Both predators and parasitoids can have significant effects on species’ life history traits, such as longevity or clutch size. In the case of gall inducers, sporadically there is evidence to suggest that both vertebrate predation and insect parasitoid attack may shape the optimal gall size. While the effects of parasitoids have been studied in detail, the influence of vertebrate predation is less well-investigated. To better understand this aspect

We demonstrate by multivariate ratio analysis (MRA) the validity of two female colour morphs as separate species in what was previously regarded as a single species, Trigonoderus cyanescens (Förster, 1841) (Hymenoptera: Pteromalidae). As a result, T. pedicellaris Thomson, 1878 stat.r., is resurrected from synonymy under T. cyanescens and T. filatus binubilatus Erdos, 1960 syn.n. is synonymized with T. cyanescens. More than 20 characters were measured

We tested the enemy hypothesis for gall morphology on a model system comprising two Diplolepis rose gall wasp species and their associated parasitoids. The enemy hypothesis predicts both that gall traits will influence parasitoid attack rates within species, and that galls with contrasting morphologies will support different parasitoid communities. This hypothesis is supported by studies at both intraspecific and broader taxonomic levels (i.e. between

When resources are spatially fragmented, strength of competition between species is diminished by alternative patterns of resource use and parasitoids of the same host species become potential competitors. The coexistence of competing species in spatially fragmented habitats may be achieved, however, due to niche partitioning and alternative responses to patch characteristics. To evaluate responses to resource patterns facilitating coexistence, we

A new species of the genus Dipara WALKER, 1833, Dipara alata sp. n., from Hungary is described. Diagnosis, synonymy and a short review of valid Dipara species are given.

We tested the hypothesis that population density alters male territorial and mating behaviour of dragonflies. We predicted that males at higher densities fight more and mate less. During five years we studied two Libellula fulva populations along two small lowland creeks in East Hungary. Using mark-resight method we marked a total number of 1454 dragonfly males. Our results show that on the two study sites there were different population densities.

Clutch size of the gall wasp Diplolepis rosae was studied in galls on Rosa spp. in Eastern Hungary and Romania, Transylvania on four dry pastures.We hypothesised that there was an optimal clutch size, and it was controlled by the emerging rate of the gall inducer and the escaping failure of hatched adults. The most frequent clutch size was 25–30 chambers, and there was a second peak around 60 chambers in each frequency distribution. The most common

The influence of inquiline on the gall of Diplolepis rosae (Hymenoptera: Cynipidae) and its community was investigated. It is expectable that inquilines should cause major changes in the gall-community. Evidences for inquiline effect on multilocular galls are provided and the result suggests that the outcome shows similarity with unilocular ones. Gall size, number of emerged individuals and diversity increased significantly for inquilined galls.

We studied the effect of rose shrub spatial pattern and density toward its parasitism by Diplolepis rosae gall wasps, considering host shrubs’ size. There were eight sample sites on dry pastures and/or on the edges of these pastures. Our results show that high densities rose shrubs show uniform distribution, while the low densities ones appear aggregated. Gall density and prevalence are affected by host plant aggregation. Gall aggregation is inversely

Host plants have significant effects on parasitoid and herbivore distribution. There are just a few reports on tritrophic interactions. We aimed to study the relationships between rose host shrub and Bedeguar gall density with special attention to densities and prevalence of parasitoids at two scales: host shrub and gall. We found that gall density was inversely density dependent of shrub density. Parasitoid density was density dependent of both