Vaughn Walton

• PhD
• Professor at Oregon State University

Life tables allow the exploration of insects' and terrestrial arthropods' biology , and how they respond to external factors. Data collection process has been partially standardized, but the presentation of results mainly depends on the purpose of the study. Two different data representations can be obtained from the raw dataset: the differential r...

In recent years, there has been an increase in the adventive establishment and spread of parasitoid wasps outside of their native range. However, lack of taxonomic tools can hinder the efficient screening of field-collected samples to document the establishment and range expansion of parasitoids on continent-wide geographic scales. Here we report t...

Drosophila suzukii (Diptera: Drosophilidae), also known as spotted wings drosophila (SWD), is an economic pest that oviposits and feeds on soft-skinned fruits. Different management practices have been employed in managing SWD because of the economic losses to growers. A promising alternative to conventional broad-spectrum insecticide strategy i.e....

Life tables are one of the most common tools to describe the biology of insect species and their response to environmental conditions. Although the benefits of life tables are beyond question, we raise some doubts about the completeness of the information reported in life tables. To substantiate these doubts, we consider a case study (Corcyra cepha...

Background Drosophila suzukii is a significant invasive pest that has caused high management costs and economic losses for blueberry growers in the United States. The status quo control strategy commonly used by growers is to apply pesticides proactively and frequently to reduce infestation. Recent studies have shown that the calendar‐based sprayin...

Drosophila suzukii Matsumura (Diptera: Drosophilidae) is a key pest of soft-skinned fruit such as blackberry and blueberry. Differing seasonal spray regimes are expected to have variable effects on D. suzukii populations. Semi-field cage trials were performed at three locations in the United States (Georgia, Oregon, and North Carolina) on blueberry...

The invasion of Drosophila suzukii , spotted-wing drosophila, across Europe and the US has led to economic losses for berry and cherry growers, and increased insecticide applications to protect fruit from damage. Commercial production relies heavily on unsustainable use of conventional toxic insecticides. Non-toxic insecticide strategies are necess...

Simple Summary Brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive pest species that causes significant economic damage to many crops. One of the crucial aspects of management strategies rely on understanding the biology and life-table parameters of H. halys. Here, we described the temperature dependent li...

Spotted-wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is an invasive pest of thin-skinned fruits in the United States. Monitoring traps are an integral part of SWD integrated pest management, allowing early detection and timely management of this pest. An ideal monitoring trap should be easy to use, effective in capt...

Surface wax and other cellular building blocks play an important role in preserving fruit integrity from biotic and abiotic adversities. Huge energy expenses are made by plants to place these protective compounds onto the epidermal cuticle. Sprayable plant and fruit coatings have been developed to protect plant tissues from environmental stresses,...

Comparison of liquid versus sticky traps for the season-long monitoring of spotted-wing drosophila in berry and cherry crops in US states.

Drosophila suzukii (Matsumura), spotted-wing drosophila, is a major pest in small fruit crops including highbush blueberry. Controlling D. suzukii is challenging and chemical control is the main method to manage D. suzukii populations. Growers have expressed interest in using micro-sprinklers as an alternative method to apply insecticides. The curr...

This datasheet on Halyomorpha halys covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Prevention/Control, Further Information.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) also known as spotted-wing drosophila (SWD), is a pest native to Southeast Asia. In the last few decades, the pest has expanded its range to affect all major European and American fruit production regions. SWD is a highly adaptive insect that is able to disperse, survive, and flourish under a...

The spotted-wing drosophila, Drosophila suzukii Matsumura, is an invasive pest causing significant damage to soft skinned fruits. Control of D. suzukii is critical since there is no tolerance for infested fruit in the market. While most insecticides control one or more D. suzukii life-stages (e.g., egg, larvae, and adult), the impact of insecticide...

The invasive spotted-wing drosophila, Drosophila suzukii (Matsumura), is a key insect pest of berries globally, causing lost revenues and increased production costs associated with applications of insecticides. The insecticides utilized are commonly broad-spectrum pyrethroids, organophosphates, or carbamates in conventionally managed fields and spi...

The olive fruit fly, Bactrocera oleae , has been a key pest of olives in Europe and North America. We conducted the largest exploration for parasitoids associated with the fly across Sub-Saharan Africa (Kenya, Namibia, and South Africa) including some of the fly’s adjoining regions (Canary Islands, Morocco, Réunion Island and Tunisia). From Sub-Sah...

Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge...

Simple Summary Integrated Pest Management (IPM) is a science-based decision-making process that uses a variety of management approaches to increase farm profitability while protecting human health and the environment, with pesticides used only as a last resort. An important alternative to pesticides, cultural controls modify production practices an...

