Jason M. Schmidt

University of Georgia | UGA · Department of Entomology

Generalist arthropod predators have historically contributed to the suppression of arthropod pests in many agroecosystems. The successful implementation of integrated pest management (IPM) programs hinges on the incorporation of insecticides that are compatible with the biological attributes of natural enemies of pests. A potentially promising path...

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), commonly known as spotted-wing Drosophila (SWD), is an invasive insect pest threatening the economy of many small fruit farms in the Americas and Europe. Biological control using parasitoids is a promising strategy for improving the sustainable management of SWD. To use the parasitoids as bio...

https://extension.uga.edu/publications/detail.html?number=B1562&title=natural-enemies-of-pests-in-the-southeast-blueberry-systems-of-georgia

Metarhizium (Hypocreales: Clavicipitaceae) has a multifunctional life cycle, establishing as a plant endophyte and acting as entomopathogenic fungi. Metarhizium robertsii and Metarhizium brunneum can be associated with coffee plants and provide enhanced protection against a major pest of coffee, the coffee leaf miner (CLM) (Leucoptera coffeella). T...

Pecan is a valuable nut crop cultivated in the southeastern US. Among the major yield-limiting factors in the region is scab, caused by the plant pathogenic fungus Venturia effusa. Managing scab in tall trees (15 to 25+ m) in pecan orchards is challenging due to the limitations of getting sufficient spray coverage throughout the canopy. We explored...

Promoting arthropod biodiversity to increase ecosystem services through ecological intensification is a challenge for agriculture. And recent evidence suggests that standard pesticide applications not only harm natural enemies but may also fail to deliver long-term pest control solutions. To fuel ecological intensification and build predictive fram...

Advances in molecular ecology can overcome many challenges in understanding host–parasitoid interactions. Genetic characterization of the key-players in systems helps to confirm species and identify trophic linkages essential for ecological service delivery by biological control agents; however, relatively few agroecosystems have been explored usin...

Weed management is challenging for vegetable crops that are highly sensitive to weed competition, such as onions. Thrips (Thysanoptera: Thripidae) are major insect pests of onions, causing damage through feeding, and vectoring bacterial pathogens causing bulb rot. Both thrips and their associated pathogens are known to survive on many weed species...

Visual overview of wildbees in SE Georgia blueberries. https://extension.uga.edu/publications/detail.html?number=C1295&title=visual-guide-to-common-bees-of-blueberry-fields-in-southeast-georgia

Conservation biological control efforts depend on accurately estimating predator roles in crop fields, and knowledge of plant resources generalist predators utilize in agricultural landscapes. Generalist predators move among habitats to feed on insect prey and some predators feed on plants for non-prey nutrients. Studying preda-tion with molecular...

BACKGROUND Rising global temperatures are associated with emerging insect pests, reflecting earlier and longer insect activity, faster development, more generations per year and changing species' ranges. Insecticides are often the first tools available to manage these new threats. In the southeastern US, sweet potato whitefly (Bemisia tabaci) has r...

Introduced species alter established trophic interactions and molecular analysis can resolve changes in community structure and associated foraging links. Joro spiders (Trichonephila clavata) were recently introduced to the United States and their range is rapidly expanding across the east coast. Here, we used DNA metabarcoding of fecal samples, pr...

In many agroecosystems, brown marmorated stink bugs (Halyomorpha halys) (Hemiptera: Pentatomidae) are polyphagous pests that cause significant economic losses to numerous crops every year. Insectivorous birds may provide a means of sustainable predation of invasive pests, such as H. halys. In forest margins surrounding peach, pecan, and interplante...

Plant defense traits such as trichomes along with biocontrol agents may provide alternatives to insecticide use in tomatoes, Solanum lycopersicum L. (Solanaceae). However, plant‐herbivore‐natural enemy interactions are not always complementary. In a series of greenhouse and field experiments, we explored whether augmented defense traits (i.e., prod...

Using artificial intelligence (AI) and the IoT (Internet of Things) is a primary focus of applied engineering research to improve agricultural efficiency. This review paper summarizes the engagement of artificial intelligence models and IoT techniques in detecting, classifying, and counting cotton insect pests and corresponding beneficial insects....

In agricultural systems, aphids (Hemiptera: Aphididae) have been shown to exhibit differences in within plant vertical distribution in vegetation. In addition, natural enemies, such as parasitoids, may have canopy micro-climate preferences. Currently, the within plant vertical distribution of aphids is primarily documented in row crops with few stu...

