General science-technology orientation, specific benefit-risk assessment frame, and public acceptance of gene drive biotechnology.

With limited understanding of most new biotechnologies, how do citizens form their opinion and what factors influence their attitudes about these innovations? In this study, we use gene drive biotechnology in agricultural pest management as an example and theoretically propose that given low levels of knowledge and awareness, citizens' acceptance of, or opposition to, gene drive is significantly shaped by two predisposition factors: individuals' general orientation toward science and technology, and their specific benefit-risk assessment frame. Empirically, we employ data collected from a recent US nationally representative public opinion survey (N = 1220) and conduct statistical analyses to test the hypotheses derived from our theoretical expectations. Our statistical analyses, based on various model specifications and controlling for individual-level covariates and state-fixed effects, show that citizens with a more favorable general orientation toward science and technology are more likely to accept gene drive. Our data analyses also demonstrate that citizens' specific gene drive assessment frame-consisting of a potential benefit dimension and a potential risk dimension, significantly shapes their attitudes as well-specifically, people emphasizing more on the benefit dimension are more likely to accept gene drive, whereas those who place more importance on the risk dimension tend to oppose it. We discuss contributions of our study and make suggestions for future research in the conclusion.

A comparative evaluation of northern and southern Ixodes scapularis questing height and hiding behaviour in the USA.

Ticks display a distinct type of host-seeking behaviour called questing. It has been proposed that the questing behaviour of Ixodes scapularis explains the geographic variation in Lyme disease (LD) risk in the eastern USA because the northern population has been shown to quest more often than the southern population. The height at which questing occurs is variable and this study aimed to characterize questing height for I. scapularis. Ticks were collected from a northern and southern state (i.e. Maryland and Texas) and bioassays were conducted. We report that nymphs from Texas quested at lower heights compared to nymphs from Maryland. In addition, only Texas nymphs exhibited a behaviour we call 'hiding behaviour'. These results may reflect the different composition of hosts between these two areas as the south has a higher abundance of lizards. In contrast, there was no significant difference in questing height between Maryland adults and Texas adults which was to be expected since adults are feeding on white-tailed deer in both locations. If all southern I. scapularis nymphs are questing at lower heights, this might make them less likely to come into contact with humans and this may be contributing to the geographical difference in LD prevalence.

Coronary Revascularization in Chronic and End-Stage Renal Disease: A Systematic Review and Meta-analysis.

Patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) on dialysis have an increased risk for cardiovascular mortality and morbidity secondary to occlusive coronary artery disease. Optimal revascularization strategy is unclear in this high-risk population. We have performed a meta-analysis to compare coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) in patients with ESRD and CKD. We searched PubMed, Ovid, MEDLINE, CINAHL, and EMBASE (1980-2013) and found 17 trials (N = 33,584) in the ESRD arm and 6 studies (n = 15,493) in the CKD arm. Two investigators independently collected the data. All the studies were retrospective trials. In the ESRD and CKD groups, we found significantly reduced early mortality with the PCI group with the odds ratio of 2.08 (1.90-2.26; P < 0.00001) and 2.55 (1.45-4.51; P = 0.001), respectively. Contrary to the early mortality results, we found decreased late mortality with the CABG group when compared with the PCI group [odds ratio: 0.86 (0.83-0.89; P < 0.000001) and 0.82 (0.76-0.88; P < 0.00001)] in the ESRD and CKD arm, respectively. When compared with PCI, there was decreased cardiovascular mortality with an odds ratio of 0.61 (0.40-0.92; P = 0.02) in patients who underwent CABG in ESRD population. Similar trends were observed in the incidence of myocardial infarction and repeat revascularization. There is a strong trend for decreased risk of stroke with PCI when compared with CABG in ESRD and CKD populations.

TRANSLATING ECOLOGY, PHYSIOLOGY, BIOCHEMISTRY, AND POPULATION GENETICS RESEARCH TO MEET THE CHALLENGE OF TICK AND TICK-BORNE DISEASES IN NORTH AMERICA.

Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks.

Determination of Growth Stage-Specific Response of Soybean to Redbanded Stink Bug (Hemiptera: Pentatomidae) and its Relationship to the Development of Flat Pods.

