02493nas a2200169   4500008004100000020001400041245007600055210006900131260000900200300001200209490000800221520194600229653001302175100001602188700001902204856010002223       2007                        eng d  a0029-854900aMulti-trophic effects of ungulate intraguild predation on acorn weevils0 aMultitrophic effects of ungulate intraguild predation on acorn w  cJune  a533-5400 v1523 aPredators and parasitoids may contribute to controlling the population sizes of phytophagous insects, and this has been shown to benefit plants. Phytophagous insects may also be killed by other herbivores (intraguild predation), usually larger-sized vertebrates that ingest insects accidentally while feeding on common food sources. We studied the intraguild predation on acorn weevils by ungulates and assessed the consequences for weevil populations. Infested acorns are prematurely abscised and the weevil larvae finish their development inside the acorns after being dropped. Our results show that weevil larvae were killed by ungulates eating the infested acorns on the ground. Ungulates did not discriminate between infested and sound acorns, and the probability of a larva being incidentally eaten was inversely related to acorn availability. Thus, predation risk was enhanced by the premature drop of infested acorns when acorn availability on the ground was low. Predation rates on infested acorns were much higher where ungulates were present, and acorn infestation rates were significantly lower. However, ungulates did not provide the oaks any net benefit, since the reduction of infestation rates was not enough to compensate for the large amounts of sound acorns eaten by ungulates. Seed predation is usually studied as a progressive loss of seeds by pre- and post-dispersal predators, but the interactions between them are usually not considered. We show that intraguild predation on insects by large ungulates had an effect on the structure of the foraging guild, as the proportion of acorns predated by insects decreased; however, replicating the same experimental design in different ecological scenarios would increase the strength of these results. In conclusion, the present study shows the importance of considering the multi-trophic interactions between seed predators in order to have a complete picture of granivory.10aCurculio1 aBonal, Raul1 aMunoz, Alberto  uhttps://weevil.myspecies.info/multi-trophic-effects-ungulate-intraguild-predation-acorn-weevils02525nas a2200193   4500008004100000020001400041245012500055210006900180260000800249300001400257490000800271520181700279653001302096653002102109100001602130700002602146700002402172856013502196       2011                        eng d  a0029-854900aComplex selection on life-history traits and the maintenance of variation in exaggerated rostrum length in acorn weevils0 aComplex selection on lifehistory traits and the maintenance of v  cDec  a1053-10610 v1673 aTrophic interactions can trigger the development of exaggerated specialized characters and promote morphological diversification. For example, acorn weevils (genus Curculio) present strikingly long rostrums, which are used by females to perforate oviposition holes through the seed coat. Species exhibiting longer rostrums are known to exploit larger acorns, and therefore rostrum length is thought to be subject to selection to match the preferred acorn type. However, rostrum length is strongly correlated with body size, and morphological divergence could result from either selection on rostrum length for optimal food exploitation or from other pressures acting on body size. We collected infested acorns at oak forests where the large Curculio elephas and the small-bodied Curculio glandium co-occur. There were no interspecific differences in adult female body size to rostrum length allometric relationships, and rostrum length is equally correlated with body size in either species. MtDNA-based species identification showed that C. glandium larvae were present within acorns of all sizes, whereas C. elephas larvae were restricted to acorns above a minimum size, irrespective of oak species. Hence, exploitation of large acorns can hardly have triggered rostrum enlargement, as the small sized C. glandium adults (with short rostrums) could perforate and oviposit in both small and large acorns. Rather, increased rostrum length is probably a by-product of the larger body sizes of individuals emerging from bigger acorns, which allow increased larval size and enhance larval survival likelihood. Summarizing, when exaggerated feeding traits co-vary with other body features, interspecific morphological variability may result from contrasting selective pressures acting on these correlated characters.10aCurculio10aCurculio elephas1 aBonal, Raul1 aEspelta, Josep, Maria1 aVogler, Alfried, P.  uhttps://weevil.myspecies.info/complex-selection-life-history-traits-and-maintenance-variation-exaggerated-rostrum-length-acorn-wee