Effects of sweet alyssum flowers and their volatile compounds on Drosophila suzukii (Matsumura) in the laboratory

Drosophila suzukii (Matsumura) is a major global pest of soft fruit crops. Based on field observations, we tested in the laboratory whether sweet alyssum (Lobularia maritima (L.)) flower volatiles and their major constituent compounds, acetophenone and benzaldehyde, repelled D. suzukii flies. Volatiles from cut flowers and acetophenone reduced numbers of D. suzukii attracted to raspberries, and acetophenone reduced numbers of larvae in the raspberries. Testing of sweet alyssum plantings or dispensing acetophenone to repel D. suzukii in fields and lower fruit infestation should be conducted.     

Bacillus thuringiensis serovar. israelensis has no effect on Drosophila suzukii Matsumura

The spotted wing drosophila (SWD), Drosophila suzukii, is an invasive species to the USA, and Europe and biological control methods are urgently sought for. In this study, the potential of commercial microbial control products based on the Dipteran‐specific B. thuringiensis serovar. israelensis (B.t.i.) were evaluated in laboratory experiments. These products were tested on SWD larvae and adults but neither one showed more than 10% mortality. A repellent effect of the products to SWD adults was also ruled out. We conclude that B.t.i. products are not suitable for SWD control.     

Estimating temperature effects on Drosophila suzukii life cycle parameters

1. Drosophila suzukii is an invasive, polyphagous pest of soft-skinned fruits, having huge impact on fruit production in Asia, North and South America and Europe including Germany.
2. To investigate the effect of temperature on oviposition, egg-to-adult development success and duration, as well as immature heat survival and adult cold survival for a German D. suzukii population several experiments were conducted under different constant temperatures in the laboratory. The resulting life cycle data were described mathematically as functions of temperature and compared with experimental results of other researchers in a summary table.
3. Curve fittings used herein revealed that minimum, optimum and maximum temperatures are: 13.2, 26.7 and 33.6 °C for oviposition, 14.1, 22.6 and 30.0 °C for egg-to-adult development success, and 9.6, 27.3 and 35.7 °C for egg-to-adult development duration. Eggs and larvae of D. suzukii showed a reduced heat survival within the tested temperature range of 29 to 41 °C and exposure durations from 1 to 8 h. A cold survival rate of 50% was measured at e.g. −6 °C for 4 h in summer morph adults and at e.g. −6 °C for 45 h in winter morph adults confirming that the latter are more cold tolerant.
4. Results obtained in this study for a German population of D. suzukii are similar to those obtained for populations of other origins such as Canada, Japan, Spain and USA. Thus, presumably, present data based on a German D. suzukii population can be used for a new or fine-tune of already existing population dynamics models of D. suzukii in order to support an effective pest management strategy.

     

Compatibility of flonicamid and a formulated mixture of pyrethrins and azadirachtin with predators for soybean aphid (Hemiptera: Aphididae) management

The invasive soybean aphid, Aphis glycines Matsumura, is an important pest in North American soybean production. Predators can play an important role in suppressing A. glycines. However, current A. glycines management practices rely primarily on broad-spectrum insecticides, which can adversely affect natural enemy populations. An alternative is the use of selective insecticides that control the targeted pest species, while having a reduced impact on natural enemies. In greenhouse and laboratory assays, we tested the effects of lambda-cyhalothrin, two rates of flonicamid, which is currently not registered for use in soybean, and a formulated mixture of pyrthrins and azadirachtin on A. glycines and its natural enemies, Chrysoperla rufilabris (Burmeister), Orius insidiosus (Say) and Hippodamia convergens (Guerin-Meneville). All insecticides significantly reduced A. glycines populations. Lambda-cyhalothrin was highly toxic to the natural enemies tested. Flonicamid showed the lowest toxicity to natural enemies, but the high rate did decrease survival of O. insidiosus. The mixture of pyrethrins and azadirachtin was toxic to larvae of C. rufilabris and adult O. insidiosus. Moreover, the mixture of pyrethrins and azadirachtin increased the developmental time of C. rufilabris. These results indicate potential for flonicamid and the mixture of pyrethrins and azadirachtin to increase compatibility between chemical and biological controls.     