The redbanded stink bug, Piezodorus guildinii Westwood (Hemiptera: Pentatomidae), has recently emerged as a serious pest of soybean in the southern United States. Field cage studies were conducted to determine the response of R2 to R6 stage soybean to P. guildinii infestation. Soybean at R2 to R6 stages was infested with zero, one, two, and four P. guildinii adults per 0.3 m for 10 d using cylindrical wire mesh cages. Plant response was measured in terms of number of flat pods, seed yield, test weight, and number of seeds per pod. Results from a 2012 study showed significant yield reduction in response to P. guildinii infestations during the R3 to R6 stages. While results from a similar 2013 study showed a significant yield reduction only when R5 and R6 stage soybean were infested. Decrease in yield was owing to the combination of reduced seed weight and increased numbers of flat pods as a result of P. guildinii infestation. In addition, a field experiment was conducted to determine if flat pods are localized to the regions of P. guildinii feeding. Adults were confined to certain portions of plants (bottom, top, and both) using specially designed cages isolating these portions of the plants. Results from this experiment showed a significantly higher percentage of flat pods on plant portions infested with P. guildinii than those kept free of P. guildinii infestation, indicating that flat pods are the result of direct P. guildinii damage and are localized to the area of P. guildinii feeding.

Redbanded Stink Bug (Hemiptera: Pentatomidae) Infestation and Occurrence of Delayed Maturity in Soybean.

Studies done in Brazilian soybean, Glycine max (L.) Merril, in the 1970s suggested the redbanded stink bug, Piezodorus guildinii (Westwood), is principally responsible for delayed maturity in this crop. This stink bug species has recently emerged as a serious pest of soybean in the southern United States, where little is known about its association with the occurrence of delayed maturity disorder. Also, the mechanism behind stink bug-induced soybean delayed maturity remains unknown. It is believed that stink bug feeding during pod development stages results in reduced pod-seed load, causing alteration of source-sink ratio and eventually delayed maturity. To determine the P. guildinii threshold triggering delayed maturity in soybean, experiments were conducted with varying levels of P. guildinii infestation (0, 2, 4, and 8 adults per 0.3 m) during the R4 to R5 soybean growth stages. In addition, to determine if soybean delayed maturity is exclusively because of reduced pod load, experiments with different levels of mechanical pod removal (0, 25, 50, and 75%) were conducted on field-grown soybeans. P. guildinii densities up to 4 adults per 0.3 m did not trigger occurrence of delayed maturity. However, a density of 8 adults per 0.3 m produced a significant increase in the number of green leaves retained on plants at maturity (i.e., delayed maturity). There was no effect of mechanical pod removal on green leaf retention. The lack of a significant positive correlation between mechanical pod removal and green leaf retention indicates the involvement of mechanism(s) other than reduced pod load in the occurrence of soybean delayed maturity.

The actin cytoskeleton organization and disorganization properties of the photosynthetic dinoflagellate Symbiodinium kawagutii in culture.

The actin cytoskeleton organization in symbiotic marine dinoflagellates is largely undescribed; most likely, due to their intense pigment autofluorescence and cell walls that block fluorescent probe access. Using a freeze-fracture and fixation procedure, we observed the actin cytoskeleton of Symbiodinium kawagutii cultured in vitro with fluorescently labeled phalloidin and by indirect immunofluorescence with monoclonal antibodies specific for actin. The cytoskeleton appeared as an organized network with interconnected cortical and cytoplasmic thick filaments, along with some intertwined fine filaments. It showed a grid-type, reticular pattern organized in a lattice-like structure within the cell and throughout the cytoplasm. This organization was similar when the observations were done with either fluorescein isothiocyanate (FITC)-phalloidin or anti-actin, although the latter showed a more evenly distributed fluorescence characteristic of nonpolymerized actin. The network organization collapsed upon treatment with latrunculin, resulting in bright foci and diffuse fluorescence. A similar effect was obtained upon butanedione monoxime treatment, except that no bright foci were observed. We have been able to successfully visualize the actin cytoskeleton of S. kawagutii cells using fluorescence-based procedures. This is the first report on the visualization of the organization of the actin cytoskeleton under various conditions in these walled, highly autofluorescent cells.

Lagrangian modelling of oil concentrations at sea: A sensitivity analysis to the grid resolution and number of Lagrangian elements.