Coenosia attenuata is a member of the tigrina-group of Coenosia (sensu Hennig 1964) and is a capable generalist predator in its larval and adult stages. C. attenuata is common in greenhouses worldwide, however, there are few documented cases of its presence in the wild. Here, we estimated C. attenuata presence in the southeastern USA peach orchards...

Extension report on the joro spider. https://extension.uga.edu/publications/detail.html?number=C1273&title=joro-spider-trichonephila-clavata

Toxicity of the metabolites of two bacteria, Photorhabdus luminescens and Xenorhabdus bovienii, symbionts of entomopathogenic nematodes, were tested in the laboratory against the multicolored Asian lady beetle, Harmonia axyridis, the black pecan aphid, Melanocallis caryaefoliae, and the blackmargined aphid, Monellia caryella. Bacterial broth prepar...

post-feeding detection times in three dominant predator functional groups (chewing, piercing/sucking, and spiders). This was based on three published B. tabaci-specific primers. These data reveal that primer choice generated significantly different B. tabaci DNA half-lives in predator gut content. The primers with longer half-life resulted in highe...

In this study, we have compared YOLOv4, a single-shot detector to Faster-RCNN, a two-shot detector to detect and classify whiteflies on yellow-sticky tape (YST). An IoT remote whitefly monitoring station was developed and placed in a whitefly rearing room. Images of whiteflies attracted to the trap were recorded 2× per day. A total of 120 whitefly...

The reproductive success of animals breeding in cities is often lower compared to counterparts that inhabit rural, suburban, and peri-urban areas. Urban dwelling may be especially costly for offspring development and survival. Diet composition and diversity may underlie factors that lead to lower fitness, particularly if prey abundance and quality...

Despite a developing understanding of how landscape level processes moderate biodiversity patterns and ecosystem functioning, key questions remain unresolved, therefore limiting our ability to manage for biodiversity conservation and ecosystem functioning at the most appropriate scales. These questions have remained unanswered because studies in ag...

Polyphagous pests cause significant economic loss worldwide through feeding damage on various cash crops. However, their diets in agricultural landscapes remain largely unexplored. Pest dietary evaluation in agricultural fields is a challenging task currently approached through visual observation of plant feeding and microscopic identification of s...

Wild bees are major contributors to pollination of economically important crops. However, widespread habitat conversion to agriculture and pesticide exposure are associated with declines in wild bee abundance and biodiversity. A growing number of studies have investigated the incorporation of a variety of flower species in agroecosystems to augment...

Despite the dynamic nature of annual cropping systems, few studies have investigated how the structure of predator communities and their interactions with prey corresponds with crop seasonality. Adding winter habitat, such as cover crops, improves soil health and likely contributes seasonal habitat availability for arthropod communities. Stable hab...

In blueberry crops, there are multiple pest species, and some of those can be suppressed by natural enemies including parasitoid wasps and predators. Parasitoid wasps occur within the environment often tracking pest species for food resources to complete their lifecycle. These small wasps are also sensitive to agricultural environments including ag...

Coffee leaf miner (CLM), Leucoptera coffeella, is a key pest of unshaded coffee in hot, dry neotropical production areas. Control is hampered by CLM mining behavior that reduces biological control and pesticide efficacy. Therefore, finding natural enemies that can efficiently control CLM could improve conservation and augmentative biological contro...

Biodiversity is an essential attribute of sustainable agroecosystems. Diverse arthropod communities deliver multiple ecosystem services, such as biological control, which are the core of integrated pest management programs. The molecular analysis of arthropod diets has emerged as a new tool to monitor and help predict the outcomes of management on...

Precision agriculture (PA) is the application of management decisions based on identifying, quantifying, and responding to space-time variability. However, knowledge of crop pest responses to within-field environmental variability, and the spatial distribution of their natural enemies, is limited. Quantitative methods providing insights on how pest...

The whitefly, Bemisia tabaci, has developed resistance to many insecticides, renewing interest in the biological control of this global pest. Generalist predators might contribute to whitefly suppression if they commonly occur in infested fields and generally complement rather than interfere with specialized natural enemies. Here, we review literat...

• Plant–animal interactions are diverse and widespread shaping ecology, evolution, and biodiversity of most ecological communities. Carnivorous plants are unusual in that they can be simultaneously engaged with animals in multiple mutualistic and antagonistic interactions including reversed plant–animal interactions where they are the predator. Com...

