Evaluation of Economic Injury Level, Biological Control, and Host Plant Resistance for Soybean Aphid in NY

Objectives: 1. Evaluate soybean yield loss at different aphid densities in a field cage experiment and in field surveys in order to define an economic injury level (EIL) for New York. 2. Conduct a survey of soybean variety trials to determine relative abundance and yield impacts of soybean aphid, Aphis glycines Matsumura on commonly grown soybean varieties in New York. Soybean rust, Phakopsora pachyrhizi , will also be surveyed for detection. 3. Survey natural enemies (predators, parasitoids and fungal pathogens) affecting soybean aphid in New York State. Evaluate the importance of these natural enemies (especially fungal epizootics) for controlling soybean aphids while soybean plants grow and soybeans develop. 4. Enhance cooperative extension outreach efforts, communication, networking, regarding soybean aphid, optimize rapid and early detection of this exotic pest: Continue to increase awareness of soybean aphid and its importance to NY field personnel (producers, crop consultants, agricultural industry, field crop extension educators). Utilize electronic technology and traditional approaches to strengthen timely communication and convey survey activities and findings to Northeast region clientele, and other stakeholders. 5. Share survey findings with appropriate soybean IPM workers in the Northeast and north central US (Northeast IPM and NC 502), state and federal agencies (USDA National Agricultural Pest Information System (NAPIS), USDA Cooperative Agricultural Pest Survey (CAPS), and USDA Animal Plant Health Inspection Service (APHIS))

Oviposition preference and larval performance of monarch butterflies (Danaus plexippus) on two invasive swallow-wort species

Abstract The potential of two invasive herbaceous vines Vincetoxicum nigrum (L.) Moench and Vincetoxicum rossicum (Kleopow) Barbar. (Asclepiadaceae) to reduce monarch butterfly ( Danaus plexippus L.) (Lepidoptera: Nymphalidae, Danainae) populations was investigated by evaluating oviposition selection in adult monarch butterflies and larval feeding preference in choice tests comparing the native host plant of monarch butterflies, Asclepias syriaca L. (Asclepiadaceae) and the two non-indigenous Vincetoxicum species. In both choice and no-choice tests, no eggs were oviposited on either of the two Vincetoxicum species whereas over 66 eggs per female were oviposited on A. syriaca plants. All first instar larvae allowed to feed on A. syriaca for 48 h survived while a significantly lower proportion survived on V. rossicum (44%) and V. nigrum (14%). Mean weight of larvae that did survive on the Vincetoxicum species was significantly lower than the mean weight of larvae that fed on A. syriaca . The mean weight of surviving larvae, however, did not differ between the two Vincetoxicum species. The mean proportion of leaves consumed by larvae feeding on A. syriaca was significantly greater than the mean proportion of leaves consumed by larvae feeding on either Vincetoxicum species. Findings from this research indicate that V. rossicum and V. nigrum are not viable hosts of monarch butterflies and are likely to pose little direct threat to their populations as oviposition sinks. The ability of these highly aggressive plants, however, to out-compete and displace the native host of monarchs, A. syriaca , may pose a more serious threat. The potential of monarch populations to adapt to the two Vincetoxicum species as host plants over the long-term is discussed

The Mars Science Laboratory Touchdown Test Facility

In the Touchdown Test Program for the Mars Science Laboratory (MSL) mission, a facility was developed to use a full-scale rover vehicle and an overhead winch system to replicate the Skycrane landing event

Habitat Persistence Underlies Intraspecific Variation in the Dispersal Strategies of Planthoppers

Dispersal is considered a vital life history characteristic for insects exploiting temporary habitats, and life history theorists have often hypothesized an inverse relationship between dispersal capability and habitat persistence. Most often, this hypothesis has been tested using interspecific comparisons of dispersal capability and qualitative estimates of habitat persistence. Consequently, most assessments have failed to control for possible phylogenetic nonindependence and they also lack quantitative rigor. We capitalized on existing intraspecific variation on the dispersal capability of Prokelisia planthoppers to examine the relationship between habitat persistence and dispersal, thereby minimizing possible phylogenetic effects. Two congeneric species (Prokelisia marginata and P. dolus) occur in the intertidal marshes of North America, where they feed exclusively on cordgrasses (Spartina). Because these planthoppers exhibit wing dimorphism, flight-capable adults (macropters with fully developed wings). Thus, dispersal capability can be readily estimated by the percentage of macropters in a population. At a regional spatial scale, we found a highly significant negative relationship between dispersal capability (present macroptery) and habitat persistence. In this system, habitat persistence is influenced by a combination of marsh elevation, winter severity, and tidal range, which interact to determine the ability of planthoppers to endure through winter in their primary habitat for development. P. marginata develops primarily in low-marsh habitats during summer, habitats that can be subjected to pronounced winter disturbance due to ice scouring and/or extensive tidal inundation. Levels of winter disturbance of the low marsh are extreme along the Atlantic coast, intermediate along the Pacific, and low along the Gulf. Both the failure of P. marginata populations to remain through winter in the habitat, and the dispersal ability of these populations (92%, 29%, and 17% macroptery, respectively), are correlated with levels of disturbance. Thus, in regions where winter disturbance is high, levels of dispersal are correspondingly high to allow for recolonization of extirpated habitats from overwintering sites on the high marsh. Unlike P. marginata, P. dolus develops primarily in high-marsh habitats, which are much less disturbed on all coasts during winter. Consequently, this species remains year-round in its primary habitat for development, and most populations exhibit relatively low levels of macroptery (\u3c10%). When raised under common garden conditions, many more macropters of both species were produced from Atlantic compared to Gulf populations. Thus the proportion of macropters produced from the populations used in this experiment paralleled the incidence of macroptery measured in the field, providing evidence that the geographic variation in dispersal capability in both species has in part a genetic basis. The results of this study provide strong intraspecific evidence for an inverse relationship between the dispersal capability of insects and the persistence of their habitats

An aluminum resist substrate for microfabrication by LIGA.