Insights into the susceptibility of raspberries to Drosophila suzukii oviposition

The spotted wing drosophila (SWD) causes massive losses in red raspberry (Rubus idaeus L.) cultivation by direct oviposition leading to damages of the soft skin fruits. Knowledge of the fly's host preference could help farmers in managing the pest. We used a laboratory-based oviposition assay for screening the germplasm of Rubus to ascertain whether the spotted wing drosophila prefers certain cultivars to others for oviposition and if preference is based on citric acid and Brix content or firmness. Correlation analyses of evaluated characters with no-choice tests results in 3 years obtained no correlation between citric acid, Brix content and oviposition. Primocane raspberries were lower affected by SWD than floricane raspberries. The Rubus hybrid cultivar “Dorman Red” and the primocane cultivar “Pokusa” showed the lowest oviposition rate compared to the other 58 evaluated genotypes. We found that oviposition correlates to firmness of the investigated cultivars, which strongly indicates that host preference is partly connected to that character in raspberries. The results are discussed regarding the use of Rubus genetic resources in breeding and integrated pest management to control spotted wing drosophila in the field.     

Humidity affects populations of Drosophila suzukii (Diptera: Drosophilidae) in blueberry

Temperature and humidity affect insect physiology, survival, fecundity, reproductive status and behaviour. Complementing previous work investigating the effects of temperature on adult survival and fecundity of the invasive frugivorous pest, Drosophila suzukii (Matsumura), this study was conducted to determine the effect of humidity on D. suzukii larval development, adult survival, fecundity and reproductive status using blueberry as a host substrate. The five constant humidity levels in laboratory bioassays were 20, 33, 71, 82 and 94% RH at 20.6 ± 0.2°C. As RH increased, fecundity and longevity increased. At the higher humidity levels, RH had limited impact on mean generation times (T), larval development and eclosion times. The highest net reproductive rate (R_o = 68) and highest intrinsic rate of population increase (r_m = 0.17) were both recorded at 94% RH. The reproductive status of females, as indicated by the number of mature oocytes per female, was significantly greater at 82 and 94% RH, compared to 71% RH. In addition to the laboratory procedures, we correlated field trap captures over an 81‐day summer period to relative humidity (RH) levels in close proximity to those traps. In the field, low ambient humidity levels resulted in decreased trap captures. A humidity‐dependent population model predicted lower densities of D. suzukii relative to populations at higher humidity. This study supports the hypothesis that cultural practices that minimize lower humidity levels in crops can contribute to the management of D. suzukii. Such methods may include open pruning, drip irrigation and field floor management.     

Evaluation of organic insecticides for management of spotted‐wing drosophila (Drosophila suzukii) in berry crops

Spotted‐wing drosophila, Drosophila suzukii (Matsumura), is an invasive pest affecting fruit production in many regions of the world. Insecticides are the primary tactic for controlling D. suzukii in organic as well as conventional production systems. Organic growers have a greater challenge because fewer insecticides are approved for use in organic agriculture. The most effective organically approved product is spinosad, but alternatives are needed because of label restrictions limiting the number of applications per year, toxicity to beneficial arthropods and the risk of developing resistance. We evaluated several organically approved insecticides against D. suzukii in laboratory assays and field trials conducted on organic blueberry and raspberry farms. Spinosad was consistently the most effective insecticide, but a few other insecticides such as azadirachtin + pyrethrins, Chromobacterium subtsugae and sabadilla alkaloids showed moderate activity. None of the treatments had long residual activity. Mortality started to decline by 3 days after treatment, and by 5 days after application, the treatments were not different from the controls. These products may be useful in rotation programmes, necessary for reducing reliance on spinosad and mitigating resistance. Cultural and biological control approaches are needed in fruit production for D. suzukii management, but insecticides will likely continue to be the dominant management tactic while these other approaches are being optimized and adopted.     

Developmental inhibition of Drosophila suzukii by ionizing radiation

Spotted wing drosophila (SWD) has emerged as a major invasive insect pest of small berry fruits in the Americas and Europe since the late 2000s. Thus, phytosanitary treatment of commodities for export is imperative to prevent the movement of viable SWD to newer areas. In the present study, all developmental stages of SWD were irradiated with different doses of gamma and electron beam radiation to assess developmental inhibition to identify potential quarantine doses of the radiations. Ionizing radiation induced developmental inhibition of all stages of SWD. The effective doses for 99% inhibition (ED₉₉) of hatching, pupariation, and adult emergence from irradiated eggs for gamma radiation were 882, 395 and 39 Gy, respectively, compared with 2849, 687, and 41 Gy, respectively, for electron beam radiation. The ED₉₉ for inhibition of pupariation and adult emergence in irradiated larvae were 703 and 47 Gy, respectively, for gamma radiation, and 619 and 33 Gy, respectively, for electron beam radiation. Pupal irradiation did not completely inhibit adult emergence, even at 300 Gy. However, irradiation with ≥100 Gy of puparia induced adult sterility, with no egg production at all. The ED₉₉ for inhibition of F₁ egg hatchability from adults irradiated with gamma radiation and electron beam radiation was estimated to be 424 and 125 Gy, respectively. The results of the present study suggest that gamma radiation and electron beam radiation are alternatives for phytosanitary treatment. Irradiation with 100 Gy could be suggested as a potential dose for egg, larval, and pupal quarantine treatment of SWD.     