Simple Summary Among the challenges arising from climate change and the transformation of agroecosystems is that agricultural production is heavily affected by invasive insect species. Invasive insects can establish in new areas where their development can progress due to a suitable climate and lack of natural enemies. Farmers have few options to m...

The olive fruit fly, Bactrocera oleae , has been a key pest of olives in invaded regions Europe and North America. We conducted the largest modern exploration for the fly’s co-evolved parasitoids across Sub-Saharan Africa (Kenya, Namibia, and South Africa) and some of the fly’s expanded regions (Canary Islands, China, India, Morocco, Pakistan, Réun...

Cold winter temperatures can influence insects' survival in temperate zones. Brown marmorated stink bug, Halyomorpha halys (Stål) overwinters as adults in natural and human-made structures. In this study, we characterized low temperature mortality rates of H. halys adults that were either entering (ENA) or exiting (EXA) overwintering microhabitats....

Simple Summary The vine mealybug is a key insect pest of vineyards that currently is controlled by one or more insecticide applications per season. Here, we sought to develop a more sustainable control tool by using the mealybug’s sex pheromone to reduce mating and thereby lower pest damage. The mature female mealybug emits a sex pheromone that the...

Drosophila suzukii Matsumura is an economically important pest of small and stone fruits. Its establishment in the Americas and Europe marked an important turning point in crop management programs. Ten years after its first detection, an effective integrated pest management program has yet to be developed and pesticides are mainly used to control t...

Treehopper insect populations (Hemiptera: Membracidae) were surveyed in 2018 in Benton, Josephine, and Yamhill Counties, Oregon to determine their potential roles in the epidemiology of Grapevine red blotch virus. Stictocephala basalis and Tortistilus albidosparsus were identified through a taxonomic assessment of samples collected by hand near vin...

Drosophila suzukii (Matsumura) is a vinegar fly species that originates from Eastern Asia and has spread throughout Europe and the Americas since its initial detection in United States in 2008. Its relatively large, sclerotized, and serrated ovipositor enables the ability to penetrate ripening fruits, providing a protected environment for its egg a...

A clearer understanding of the structure of pest populations in newly invaded areas is a key step towards their effective management. Here, we use Drosophila suzukii as a model to highlight how populations from separate geographical regions differ in their genetic and phenotypic traits, including those associated with their invasiveness. New X-link...

Overhead irrigation increases humidity—creating more favorable conditions for the development of spotted-wing drosophila (SWD) pest populations. Drip irrigation can limit conditions that favor SWD population increase. Pachycrepoideus vindemmiae is a parasitic wasp (parasitoid) that attacks SWD by laying its eggs on SWD pupa. Drip irrigation may inc...

Multiple biological control agents target SWD, including predators, parasitoids, nematodes and microorganisms such as fungi and bacteria. Predators ambush and eat SWD, removing a substantial portion of them from the production system.

Cultural controls can reduce spotted-wing drosophila population pressure by modifying the microclimate within the crop so that the environment does not promote SWD reproduction and survival.

BACKGROUND Insecticide applications in blueberry production systems play a crucial role in the control of Drosophila suzukii populations. Here, quantitative spray deposition patterns were obtained under replicated field experiments in blueberry during two field seasons with three sprayers, i.e. cannon, electrostatic, and air‐blast. Seven insecticid...

Key points in this fact sheet ¾ SWD infests a wide range of wild and cultivated host plants. ¾ The SWD host plant list is expanding as new knowledge emerges. ¾ Vegetation near production fields can improve environmental conditions for SWD, providing shelter and alternative food sources for SWD. ¾ Alternate host plants near production fields can sig...

Key points from this fact sheet ¾ Most spotted-wing drosophila (SWD) are found in the center of the fruit crop canopy, where they find shade, cooler temperatures and higher humidity. ¾ Sprayer calibration, nozzle orientation, and adequate spray volume are key to good coverage. ¾ Apply sprays using appropriate tractor speeds. ¾ Air-blast sprayers pr...

Key points from this fact sheet ¾ During the growing season, only 10% to 15% of the total spotted-wing drosophila (SWD) population is in the adult life stage. ¾ Most insecticides are effective in the field for a maximum of 10 days. Rain or overhead irrigation significantly reduce this time. ¾ Early in the growing season, insecticides can be applied...

Key points in this fact sheet ¾ Spotted-wing drosophila (SWD) are less active during cold winter months, and mostly survive as adult females during this period. ¾ SWD exist as adult In two morphs or body types. In cold-winter climates, SWD adults can assume a larger, darker-colored winter morph or body type.. ¾ When temperatures rise above 50°F (10...

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an insect pest originating in South-East Asia that has invaded Europe (EU) and the Americas. This insect has caused extensive economic damage to the soft fruit industry in all countries to which it has spread. Drosophila suzukii population management relies primarily on chemical pesticides,...

