@article {10446, title = {Intra-specific variability in life-cycle synchronization of an ectoparasitic fly to its avian host}, journal = {Oikos}, volume = {122}, year = {2013}, pages = {274{\textendash}284}, abstract = {

The role of environmental and host-associated factors in synchronization of host\–parasite life-cycles is an important question of evolutionary ecology. Yet, only handsome of studies examined this question at the intraspecific level. Here we explore how host-associated traits, such as breeding phenology and host breeding habitat, can influence parasite phenology and co-occurrence at different spatial scales. We studied the system comprised of a generalist ectoparasitic fly Carnus hemapterus and one of its avian hosts, the European roller Coracias garrulus. Inter-annual variation in phenology was larger for parasites than hosts. Host predictability in terms of occurrence and phenological regularity was moderate, suggesting that this resource can be difficult to be tracked by the parasite. A large proportion of flies consistently emerged before the appearance of suitable host resources at both the nest and population level. Consequently, we revealed low and highly variable inter-annual host\–parasite synchronization rates. Nevertheless, we found that parasites from nests of early and progressively earlier breeding European rollers were more synchronized with their hosts than parasites from nests of late and progressively later breeding hosts, respectively. Temporal trends in host suitability and parasite emergence at the population scale suggest that other mechanisms, such as dispersal or exploitation of other host species, ensure parasites access to resources and counteract asynchrony with the host at the nest scale.

}, doi = {10.1111/j.1600-0706.2012.20374.x}, author = {Calero-Torralbo, M. A. and Vaclav, Radovan and Valera, F.} } @article {8814, title = {Synchronization of host-parasite cycles by means of diapause: host influence and parasite response to involuntary host shifting}, journal = {Parasitology}, volume = {135}, number = {11}, year = {2008}, month = {September}, pages = {1343-1352}, type = {Article}, abstract = {Many parasites require synchronization of their infective phases with the appearance of susceptible host individuals and, for many species, diapause is one of the mechanisms contributing to such coincidence. A variety of ecological factors, like changes in host temperature produced by involuntary host shifting (Substitution of the usual host by an infrequent one), can modify host-parasite synchronization of diapausing ectoparasites of endothermic species. To understand the influence of host shifting on the mechanisms of parasite synchronization, we conducted experiments using the system formed by the ectoparasitic fly Carnus hemapterus and its avian hosts. We simulated the occurrence of the usual host and natural cases of host shifting by exposing overwintering carnid Pupae from Bee-eater nests (Merops apiaster) to the earlier incubation periods of two Carnus host species that frequently reoccupy Bee-eater nests. Pupae exposed to host shifting treatments advanced the mean date of emergence and produced an earlier and faster rate of emergence in comparison with Pupae exposed both to the control (absence of any host) and Bee-eater treatments. The effect was more evident for the treatment resembling the host with the most dissimilar phenology to the one of the usual host. Our results show that host temperature is an environmental cue used by this nest-dwelling haematophagous ectoparasite and reveal that Carnus hemapterus has some potential to react to involuntary host shifting by means of plasticity in the termination of diapause.}, keywords = {Carnidae, Carnus hemapterus, on Merops apiaster, Spain}, isbn = {0031-1820}, url = {://ZOOREC:ZOOR14503013830 }, author = {Calero-Torralbo, M. A. and Valera, F.} } @article {2282, title = {Prolonged diapause in the ectoparasite Carnus hemapterus (Diptera: Cyclorrhapha, Acalyptratae) - how frequent is it in parasites}, journal = {Parasitology}, volume = {133}, number = {2}, year = {2006}, month = {August}, pages = {179-186}, abstract = {Prolonged diapause is usually interpreted as an adaptation to unpredictable environmental conditions and resource availability. Many parasites usually face highly unpredictable environments, therefore prolonged diapause should be common among these organisms. Here we examine the occurrence and frequency of prolonged diapause in the ectoparasite Carnus hemapterus (Diptera: Cyclorrhapha, Acalyptratae). We found that the studied population is polymorphic with respect to diapause duration. Emergence of carnid flies after 2 and 3 wintering seasons was therefore detected in around 17\% and 21\% of the samples respectively. The number of flies with prolonged diapause ranked 0.88-50\% with respect to the number of flies emerging during the first spring. Both the occurrence of prolonged diapause and the number of flies with a long life-cycle are related to the number of flies emerging during the first spring. The emergence pattern of flies with prolonged diapause was very similar to that observed for flies with a short cycle and occurred in synchrony with the occurrence of hosts. Prolonged diapause has been frequently reported in plant-feeding insects and in some host-parasitoid systems, but this is, to our knowledge, the second report ever on prolonged diapause in true parasites of animals. We discuss the reasons for the apparent rarity of prolonged diapause among these organisms. }, keywords = {Carnidae, Carnus, Carnus hemapterus, Spain}, isbn = {0031-1820}, url = {://ZOOREC:ZOOR14211069128 }, author = {Valera, F. and Casas-Criville, A. and Calero-Torralbo, M. A.} }