Resist substrates used in the LIGA process must provide high initial bond strength between the substrate and resist, little degradation of the bond strength during x-ray exposure, acceptable undercut rates during development, and a surface enabling good electrodeposition of metals. Additionally, they should produce little fluorescence radiation and give small secondary doses in bright regions of the resist at the substrate interface. To develop a new substrate satisfying all these requirements, we have investigated secondary resist doses due to electrons and fluorescence, resist adhesion before exposure, loss of fine features during extended development, and the nucleation and adhesion of electrodeposits for various substrate materials. The result of these studies is a new anodized aluminum substrate and accompanying methods for resist bonding and electrodeposition. We demonstrate successful use of this substrate through all process steps and establish its capabilities via the fabrication of isolated resist features down to 6 {micro}m, feature aspect ratios up to 280 and electroformed nickel structures at heights of 190 to 1400 {micro}m. The minimum mask absorber thickness required for this new substrate ranges from 7 to 15 {micro}m depending on the resist thickness

Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

Agricultural landscape simplification reduces natural pest control: A quantitative synthesis

Numerous studies show that landscape simplification reduces abundance and diversity of natural enemies in agroecosystems, but its effect on natural pest control remains poorly quantified. Further, natural enemy impacts on pest populations have usually been estimated for a limited number of taxa and have not considered interactions among predator species. In a quantitative synthesis with data collected from several cropping systems in Europe and North America, we analyzed how the level and within-field spatial stability of natural pest control services was related to the simplification of the surrounding landscape. All studies used aphids as a model species and exclusion cages to measure aphid pest control. Landscape simplification was quantified by the proportion of cultivated land within a 1 km radius around each plot. We found a consistent negative effect of landscape simplification on the level of natural pest control, despite interactions among enemies. Average level of pest control was 46% lower in homogeneous landscapes dominated by cultivated land, as compared with more complex landscapes. Landscape simplification did not affect the amount of positive or negative interactions among ground-dwelling and vegetation-dwelling predators, or the within-field stability of pest control. Our synthesis demonstrates that agricultural intensification through landscape simplification has negative effects on the level of natural pest control with important implications for management to maintain and enhance ecosystem services in agricultural landscapes. Specifically, preserving and restoring semi-natural habitats emerges as a fundamental first step to maintain and enhance pest control services provided by predatory arthropods to agriculture

Ecological traits predict population changes in moths

© 2019 The Authors Understanding the ecological traits which predispose species to local or global extinction allows for more effective pre-emptive conservation management interventions. Insect population declines are a major facet of the global biodiversity crisis, yet even in Europe they remain poorly understood. Here we identify traits linked to population trends in ‘common and widespread’ UK moths. Population trend data from the Rothamsted Research Insect Survey spanning 40 years was subject to classification and regression models to identify common traits among species experiencing a significant change in occurrence. Our final model had an accuracy of 76% and managed to predict declining species on 90% of occasions, but was less successful with increasing species. By far the most powerful predictor associated for declines was moth wingspan with large species declining more frequently. Preference for woody or herbaceous larval food sources, nocturnal photoperiod activity, and richness of habitats occupied also proved to be significantly associated with decline. Our results suggest that ecological traits can be reliably used to predict declines in moths, and that this model could be used for Data Deficient species, of which there are many

The harlequin ladybird, Harmonia axyridis: global perspectives on invasion history and ecology

The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is native to Asia but has been intentionally introduced to many countries as a biological control agent of pest insects. In numerous countries, however, it has been introduced unintentionally. The dramatic spread of H. axyridis within many countries has been met with considerable trepidation. It is a generalist top predator, able to thrive in many habitats and across wide climatic conditions. It poses a threat to biodiversity, particularly aphidophagous insects, through competition and predation, and in many countries adverse effects have been reported on other species, particularly coccinellids. However, the patterns are not consistent around the world and seem to be affected by many factors including landscape and climate. Research on H. axyridis has provided detailed insights into invasion biology from broad patterns and processes to approaches in surveillance and monitoring. An impressive number of studies on this alien species have provided mechanistic evidence alongside models explaining large-scale patterns and processes. The involvement of citizens in monitoring this species in a number of countries around the world is inspiring and has provided data on scales that would be otherwise unachievable. Harmonia axyridis has successfully been used as a model invasive alien species and has been the inspiration for global collaborations at various scales. There is considerable scope to expand the research and associated collaborations, particularly to increase the breadth of parallel studies conducted in the native and invaded regions. Indeed a qualitative comparison of biological traits across the native and invaded range suggests that there are differences which ultimately could influence the population dynamics of this invader. Here we provide an overview of the invasion history and ecology of H. axyridis globally with consideration of future research perspectives. We reflect broadly on the contributions of such research to our understanding of invasion biology while also informing policy and people