The effect of border sprays and between‐row soil tillage on Drosophila suzukii in organic blackberry production

Drosophila suzukii (Matsumura) is a major pest of soft‐skinned fruit. Females have an enlarged serrated ovipositor that is used to cut into ripening fruit and lay their eggs. Larvae develop inside infested fruit, rendering fruit unmarketable. Previous research has indicated that D. suzukii can move from adjacent woodlands into cultivated fields. Furthermore, multiple generations can occur in a single season as a result of fallen, infested fruit in the fields. Our hypothesis was that border sprays and soil tillage of field aisles can reduce D. suzukii presence in commercial blackberry fields (Rubus spp.). To test our hypothesis, we conducted split‐plot field trials in organic blackberry fields for 3 and 4 weeks in 2014 and 2015, respectively. Treatments were border sprays (whole plot, pyrethrins + azadirachtin) and tillage (subplot, ~15 cm). We evaluated adult D. suzukii in both years and berry infestation and natural enemies in 2015 only. We found that plots with border treatments had fewer D. suzukii (larvae and adults) than plots without border sprays. Tilling the soil between rows of blackberry bushes did not have a significant effect on adult captures or larval infestation of fruit. Natural enemies were unaffected by the border spray and tillage treatments. Our results confirmed our hypothesis that border sprays can be utilized to reduce populations of D. suzukii in organic blackberry fields, while maintaining populations of natural enemies. However, the effect of soil tillage is unclear and requires further investigation. Additional research should investigate the timing of border sprays and their effect on high infestations of D. suzukii as well as quantify fruit fall and depth of burial to reduce D. suzukii emergence using soil tillage.     

Screening of 25 different natural crop protection products against Drosophila suzukii

Drosophila suzukii is a major pest of soft‐skinned fruits, and insecticides are often used to prevent fruit damage caused by oviposition. As D. suzukii produces many generations per year, repeated insecticide applications are required. Furthermore, D. suzukii attacks ripening and ripe fruits shortly before harvest. Therefore, the use of synthetic insecticides is limited by long pre‐harvest intervals and maximum residue limits. To be able to offer producers immediate and sustainable solutions, we tested 25 natural crop protection products with three different application methods in a laboratory screening. We show that application method is an important factor for the efficacy of the tested products. Of six natural insecticides, only Spinosad was toxic for D. suzukii and reduced the oviposition on treated blueberries. The tested oil products had no control effect and products based on different entomopathogenic fungi and Bacillus thuringiensis rather enhanced oviposition. Mineral products (Kaolin, CaCO₃, Ca(OH)₂ and clinoptilolith) applied as spray solutions were not toxic, but significantly reduced oviposition on blueberries. We provide the first study in which different application methods have been used to compare numerous, commercially available, natural crop protection products with different modes of action against adult D. suzukii. Our findings provide consultants and producers with important insights for the development of sustainable pest control strategies against D. suzukii.     

Limited protection of the parasitoid Pachycrepoideus vindemiae from Drosophila suzukii host‐directed spinosad suppression