Maintaining habitat throughout the season in annual cropping systems provides resource stability for arthropod communities. Stabilizing resource availability should lead to diverse predatory communities and their associated ecosystem services such as biological control. There is a need for studies to test change in predator communities due to habit...

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Heteroptera: Aphididae), was recently recognized as a pest of grain sorghum, Sorghum bicolor (L.) Moench, in the southeastern United States. The objectives of the study reported herein were to evaluate the suitability of using a consensus-based scouting network and determine the timing of insecti...

A shift to more ecologically based farming practices could improve the sustainability and economic stability of agricultural systems. Habitat management in and around agricultural fields can provide stable environments that aid in the proliferation of natural enemy communities that moderate pest populations and injury. Winter cover crops offer a po...

A shift to more ecologically based farming practices would improve the sustainability and economic stability of agricultural systems. Habitat management in and around agricultural fields can provide stable environments that aid in the proliferation of natural enemy communities that moderate pest populations and injury. Winter cover crops offer a po...

Georgia has a wealth of wetland resources, with the Okefenokee and Chickasawhatchee swamps, the Altamaha River floodplain, and Georgia’s coastal saltmarshes being among the most renowned wetland habitats in the world. Historically, many people have viewed wetlands as “wastelands,” having few virtues. But that perception has changed. Now it is know...

https://extension.uga.edu/publications/detail.html?number=C1161

An adventive aphid and novel host-parasitoid association from cultivated strawberry (Fragaria × ananessa Duch. cv. Chandler; Fragaria × ananessa Duch. cv. Camarosa) in Mississippi, USA are reported herein. The aphid, first detected in high tunnel cultivation, was found predominately on newly emerged, not fully developed leaflets of daughter plants...

Like natural enemies, invasive polyphagous pests may respond positively to local and landscape-scale diversity, making them more serious challenges to sustainable management than specialists. Yet the current view of landscape effects on pests rarely considers perennial systems or polyphagous pests. We investigated Drosophila suzukii (SWD) and natur...

Like natural enemies, invasive polyphagous pests may respond positively to local and landscape-scale diversity, making them more serious challenges to sustainable management than specialists. Yet the current view of landscape effects on pests rarely considers perennial systems or polyphagous pests. We investigated Drosophila suzukii (SWD) and natur...

Studies show that agricultural land requires investment in the habitat management of non-cropped areas to support healthy beneficial arthropods and the ecosystem services they provide. In a previous small plot study, we manually counted blooms over the season, and found that plots providing greater numbers of flowers supported significantly higher...

Cowpea curculio, Chalcodermus aeneus (Boheman), is the major pest of southern peas or cowpea, Vigna unguiculata (L.). Throughout the southeastern United States, current management recommendations for cowpea curculio rely on insecticide applications; however, resistance has been observed. Entomopathogenic biocontrol agents, specifically nematodes in...

Natural enemies are valuable components of agroecosystems as they provide biological control services to help regulate pest populations. Promoting biocontrol services can improve sustainability by decreasing pesticide usage, which is a major challenge for the blueberry industry. Our research is the first to compare natural enemy populations in mana...

Background Deciphering the amount of work provided by different co-authors of a scientific paper has been a recurrent problem in science. Despite the myriad of metrics available, the scientific community still largely relies on the position in the list of authors to evaluate contributions, a metric that attributes subjective and unfounded credit to...

Marginal agricultural land provides opportunities to diversify landscapes by producing biomass for biofuel, and through floral provisioning that enhances arthropod-mediated ecosystem service delivery. We examined the effects of local spatial context (adjacent to woodland or agriculture) and irrigation (irrigation or no irrigation) on wildflower blo...

Marginal agricultural land provides opportunities to diversify landscapes by producing biomass for biofuel, and through floral provisioning that enhances arthropod-mediated ecosystem service delivery. We examined the effects of local spatial context (adjacent to woodland or agriculture) and irrigation (irrigation or no irrigation) on wildflower blo...

In greenhouse systems it is commonplace to release a suite of predators or parasitoids to combat pest populations that grow in both the vegetative portion of plants and soil. For instance, to control thrips and fly pests, a combination of Neoseiulus cucumeris (Oudemans 1930), a foliar predatory mite, Stratiolaelaps miles (Berlese 1892), a soil dwel...

