Jason M. SchmidtUniversity of Georgia | UGA · Department of Entomology
Jason M. Schmidt
PhD
About
72
Publications
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602
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Citations since 2017
Introduction
Additional affiliations
November 2014 - January 2015
June 2011 - October 2013
Publications
Publications (72)
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...
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 unex-plored. Pest dietary evaluation in agricultural fields is a challenging task currently approached through visual observation of plant feeding and microscopic identification of...
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...
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...
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...
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...
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...
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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...
Intraguild interactions are influenced by the density of predators present in an ecosystem. In holometabolous organisms, larvae are vulnerable to predation and represent an alternative food source. Both lady beetles and lacewings are biological control agents of aphids, one of the most detrimental pest insects in crop production systems. Therefore,...
Low natural enemy diversity and abundance in agroecosystems often result in detrimental pest outbreaks. Conventional agriculture often relies on application of synthetic insecticides to manage pests, while organic systems typically combine exclusion tactics and naturally-derived insecticides. Our study was designed to quantify the effects of exclus...
While foraging theory predicts that predatory responses should be determined by the energy content and size of prey, it is becoming increasingly clear that carnivores regulate their intake of specific nutrients. We tested the hypothesis that prey nutrient composition and predator nutritional history affects foraging intensity, consumption, and prey...
Results from analyses to determine the equivalence of spider size and condition across treatments.
(DOCX)
Summary statistics and analyses of the number of partially consumed prey left behind in experiments.
(DOCX)
Despite the widely held assumption that ‘generalist’ predators consume most prey available to them, there is a growing body of evidence suggesting otherwise. Generalists are expected to perform well in disturbed areas because they can switch between prey pathways when one food source becomes depleted. Indeed, these predators have the potential to p...
Structural features of habitat are known to affect the density of predators and prey, and it is generally accepted that complexity provides some protection from the environment and predators but may also reduce foraging success. A next step in understanding these interactions is to decouple the impacts of both spatial and trophic ingredients of com...
Background/Question/Methods The ability to maintain high densities of natural enemies in managed systems may depend on the strength of agonistic interactions both within and among species. One explanation is that interference between predators decreases predator performance. There are few empirical tests of the interaction between prey and predator...
Background/Question/Methods Feeding patterns of generalist predators present intriguing challenges for ecologist due to the complexity of these food webs. Spiders (Araneae) comprise one of the most common predatory groups in terrestrial systems. It is difficult to quantify their feeding frequency, because they use extraoral digestion, and are docum...
Understanding how animals weigh habitat features, exposure to predators and access to resources is important to determining their life history and distribution across the landscape. For example, when predators accumulate in structurally complex habitats, they face an environment with different competitive interactions, foraging opportunities and pr...
Projects
Projects (4)
Our goal is to elucidate the roles of natural enemies and potential modulators of their trophic networks and spatial-temporal distribution in perennial tall tree systems. This project is funded by Sustainable Agriculture Research and Education (SARE) through the Graduate Student Grant awarded to Mr. Toledo in 2021.
The goals of this project are to 1) understand how agricultural landscape complexity can alter B. tabaci/ generalist predators interaction in agricultural fields and its consequences for whitefly biological control in cotton and peanut agroecosystems in Georgia.
2) Using multiplex PCR and DNA metabarcoding approaches, determine the diets of B. tabaci in the agroecosystem, and try to understand how landscape metrics (e.g., composition and configuration) can shift the whitefly diet in cotton and peanut agroecosystems.