Spider Community Composition and Structure In A Shrub-Steppe Ecosystem: The Effects of Prey Availability and Shrub Architecture

Habitat structure is an important driver of many ecological patterns and processes, but few studies investigate whether habitat structure interacts with other environmental variables to affect community dynamics. The main objective of this study was to disentangle the relative importance of prey availability and shrub architecture on the distribution, abundance, and biodiversity of spiders of northern Utah, USA. We conducted field experiments which focused on: (1) describing the importance of these factors on spider community organization, (2) specifically evaluating whether prey availability mediates the relationship between shrub architecture and spider abundance and biodiversity, and (3) investigating spider and prey responses to manipulations of surrounding vegetation structures. For the first two experiments, big sagebrush shrubs were randomly assigned to six experimental treatments: two levels of prey attractant (shrubs were either baited or not baited) and three levels of foliage density (low, natural/control, or high). The purpose of manipulating both prey availability and shrub architecture was to delineate their significance to spiders. For the last experiment, changes in these factors were investigated at two different levels of spatial context (a single manipulated shrub surrounded by untreated shrubs vs. a manipulated shrub surrounded by a patch of similarly treated shrubs). We found both prey availability and shrub architecture directly influenced patterns of spider abundance and species richness and that spider species diversity and community composition varied in response to shrub architecture alone. Preferences of some spiders for certain shrub types likely reflect differences in foraging strategies or the substrate required to support different types of webs. We also demonstrate that spider response to shrub architecture is the result of multiple processes (i.e., a combination of direct and indirect effects via prey availability) and that surrounding vegetation structures affect spider abundances on shrubs. In addition, prey composition varied among different shrub foliage density treatments, but only when surrounding vegetation structures were also manipulated. More generally, this study suggests that ecological responses to habitat structure are in part mediated by associated variables and the significance of shrub architecture varies depending on the organisms examined and the spatial scale to which they respond most strongly

Quagga Mussel and Zebra Mussel

Quagga mussel and zebra mussel can cause significant ecological, economical, and recreational impacts. This fact sheet describes these two-sided mollusks and reviews impacts, monitoring, and management of these invasive species

Spotted Lanternfly [Lycorma delicatula (White)]

This fact sheet describes spotted lanternfly, an invasive planthopper that is native to China and first detected in the U.S. in 2014. It includes information on plant hosts, damage symptoms, life history, monitoring, and management

Asian Longhorned Beetle

Asian longhorned beetle (ALB) is a large wood-boring pest that threatens maple and other North American hardwood tree species. This fact sheet describes its life stages, plant hosts, damage symptoms, and monitoring, prevention, and management

Lily Leaf Beetle

The lily leaf beetle (LLB) (Coleoptera: Chrysomelidae) is an important pest from Eurasia that threatens native and cultivated true lilies (Lilium spp.) and fritillaries (Fritillaria spp.). It is also known as the red lily leaf beetle or scarlet lily beetle. LLB was first reported in North America in Montréal, Canada, in 1945 and in the U.S. in 1992 in Massachusetts, likely arriving via European shipments of lily bulbs. LLB has been detected in nine of the 10 Canadian provinces and 14 U.S. states, including the New England states, Pennsylvania, Wisconsin, Minnesota, and Washington (EDDMapS, 2021). Based on LLB’s native distribution and habitat suitability, it is likely capable of establishing throughout most of the U.S. where plants in the Liliaceae family occur (Freeman et al., 2020), which includes Utah. In its native range, LLB outbreaks are rare, but significant losses to lily crops are currently occurring where LLB has been introduced, including the Netherlands and Great Britain. This fact sheet includes a description of LLB and provides reliable information on plant hosts, damage symptoms, life cycle, monitoring, and management

Spongy Moth (Lymantria dispar dispar Linnaeus)

Spongy moths (Lepidoptera: Erebidae) are invasive leaf-eating (defoliating) pests that threaten trees and shrubs in urban, suburban, and rural landscapes. The spongy moth was accidentally introduced to the U.S. in 1869 by an amateur French entomologist in Massachusetts who sought to establish a hardier American silkworm industry. These moths now commonly occur in the northeastern U.S. and are also found in parts of Illinois, Indiana, Michigan, Minnesota, North Carolina, Ohio, Virginia, West Virginia, Wisconsin, California, Oregon, and Washington. In Utah, according to the Utah Department of Agriculture and Food (2021), the spongy moth is anticipated to survive and multiply rapidly if populations become established. This pest was first detected in Utah in1988 in monitoring traps and was quickly eradicated via extensive trapping and spray applications of Bacillus thuringiensis kurstaki (Btk), a naturally occurring bacterium. Since that time, additional specimens have been detected and eradicated, most recently in 2016 (1 moth) and 2020 (1 moth). This fact sheet describes this pest, its hosts, life stages and history, damage symptoms, and management

European Cherry Fruit Fly Rhagoletis cerasi (Linnaeus)

European cherry fruit fly (ECFF) is a new invasive cherry-infesting pest from Europe. It was first detected in the U.S. in New York in 2017. This fact sheet describes it and includes life history, plant hosts, damage symptoms, monitoring, and management

Small Hive Beetle [Aethina tumida (Murray)]

Small hive beetle (SHB) is an exotic pest of honey and bumble bee colonies that is native to Africa. SHB feeds on pollen and honey, kills bee brood and workers, and causes honey to discolor and ferment. This pest is now found throughout much of the U.S. with highest infestations occurring in the Southeast. It was first detected in Utah in 2016 and is now confirmed in Washington and Davis counties. Infestations can be prevented by early detection, using good husbandry techniques, maintaining a high ratio of bees to comb, and keeping hives in partial to full sun. Chemical control options for SHB are limited due to toxicity to bees. Coumaphos strips placed in the bottom of the hive can reduce infestations

Asian Giant Hornet (Vespa mandarinia Smith)

This fact sheet describes Asian giant hornet and reviews similar-looking insects, its life cycle, predatory strategies, monitoring and management, and the related public health concerns

Imported Fire Ants

Imported fire ants (Order Hymenoptera, Family Formicidae) (IFA) are social insects representing two South American ant species: the red imported fire ant (Solenopsis invicta Buren) and black imported fire ant (Solenopsis richteri Forel), along with their hybrid offspring. IFA are native to South America, where their colonies are kept in check by native competitors, predators, and parasites. However, they have invaded other countries, including Australia, New Zealand, and the U.S., causing agricultural, ecological, economical, nuisance, and public health problems, which are described in more detail in this fact sheet. Management is also addressed