This paper presents a novel method to select the optimal combination of grid resolution and number of Lagrangian elements (LEs) required in numerical modelling of oil concentrations at sea. A sensitivity analysis in terms of grid resolution and the number of LEs, was carried out to understand the uncertainty that these user-dependent parameters introduce in the numerical results. A dataset of 211,200 simulations performed under 400 metocean patterns, 6 initial volumes, 11 grid resolutions, and different numbers of LEs (100 to 500,000), was used to analyze the sensitivity of the model along different Thresholds of Concern. Results show the importance of a correct selection of the number of LEs and the grid resolution in Lagrangian modelling of surface oil concentrations. The method proposed will allow selecting the optimal combination of these parameters to find an optimal balance between the accuracy and the computational cost of the simulation.

Preparation of a Molecularly Imprinted Polymer on Polyethylene Terephthalate Platform Using Reversible Addition-Fragmentation Chain Transfer Polymerization for Tartrazine Analysis via Smartphone.

This work describes the preparation of a molecularly imprinted polymer (MIP) platform on polyethylene terephthalate (MIP-PET) via RAFT polymerization for analyzing tartrazine using a smartphone. The MIP-PET platform was characterized using Fourier transform infrared (FTIR) techniques, Raman Spectroscopy, X-ray photoelectron spectroscopy (XPS), and confocal microscopy. The optimal pH and adsorption time conditions were determined. The adsorption capacity of the MIP-PET plates with RAFT treatment (0.057 mg cm-2) was higher than that of the untreated plates (0.028 mg cm-2). The kinetic study revealed a pseudo-first-order model with intraparticle diffusion, while the isotherm study indicated a fit for the Freundlich model. Additionally, the MIP-PET demonstrated durability by maintaining its adsorption capacity over five cycles of reuse without significant loss. To quantify tartrazine, images were captured using a smartphone, and the RGB values were obtained using the ImageJ® free program. A partial least squares regression (PLS) was performed, obtaining a linear range of 0 to 7 mg L-1 of tartrazine. The accuracy of the method was 99.4% (4.97 ± 0.74 mg L-1) for 10 samples of 5 mg L-1. The concentration of tartrazine was determined in two local soft drinks (14.1 mg L-1 and 16.5 mg L-1), with results comparable to the UV-visible spectrophotometric method.

The PsbO homolog from Symbiodinium kawagutii (Dinophyceae) characterized using biochemical and molecular methods.

A photosystem II component, the PsbO protein is essential for maximum rates of oxygen production during photosynthesis, and has been extensively characterized in plants and cyanobacteria but not in symbiotic dinoflagellates. Its close interaction with D1 protein has important environmental implications since D1 has been identified as the primary site of damage in endosymbiotic dinoflagellates after thermal stress. We identified and biochemically characterized the PsbO homolog from Symbiodinium kawagutii as a 28-kDa protein, and immunolocalized it to chloroplast membranes. Chloroplast association was further confirmed by western blot on photosynthetic membrane preparations. TX-114 phase partitioning, chromatography, and SDS-PAGE for single band separation and partial peptide sequencing yielded peptides identical or with high identity to PsbO from dinoflagellates. Analysis of a cDNA library revealed three genes differing by only one aminoacid residue in the in silico-translated ORFs despite greater differences at nucleotide level in the untranslated, putative regulatory sequences. The consensus full amino acid sequence displayed all the characteristic domains and features of PsbO from other sources, but changes in functionally critical, highly conserved motifs were detected. Our biochemical, molecular, and immunolocalization data led to the conclusion that the 28-kDa protein from S. kawagutii is the PsbO homolog, thereby named SkPsbO. We discuss the implications of critical amino acid substitutions for a putative regulatory role of this protein.

On-capillary fluorescent labeling and capillary electrophoresis laser-induced fluorescence analysis of glycoforms of intact prostate-specific antigen.

The test used in clinics as prostate cancer (PCa) biomarker, based on the concentration of the glycoprotein prostate-specific antigen (PSA) in serum, leads to an elevated number of false positives. In the search for new PCa biomarkers, analysis of the proportions of different groups of glycoforms of PSA is promising. Peaks of PSA, called isoforms and containing one or several glycoforms of the glycoprotein, can be separated by CE. For those samples in which PSA concentration is very low, a very sensitive detection technique, such as LIF, would be required. However, CE separation of fluorescently labeled isoforms of glycoproteins is challenging. In this work, three different methods of fluorescent derivatization of PSA were assayed with the aim of finding conditions allowing labeling of the glycoprotein compatible with CE resolution of its isoforms. NanoOrange, as a noncovalent label; 5-(iodoacetamide) fluorescein and BODIPY® FL C1 -IA, as covalent tags of thiol groups; and Chromeo™ P503, as a covalent tag of amino groups, were tried. Only the derivatization with the P503 fluorogenic dye led to the resolution by CE-LIF of several isoforms of labeled PSA. Adapting this derivatization method to be performed on-column leads to a reduction in labeling time from 4 h to 45 s. Automation of the whole analysis permitted to carry out fluorescent labeling and CE separation of PSA isoforms in less than 12 min.

