Diurnal and Seasonal Activity Patterns of Drosophilid Species (Diptera: Drosophilidae) Present in Blackberry Agroecosystems With a Focus on Spotted-Wing Drosophila

Drosophilid species with different life histories have been shown to exhibit similar behavioral patterns related to locating and utilizing resources such as hosts, mates, and food sources. Drosophila suzukii (Matsumura) is an invasive species that differs from other frugivorous drosophilids in that females lay eggs in ripe and ripening fruits instead of overripe or rotten fruits. We hypothesized that there may be diurnal and/or seasonal patterns associated with the movement of drosophilid species into and out of crop fields and their attraction to fermentation-odor-based monitoring traps, and that D. suzukii would conform to similar patterns. To test these hypotheses, we deployed passive, 2-headed Malaise traps between crop fields and wooded edges to simultaneously catch flies moving into and out of crop fields. We also deployed monitoring traps with a fermentation-based bait between crop fields and wooded edges and within crop rows. Traps were deployed weekly in June–August in 2014 and 2015 at two commercial blackberry farm in Cleveland County, NC, and were checked hourly for 24 h, except during darkness. Both D. suzukii and other drosophilid species moved between crop fields and wooded edges and were attracted to monitoring traps primarily during the morning and evening hours. Whereas other drosophilids were captured in traps throughout the season, few D. suzukii were caught in traps until early to mid-July in both years and increased as the season progressed. Understanding D. suzukii movement and activity patterns is essential for the development of effective management strategies

Diurnal and Seasonal Activity Patterns of Drosophilid Species (Diptera: Drosophilidae) Present in Blackberry Agroecosystems With a Focus on Spotted-Wing Drosophila

Drosophilid species with different life histories have been shown to exhibit similar behavioral patterns related to locating and utilizing resources such as hosts, mates, and food sources. Drosophila suzukii (Matsumura) is an invasive species that differs from other frugivorous drosophilids in that females lay eggs in ripe and ripening fruits instead of overripe or rotten fruits. We hypothesized that there may be diurnal and/or seasonal patterns associated with the movement of drosophilid species into and out of crop fields and their attraction to fermentation-odor-based monitoring traps, and that D. suzukii would conform to similar patterns. To test these hypotheses, we deployed passive, 2-headed Malaise traps between crop fields and wooded edges to simultaneously catch flies moving into and out of crop fields. We also deployed monitoring traps with a fermentation-based bait between crop fields and wooded edges and within crop rows. Traps were deployed weekly in June–August in 2014 and 2015 at two commercial blackberry farm in Cleveland County, NC, and were checked hourly for 24 h, except during darkness. Both D. suzukii and other drosophilid species moved between crop fields and wooded edges and were attracted to monitoring traps primarily during the morning and evening hours. Whereas other drosophilids were captured in traps throughout the season, few D. suzukii were caught in traps until early to mid-July in both years and increased as the season progressed. Understanding D. suzukii movement and activity patterns is essential for the development of effective management strategies

\u3ci\u3eDrosophila suzukii\u3c/i\u3e infestation in ripe and ripening caneberries

Drosophila suzukii (Matsumura) is a highly invasive vinegar fly that was first detected in the continental United States in 2008. Females use their saw-like ovipositor to lay eggs in soft-skinned fruits and severely threaten the viability of raspberry, blackberry, blueberry, cherry, and strawberry production. In a recent study, females in no-choice laboratory bioassays laid eggs in ripening blueberries and blackberries. However, most of the eggs failed to develop, perhaps because the ripening process was interrupted in the prematurely-harvested fruit. We hypothesized that eggs laid in ripening fruit in a field may be able to complete development as the fruit continues to ripen. To test this hypothesis, we used fine mesh cages to prevent later egg laying by D. suzukii in fruit at several ripeness stages: green-pink, pink, and ripe raspberries and in green-pink, red, purple, and ripe blackberries. We collected the fruit once they were ripe, and reared out and counted all D. suzukii present. This experiment was conducted at two locations during 2013 and 2014, one with very high fly populations and one with low populations. Very few flies emerged from blackberry clusters that were bagged at the green-pink stage, and in general, more flies emerged from clusters bagged at later stages of ripening (purple and red blackberries and pink raspberries) than from green-pink fruit. Knowing what ripeness stages are susceptible to D. suzukii infestation will help growers to better pinpoint when to begin applying management tools

Influence of edible fruit coatings on \u3ci\u3eDrosophila suzukii\u3c/i\u3e (Matsumura) (Diptera: Drosophilidae) oviposition and development

