First Record of \u3ci\u3eHippodamia variegata\u3c/i\u3e (Coleoptera: Coccinellidae) in Illinois, U.S.A., and Relation to Its Other Midwestern Collection Records

Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae) is an Afro-Eurasian lady beetle first discovered in North America near Montreal, Canada, in 1984. Subsequent records of H. variegata have occurred over a gradually expanding area radiating from the initial detection site and also include a disjunct record from British Columbia. Here, we report the first Illinois specimen of H. variegata, collected in 2004, and discuss this in relation to previous reports of H. variegata in North America

Non-target Effects of Clothianidin on Monarch Butterflies

Monarch butterflies (Danaus plexippus) frequently consume milkweed in and near agroecosystems and consequently may be exposed to pesticides like neonicotinoids. We conducted a dose response study to determine lethal and sublethal doses of clothianidin using a 36-h exposure scenario. We then quantified clothianidin levels found in milkweed leaves adjacent to maize fields. Toxicity assays revealed LC10, LC50, and LC90 values of 7.72, 15.63, and 30.70 ppb, respectively. Sublethal effects (larval size) were observed at 1 ppb. Contaminated milkweed plants had an average of 1.14 ±0.10 ppb clothianidin, with a maximum of 4 ppb in a single plant. This research suggests that clothianidin could function as a stressor to monarch populations

Detection of Predation Using qPCR: Effect of Prey Quantity, Elapsed Time, Chaser Diet, and Sample Preservation on Detectable Quantity of Prey DNA

Using quantitative PCR that amplified a prey-specific mtDNA 214 bp amplicon from the COI mitochondrial gene of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), prey eggs of known age and number were fed to larvae of the generalist predator lady beetle Coleomegilla maculata (De Geer) (Coleoptera: Coccinellidae), to elucidate the effects of time and diet since consumption, number of prey eggs, and methods for sample fixation and preservation, on the quantity of target DNA detected. Signal was strongly attenuated directly after cessation of feeding, even when predators were immediately frozen at -20°C. However, the quantity of target detected was significantly related to the number of eggs consumed and the time elapsed since eating. Decrease in detected prey DNA was consistent with a negative exponential model. The target DNA sequence disappeared from starved predators (quantitative half-life estimate of 59 min) more slowly than those fed potato aphids after consuming the target prey eggs (half-life estimate 16 min), whereas those fed C. maculata eggs as a chaser were intermediate in the rate at which they degraded the target prey DNA sequence. Fixative protocols are of critical importance in proper use of the qPCR technique. Among seven methods tested, storing the predator immediately in 70% ethanol prechilled to -20°C yielded the highest amount of target sequence, 22.8% of that recovered directly from a single intact prey egg. Samples frozen without solvent at -80°C and -20°C yielded only 6.0% and 2.3% of the target DNA respectively, and room temperature ethanol and ethylene glycol-based antifreeze averaged below 1% recovery of target DNA. Nevertheless, target prey was detected in more than 80% of antifreeze-stored predators. Predators killed and held at room temperature for 4 h or 5 days yielded no target prey DNA in 18 of 20 cases. These results emphasize both the value and the complexities of application of the qPCR technique to field predation studies

Crop Choice, Non-Target Pest Levels, Yield Loss and Their Effect on Insecticide Use in South Dakota

Agriculturally, South Dakota is a unique state possessing the highest rate of adoption for genetically modified crop varieties. In 2009 ninety-six percent of corn acres planted in South Dakota were genetically modified compared with eighty-five percent nationally (Economic Research Service). Additionally, South Dakota has seen a dramatic increase in the number of acres treated with insecticide over the past 20 years. These two situations taken together seem to be counterintuitive. Some genetically modified varieties, such as Bt corn, are equipped with genetic defenses so that they can protect the plant from target pests. Intuitively, one would expect to see a decrease in insecticide use as adoption of genetically modified varieties increase. Recent studies have found that there is a reduction in herbicides applied to herbicide tolerant varieties. Here in South Dakota, though, producers have expressed the opinion that the increase in insecticide use is the result of the emergence and spread of the soybean aphid in the state. This research seeks to address the underlying causes of the increase in insecticide use.Bt corn,GM crops,insecticide

Crop Choice, Non-Target Pest Levels, Yield Loss and Their Effect on Insecticide Use in South Dakota

Agriculturally, South Dakota is a unique state possessing the highest rate of adoption for genetically modified crop varieties. In 2009 ninety-six percent of corn acres planted in South Dakota were genetically modified compared with eighty-five percent nationally (Economic Research Service). Additionally, South Dakota has seen a dramatic increase in the number of acres treated with insecticide over the past 20 years. These two situations taken together seem to be counterintuitive. Some genetically modified varieties, such as Bt corn, are equipped with genetic defenses so that they can protect the plant from target pests. Intuitively, one would expect to see a decrease in insecticide use as adoption of genetically modified varieties increase. Recent studies have found that there is a reduction in herbicides applied to herbicide tolerant varieties. Here in South Dakota, though, producers have expressed the opinion that the increase in insecticide use is the result of the emergence and spread of the soybean aphid in the state. This research seeks to address the underlying causes of the increase in insecticide use.Bt corn, GM crops, insecticide, Agricultural and Food Policy, Crop Production/Industries, Q1, Q2, Q5,

