Invasive Vinegar Fly Research Articles

Functional expression and characterization of CAPA receptor in the digestive tract and life stages of Drosophila suzukii, and differential activities with insect PRXamide peptides.

Spotted-wing drosophila, Drosophila suzukii (Matsumura), is an invasive vinegar fly that is a major threat to the small fruits industries globally. Insect capa genes encode multiple neuropeptides, including CAPA-periviscerokinin (CAPA-PVK) peptides, that are specifically known to cause diuresis or anti-diuresis in various organisms. Here we identified and characterized a corresponding G protein-coupled receptor (GPCR) of the D. suzukii CAPA-PVK peptides: CAPA receptor (CAPA-R). To better characterize the behavior of D. suzukii CAPA-R, we used insect cell-based functional expression assays to evaluate responses of CAPA-RagainstD. suzukii CAPA-PVKs, CAPA-PVKs from five species in Insecta, one species from Mollusca, modified CAPA-PVK peptides, and some PRXamide family peptides: pyrokinin (PK), diapause hormone (DH), and ecdysis-triggering hormone (ETH). Functional studies revealed that the D. suzukii CAPA-R is strongly activated by both of its own natural D. suzukii CAPA-PVKs, and interestingly, it was strongly activated by other CAPA-PVK peptides from Frankliniella occidentallis (Thysanoptera), Solenopsis invicta (Hymenoptera), Helicoverpa zea (Lepidoptera) and Plutella xylostella (Lepidoptera). However, D. suzukii CAPA-R was not activated by Mollusca CAPA-PVK or the other PRXamide peptides. Gene expression analyses showed that the CAPA-R was highly expressed in the Malpighian tubules and moderately in hindgut compared to other digestive organs or the rest of body, supporting diuretic/antidiuretic functionality. When compared across life stages of D. suzukii, expression of CAPA-R was approximately 1.5x greater in the third instar than the other stages and minimally detected in the eggs, 4-day old pupae and 3-day old adults. Our results functionally characterized the D. suzukii CAPA-R and a few short peptides were identified as potential biological targets to exploit the CAPA-R for D. suzukii management.

Propensity for resistance development in the invasive berry pest, spotted-wing drosophila (Drosophila suzukii), under laboratory selection.

Over the past 14 years, the invasive vinegar fly, spotted-wing drosophila (Drosophila suzukii), has become one of the most damaging fruit pests in the United States. With regional economic losses estimated as high as $500million for moderate infestations, D. suzukii control represents an often-untenable cost to growers. Management relies heavily on chemical control, which may be applied up to nine times in one season. The widespread use of chemical controls has led to concerns about insecticide resistance, and resistant field populations have already been documented in California and Michigan. We cultured sub-populations of three different Minnesota field populations of D. suzukii in the laboratory and exposed them to increasing concentrations of two commonly-used insecticides, zeta-cypermethrin (pyrethroid) and spinetoram (spinosyn). Over the exposure period, the sub-populations experienced an 8- to 45-fold increase in insecticide concentration. We saw significant increases in the median lethal concentration (LC50 ) values of one sub-population exposed to zeta-cypermethrin and one exposed to spinetoram. Across the spinetoram exposures, we also observed significant reductions in the top mortality values for three different sub-populations. Our results suggest that field populations of D. suzukii can develop resistance to zeta-cypermethrin and spinetoram in short periods of time under laboratory selection but that resistance to spinosyns occurs more readily than to pyrethroids. These results support other studies that have documented spinosyn resistance in field populations and in laboratory selections. Resistance evolution to spinosyns is a particularly important issue, as they represent one of few organic insecticide options for D. suzukii. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Behavioral Responses of Drosophila suzukii (Diptera: Drosophilidae) to Blends of Synthetic Fruit Volatiles Combined With Isoamyl Acetate and β-Cyclocitral

Baits and lures for trapping and monitoring the invasive vinegar fly Drosophila suzukii Matsumura (Diptera: Drosophilidae) are currently derived from fermentation volatiles. Volatile organic compounds from alternative sources could improve monitoring efforts and optimize capture of gravid females. Through electroantennography and behavioral assays, we evaluated male and female D. suzukii responses to blends of selected synthetic fruit volatiles in combination with the fruit compound isoamyl acetate and the strawberry leaf terpenoid β-cyclocitral. Blends that were attractive to both male and female D. suzukii were then evaluated for attractiveness to a non-target drosophilid, Drosophila melanogaster. A simple 3-component blend of isoamyl acetate, β-cyclocitral and methyl butyrate was attractive to D. suzukii, particularly females, relative to fresh blueberry volatiles. The 3-component blend was not attractive to D. melanogaster. Additional research is needed to determine the effectiveness of this blend to attract D. suzukii under field conditions.

