Metopolophium festucae cerealium (Hemiptera: Aphididae) : a new addition to the aphid fauna of North America

Metopolophium festucae cerealium (Stroyan) (Hemiptera: Aphididae) was found in wheat fields in the Pacific Northwest in 2011 and 2012. This is the first record of M. f. cerealium in North America. This subspecies can be a serious pest of cereal crops

Behavior of Neonate Diamondback Moth Larvae (Lepidoptera: Plutellidae) on Glossy-Leafed Resistant Brassica oleracea L

The dispersal and survival of neonate diamondback moth larvae, Plutella xylostella (L.), were measured on normal bloom susceptible ‘Round-Up' cabbage and a resistant genotype descended from glossy cauliflower, PI 234599. During the first 24 h after hatching, neonate P. xylostella dispersed more rapidly and initiated fewer mines on the resistant glossy 2518 than on ‘Round-Up'. Also, a greater proportion of neonates were found dead on 2518 than on ‘Round-Up'. Individual neonates had significantly higher movement rates on three glossy resistant genotypes of Brassica oleracea than on two normal bloom types. Movement rates were negatively correlated with percentage of larvae surviving to fourth instar. Removal of leaf epicuticular waxes with dichloromethane or disruption of the wax morphology eliminated the difference in movement rate on ‘Round-Up' and 8329, a glossy cabbage descended from PI 234599. Headspace vapor of 8329 or ‘Round-Up' plants did not affect movement rates of neonate P. xylostella. The results indicate that wax morphology is of primary importance in producing increased larval movement rates on glossy resistant lines. Wax chemistry may also contribute to the effect. Neonate nonpreference for leaf wax characteristics is proposed as the mechanism of resistance to P. xylastella in glossy B. olerace

Arthropod diversity in peas with normal or reduced waxy bloom

Crop traits can alter economically important interactions between plants, pests, and biological control agents. For example, a reduced waxy bloom on the surface of pea plants alters interactions between pea aphids and their natural enemies. In this study, we assess whether the effect of wax reduction extends beyond the 2 or 3 arthropod species closely associated with the plants and into the structure of the broader arthropod community of over 200 taxa at our site. We sampled arthropods on lines of peas with normal and reduced wax in Latah Co., Idaho using pitfall traps within randomly assigned pairs of 5 × 5 meter plots. During the 1998 and 1999 growing seasons, we collected 12,113 individual arthropods from 221 unambiguously identified morphospecies. The number of individuals collected from each morphospecies responded idiosyncratically to the reduced wax peas. To test whether arthropod community structure differed between the collections from plots having peas with normal or reduced wax, we performed a randomization test. The collection from peas with reduced wax had higher species evenness and thus higher community diversity despite having lower species richness. Our results demonstrate the potential of a single plant trait, epicuticular wax, to affect a community of arthropods. Two pests of peas had opposite responses to peas with reduced wax. The number of pea aphids collected was greater from peas with normal wax peas than those with reduced wax. In contrast, the number of pea leaf weevils collected was greater from peas with reduced wax

A SYSTEM FOR QUANTIFYING BEHAVIOR OF NEONATE CATERPILLARS AND OTHER SMALL, SLOW-MOVING ANIMALS

We have developed a system for recording and quantifying animal behavior on artificial or natural substrates. The system is designed for subjects such as insects and mites with movement rates as high as 4 cm/min. The principle is the same as in automatic stage or sphere centering devices (Berg 1971; Kramer 1976; Thiery and Visser 1986), but the compensations are made manually by an observer who may also simultaneously enter codes for specific behaviors on a microcomputer keypad. Data files produced are analyzed or plotted using programs in SAS® (SAS Institute 1985a) or similar data analysis package

The native bee fauna of the Palouse Prairie (Hymenoptera: Apoidea)

While synoptic collections provide data on the range and general composition of the North American bee fauna, bee communities associated with specific habitats are largely uncharacterized.  This report describes the community of native bees currently found in remnant fragments of the Palouse Prairie of northern Idaho and southeastern Washington State.  Native bees were collected using standardized collection techniques including blue vane traps, colored pan traps and aerial netting.  More than 13,000 individuals were collected, representing at least 174 species and 36 morphospecies in 29 genera.  These data provide the most thorough characterization of the bee fauna of this vulnerable ecosystem, as well as community level information on bee species of unknown conservation status.  These results are relevant to regional conservation efforts and, more broadly, are representative of conditions in fragmented grasslands surrounded by intense agriculture, a common global land use pattern of conservation concern

Two Types of Resistance to the Diamondback Moth (Lepidoptera: Plutellidae) in Cabbage

Survival of larvae of the diamondback moth, Plutella xylostella (L.) was reduced on several genotypes of cabbage from the breeding program at Geneva, N.Y. Polar fractions of ethanol extracts of partially resistant lines 2535 and 2503, when incorporated into diet, reduced survival of P. xylostella larvae by 14.9 and 19.0%, respectively. Whether this effect was due to reduced feeding or postingestive toxicity was not determined. Although survival on glossy-leafed line 2518 was very low in the field and larvae on this line failed to form visible feeding mines during the first 72 h after egg hatch, extracts from 2518 had no activity. Survival of larvae confined on leaf disks of 2518 in the laboratory was much greater (80% of controls) than it was on whole plants in the field (0.36% of controls). In the field, neonate P. xylostella dispersed two to three times more rapidly on the leaves of 2518 than on other lines. Resistance to P. xylostella in the lines investigated was therefore due to at least two mechanisms, (1) antibiosis or nonpreference due to extractable compounds present in normal bloom resistant cabbage genotypes, 2503 and 2535, and (2) possible nonpreference for glossy-leafed 2518 by neonate larvae, as suggested by the greater dispersal rates of neonates on these plants. Survival is relatively high on 2518 in leaf disk bioassays in the laboratory, suggesting that nonpreference in combination with environmental stresses to larvae in the field may produce P. xylostella resistance in the glossy 251

