Global analyses of interspecific interactions are rapidly increasing our understanding of patterns and processes at large scales. Understanding how biodiversity assembles and functions on a global scale will increasingly require analyses of complex interactions at different ecological and phylogenetic levels. We present an analysis of host-plant associations in the sap-sucking Psylloidea (∼3,800 species) using the most comprehensive assemblage of host data for this group compiled from 66 % of published records. Psyllids are known for high levels of host specificity and host switching between related plants at local scales, but a global survey implicates historical processes that are not entirely consistent with those at local scales. In particular, saltationary host switching events appear to have been a key factor explaining the wide but patchy distribution of psyllid host-plants throughout the angiosperm phylogeny. Alternative explanations involving co-diversification with subsequent extinction seem implausible. At the seed plant family level, we compare associations for psyllids with those of their relatives the aphids, but, despite notable differences in biogeographic distributions, find few plant families (2%) that host only psyllids but not aphids, while a much larger percentage (31%) host aphids but not psyllids, and 43% of plant families distributed throughout the plant phylogeny host neither group.

The efficacy of 3 different insecticides—Applaud, Brigade and Movento—for mealybug control were evaluated at 2 commercial vineyards in Orange County and Nelson County in Virginia. The study was conducted by using spot spray applications with 12 single-vine replicates of each of the 4 treatments, i.e., 3 insecticides and an untreated check in CRD design. Each replicate of single-vine treatment was randomly selected, and a distance of at least a 2-vine buffer was maintained between the treatments and the replicates. Prior to the applications, plots were evaluated for the presence of mealybugs on the vines and were flagged. Foliar, trunk, and cordon application of insecticides were applied with a SOLO 11.4 L (3-gallon) backpack sprayer. Mealybug numbers were recorded using a 5-min sampling on each of the treatments, 20 days before the treatment (DBT) and multiple days after the first and second treatment (DAT). The evaluation was conducted on 10 random vines per treatment and the average value was used for analysis. Tables 1 and 2 represent field trial carried out in 2 different field sites located in Orange County and Nelson County in Virginia. The treatments were applied 2 times per growing season in site 1 and 1 time in site 2 using the recommended application rate and spray volume per growing season. The first application was scheduled on 31 May 2022, and second on 11 July 2022. Analysis of the mean number of mealybugs on different treatments was carried out using nonparametric comparisons for each pair using the Wilcoxon test of each pair at P ≤ 0.05. For the statistical analysis, the JMP Pro software was used.

Mealybugs (Hemiptera: Pseudococcidae) are one of the prevalent pests infesting wine grapes in the eastern United States. Their close association with ants (Hymenoptera: Formicidae) provides them with protection against natural enemies. Although sugar-based dispensers have been proposed as a strategy to disrupt this trophobiotic interaction, their field performance and indirect effects on mealybug infestation remain poorly understood. This study addresses this gap by identifying mealybug species present in Virginia vineyards, characterizing dominant ant genera associated with mealybugs, and evaluating the impact of sugar dispensers (with and without insecticide) on ant activity, mealybug density, and fruit cluster infestation. Field trials were conducted in two commercial vineyards in Virginia, USA, both with a history of mealybug infestations. Sampling plots with or without sugar dispensers were compared to assess differences in mealybug and ant population densities and fruit cluster infestation levels. Two mealybug species, Pseudococcus maritimus (Ehrhorn) and Ferrisia gilli Gullan, were detected at both sites. Some dominant ant genera, including Tetramorium Mayr, Lasius Fabricius, Solenopsis molesta (Say), Crematogaster Lund, and Pheidole Westwood, were found in close association with mealybugs. Ant activity remained low in untreated plots, whereas insecticide-treated dispensers initially attracted high ant numbers, which declined over time. Fruit cluster infestation was highest in plots lacking dispensers, indicating that dispenser deployment reduced mealybug impact. These findings demonstrate that sugar dispensers, particularly those containing insecticide, can suppress ant activity and reduce mealybug-related fruit damage, offering a practical non-disruptive tool for integrated pest management in small- and medium-sized vineyards.