The Presence and Accessibility of Competitive Resources Affect Trapping Efficiency of Spotted-Wing Drosophila (Diptera: Drosophilidae).

Spotted-wing drosophila (Drosophila suzukii, (Matsumura)) is an invasive vinegar fly that has become a serious threat to soft fruit crops. Monitoring for this pest is typically performed using drowning traps baited with live yeast cultures or fermentation volatile blends. Trapping programs using these compounds provide highly variable results across production systems, geographic regions, and growing seasons. Trap competition with fruit is one hypothesis for this inconsistency. This study evaluated the trapping efficiency of yeast and wine baits in the presence and absence of small quantities of host fruits in two binary-choice laboratory experiments. The first experiment evaluated trap capture in clear 946-ml traps with easily accessible water, apple pomace, blueberry, raspberry, strawberry, cherry, or grape as competitive influences. The second experiment evaluated the same competitors, but they were made less accessible. Recapture of flies in arenas containing competitive fruit was reduced by 64-88% when fruit was 'accessible' and from 0 to 51% when it was 'inaccessible' compared with arenas containing a water competitor. All fruit types provided statistically similar levels of trap interference. In the first experiment, yeast captured more flies compared with wine, whereas in the second experiment, wine captured more flies than yeast. Our results support the hypothesis that the presence of fruit or other reproductive resources will reduce trap captures and that this reduction is likely mediated by the relative accessibility of the fruit versus the trap. Thus, attempts to develop population estimates based on traps should incorporate fruit availability/accessibility.

Optimizing Caneberry Spray Coverage for Drosophila suzukii (Diptera: Drosophilidae) Management on Diversified Fruit Farms.

Spray coverage may influence the efficacy of insecticides targeting the invasive vinegar fly Drosophila suzukii (Matsumura), a primary pest of raspberries and blackberries. In commercially managed caneberries, spray coverage is typically lowest in the inner and lower plant canopy, regions that overlap with higher levels of adult D. suzukii activity. To understand how spray coverage of fruit impacts efficacy against D. suzukii, laboratory bioassays were conducted using raspberries. In laboratory bioassays, higher spray coverage did not impact larval infestation rates but did increase adult mortality, indicating that flies can avoid a lethal dose of insecticide when applications do not achieve adequate coverage. We also evaluated how carrier water volume impacts spray coverage patterns throughout the canopy of raspberry and blackberry plants using both airblast and CO2 backpack sprayers. Increasing carrier water volume generally improved spray coverage in the lower plant canopy. However, effects in the upper plant canopy were inconsistent and varied between sprayer types. In addition to carrier water volume, other approaches, including adjusting the pesticide sprayer equipment used and/or sprayer calibration, should also be explored to improve coverage. Growers should evaluate spray coverage in their caneberries to identify and troubleshoot coverage issues. Results from this study indicate that taking the time to optimize this aspect of pesticide application may improve chemical management of D. suzukii and will likely also improve control of other important caneberry pests.

Factors affecting the implementation of exclusion netting to control Drosophila suzukii on primocane raspberry