The importance of dung beetles and arthropod communities on degradation of cattle dung pats in eastern South Dakota

Background Dung accumulation in rangelands can suppress plant growth, foul pastures, and increase pest pressure. Here, we describe the arthropod community of dung in eastern South Dakota, and quantify their contributions to dung degradation using an exclusion cage design. Methods Various arthropod community and degradation characteristics were measured in caged and uncaged dung pats over time in early and late summer. Results A total of 86,969 specimens were collected across 109 morphospecies (13 orders) of arthropods, and cages effectively reduced arthropod abundance, species richness, and diversity. Uncaged dung pats degraded significantly faster than the caged pats, with the largest difference occurring within 2 d of pat deposition. Dung organic matter was degraded more slowly (by 33–38 d) in the caged pats than where insects had free access to the pats. Although dung beetles only represented 1.5–3% of total arthropod abundance, they were significantly correlated to more abundant and complex total arthropod communities. Discussion A diverse community contributes to dung degradation in rangelands, and their early colonization is key to maximizing this ecosystem service

Extrapolating non-target risk of Bt crops from laboratory to field

The tiered approach to assessing ecological risk of insect-resistant transgenic crops assumes that lower tier laboratory studies, which expose surrogate non-target organisms to high doses of insecticidal proteins, can detect harmful effects that might be manifested in the field. To test this assumption, we performed meta-analyses comparing results for non-target invertebrates exposed to Bacillus thuringiensis (Bt) Cry proteins in laboratory studies with results derived from independent field studies examining effects on the abundance of non-target invertebrates. For Lepidopteran-active Cry proteins, laboratory studies correctly predicted the reduced field abundance of non-target Lepidoptera. However, laboratory studies incorporating tri-trophic interactions of Bt plants, herbivores and parasitoids were better correlated with the decreased field abundance of parasitoids than were direct-exposure assays. For predators, laboratory tri-trophic studies predicted reduced abundances that were not realized in field studies and thus overestimated ecological risk. Exposure to Coleopteran-active Cry proteins did not significantly reduce the laboratory survival or field abundance of any functional group examined. Our findings support the assumption that laboratory studies of transgenic insecticidal crops show effects that are either consistent with, or more conservative than, those found in field studies, with the important caveat that laboratory studies should explore all ecologically relevant routes of exposure

Broad Absorption Line Variability in Repeat Quasar Observations from the Sloan Digital Sky Survey

We present a time-variability analysis of 29 broad absorption line quasars (BALQSOs) observed in two epochs by the Sloan Digital Sky Survey (SDSS). These spectra are selected from a larger sample of BALQSOs with multiple observations by virtue of exhibiting a broad CIV $\lambda$1549 absorption trough separated from the rest frame of the associated emission peak by more than 3600 km s$^{-1}$. Detached troughs facilitate higher precision variability measurements, since the measurement of the absorption in these objects is not complicated by variation in the emission line flux. We have undertaken a statistical analysis of these detached-trough BALQSO spectra to explore the relationships between BAL features that are seen to vary and the dynamics of emission from the quasar central engine. We have measured variability within our sample, which includes three strongly variable BALs. We have also verified that the statistical behavior of the overall sample agrees with current model predictions and previous studies of BAL variability. Specifically, we observe that the strongest BAL variability occurs among the smallest equivalent width features and at velocities exceeding 12,000 km s$^{-1}$, as predicted by recent disk-wind modeling.Comment: 11 pages, 7 figures. Accepted for publication in Ap

Understanding and Enhancing Soil Biological Health: The Solution for Reversing Soil Degradation

Our objective is to provide an optimistic strategy for reversing soil degradation by increasing public and private research efforts to understand the role of soil biology, particularly microbiology, on the health of our world’s soils. We begin by defining soil quality/soil health (which we consider to be interchangeable terms), characterizing healthy soil resources, and relating the significance of soil health to agroecosystems and their functions. We examine how soil biology influences soil health and how biological properties and processes contribute to sustainability of agriculture and ecosystem services. We continue by examining what can be done to manipulate soil biology to: (i) increase nutrient availability for production of high yielding, high quality crops; (ii) protect crops from pests, pathogens, weeds; and (iii) manage other factors limiting production, provision of ecosystem services, and resilience to stresses like droughts. Next we look to the future by asking what needs to be known about soil biology that is not currently recognized or fully understood and how these needs could be addressed using emerging research tools. We conclude, based on our perceptions of how new knowledge regarding soil biology will help make agriculture more sustainable and productive, by recommending research emphases that should receive first priority through enhanced public and private research in order to reverse the trajectory toward global soil degradation