Drosophila suzukii (Matsumura) is a highly invasive vinegar fly recently detected in the United States that severely threatens the viability of soft skinned fruit production. Insecticides mitigate some of this damage, but alternative methods to manage D. suzukii infestation are needed. We tested three edible coatings to determine if they could prevent or reduce oviposition by D. suzukii females or affect immature survivorship and development in two important host crops, blueberry and raspberry. None of the coatings prevented oviposition, but some reduced the number of eggs laid. Two carnauba wax-based coatings, PrimaFresh 45 and Raynox, dramatically reduced survivorship of immature D. suzukii in raspberries, but not in blueberries. Our results suggest that obtaining thorough, even coverage in the field will be essential if edible coatings are to be used as a management strategy for D. suzukii

Effects of an Unregistered Insecticide on Adult Spotted Wing Drosophila Mortality and Field Infestation Rates, 2015

The effectiveness of an unregistered material at reducing Drosophila suzukii (SWD) infestation rates in blackberry field plots and its toxicity to adult SWD in laboratory bioassays was tested during the 2015 growing season. Field trials were conducted at the Sandhills Research Station near Jackson Springs, NC, in a 0.11-acre planting consisting of two rows of ‘Ouachita’ blackberries. Six treatments, including an untreated check (UTC), were applied to 5-plant plots and were arranged in an RCB design with four replicates per treatment, blocked by row, with two blocks per row. Delegate was the standard material. Some of the treatments were combined with an adjuvant, Syntact, at a concentration recommended by the manufacturer (Table 1). Applications were made twice, on 11 and 30 Jun. Treatments were applied to both sides of each row to fully cover plants using a CO2- pressurized backpack sprayer fitted with three flat fan nozzles at 45 psi pressure and 50 gal/acre spray volume. The desired application frequency for these materials is 7 days; however, additional applications could not be made due to unseasonably hot weather. Ten to 20 ripe berries, depending on availability, were collected from the middle three plants in each plot pre-treatment and 7 days after treatment (DAT) to measure infestation in the field. Fruit were held in plastic containers vented with fine mesh on the bottom to allow fruit to drain at 20°C, 65% RH, and 12:12 (L:D) h conditions. After 7 days, larvae and pupae were counted to determine infestation rates per berry

Reproductive Status of \u3ci\u3eDrosophila suzukii\u3c/i\u3e (Diptera: Drosophilidae) Females Influences Attraction to Fermentation-Based Baits and Ripe Fruits

Drosophila suzukii (Matsumura) is an invasive species that is a devastating pest of soft-skinned fruit crops. Although much effort has been directed toward developing traps and attractants to monitor for D. suzukii, current monitoring tools do not reliably predict fruit infestation. The objective of this study was to determine if D. suzukii females at different developmental stages are differentially attracted to monitoring traps with fermentation-based baits and ripe fruits. Females were collected on the surface of traps, within traps, and on ripe fruits during three experiments at field locations in North Carolina, USA, and were dissected to determine their reproductive status. In general, females collected on ripe fruits were more likely to have mature eggs present in their ovaries and had higher numbers of mature eggs than females collected on the surface of or within monitoring traps. The results of this study have implications for D. suzukii monitoring and the development of effective baits for use in integrated pest management programs

Ovipositional preference, fidelity, and fitness of \u3ci\u3eDrosophila suzukii\u3c/i\u3e in a co-occurring crop and non-crop host system

Drosophila suzukii (Matsumura) is a devastating pest of soft-skinned fruits including blackberries and raspberries. Management of this pest is focused on preventing infestation in crops, but non-crop hosts may play an important role in enabling D. suzukii to persist in the absence of cultivated hosts. Drosophila suzukii may also infest fruits of both crop and non-crop hosts concurrently. Our goals were to determine whether (1) D. suzukii prefers to oviposit in cultivated blackberry, Rubus L. subgenus rubus Watson, or American pokeweed, Phytolacca americana, a non-crop host commonly found along field edges, (2) D. suzukii prefers to oviposit into the same host from which it emerged, and (3) performance differs between D. suzukii progeny that develop in blackberries or pokeweed berries. Although the pest was able to infest both hosts at the same rate, we found that D. suzukii females emerging from pokeweed preferred to oviposit into blackberries, while females emerging from blackberry had no preference. Progeny that developed in blackberries were more fit than progeny that developed in pokeweed berries based on several measures. In field locations, cultivated blackberries and pokeweed berries only overlapped in availability for a short period of time, and infestation rates were variable between blackberries and pokeweed berries collected during that period. Nonetheless, these results suggest that noncrop hosts may facilitate the invasion of D. suzukii and perpetuate infestation of cultivated hosts under certain circumstances

A natural histone H2A variant lacking the Bub1 phosphorylation site and regulated depletion of centromeric histone CENP-A foster evolvability in Candida albicans.