Sustainable management of invasive arthropod pests requires insecticide-alternative, integrated strategies, such as protected culture. During 2016–2017, we studied the efficacy of exclusion netting at reducing infestation damage in fall-bearing raspberries caused by an invasive vinegar fly, Drosophila suzukii Matsumura. In an effort to manage outbreak infestation, we studied the efficacy of baited attracticidal spheres in netted and open plots. We also monitored the effects of netting on fruit marketability, abiotic conditions near the fruiting zone, and pollination effects due to exclusion. The results showed that while 80 g HDPE netting sufficiently deterred D. suzukii infestation early in the season, late-season infestation was often greater in netted zones compared to insecticide-treated open plots. The introduction of baited attracticidal spheres under the netting did not consistently reduce infestation, and in some cases even increased infestation late in the season, likely due to the presence of the olfactory bait. During both test years, fruit marketability was greater in netted plots compared with open plots, and in open plots, we observed more overripe fruit and additional feeding damage caused by other herbivores. However, the incidence of crumbly berry was higher in netted plots, indicating pollination deficits. Supplemental pollination appeared to reduce these effects. Although temperature did not differ significantly between netted and open plots, we also observed greater incidence of botrytis infection in netted plots containing attracticidal spheres, which was not present in netted plots alone. These data suggest that while exclusion netting may be a valuable tool for D. suzukii pest management, unless outbreak infestation under the netting and supplementation pollination are addressed, significant challenges may impede large scale implementation.

Morphometric criteria to differentiate Drosophila suzukii (Diptera: Drosophilidae) seasonal morphs

Temperate insect species often enter diapause in preparation for overwintering. One such species is the invasive vinegar fly, Drosophila suzukii (Matsumura), which has seasonal polymorphisms, considered winter and summer morphs. To date, the morphs have been differentiated by color and size with winter morphs typically being darker and larger compared to summer morphs. ‘Dark’ and ‘large’ are subjective, however, and standardizing an identification process can ensure that the morph of interest is being accurately characterized. The goal of our research was to investigate a quantitative method to distinguish between D. suzukii morphs based on body and wing size. We reared winter and summer morph D. suzukii in the laboratory using standard procedures, and measured wing length, wing width, and hind tibia length. Additionally, we collected field D. suzukii to document the seasonal phenology of the morphs in Minnesota based on our model’s cutoff criteria. A classification and regression tree analysis were used to determine which metrics would be best for predicting field-caught D. suzukii morphs. Using laboratory-reared flies as our known morphs for the training data in the classification model we developed classification trees based on wing length and the ratio of wing length to hind tibia length. The frequency of winter and summer morphs present in the field varied based on which classification tree was used. Nevertheless, we suggest ratio of wing length to hind tibia length as the most robust criteria for differentiating D. suzukii morphs because the ratio accounts for the size variability between laboratory-reared and field-caught flies and the error rate of misclassification is reduced to 0.01 for males. The results from this work can aid in future D. suzukii research by allowing scientists to objectively differentiate the morphs, and thereby improve our understanding of the biology and phenology of seasonal morph dynamics.

Trichopria drosophilae parasitizes Drosophila suzukii in seven common non-crop fruits

The invasive vinegar fly Drosophila suzukii not only infests and damages numerous fruit crops but also develops in many wild fruit species in semi-natural habitats. Biological control in these refuges could reduce D. suzukii populations and minimize their dispersal into fruit crops. We investigated parasitization of D. suzukii by the pupal parasitoid Trichopria drosophilae in seven common wild fruit species. Development and nutrient content of D. suzukii differed among the fruit species. Nevertheless, T. drosophilae significantly reduced D. suzukii numbers in all fruits. The development of T. drosophilae was affected by both the fruit species and the quality of the pupal host (size, nutrient content). In olfactometer assays, parasitoid females preferred infested fruits to an empty control and to most non-infested fruits, but spent an equal amount of time on the walking arena above the infested and non-infested fruits of Rhamnus cathartica and Viscum album. Our results show that T. drosophilae can utilize D. suzukii hosts from a variety of wild fruit species and therefore has the potential to be used as a control agent of D. suzukii in semi-natural habitats.

Predicting Within- and Between-Year Variation in Activity of the Invasive Spotted Wing Drosophila (Diptera: Drosophilidae) in a Temperate Region.

Invasive insect pests can be challenging to manage because their recent arrival provides limited information on which to build predictive population models. The magnitude and timing of activity by the invasive vinegar fly, Drosophila suzukii, in crop fields has been unpredictable due to its recent arrival in many new regions of the world and changes in methods for its detection. Using 7 yr of consistent trapping of adults at four blueberry farms in Michigan, United States, we modeled the temporal and environmental factors influencing D. suzukii activity. We found that this pest established high levels within 2 yr of being detected, with peak fly activity continuing to increase. Fly activity timing and abundance were predicted by the annual number of days below 0°C, the number of winter and spring days above 10°C, and by the fly activity in the preceding year, providing support for overwintering in our region. We monitored larval infestation for 4 yr at these same sites and found a moderate positive correlation between larvae in fruit and adults in traps. Finally, we developed a generalized additive model to predict D. suzukii fly capture throughout the season based on relevant environmental factors and examined the relative timing and magnitude of activity under varying winter and spring temperature conditions. Our results suggest that D. suzukii activity is predictable and that environmental conditions can be used in temperate regions to provide regional risk warnings as a component of strategies to manage this invasive insect pest.