The invasive spotted-wing drosophila, Drosophila suzukii (Matsumura), is a major pest of soft-skinned fruits. Since its introduction into North America and Europe, significant progress has been made in understanding the volatile cues used by this fly during food, oviposition site, and mate finding. Despite this progress, commercially available lure...

BACKGROUND Fruit growers largely depend on chemical control to reduce populations of the economically damaging invasive fly, Drosophila suzukii (Matsumura). Drosophila suzukii is susceptible to high temperatures and low humidity; therefore, it may be possible to implement cultural control practices that create microclimates unfavorable for its deve...

Pachycrepoideus vindemmiae is a wasp that parasitizes and host-feeds on pupae of the invasive spotted-wing drosophila (SWD, Drosophila suzukii). Few studies have addressed interactions between these two species and little is known about the potential of this parasitoid as a biocontrol agent of SWD and the different variables that may affect it. Her...

Pachycrepoideus vindemmiae is a parasitoid of the invasive spotted-wing drosophila (SWD, Drosophila suzukii) in the U.S. Few studies have addressed interactions between these two species and little is known about the potential of this parasitoid as a biocontrol agent of SWD. Here, we investigated the impact of extrinsic and intrinsic factors on lif...

In Drosophila, intraspecific competition (IC) may cause stress, cannibalism, and affect survival and reproduction. By migrating to less crowded environments, individuals can escape IC. Larvae of spotted-wing drosophila (SWD, Drosophila suzukii) are often exposed to IC. They are known to pupate either attached to or detached from their hosts. Here,...

Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is originally from Asia, and in the last decade it has become a global economic pest of small fruits and cherries. Growers have expressed strong interest in biological control and other sustainable tactics to reduce reliance on insecticides. Biological control of spott...

The management of filbertworm, Cydia latiferreana (Walsingham)using synthetically formulated pheromones for mating disruption was studied as an alternative to grower standard full-cover insecticide applications in the McKenzie River Valley of Oregon during 2012–2013. The data indicate a significant reduction of filbertworm caught in pheromone-baite...

Drosophila suzukii Matsumura is an invasive species affecting berry crops and cherries throughout North America, South America, and Europe. Previous research suggests that in temperate climates, the overwintering success of D. suzukii is likely dependent on access to food, shelter, and adequate cold hardening. We performed a multi-state study under...

Most organisms must ingest water to compensate for dehydration. In parasitic wasps, the importance of water and the behaviors driving its consumption are poorly understood. Here, we describe a water-intake strategy of Pachycrepoideus vindemmiae, a parasitoid of spotted-wing drosophila (SWD, Drosophila suzukii). Longevity measurements indicated that...

Invasive animals depend on finding a balanced nutritional intake to colonize, survive, and reproduce in new environments. This can be especially challenging during situations of fluctuating cold temperatures and food scarcity, but phenotypic plasticity may offer an adaptive advantage during these periods. We examined how lifespan, fecundity, pre‐ov...

Spread and in-field spatial patterns of vines infected with grapevine red blotch virus (GRBV) were documented in Oregon vineyards using field sampling, molecular diagnostics, and spatial analysis. Grapevine petiole tissue collected from 2013 to 2016 was tested using quantitative polymerase chain reaction for GRBV. At Jacksonville in southern Oregon...

Overhead sprinkler compared to drip irrigation in cropping systems can result in increased relative humidity (RH) and decreased temperature within the plant canopy. Such conditions may also result in a more favorable microclimate for pests. Drosophila suzukii Matsumura is an invasive agricultural pest of berries in America and Europe. Drosophila su...

We present a model for the population dynamics of the invasive fruit fly Drosophila suzukii and its pupal parasitoid Trichopria drosophilae. Seasonality of the environment is captured through a system of delay differential equations with variable delays. The model is used to explore optimal timing for releasing parasitoids in biological control pro...

Drosophila suzukii is an insect pest of worldwide distribution on soft-skinned fruit. This species is able to utilize different habitats and substrates for nutrition and reproduction, a capacity that can be attributed to olfactory cues. The first aim of the current study was to create and evaluate a novel gum matrix as a management tool for D. suzu...

Life history parameters are used to estimate population dynamics, mortality, and reproduction in insects relative to their surrounding environment. For Drosophila suzukii Matsumura (Diptera: Drosophilidae), an invasive agricultural pest, previous studies have estimated net reproductive rate (Ro), generation time (T), and intrinsic rate of populatio...

Most organisms must ingest water to compensate for dehydration. In parasitic wasps, the importance of water and the behaviors driving its consumption are poorly understood. Here, we describe a water- intake strategy of Pachycrepoideus vindemmiae, a parasitoid of spotted-wing drosophila (SWD, Drosophila suzukii). Longevity measurements indicated tha...