Laboratory trials were conducted to determine whether the spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), puparium can provide an effective physical barrier to protect immature stages of the pupal parasitoid Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae) from spinosad treatments. Spinosad insecticides are currently an important suppression strategy for D. suzukii in organically managed fruit orchards although they are well known to cause mortality in hymenopteran parasitoids. High adult P. vindemiae female mortality (83%) occurred within 24 h of exposure to D. suzukii pupae treated with 10 mg a.i. l^?1 spinosad and female parasitoids did not avoid the pupae treated with similar low levels of spinosad in choice tests that included untreated pupae. Pachycrepoideus vindemiae develops as an idiobiont ectoparasitoid on host fly pupa within the sclerotized host puparium. Significant P. vindemiae survival and emergence was recorded when parasitized D. suzukii puparia were exposed to field treatment levels of spinosad; however, the parasitoid survival was dependent on the time of the spinosad treatment of the host post‐parasitization. Significant parasitoid survival occurred when the host puparia were treated at 2 weeks when the parasitoid was in the pupal stage but did not occur when the host puparia were treated at 1 week post‐parasitization, when the parasitoids were still in a larval stage. The parasitoid adults consumed or otherwise came in contact with residual degrading spinosad when they exited the treated host, and consequently high and low adult parasitoid mortality occurred when the adults emerged from puparia treated at 2 and 1 week(s), respectively. Our study indicates that generally the integration of P. vindemiae parasitism into a sustainable D. suzukii management program is not compatible with spinosad treatments, although P. vindemiae in the pupal stage inside sclerotized host puparia appear to be minimally impacted by spinosad treatments, provided that the spinosad degrades before parasitoid emergence.     

Metagenomic analysis reveals changes of the Drosophila suzukii microbiota in the newly colonized regions

The spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a highly polyphagous pest of a wide variety of wild or cultivated berry and stone fruit. Originating from Southeast Asia, it has recently invaded a wide range of regions in Europe and North America. It is well known that insect microbiotas may significantly influence several aspects of the host biology and play an important role in invasive species introduction into new areas. However, in spite of the great economic importance of D. suzukii, a limited attention has been given so far to its microbiota. In this study, we present the first in‐depth characterization of gut bacterial diversity from field (native and invasive range) and lab‐reared populations of this insect. The gut bacterial communities of field insects were dominated, regardless of their origin, by 2 families of the phylum Proteobacteria: Acetobacteraceae and Enterobacteriaceae, while Firmicutes, mainly represented by the family Staphylococcaceae, prevailed in lab‐reared population. Locality was the most significant factor in shaping the microbiota of wild flies. Moreover, a negative correlation between diversity and abundance of Enterobacteriaceae and the time elapsed since the establishment of D. suzukii in a new region was observed. Altogether our results indicate that habitat, food resources as well as the colonization phase of a new region contribute to shape the bacterial communities of the invasive species which, in turn, by evolving more quickly, could influence host adaptation in a new environment.     

Potential host fruits for Drosophila suzukii: olfactory and oviposition preferences and suitability for development

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), the spotted wing drosophila, is a pest endemic to Southeast Asia that invaded the Americas and Europe in 2008. In contrast to most of its congeners, D. suzukii possesses a serrated ovipositor that allows it to lay eggs in unwounded commercial fruits, resulting in severe revenue losses for the industry. The purpose of this study was to determine the susceptibility of known host fruits, including cherry, strawberry, blueberry, and grape, and potential host fruits, such as banana and apple, to attack by D. suzukii. Based on the responses to volatile cues offered in a six‐choice olfactometer, the preference of female D. suzukii was ranked in the following order: strawberry = cherry > banana = apple = blueberry = grape, but in no‐choice and choice oviposition tests, the preferences were ranked as follows: cherry > strawberry = blueberry > grape = banana > apple. Furthermore, we reconfirmed that D. suzukii mainly targets rotten fruit for feeding and ripe fruit for oviposition, and females preferred fruits with intensive mechanical damage. Based on developmental parameters, apple was the least suitable host. This study has implications for the control of D. suzukii, especially in mixed fruit orchards, by providing a promising avenue for exploiting behaviour‐based control tools and emphasizing the importance of phenology in host fruit susceptibility.     

Effects of temperature and relative humidity on mating and survival of sterile Drosophila suzukii

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is a widely distributed pest species of soft-skinned fruits. Recent studies suggest the use of sterile insect technique (SIT) as a control method for this species; however, many factors can impact effectiveness of a SIT programme, including the environmental conditions. Environmental condition is critical at the time of the release and in the days afterwards, since it may impact sterile insects’ survival and ability to mate. Thus, we verified the influence of temperature and relative humidity on mating and survival of fertile and sterile D. suzukii, when insects were food provided or deprived. Highest mating rates occurred when sterile or fertile flies provided with food were exposed to 25ºC or 81%–100% relative humidity, while temperatures of 10 and 35ºC and humidity below 60% impaired mating. Overall, mating rate among food-deprived flies was low in all temperatures and humidity levels tested, but fertile insects were more prone to mate when compared to sterile flies. Survival was negatively influenced by high temperatures, low relative humidity and food deprivation. The information present in this study is useful to be considered for release of sterile D. suzukii.     