Diversity and abundance of natural enemies of Drosophila suzukii in Wisconsin, USA fruit farms

The invasive vinegar fly, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is a major economic pest of soft-skinned fruit in the USA. In order to identify suitable biological control agents in Wisconsin, we assessed the presence and impact of potential natural enemies of D. suzukii in tart cherry and raspberry farms with documented D. suzukii populations. Yellow sticky cards and sentinel traps baited with D. suzukii or D. melanogaster larvae and pupae were deployed in these agricultural areas in the foliage and near the soil surface. Four families of parasitoids with known species that successfully parasitize D. suzukii (Pteromalidae, Braconidae, Figitidae, and Diapriidae) were found on sticky traps at all sampling sites. However, no parasitoids emerged from D. suzukii or D. melanogaster sentinel larvae or pupae throughout the duration of the field assessment. Predation was documented on sentinel D. suzukii pupae (1–4%) and sentinel D. melanogaster pupae (5–8%). The majority of sentinel pupae never emerged upon their return from the field and showed no evidence of field predation. Between 70 and 92% of recovered D. suzukii pupae were dead, and 46–72% of D. melanogaster pupae were dead. The absence of parasitoids found emerging from the sentinel drosophilid larvae and pupae and overall low levels of predation suggests that native biological control may provide limited potential as a management option against D. suzukii in Wisconsin at this time.

Associations Between Drosophila suzukii (Diptera: Drosophilidae) and Fungi in Raspberries.

The invasive vinegar fly, Drosophila suzukii Matsumura, has emerged as one of the most serious arthropod pests of primocane red raspberries (Rubus ideaus L.) in the United States. In raspberries, D. suzukii encounter a diverse community of microbes, including fruit rot pathogens such as Botrytis cinerea Pers and Cladosporium cladosporioides de Vries. In this study, our primary objectives were to evaluate D. suzukii-fungal associations and determine D. suzukii's influence on fungal communities in raspberry fruit. Through culture-based surveys of larval gut microbes, we isolated several yeast fungi (primarily Hanseniaspora spp.), as well as Cladosporium, Botrytis, and several other non-yeast fungi from larval frass, suggesting that D. suzukii larvae encounter and feed on these fungi. Subsequent field surveys confirmed that D. suzukii larvae occurred in berries affected by Botrytis fruit rot and Cladosporium fruit rot. Under laboratory conditions, D. suzukii may facilitate C. cladosporioides infections, likely through the introduction of epiphytic propagules on the fruit surface. We could not detect impacts on B. cinerea infections or establish a clear vectoring relationship for either fruit rot. These studies provide evidence for an association between D. suzukii and fungal fruit rot pathogens. Understanding interactions between raspberry fruit, D. suzukii, and fungal microbes-especially whether D. suzukii facilitates the development of fruit rots or conversely, if fruit rots influence D. suzukii infestation patterns-may improve pest and pathogen management programs.

Impact of short- and long-term heat stress on reproductive potential of Drosophila suzukii Matsumura (Diptera: Drosophilidae)

