengths of reciprocal selection pressures exerted by the interacting species. Here, we investigate the influence of an obligate social parasite, the slave-making ant Harpagoxenus sublaevis, on populations of the two main host species Leptothorax acervorum and Leptothorax muscorum from a German ant community. A combination of genetic and demographic data allowed us to analyse the consequences of raiding pressure on the hosts' life history and possible host preferences of the parasite. We can demonstrate that slave raids during which the social parasite pillages brood from neighbouring host colonies are both frequent and extremely destructive for both host species. Microsatellite analysis showed that, on average, a single slave-maker colony conducts more than three raids per year and that host colonies mostly perish in the aftermath of these parasite attacks. Only in few cases, surviving nests of previously raided host colonies were found in the surroundings of slave-maker colonies. As a consequence of the high prevalence of parasites and their recurrent and devastating slave raids on host colonies, the life expectancy of host colonies was severely reduced. Combining our results on host-specific parasitic colony founding and raiding frequencies with the post-raid survival rate, we can demonstrate an overall higher mortality rate for the smaller host species L. muscorum. This might be caused by a preference of H. sublaevis for this secondary host species as demographic data on host species usage indicate. [source] Does the mode of transmission between hosts affect the host choice strategies of parasites?OIKOS, Issue 2 2009Implications from a field study on bat fly, wing mite infestation of Bechstein's bats In a two-year field study, we analyzed the distribution of two hematophagous ectoparasites, the bat fly Basilia nana and the wing mite Spinturnix bechsteini, within and among 14 female colonies and among 26 solitary male Bechstein's bats Myotis bechsteinii. Our goal was to investigate whether differences in the transmission mode of the parasites, which result from differences in their life cycle, affect their distribution between host colonies and among host individuals within colonies. Bat flies deposit puparia in bat roosts, allowing for the transmission of hatched flies via successively shared roosts, independent of body contact between hosts or of hosts occupying a roost at the same time. In contrast, wing mites stay on the bat's body and are transmitted exclusively by contact of bats that roost together. As expected in cases of higher inter-colony transmissibility, bat flies were more prevalent among the demographically isolated Bechstein's bat colonies and among solitary male bats, as compared to wing mites. Moreover, the prevalence and density of wing mites, but not of bat flies, was positively correlated with colony size, as expected in cases of low inter-colony transmissibility. Within colonies, bat flies showed higher abundance on host individuals in good body condition, which are likely to have high nutritional status and strong immunity. Wing mites showed higher abundance on hosts in medium body condition and on reproductive females and juveniles, which are likely to have relatively weak immunity. We suggest that the observed infestation patterns within host colonies reflect different host choice strategies of bat flies and wing mites, which may result from differences in their inter-colony transmissibility. Our data also indicate that infestation with wing mites, but not with bat flies, might be a cost of sociality in Bechstein's bats. [source] Racial Differences in Division of Labor in Colonies of the Honey Bee (Apis mellifera)ETHOLOGY, Issue 2 2002Charles Brillet We measured the age at onset of foraging in colonies derived from three races of European honey bees, Apis mellifera mellifera, Apis mellifera caucasica and Apis mellifera ligustica, using a cross-fostering design that involved six unrelated colonies of each race. There was a significant effect of the race of the introduced bees on the age at onset of foraging: cohorts of A. m. ligustica bees showed the earliest onset, regardless of the race of the colony they were introduced to. There also was a significant effect of the race of the host colony: cohorts of bees introduced into mellifera colonies showed the earliest onset of foraging, regardless of the race of the bees introduced. Significant inter-trial differences also were detected, primarily because of a later onset of foraging in trials conducted during the autumn (September,October). These results demonstrate differences among European races of honey bees in one important component of colony division of labor. They also provide a starting point for analyses of the evolution of division of labor under different ecological conditions. [source] | ||||||||||