Susceptibility of cold hardy grapes to Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii (Diptera: Drosophilidae), known commonly as spotted wing drosophila, is a vinegar fly originating from South‐East Asia and a major pest to many soft‐skinned fruits. Due to the species recent arrival in North America in 2008, many fruit varieties are yet untested for susceptibility to infestation. While previous work has focused on Vitis vinifera, this study aimed to determine grape susceptibility of cold hardy varieties based on hybrids of V. labrusca, V. riparia and V. vinifera. Field sampling was conducted in Southern Wisconsin (USA) vineyards to establish adult and larval abundance and determine whether the number of adults caught in traps correlates with fruit infestation. Host susceptibility was further assessed through no‐choice bioassays of both intact and damaged fruits. The field study found D. suzukii adults present in all varieties, low larval abundance and no correlation between adult abundance and larval presence. Peak adult abundance occurred mid‐season between veraison and harvest, while larval infestation rates were highest near harvest. In laboratory no‐choice tests, significantly more eggs, larvae and adults occurred in damaged than undamaged grapes. In damaged grapes, larvae and adult abundance was comparable between varieties and to the highly susceptible control of undamaged raspberry; however, D. suzukii developed significantly faster in raspberry than grapes. Fruit characteristics (°Brix, titratable acidity, pH) in grapes were uncorrelated with D. suzukii performance. Together, these findings suggest that cold hardy grapes are overall resistant to D. suzukii if intact and highly susceptible if damaged.     

Effects of fluctuating thermal regimes on cold survival and life history traits of the spotted wing Drosophila(Drosophila suzukii)

Drosophila suzukii is an invasive pest causing severe damages to a large panel of cultivated crops.To facili tate its biocontrol with stratcgies such as sterile or incompatible insect techniques,D.suzukid must be mass-produced and then stored and transported under low temperature.Prolonged cold exposure induces chill injuries that can be mitigated if the cold period is interrupted with short warming intervals,referred to as fluctuating thermal regimes(FTR).In this study,we tested how to optimally use FTR to extend the shelf life of D.suzukii under cold storage.Several FTR parameters were asessed:temperature(15,20,25℃),duration(0.5,1,2,3 h),and frequency(every 12,24,36,48 h)of warming intervals,in two wild-type lines and in two developmental stages(pupac and adults).Generally,FTR improved cold storage tolerance with respect to constant low temperatures(CLT).Cold mortality was lower when recovery temperature was 20℃ or higher,when duration was 2 h per day or longer,and when warming interruptions occurred frequently(every 12 or 24 h).Applying an optimized FTR protocol to adults greatly reduced cold mortality over long-term storage(up to 130 d).Consequences of FTR on fitness-related traits were also investigated.For adults,poststorage survival was unaffected by FTR,as was the case for female fecundity and male mating capacity.On the other hand,when cold storage occurred at pupal stage,postorage survival and male mating capacity were altered under CLT,but not under FTR.After storage of pupae,female fecundity was lower under FTR compared to CLT,suggesting an energy trade-off between repair of chill damages and C22 production.This study provides detailed information on the application and optimization of an FTR-based protocol for cold storage of D.suzuki that could be useful for the biocontrol of this pest.     

Oviposition and development potential of the spotted‐wing drosophila,Drosophila suzukii (Diptera: Drosophilidae), on uninjured Campbell Early grape

The spotted‐wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), originally distributed across a few Asian countries including South Korea, has invaded North America and Europe but is absent from Australia. In order to export the South Korean grape cultivar Campbell Early to Australia, its potential to serve as an oviposition and development medium for SWD must first be determined. In this study, we determined the oviposition and development potential of SWD on Campbell Early, after elucidating the SWD life cycle and establishing an artificial diet‐based mass‐culturing system. An investigation of the life cycle under five temperature regimes (16, 19, 22, 25 and 28°C) showed that the durations of the egg, larval and adult stages were shortened when temperature was increased from 16, 19, 22, 25 and 28°C, but pupal duration was shortest at 25°C and extended again at 28°C. A test of oviposition and development potential of SWD on Campbell Early grape clusters showed oviposition of 30.8 ± 6.8 eggs per cluster of injured grapes and 157.7 ± 16.2 eggs on a culture dish of artificial diet. However, in a similar experiment using uninjured grape clusters, only a single egg was deposited on the grape skin, which soon dried. In light of these results, newly harvested grapes left at vineyards during daily harvests are unlikely to serve as an oviposition and development medium for SWD, as long as the grapes remain uninjured.     