Drosophila suzukii Matsumura (Diptera: Drosophilidae) is an invasive vinegar fly of Asian origin now distributed throughout North America. Due to the unique morphology of females, this fly has become one of the most serious pests of thin-skinned fruits including blueberry, blackberry, cherry, raspberry, and strawberry. Prophylactic insecticide applications are commonly used to control this fly. A more sustainable approach to managing this invasive pest may not be possible without a clear understanding of the biology of this species under extreme environmental conditions. Specifically, high temperature is known to interfere with development and reproduction of drosophilids; however, the impact of high temperature on D. suzukii needs to be further investigated. The objective of the present study was to investigate the impact of exposure to constant and relatively short-term heat stress on reproductive success of D. suzukii, and potential for recovery. Results show that the development and reproduction of D. suzukii were negatively affected by constant and relatively short-term heat stress. Under constant heat stress, oviposition rate and adult lifespan decreased as temperature increased from 24 °C to 33 °C and reproduction was completely absent at 33 °C. Under relatively short-term heat stress, oviposition, pupation, and adult eclosion were significantly decreased as temperature increased from 28 °C to 34 °C. The short-term heat stress greatly reduced the fertility of both male and female D. suzukii which was recovered eight days after treatment. This study provides basic information on thermal biology of D. suzukii to help us better understand the trends commonly observed in D. suzukii trap captures in regions with hot summer conditions, and the results can be used in population models to predict its population dynamics in regions where high temperatures prevail during the field season.

Use of a Novel Host Plant Family, Basallaceae, by Drosophila Suzukii (Diptera: Drosophilidae)

Drosophila suzukii (Matsumara) (Diptera: Drosophilidae) is a highly polyphagous invasive vinegar fly and a pest of small and stone fruits in regions where it has established. Its ability to use a wide range of food sources has likely aided in its success as an invasive species. To date, over 130 species representing 60 genera and 30 different plant families have been documented as hosts for D.suzukii. Understanding the host range of this pest is important for determining how it is able to persist locally and/or regionally when a host crop is not present. Here we describe the use of a novel host plant, Basella alba (Caryophyllales: Basellaceae), which represents the first known host from the plant family Basellaceae.

Susceptibility of Bunch Grape and Muscadine Cultivars to Berry Splitting and Spotted-Wing Drosophila Oviposition

Fruit splitting is a physiological disorder that produces surface cracks that promote disease and insect damage. The spotted-wing drosophila (SWD), <i>Drosophila suzukii</i> (Matsumura), is a species of vinegar fly that attacks berry crops worldwide, including grapes, and reduces fruit quality and yield. In this study, we tested the susceptibility of various hybrid bunch grapes and muscadines to berry splitting and SWD attack. Ten grape cultivars were harvested in 2016 and 2017, and Thompson Seedless (<i>Vitis vinifera</i>) was purchased locally. Fruit quality traits examined included Brix (soluble solids), total acidity (TA), pH, fruit firmness, and skin break force. Villard blanc and OK392 were the least susceptible to berry splitting (0%). Although muscadines showed the highest fruit firmness, they were also susceptible to splitting, especially Fry Seedless (88% splitting incidence). There were no significant correlations among soluble solids, firmness, and splitting; however, there was a negative correlation between splitting and TA. Pierce’s disease (PD)-resistant and PD-tolerant grapes also appear to be mostly resistant to or highly tolerant of SWD infestation. SWD females do not appear to be able to oviposit in fruit hosts that have a fruit firmness exceeding 300 g/mm. Wounds or splits in the grape epidermis increased reproductive success of SWD by 400%, suggesting that a well-managed vineyard will not host large SWD populations. Vineyards suffering from severe berry damage might provide SWD with a summer fruit host. Overall, PD-resistant hybrids and muscadines are highly adaptive to subtropical climates and are tolerant of this new invasive vinegar fly.

Pupation Behavior and Predation on Drosophila suzukii (Diptera: Drosophilidae) Pupae in Maine Wild Blueberry Fields

Drosophila suzukii (Matsumura; Diptera: Drosophilidae) is an invasive vinegar fly and pest of soft fruits in North America, including wild blueberries (Vaccinium angustifolium Aiton) in Maine. Despite its presence in the continental United States for 9 yr, little is known about its natural enemy complex. Here we report the results of a 3-yr study designed to identify naturally-occurring predators in Maine's wild blueberry fields. Experiments were conducted to determine pupation site and pupation depth to understand D. suzukii's predation vulnerability. Predation rates in the field of fully-exposed, caged, and buried pupae were measured. Pitfall traps were deployed to identify the potential predator assemblage, and laboratory experiments were conducted to determine how many pupae were consumed by commonly occurring ground beetle species (Carabidae) and field crickets (Gryllus pennsylvanicus Burmeister). The most commonly collected predators were ants, ground beetles, harvestmen, and field crickets. Significantly more pupae were found to occur in the soil compared to blueberry fruit, with most pupae in the top 0.5 cm layer of soil. Pupal predation rates in the field were high, with higher rates of predation on exposed pupae compared to buried pupae. Laboratory studies revealed that ground beetles and field crickets are likely predators of D. suzukii pupae.

