| dc.description.abstract | Crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana), a new non-native pest from Asia first discovered in the U.S. in 2004 has now been reported in 14 states. The scale jeopardizes the future of crapemyrtles use as a popular ornamental landscape tree in the U.S. Management of this pest will likely include biological strategies. Before such strategies can be implemented it is important to examine relative abundances and distributions of arthropod species associated with the scale in the geographic area targeted for biological control. In the first objective, surveys of crapemyrtle ecology from two varietal groups of crapemyrtle trees (Lagerstroemia spp.) were undertaken in Tarrant and Brazos counties across six consecutive seasons in 2018 – 2019. A rich arthropod community was discovered. The most common predators were spiders, coccinellids, and chrysopids. Insects in the families Eriococcidae, Aphididae, and Thripidae were common herbivores on Lagerstroemia spp. Numerous phytophagous and mycophagous mites were also collected. These herbivores constitute a reservoir of alternative prey for generalist predators that may also feed on A. lagerstroemiae. A food web was constructed to illustrate direct and indirect effects of the predator community on A. lagerstroemiae in Texas. This approach should identify available niches whereby the release of natural enemies not occurring in Texas could lead to effective and sustainable biological control. In the second objective habitat variables associated with crapemyrtles, Lagerstroemia spp. were characterized. Data were analyzed using principal component analysis to create a reduced set of independent variables. The principal components were then included in a least squares stepwise multiple progression procedure to test for the influence of landscape composition on scale and select associated arthropod populations. Though some variables were statistically significant (p<0.05), no models had an adjusted R2 value greater than 0.10. In these minimal input landscapes where trees, turf, and hardscape represent the dominant habitat variables, landscape variables were not a strong predictor of A. lagerstroemiae populations or A. lagerstroemiae natural enemy populations, suggesting that manipulation of these parameters will have minimal effects on the abundances and distributions of these species. | en |