Drosophila suzukii (Diptera: Drosophilidae) is an invasive alien species devastating soft fruit crops in newly invaded territories. Little is known about the importance and potential of long-distance dispersal at a regional scale. The goal of this work is to investigate D. suzukii dispersal ability during different times of the season, and along an...

Preliminary results testing the effects of ABA application on Red Blotch-infected grapevines in two growing regions to improve fruit composition.

Organic management of spotted wing drosophila in organic berry crops.

Globally distributed nonnative insects thrive by having a generalist diet and persisting across large latitudinal gradients. Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is a cold-tolerant invasive species that enters reproductive diapause in temperate North American and European climates. While it can survive the acute effects of subzero (°C...

Pachycrepoideus vindemiae (Rondani) and Trichopria drosophilae (Perkins) are among a few indigenous parasitoids attacking the invasive Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) in North America. Both parasitoid species occur in California, whereas only P. vindemiae has been reported from Oregon. We compared the thermal performance of...

Determining the most likely source of an invasive pest species might help to improve their management by establishing efficient quarantine measures and heading the search of efficient biological control agents. Planococcus ficus is an invasive mealybug pest of vineyards in Argentina, California, Mexico, Peru and South Africa. This mealybug pest had...

Sample locations and information collected. Vine mealybug, Planococcus ficus (Hem.: Pseudococcidae) collection information showing country and locality (city or region), Global Position Satellite (GPS) coordinates when available, collector and date, whether samples were processed by CO1 or ITS1, if there is a museum deposited slide mount for the lo...

Drosophila suzukii (Matsumura; Diptera: Drosophilidae) is a key pest of sweet cherry and small fruits worldwide. The present studies were designed to describe the reproductive physiology in both sexes, through dissections of their reproductive organs. We extensively dissected female D. suzukii throughout the season from 2013 to 2016 and classified...

This research aimed to more clearly describe the interactions of Drosophila suzukii (Matsumura; Diptera: Drosophilidae) with microorganisms that may contribute to spoilage or quality loss of wine grapes during harvest. Experiments were conducted in controlled laboratory experiments and under field conditions to determine these effects. Laboratory t...

Figure 1. Pupation behavior of SWD in environments with low (left) and high intraspecific competition among larvae. Arrows indicate pupae found off the host plate.

Insect parasitoids are often manipulated to improve biological control programs for various arthropod pests. Volatile compounds can be a relevant cue used by most parasitoid hymenoptera for host or host microhabitat location. Here, we studied olfactory responses of the braconid Asobara japonica Belokobylskij, an Asiatic endoparasitoid of the invasi...

A direct large volume injection (DI-LVI) high performance liquid chromatography – tandem mass spectrometry (HPLC–MS/MS) method was developed and validated for the quantitative determination of 16 systemic insecticides and their main plant metabolites. The assays were conducted on commercial red and white wines made from grapes grown in major wine-p...

Brown marmorated stink bugs (BMSB) release stress compounds, tridecane and (E)-2-decenal, that effect final wine quality. This study focuses on determining the effect of wine processing on (E)-2-decenal and tridecane release in both red and white wines. Wines were produced by adding live BMSB to grape clusters at densities of 0, 0.3, 1 and 3 bugs p...

The invasive spotted wing drosophila, Drosophila suzukii Matsumura (Dipt.: Drosophilidae), a native of East Asia, has widely established in North America and Europe, where it is a serious pest of small and stone fruit crops. The lack of effective indigenous parasitoids of D. suzukii in the recently colonized regions prompted the first foreign explo...

Drosophila suzukii is a serious pest of several fruit crop systems in California’s Central Valley, which is one of the world’s major fruit growing regions. This study followed D. suzukii seasonal population dynamics in multiple cropping and riparian systems in four cherry-producing counties of the Valley. Apple cider vinegar baited traps were used...

Spotted wing drosophila, Drosophila suzukii, is a devastating invasive pest of small and stone fruits in the Americas and Europe. To better understand the population dynamics of D. suzukii, we reviewed recent work on juvenile development, adult reproduction, and seasonal variation in life history parameters including the abiotic/biotic factors that...

Drosophila suzukii causes economic damage to berry and stone fruit worldwide. Laboratory-generated datasets were standardized and combined on the basis of degree days (DD), using Gompertz and Cauchy curves for survival and reproduction. Eggs transitioned to larvae at 20.3 DD; larvae to pupae at 118.1 DD; and pupae to adults at 200 DD. All adults ar...

Drosophila suzukii, spotted wing drosophila, is a serious pest of small fruits and cherries in many regions of the world. While host usage has been well studied at the ovipositional and larval feeding stages, little is known about the feeding ecology and nutrient requirements of adults. This study addressed the impact of feeding on the survival and...