We evaluated pest and predator spatial distributions in relation to asparagus field margins, developed molecular gut content analysis methods for two key asparagus pests, and determined trophic links between the two pests and arthropod predators. Our results indicated that the abundance of natural enemies is higher outside asparagus fields than ins...

Deciphering the amount of work provided by different co-authors of a scientific paper has been a recurrent problem in science. Despite the myriad of metrics available, the scientific community still largely relies on the position in the list of authors to evaluate contributions, a metric that attributes subjective and unfounded credit to co-authors...

Habitat management enhances heterogeneity in agroecosystems and also has the potential to increase recruitment of spiders, which can improve the biological control services afforded by these important predators. A paucity of studies has documented the associations of spiders with plant communities or the efficacy of non-crop plants for increasing t...

Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), plum curculio, is a serious direct pest of North American tree fruit including, apples, cherries, peaches and plums. Historically, organophosphate insecticides were used for control, but this tool is no longer registered for use in tree fruit. In addition, few organically approved insecti...

With global increases in the production of cellulosic biomass for fuel, or “biofuel,” concerns over potential negative effects of using land for biofuel production have promoted attention to concepts of agricultural landscape design that sustainably balance tradeoffs between food, fuel, fiber, and conservation. The southeastern region of the USA ha...

Environmental heterogeneity can have profound effects on agroecosystem function and it is important for improving ecosystem services such as biological control. Promoting system diversity via non-crop plants is one method for increasing habitat heterogeneity within farmscapes. Non-crop plants provide access to refuges and alternative food resources...

Improving the diversity of farm systems or landscapes can lead to more effective biological control by providing refuge and alternative resources for colonising natural enemies. Within an experimental cabbage agroecosystem, we examined the effects of habitat management (i.e. herbicide use and cover crops) on pest populations and predator community...

One challenge of organic farming is to sustainably prevent the establishment of damaging pest populations. Two ways of achieving this goal include the use of row cover and organic pesticides. However both methods can cause potential problems for growers; row covers prevent pollinators and natural enemies from accessing the crop, while pesticides ma...

Acorn squash (Cucurbita pepo var. turbinata) is one of the most widely grown crops in the North Central US, yet it is also one of the most likely to face pest pressure and biological control deficits. Promoting biological control services requires habitat and resources to increase the abundance and efficacy of natural enemies, which are often lacki...

Asparagus miner (AM), Ophiomyia simplex Loew (Diptera: Agromyzidae), is a major pest of asparagus and has been identified as a putative vector for pathogenic Fusarium spp. Presently, the naturally occurring predators of AM are unknown, but field observations suggest that spiders are among the predators that consume these insects as adults. The goal...

Background/Question/Methods Enhancing the habitat diversity of agroecosystems can promote biological control by encouraging colonization and population growth of natural enemies. However, few studies have taken the next step to estimate the corresponding effects of habitat management on biological control services and trophic structure of the res...

Interactions between predators foraging in the same patch may strongly influence patch use and functional response. In particular, there is continued interest in how the magnitude of mutual interference shapes predator-prey interactions. Studies commonly focus on either patch use or the functional response without attempting to link these important...

A broad range of environmental conditions likely regulate predator-prey population dynamics and impact the structure of these communities. Central to understanding the interplay between predator and prey populations and their importance is characterizing the corresponding trophic interactions. Here we use a well-documented molecular approach to exa...

Uncertainties exist about the value of non-prey food for predators that are commonly food-limited, and the dietary conditions where non-prey foods are beneficial for carnivorous species. Prior studies show that large quantities of pollen grains are intercepted in the webs of web-building spiders. We examined the nutritional benefits of pollen as a...

The intensive use of high quantities of insecticides is the most common tactic for pest management in the United States despite its widely recognized non-target effects in ecosystems. Organic management schemes aim to limit chemical inputs thus, there is a need to adopt alternative management practices for pest control. The integration of conservat...

Green lacewings (Chrysopidae:Neuroptera) and ladybeetles (Coccinellidae:Coleoptera) are recognized as aphid predators, and promoting these natural enemies reduce the need for pesticides. However, these predators consume similar resources and with overlapping distributions, intraguild predation (IGP) may disrupt biological control. In this study, we...

Foraging by an organism varies over the season in response to environmental conditions. Predatory arthropods, such as spiders, are frequently in a food-limited state despite their polyphagous habits and may feed opportunistically to enhance rates of growth, survival and reproduction. We predicted that, to circumvent food limitation, spider foraging...