Influences of blackberry margins on population dynamics of Drosophila suzukii and grape infestation in adjacent vineyards

Understanding the dynamics of pest insect populations in relation to the presence of non‐crop habitats and infestation levels of adjacent crops is essential to develop sustainable pest management strategies. The invasive pest species Drosophila suzukii (Diptera: Drosophilidae) is able to utilize a broad range of host plants. In viticulture, scientific risk assessment for D. suzukii has only recently started and studies assessing the effects of field margins containing wild host plants on D. suzukii population dynamics and on infestation risks in adjacent vineyards are lacking. Thus, in a one‐year field study, the role of different field margins on fly abundance and crop infestation in adjacent vineyards of Vitis vinifera, variety “Pinot Noir,” were investigated. Different monitoring methods were conducted to assess fly distribution, sex ratio and grape infestation in 14 vineyards adjacent to field margins containing either blackberry (BB) Rubus spp. or non‐host (NH) plants. Our results show that blackberries strongly enhanced D. suzukii abundance within field margin vegetation all year long, whereas fly abundance in vineyards adjacent to BB margins was just enhanced in some seasonal periods. Moreover, the influence of BB margins was limited by distance. However, high fly numbers in BB field margins did result in zero egg infestation of “Pinot Noir” berries. These results may have important implications for winegrowers to make efficient management decisions: regardless of high abundance of adult D. suzukii, only grape berry monitoring can assess the actual infestation risk and the potential need to take management action.     

The effects of non-crop habitat on spotted wing drosophila (Drosophila suzukii) abundance in fruit systems: A meta-analysis

1. Drosophila suzukii (SWD) poses a threat to soft and stone fruit globally. SWD inhabits non-crop areas adjacent to farms from where it moves into crops to cause damage. Effective IPM control strategies, considering both the crop and non-crop area, are needed to control this economically important pest.
2. We conducted a meta-analysis to quantify the impacts of different non-crop habitats around fruit farms on SWD populations, comparing abundance of SWD trapped in crop and non-crop habitats.
3. Overall, SWD abundance was greater in non-crop habitats than in cropped areas and this difference was greatest in farms adjacent to woodland, or field margins containing known SWD host plants.
4. The difference in SWD abundance between crop and non-crop habitats was not affected by crop type but was greatest in the winter months and in conventional compared to organic farms, indicating conventional approaches can reduce relative SWD abundance.
5. Drosophila suzukii overwinter in non-crop habitats which provide refuge outside the cropping season. However, certain habitats support greater relative abundance of SWD than others and this is also affected by farm management. We discuss what these findings mean for effective control of SWD.

     

Evaluating Drosophila suzukii immunomarking for mark‐capture research

Drosophila suzukii Matsumura (Diptera: Drosophilidae) utilizes ‘Himalaya’ blackberry, Rubus armeniacus Focke (Rosaceae), as a host and may invade berry and stone fruit crops from field margins containing this invasive weed. Laboratory and semi‐field studies were conducted to determine (1) the persistence of protein marks including 10% chicken egg whites (egg albumin protein), 20% bovine milk (milk casein protein), and 20% soy milk (soy trypsin inhibitor protein) on topically sprayed D. suzukii, (2) protein retention on blackberry leaves, and (3) D. suzukii acquisition of protein after exposure to marked blackberry leaves for up to 14 days after application. All flies and leaves were assayed for the presence of the protein marks using protein‐specific enzyme‐linked immunosorbent assays. Egg albumin, milk casein, and soy trypsin proteins persisted on 94, 49, and 25% of the topically marked D. suzukii, respectively, throughout the 14‐day study period. Egg albumin was retained on 100% of treated leaves for 14 days, regardless of environmental conditions. At least 50% of flies exposed residually to egg albumin‐treated leaves were marked for 3 days, regardless of exposure time and environmental conditions. However, increasing fly exposure time to treated leaves in April and June appeared to improve protein mark acquisition. Acquisition of protein by flies from treated leaves for milk casein was inconsistent, and poor for soy trypsin, despite detectable levels on treated leaves. Egg albumin had the longest and most consistent persistence on flies, leaves, and flies exposed to leaves in laboratory and semi‐field studies, under a variety of environmental conditions and exposure times.