Diurnal Activity of Drosophila suzukii (Diptera: Drosophilidae) in Highbush Blueberry and Behavioral Response to Irrigation and Application of Insecticides.

Spotted wing Drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is an invasive vinegar fly that has become a primary direct pest of berry crops worldwide. We conducted 2 yr of behavioral studies in blueberry plantings to determine how fly activity varied throughout the day. Observations of diurnal activity of adult D. suzukii found the greatest activity in the morning hours between 0600 and 0800 hours, when the majority of flies were on the berries. Flies were also active in the evening mainly between 1800 and 2000 hours; however, this trend was more prominent in 2015, which had cooler and more humid evenings. Experiments examining the effect of irrigation on D. suzukii behavior showed that flies remained active during and after irrigation. The effect of insecticide treatments alone and in combination with irrigation revealed that treatment with spinosad had limited effects on the number of flies per bush, whereas spinetoram reduced the number flying and on the bushes in some cases. Zeta-cypermethrin caused longer and more consistent reduction in D. suzukii flying and on bushes. In all treatments, we observed surviving flies flying near and on treated bushes, indicating that these insecticides do not completely deter fly activity. Irrigation did not influence the effects of zeta-cypermethrin on fly behavior during daily observations up to 3 d after application. Our results highlight that the diurnal patterns of activity of D. suzukii on host plants are flexible and are relatively unaffected by irrigation or insecticide applications.

Economic analysis of revenue losses and control costs associated with the spotted wing drosophila, Drosophila suzukii (Matsumura), in the California raspberry industry.

The spotted wing drosophila (SWD), Drosophila suzukii (Matsumura), is an invasive vinegar fly with a preference for infesting commercially viable berries and stone fruits. SWD infestations can reduce yields significantly, necessitating additional management activities. This analysis estimates economic losses in the California raspberry industry that have resulted from the SWD invasion. California raspberry producers experienced considerable revenue losses and management costs in the first years following SWD's invasion of North America. Conventional producers have since developed effective chemical management programs, virtually eliminating revenue losses due to SWD and reducing the cost of management to that of purchasing and applying insecticides more often. Organic raspberry producers, who do not have access to the same chemical controls, continue to confront substantial SWD-related revenue losses. These losses can be mitigated only by applying expensive insecticides registered for organic use and by performing labor-intensive field sanitation. SWD's invasion into North America has caused extensive crop losses to berry and cherry crops in California and elsewhere. Agricultural producers and researchers have responded quickly to this pest by developing management programs that significantly reduce revenue losses. Economic losses are expected to continue to fall as producers learn to manage SWD more efficiently and as new control tactics become available. © 2016 Society of Chemical Industry.

Infestation of Wild Fruit byDrosophila suzukiiSurrounding Maine Wild Blueberry Fields1

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an invasive vinegar fly that attacks a large variety of soft fruits including wild blueberries in Maine. Wild blueberry fields in Maine are commonly surrounded by woodland edges that contain wild fruit. These edges are important refugia as they provide the fly with needed shade and moisture during the hottest parts of the day. The wild fruit in these wooded edges are also potential alternative hosts for D. suzukii. We surveyed wild fruit along blueberry fields to determine the types of fruit present and measured D. suzukii infestation levels in surveyed fruit. We also measured the number of adult D. suzukii along field edges and the level of infestation in the wild blueberry crop. Drosophila suzukii was found in nine out of seventeen surveyed wild fruit species along field edges. Our results suggest a correlation between wild fruit infestation levels and adult fly densities in the crop fields. Blueberry fields with higher levels of wild fruit infestation also showed higher levels of adult D. suzukii trap captures in the commercial blueberry fields. These wild fruit hosts may allow D. suzukii to increase its population abundance prior to moving into commercial blueberry fields.