Population genetic structure of Pseudatomoscelis seriatus (Hemiptera: Miridae) in the cotton-growing regions of the United States.

The cotton fleahopper, Pseudatomoscelis seriatus (Reuter) (Hemiptera: Miridae) is an economically important insect pest of cotton in the United States. However, reports of cotton fleahopper infestation and its management in cotton fields are restricted primarily to Texas, Oklahoma, and Arkansas. The objective of this study was to understand the genetic diversity of cotton fleahopper populations infesting cotton in the cotton-growing areas of the United States. Amplified fragment length polymorphism markers were used to detect genetic diversity and to characterize geographic genotypes across the distribution of the cotton fleahopper in the United States. We used 172 individuals and 559 amplified fragment length polymorphism loci in this study and found significant, but low, level of genetic differentiation among geographic populations (F(ST) = 0.02; P < 0.0001). Molecular fingerprints of cotton fleahopper populations were partitioned into three broad regional genetic populations with a western, central, and eastern distribution. The western (Arizona) and eastern (Florida, Georgia, South Carolina, and North Carolina) populations are genetically distinct, whereas the central (Texas, Oklahoma, Arkansas, Mississippi, Louisiana, and Alabama) population represents an admixed population, which include both western and eastern populations. These results suggest considerable gene flow among the populations within regions but restricted gene flow among populations from eastern and western region.

Wave-induced cross-shore distribution of different densities, shapes, and sizes of plastic debris in coastal environments: A laboratory experiment.

Plastic debris is a significant threat to marine and coastal ecosystems. Previous research found that waves, wind, as well as density, size, and shape of microplastics, drive their transport and dispersion. In this paper, a set of laboratory experiments on the effect of waves and wave-induced currents on the input rate and cross-shore transport and dispersion of different types of plastic debris, including the macro and mesosizes, in addition to microplastics is presented. 15 plastic-debris types characterized by different sizes, shapes, and densities, including facemasks, were analyzed under regular and irregular wave conditions. The results show that input and transport rates of plastics depend on their terminal velocities and wave steepness. Plastics with higher settling velocities under less-steep wave conditions are likely to escape coastal entrapment and end up in the breaking zone. However, plastics with greater buoyancy rates under steeper waves show a predominant accumulation closer to the shoreline.

Biofilm-induced effect on the buoyancy of plastic debris: An experimental study.

Plastic floating on the ocean surface represents about 1 % of all plastic in the ocean, despite the buoyancy of most plastics. Biofouling can help to sink debris, which could explain this discrepancy. A set of laboratory experiments was conducted to investigate biofilm-induced effects on the buoyancy of different plastic debris. Ten materials of different densities (buoyant/non-buoyant), sizes (micro/meso/macro), and shapes (irregular/spherical/cylindrical/flat), including facemasks and cotton swabs, were evaluated. Biofilm was incubated in these materials from a few weeks to three months to investigate the effect of different growth levels on their buoyancy. Biofilm levels and rising/settling velocities were measured and compared at seven time-points. The results show a hindered buoyancy for solid materials, while hollow and open materials showed the opposite trend in early biofilm colonization stages. A relationship was established between biofilm-growth and equivalent sphere diameter that can be used to improve predictive modeling of plastic-debris transport.

Transcriptomic analysis of the honey bee (Apis mellifera) queen brain reveals that gene expression is affected by pesticide exposure during development.