Going belowground: burying anthropomorphic biases on gustation and olfaction

Chemical signaling underpins behavioral interactions among organisms in the soil. Understanding chemical communication in the soil requires a paradigm shift in methodology and perspectives compared to aboveground ecosystems because olfaction and gustation, accepted modalities of chemosensation aboveground, may not accurately represent chemical communication in the soil. To fully understand chemical communication in the soil, it is essential to consider how soil properties, such as moisture, pH, and adsorption, affect the transport and perception of semiochemicals. De-anthropomorphizing the study of chemosensation can avoid potential biases, particularly in soil systems, where distinctions between olfaction and gustation are confounded by the heterogeneity of the soil environment and its effects on the mobility of chemical signals. In this perspective, we first explore how soil heterogeneity confounds the dichotomy between olfaction and gustation with hypothetical but ecologically relevant examples. Then we examine how anthropomorphic biases in aboveground chemical ecology have influenced soil chemical ecology. Our examples and discussion are prepared primarily in reference to soil arthropods. We conclude by discussing seven future research directions and outstanding questions. The soil is a premier example of a system where investigators should avoid anthropomorphisms when studying behavioral and chemical ecology. Research in soil chemical ecology should further efforts towards developing a unified view of chemosensation that could apply to all environments where chemical communication occurs

BOOTSTRAP ESTIMATION AND COMPARISON OF AN INDEX OF PHYLOGENETIC CORRELATION

A common objective of bioinformatic analyses is to assess the similarity of species, given a biological trait or characteristic. Phylogenetic correlation is one means to achieve this objective. Such measures provide a means to evaluate evolutionary models and history as well as having potential application to ecological relationships including host preference selection. Typically, these measurements are based on the deviation of an observed phylogeny from a Brownian evolutionary model. Statistical inference for this difference is assessed through likelihood ratio tests. These tests, in turn, rely on the assumption of a Normal likelihood within the phylogenetic trait. In addition, statistical comparison of estimated phylogenetic correlations between competing phylogenies or traits has not been addressed. In this paper, a bootstrap resampling methodology is proposed for two common phylogenetic correlation metrics, Pagel’s λ and Blomberg’s K. The underlying bootstrap distribution of the estimates will be utilized as a means of computing confidence limits as well as carrying out hypothesis testing. The method will be demonstrated using phylogenetic and metabolomic data related to the host specificity of an insect, Ceutorhynchus cardariae Korotyaev, on a wide range of Brassicaceae species

MODELING THE OCCURRENCE OF FOUR CEREAL CROP APHID SPECIES IN IDAHO

Idaho is ranked 5th in the United States in overall wheat production and makes over $500 million in profit annually from wheat. Many pests have detrimental effects on wheat; some of the most predominant ones are aphids. Four species of aphids having economic effects on wheat crops in Idaho are: Diuraphis noxia, Metopolophium dirhodum, Rhopalosiphum padi, Sitobion avenae. Predictive regression models could be useful for better understanding of the occurrence of these aphid species. Count data for the four species were collected over 17 years via suction traps at 12 locations in wheat fields throughout Idaho. Species specific nonlinear logistic growth models were fitted to each suction trap location to model the aphid accumulation process during the wheat growing season. The nonlinear model used was parameterized to provide inference on three main aphid characteristics, the onset of trapped aphid accumulation, the rate of increase in aphid accumulation, and the maximum accumulated abundance of trapped aphids. Suction trap locations were further aggregated into 5 environments using hierarchical clustering based on climate data. Species specific models were then fitted to each of the 5 environments. Within each environment, the maximum yearly aphid abundance was determined to have a lag (1) autocorrelation structure across years, indicating a biotic feedback. A full nonlinear logistic growth model was then fitted to the entire data set using dummy variable regression to investigate potential climatic environmental patterns in the aphid accumulation process. Predicted models were validated both externally and internally. External validation used suction trap locations in Idaho that were excluded from the model building process to assess the predictive capabilities of the specified models. Internal validation was conducted using bootstrap simulation of the residuals for each model. Statistical models similar to those developed in this study can aid in understanding and evaluating the dynamics of the abundance of cereal crop aphid species in Idaho

Evidence for \u3cem\u3eBombus Occidentalis\u3c/em\u3e (Hymenoptera: Apidae) Populations in the Olympic Peninsula, the Palouse Prairie, and Forests of Northern Idaho

Since the mid-1990s, Bombus occidentalis (Green) has declined from being one of the most common to one of the rarest bumble bee species in the Pacific Northwest of the United States. Although its conservation status is unresolved, a petition to list this species as endangered or threatened was recently submitted to the U.S. Fish and Wildlife Service. To shed light on the conservation situation and inform the U.S. Fish and Wildlife Service decision, we report on the detection and abundance of B. occidentalis following bumble bee collection between 2012 and 2014 across the Pacific Northwest. Collection occurred from the San Juan Islands and Olympic peninsula east to northern Idaho and northeastern Oregon, excluding the arid region in central Washington. B. occidentalis was observed at 23 collection sites out of a total of 234. With the exception of three sites on the Olympic peninsula, all of these were in the southeastern portion of the collection range