Parasitism and Predation on Sentinel Egg Masses of Three Stink Bug Species (Hemiptera: Pentatomidae) in Native and Exotic Ornamental Landscapes.

This study evaluated parasitism and predation on sentinel egg masses of three stink bug species, the spined soldier bug, Podisus maculiventris (Say), the brown stink bug, Euschistus servus (Say), and the invasive brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), in ornamental landscapes composed of either native or exotic plants. This study also compared the species composition of parasitoids attacking two native stink bug species (P. maculiventris and E.

The detectability half-life in arthropod predator-prey research: what it is, why we need it, how to measure it, and how to use it.

Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Most assays produce only qualitative results, with each predator testing either positive or negative for target prey remains. Nevertheless, they have yielded important insights into community processes.

Removing external DNA contamination from arthropod predators destined for molecular gut-content analysis.

Ecological research requires large samples for statistical validity, typically hundreds or thousands of individuals, which are most efficiently gathered by mass-collecting techniques. For the study of interspecific interactions, molecular gut-content analysis enables detection of arthropod predation with minimal disruption of community interactions. Field experiments have demonstrated that standard mass-collection methods, such as sweep netting, vacuum sampling and foliage beating, sometimes lead to contamination of predators with nontarget DNA, thereby compromising resultant gut-content data.

Barcode haplotype variation in north American agroecosystem lady beetles (Coleoptera: Coccinellidae).

DNA barcodes have proven invaluable in identifying and distinguishing insect pests, most notably for determining the provenance of exotic invasives, but relatively few insect natural enemies have been barcoded. We used Folmer et al.'s (1994) universal invertebrate primers and Hebert et al.

Unnecessary roughness? Testing the hypothesis that predators destined for molecular gut-content analysis must be hand-collected to avoid cross-contamination.

Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Mass-collection methods, such as sweep-netting, vacuum sampling and foliage beating, could lead to regurgitation or rupturing of predators along with uneaten prey, thereby contaminating specimens and compromising resultant gut-content data. Proponents of this 'cross-contamination hypothesis' advocate hand-collection as the best way to avoid cross-contamination.

Tracking the role of alternative prey in soybean aphid predation by Orius insidiosus: a molecular approach.

The soybean aphid, Aphis glycines (Hemiptera: Aphididae), is a pest of soybeans in Asia, and in recent years has caused extensive damage to soybeans in North America. Within these agroecosystems, generalist predators form an important component of the assemblage of natural enemies, and can exert significant pressure on prey populations. These food webs are complex and molecular gut-content analyses offer nondisruptive approaches for examining trophic linkages in the field.

Molecular markers for identification of the hyperparasitoids and in parasitizing cereal aphids.

Polymerase chain reaction (PCR)-based molecular markers have been developed to detect the presence of primary parasitoids in cereal aphids and used to estimate primary parasitism rates. However, the presence of secondary parasitoids (hyperparasitoids) may lead to underestimates of primary parasitism rates based on PCR markers. This is because even though they kill the primary parasitoid, it's DNA can still be amplified, leading to an erroneous interpretation of a positive result.

Prey preference and host suitability of the predatory and parasitoid carabid beetle, Lebia grandis, for several species of Leptinotarsa beetles.

Lebia grandis (Coleoptera: Carabidae), recorded as a parasitoid only on Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), is capable of parasitizing the false potato beetle, L. juncta, and also L. haldemani.

Overlapping confidence intervals or standard error intervals: what do they mean in terms of statistical significance?

We investigate the procedure of checking for overlap between confidence intervals or standard error intervals to draw conclusions regarding hypotheses about differences between population parameters. Mathematical expressions and algebraic manipulations are given, and computer simulations are performed to assess the usefulness of confidence and standard error intervals in this manner. We make recommendations for their use in situations in which standard tests of hypotheses do not exist.

Determinants of web spider species diversity: Vegetation structural diversity vs. prey availability.

The hypotheses that vegetation structural diversity and prey availability determine alpha diversity were examined for scrub- and meadow-inhabiting web spider species assemblages along elevational gradients in Costa Rica and California. Prey availabilities were estimated by sticky trap catches, using only the orders and size classes of insects actually captured by the spiders. The measured component of vegetation structural diversity was the maximum tip height in 20 cm increments from 0 to 2.

Site-specificity and site tenacity in a wolf spider: A serological dietary analysis.

The wolf spider Pardosa ramulosa is a dietary specialist on aquatic insects. Site tenacity of this species was determined by serological analysis of spiders collected on the margins of and at known distances from each of eight closely-spaced pools whose prey compositions were known. Remains of a mosquito species found uniquely in three of these pools were found only in spiders closely associated with them, despite the presence of otherwise suitable pools less than 10 m away.