Honey bees (Apis mellifera) play a pivotal role in agricultural production worldwide, primarily through the provision of pollination services. But despite their importance, honey bee health continues to be threatened by many factors, including parasitization by the mite Varroa destructor, poor queen quality, and pesticide exposure. Accumulation of pesticides in the hive's comb matrix over time inevitably leads to the exposure of developing brood, including queens, to wax contaminated with multiple compounds. Here, we characterized the brain transcriptome of queens that were reared in wax contaminated with pesticides commonly found in commercial beekeeping operations including either (a) a combination of 204,000 ppb of tau-fluvalinate and 91,900 ppb of coumaphos ("FC" group), (b) a combination of 9,800 ppb of chlorpyrifos and 53,700 ppb of chlorothalonil ("CC" group), or (c) 43,000 ppb of amitraz ("A" group). Control queens were reared in pesticide-free wax. Adult queens were allowed to mate naturally before being dissected. RNA isolated from brain tissue from three individuals per treatment group was sequenced using three technical replicates per queen. Using a cutoff log2 fold-change value of 1.5, we identified 247 differentially expressed genes (DEGs) in the FC group, 244 in the CC treatment group, and 668 in the A group, when comparing each group to the control. This is the first study to examine the sublethal effects of pesticides commonly found in wax (particularly amitraz) on the queen's brain transcriptome. Future studies should further explore the relationship between our molecular findings and the queen's behavior and physiology.

Biochemical and molecular characterization of the SBiP1 chaperone from Symbiodinium microadriaticum CassKB8 and light parameters that modulate its phosphorylation.

The coding and promoter region sequences from the BiP-like protein SBiP1 from Symbiodinium microadriaticum CassKB8 were obtained by PCR, sequenced and compared with annotated sequences. The nucleotides corresponding to the full sequence were correctly annotated and the main SBiP1 features determined at the nucleotide and amino acid level. The translated protein was organized into the typical domains of the BiP/HSP70 family including a signal peptide, a substrate- and a nucleotide-binding domain, and an ER localization sequence. Conserved motifs included a highly conserved Thr513 phosphorylation site and two ADP-ribosylation sites from eukaryotic BiP's. Molecular modeling showed the corresponding domain regions and main exposed post-translational target sites in its three-dimensional structure, which also closely matched Homo sapiens BiP further indicating that it indeed corresponds to a BiP/HSP70 family protein. The gene promoter region showed at least eight light regulation-related sequences consistent with the molecule being highly phosphorylated in Thr under dark conditions and dephosphorylated upon light stimuli. We tested light parameter variations that could modulate the light mediated phosphorylation effect and found that SBiP1 Thr dephosphorylation was only significantly detected after 15-30 min light stimulation. Such light-induced dephosphorylation was observed even when dichlorophenyl dimethyl urea, a photosynthesis inhibitor, was also present in the cells during the light stimulation. Dephosphorylation occurred indistinctly under red, yellow, blue or the full visible light spectra. In additon, it was observed at a light intensity of as low as 1 µmole photon m-2 s-1. Our results indicate that: a) SBiP1 is a chaperone belonging to the BiP/HSP70 family proteins; b) its light-modulated phosphorylation/dephosphorylation most likely functions as an activity switch for the chaperone; c) this light-induced modulation occurs relatively slow but is highly sensitive to the full spectrum of visible light; and d) the light induced Thr dephosphorylation is independent of photosynthetic activity in these cells.

Analysis of alpha-1-acid glycoprotein isoforms using CE-LIF with fluorescent thiol derivatization.

The analysis of glycoprotein isoforms is of high interest in the biomedical field and clinical chemistry. Many studies have demonstrated that some glycoprotein isoforms could serve as biomarkers for several major diseases, such as cancers and vascular diseases, among others. Capillary zone electrophoresis (CZE) is a well-established technique to separate glycoprotein isoforms, however, it suffers from limited sensitivity when UV-Vis detection is used. On the other hand, with laser-induced fluorescence (LIF) detection, derivatization reaction to render the proteins fluorescent can destroy the resolution of the isoforms. In this work, a derivatization procedure through the thiol groups of glycoproteins using either 5-(iodoacetamide) fluorescein (5-IAF) or BODIPY iodoacetamide is presented with the model protein of alpha-1-acid glycoprotein (AGP). The derivatization process presented enabled high-resolution analysis of AGP isoforms by CZE-LIF. The derivatization procedure was successfully applied to label AGP from samples of serum and secretome of artery tissue, enabling the separation of the AGP isoforms by CE-LIF in natural samples at different concentration levels.

Quantifying the impacts of symbiotic interactions between two invasive species: the tawny crazy ant (Nylanderia fulva) tending the sorghum aphid (Melanaphis sorghi).