Eukaryotes have evolved elaborate mechanisms to ensure that chromosomes segregate with high fidelity during mitosis and meiosis, and yet specific aneuploidies can be adaptive during environmental stress. Here, we identify a chromatin-based system required for inducible aneuploidy in a human pathogen. Candida albicans utilizes chromosome missegregation to acquire tolerance to antifungal drugs and for nonmeiotic ploidy reduction after mating. We discovered that the ancestor of C. albicans and 2 related pathogens evolved a variant of histone 2A (H2A) that lacks the conserved phosphorylation site for kinetochore-associated Bub1 kinase, a key regulator of chromosome segregation. Using engineered strains, we show that the relative gene dosage of this variant versus canonical H2A controls the fidelity of chromosome segregation and the rate of acquisition of tolerance to antifungal drugs via aneuploidy. Furthermore, whole-genome chromatin precipitation analysis reveals that Centromere Protein A/ Centromeric Histone H3-like Protein (CENP-A/Cse4), a centromeric histone H3 variant that forms the platform of the eukaryotic kinetochore, is depleted from tetraploid-mating products relative to diploid parents and is virtually eliminated from cells exposed to aneuploidy-promoting cues. We conclude that genetically programmed and environmentally induced changes in chromatin can confer the capacity for enhanced evolvability via chromosome missegregation

CD8 + T Cells Control Ross River Virus Infection in Musculoskeletal Tissues of Infected Mice

Ross River virus (RRV), chikungunya virus (CHIKV), and related alphaviruses cause debilitating polyarthralgia and myalgia. Mouse models of RRV and CHIKV have demonstrated a role for the adaptive immune response in the control of these infections. However, questions remain regarding the role for T cells in viral control, including the magnitude, location, and dynamics of CD8+ T cell responses. To address these questions, we generated a recombinant RRV expressing the H-2b-restricted gp33 determinant derived from the glycoprotein (gp) of lymphocytic choriomeningitis virus (LCMV) (“RRV-LCMV”). Utilizing tetramers, we tracked gp33-specific CD8+ T cells during RRV-LCMV infection. We found that acute RRV infection induces activation of CD8+ T cell responses in lymphoid and musculoskeletal tissues that peak from 10 to 14 days post-inoculation (dpi), suggesting that CD8+ T cells contribute to control of acute RRV infection. Mice genetically deficient for CD8+ T cells or wild-type mice depleted of CD8+ T cells had elevated RRV loads in skeletal muscle tissue, but not joint-associated tissues, at 14 dpi, suggesting that the ability of CD8+ T cells to control RRV infection is tissue-dependent. Finally, adoptively transferred T cells were capable of reducing RRV loads in skeletal muscle tissue of Rag1−/− mice, indicating that T cells can contribute to the control of RRV infection in the absence of B cells and antibody. Collectively, these data demonstrate a role for T cells in the control of RRV infection and suggest that the antiviral capacity of T cells is controlled in a tissue-specific manner

Characterization and manipulation of fruit susceptibility to \u3ci\u3eDrosophila suzukii\u3c/i\u3e

Drosophila suzukii (Matsumura) is an economic pest of small fruits and cherries that attacks intact ripening fruits. Host susceptibility may be influenced by characteristics such as flesh firmness, penetration force of the skin, total soluble solids (TSS, also known as Brix), and pH. Improved knowledge of factors affecting fruit susceptibility is needed for developing thresholds and risk prediction models for IPM. A combination of laboratory and field studies was conducted to develop prediction and potential management tools. First, a direct bioassay was used to calculate the probability of oviposition in a given fruit based on various characteristics as determined across laboratory and field trials in Oregon and North Carolina, US. When multiple characteristics were evaluated simultaneously, oviposition probability consistently increased as penetration force decreased and pH increased. Oviposition probability sometimes increased as TSS increased. Second, raspberries and blueberries in unsprayed fields had substantially lower infestation in ripening fruit compared to ripe fruit. There was no or minimal infestation in green fruit. Third, given that skin penetration force influences oviposition, practices used to improve fruit quality were examined in laboratory no-choice cages for potential reduction of oviposition. Blueberry fruit sprayed with calcium silicate in the field had greater penetration force and firmness and reduced number of eggs laid by D. suzukii compared to untreated fruit. Other calcium-based treatments increased Ca content and firmness of fruit relative to untreated fruit. Timing of insecticide spray for D. suzukii might be delayed until fruit become susceptible