Variation of within‐crop microhabitat use by Drosophila suzukii (Diptera: Drosophilidae) in blackberry

AbstractDrosophila suzukii Matsumara (Diptera: Drosophilidae) is an invasive vinegar fly that infests ripe and ripening soft skinned fruits. In the south‐eastern United States, blackberry (Rubus spp.) crops are heavily impacted by D. suzukii, and current management tactics rely on the use of broad‐spectrum insecticides targeted to adult populations. An improved understanding of D. suzukii biology and ecology are necessary to create sustainable management options. Knowledge of how D. suzukii interacts with resources will enable targeted management actions in the future. In this present study, we monitored larval infestation throughout the blackberry canopy and found that infestation was highest in the inner portion of the canopy and lower in more exposed locations. We also documented higher humidity within the cane canopy relative to the edge of the field. A difference in abiotic conditions may create within‐crop microhabitats that D. suzukii is able to exploit. Future research will explore how to take advantage of these microhabitats in pest management programs.

First record of the invasive vinegar fly Drosophila suzukii (Matsumura)(Diptera: Drosophilidae) from eastern Turkey

* Correspondence: bdalgic@hacettepe.edu.tr Invasive vinegar fly Drosophila suzukii, commonly known as spotted-wing drosophila (SWD), is a fruit crop pest endemic to Southeast Asia (Walsh et al., 2011) and was first reported outside of this region in Hawaii in the 1980s (Hauser, 2011). The first records from the North American mainland were made in 2008 from central California, USA (Hauser et al., 2009), and it is now widespread throughout the central and southern states, causing agricultural damage to summer fruits such as cherries, strawberries, and peaches (Hauser, 2011). The first records in Europe of D. suzukii were in Spain and Italy in 2008, simultaneously (Raspi et al., 2011; Calabria et al., 2012; Cini et al., 2012). However, spatial analysis of its distribution across Europe suggested the south of France as the most likely spreading center (Cini et al., 2014). Considering the close proximity of these first records to ports, it is likely that the first individuals may have arrived as eggs or larvae in fruits that had been sea-traded from Asia (Rota-Stabelli et al., 2013). The first report of crop damage in Europe was in northern Italy (Grassi et al., 2009; Calabria et al., 2012). It has also been detected in various localities across Europe (as shown in Figure 1), expanding across an altitudinal range from 27 to 1550 m above sea level; SWD has spread approximately 1400 km through infested fruits (Hauser, 2011; Calabria et al., 2012; Kiss et al., 2013). D. suzukii is taxonomically classified under genus Drosophila and subgenus Sophophora as a member of the melanogaster species group and within the suzukii species subgroup (Yang et al., 2004; Ashburner et al., 2005). In contrast to common drosophilids, which oviposit on damaged or rotting fruits, females of D. suzukii lay eggs under the soft skin of healthy, ripening fruits by using their sharp and serrated ovipositor, which wounds the host physically and leaves it vulnerable to secondary contagion by pathogens (Sasaki and Sato, 1995; Cini et al., 2012). Developing larvae, hatched from eggs, cause the fruit to become soft and rotten, which leads to substantial crop deterioration, thus making D. suzukii an economically damaging pest (Goodhue et al., 2011). Although it is difficult to estimate financial damage caused by a scientifically unknown pest such as D. suzukii, yield losses of 20% and 80% were reported in the United States in 2008 and 2009, respectively (Bolda et al., 2010; Walsh et al., 2011). In Europe, losses of up to 80% occurred in the strawberry crops of southern France in 2010 (Lee et al., 2011). Originally described in insect illustrations from Japan, D. suzukii is a red-eyed drosophilid with a yellowish brown thorax and pale brown abdomen with black transverse stripes. Males are easily recognized by having a distinct apical wing spot and 2 sets of short sex Abstract: Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) is native to East Asia and invasive on the European and American continents. The first records in both Europe and the United States were in 2008. Since that year, it has widely moved across these continents. As D. suzukii females lay eggs in healthy ripening fruits of several species, particularly in small soft fruits and berries, the species causes agricultural damage. The soft thin-skinned fruit pest, identified as D. suzukii, has been found in Erzurum, Turkey, where damaged strawberry crops were observed and cultured in the middle of August and September 2014. Initially, 2 adults, 3 pupae, and several larvae were observed. Emergence of male and female adults continued for 10 more days. Here we report the first finding of D. suzukii in Turkey.