The establishment of new symbiotic interactions between introduced species may facilitate invasion success. For instance, tawny crazy ant (Nylanderia fulva Mayr) is known to be an opportunistic tender of honeydew producing insects and this ants' symbiotic interactions have exacerbated agricultural damage in some invaded regions of the world. The invasive sorghum aphid (Melanaphis sorghi Theobald) was first reported as a pest in the continental United States-in Texas and Louisiana-as recent as 2013, and tawny crazy ant (TCA) was reported in Texas in the early 2000s. Although these introductions are relatively recent, TCA workers tend sorghum aphids in field and greenhouse settings. This study quantified the tending duration of TCA workers to sorghum aphids and the impact of TCA tending on aphid biomass. For this study aphids were collected from three different host plant species (i.e., sugarcane, Johnson grass, and sorghum) and clone colonies were established. Sorghum is the main economic crop in which these aphids occur, hence we focused our study on the potential impacts of interactions on sorghum. Quantification of invasive ant-aphid interactions, on either stems or leaves of sorghum plants, were conducted in greenhouse conditions. Our results show that although these two invasive insect species do not have a long coevolutionary history, TCA developed a tending interaction with sorghum aphid, and aphids were observed excreting honeydew after being antennated by TCA workers. Interestingly, this relatively recent symbiotic interaction significantly increased overall aphid biomass for aphids that were positioned on stems and collected from Johnson grass. It is recommended to continue monitoring the interaction between TCA and sorghum aphid in field conditions due to its potential to increase aphid populations and sorghum plant damage.

Improving Natural Enemy Selection in Biological Control through Greater Attention to Chemical Ecology and Host-Associated Differentiation of Target Arthropod Pests.

Host-associated differentiation (HAD) refers to cases in which genetically distinct populations of a species (e.g., herbivores or natural enemies) preferentially reproduce or feed on different host species. In agroecosystems, HAD often results in unique strains or biotypes of pest species, each attacking different species of crops. However, HAD is not restricted to pest populations, and may cascade to the third trophic level, affecting host selection by natural enemies, and ultimately leading to HAD within natural enemy species. Natural enemy HAD may affect the outcomes of biological control efforts, whether classical, conservation, or augmentative. Here, we explore the potential effects of pest and natural enemy HAD on biological control in agroecosystems, with emphases on current knowledge gaps and implications of HAD for selection of biological control agents. Additionally, given the importance of semiochemicals in mediating interactions between trophic levels, we emphasize the role of chemical ecology in interactions between pests and natural enemies, and suggest areas of consideration for biological control. Overall, we aim to jump-start a conversation concerning the relevance of HAD in biological control by reviewing currently available information on natural enemy HAD, identifying challenges to incorporating HAD considerations into biological control efforts, and proposing future research directions on natural enemy selection and HAD.

Aphelinus nigritus Howard (Hymenoptera: Aphelinidae) Preference for Sorghum Aphid, Melanaphis sorghi (Theobald, 1904) (Hemiptera: Aphididae), Honeydew Is Stronger in Johnson Grass, Sorghum halepense, Than in Grain Sorghum, Sorghum bicolor.

How aphid parasitoids of recent invasive species interact with their hosts can affect the feasibility of biological control. In this study, we focus on a recent invasive pest of US grain sorghum, Sorghum bicolor, the sorghum aphid (SA), Melanaphis sorghi. Understanding this pest's ecology in the grain sorghum agroecosystem is critical to develop effective control strategies. As parasitoids often use aphid honeydew as a sugar resource, and honeydew is known to mediate parasitoid-aphid interactions, we investigated the ability of SA honeydew to retain the parasitoid Aphelinus nigritus. Since SAs in the US have multiple plant hosts, and host-plant diet can modulate parasitoid retention (a major component in host foraging), we measured SA honeydew sugar, organic acid, and amino acid profiles, then assessed via retention time A. nigritus preference for honeydew produced on grain sorghum or Johnson grass, Sorghum halepense. Compared to a water control, A. nigritus spent more time on SA honeydew produced on either host plant. Despite similar honeydew profiles from both plant species, A. nigritus preferred honeydew produced on Johnson grass. Our results suggest the potential for SA honeydew to facilitate augmentation strategies aimed at maintaining A. nigritus on Johnson grass to suppress SAs before grain sorghum is planted.