Rise and Fall of an Oak Gall Wasp (Hymenoptera: Cynipidae) Outbreak in Massachusetts

The recently described oak gall wasp Zapatella davisae Buffington & Melika (Hymenoptera: Cynipidae) has caused extensive damage and mortality to black oak trees, Quercus velutina L. (Fagales: Fagaceae), in coastal parts of New England, United States. Like many newly described and/or newly introduced species, it is unclear how long populations of Z. davisae have existed in this region. However, as this species forms galls on the woody-tissue of its host, it may be possible to obtain historical information about changes in its population size by examining the presence of galls in relation to annual growth nodes. Here, we explore the utility of this approach to determine population size changes in Z. davisae densities on Nantucket, Martha's Vineyard, and Cape Cod, Massachusetts, through dissection of black oak branches. In addition, we calculated parasitism rates during the years of study and obtained morphological and molecular identifications for the parasitoids associated with Z. davisae. Our results show significant changes in population sizes, with higher levels of parasitism at sites on Martha's Vineyard and Cape Cod compared to sites on Nantucket. In addition, morphological examinations, in combination with DNA sequencing, identified the associated parasitoids as five species in the genus Sycophila Walker (Hymenoptera: Eurytomidae). We comment that considerable morphological variation within several of these recovered species was observed, present the first record of males for a species from which only females have been described, and suggest that future work is required to clarify the species boundaries for this important parasitoid group.

The Impostor Syndrome from Luxury Consumption

The present research proposes that luxury consumption can be a double-edged sword: while luxury consumption yields status benefits, it can also make consumers feel inauthentic, producing what we call the impostor syndrome from luxury consumption. As a result, paradoxically, luxury consumption may backfire and lead consumers to behave less confidently due to their undermined feelings of self-authenticity. Feelings of inauthenticity from luxury consumption may arise because consumers perceive luxury as an undue privilege. These feelings are less pronounced among consumers with high levels of chronic psychological entitlement, and they are reduced when consumers’ sense of entitlement is temporarily boosted. The effects are robust across studies conducted in the lab and in field settings such as the Metropolitan Opera, Martha’s Vineyard, a luxury shopping center, and the Upper East Side in New York, featuring relevant participant populations including luxury target segments and consumption contexts including consumers’ reflections on their actual past luxury purchases.