ECOSYSTEM SERVICES PROVIDED BY NATURAL ENEMIES OF ARTHROPOD HERBIVORES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1016258
• Project Start Date: Oct 1, 2018
• Project End Date: Sep 30, 2023
• Program Code: [(N/A)]- (N/A)

Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907

Performing Department
Entomology

Non Technical Summary
Managing pests continues to be a problem in many production systems even in crops with the latest pest management technologies. Adding more technologies move these production systems farther from the influences of the surrounding environment and the benefits afforded by ecosystem services. Biological control is an ecosystem service found in nature that has been often overlooked and continues to be underappreciated. In a landmark article (Hairston et al., 1960), ecologists explained that the world was green because, although most organisms in nature are resource limited, herbivores are seldom food-limited, but subject to the impact of predators and other natural enemies in the form of biological control services.While the benefits of natural enemies in sustainable production systems are better appreciated, if not always better understood, their impact on commercial production systems has been mostly discounted. This is because many of these biological control services have not been quantified to demonstrate impact or understood so they could be managed. The objectives of this project will help us characterize the community of natural enemies available as an ecosystem resource, determine the components of this community impacting important crop pests and conferring essential biological control services, and identify general principles that can be applied to maximize the benefits of biological control available as an ecosystem service.Natural enemy communities and corresponding ecosystem services found in two distinct crop production systems are the subjects of this project. The first is cucurbit production in the Midwest where a complex of mostly endemic insect herbivores and natural enemy generalists are found in commercial production heavily dependent on pesticides. The second is cassava in Africa, a root crop grown throughout the humid and subhumid tropics, where the crop and a major spider mite herbivore are exotic species, as is a single promising predatory mite species recently introduced as a classical biological control agent. Cassava growers in Africa rarely use pesticides or other commercial inputs, however evolving agricultural production practices in associated crops have seen a dramatic increase in the use of potentially disruptive pesticides. These distinct cropping systems allow for differences in natural enemy services to be identified and characterized so that patterns of ecosystem services provided by natural enemies can be identified, measured and potentially generalized for other herbivore/natural enemy combinations in other production systems.Additional tools are needed to help manage common and persistent pest problems. The pest management strategies featured in this project have deep historical roots in agriculture and potentially broad application in other production systems where biological control can be quantified and managed. In addition to the benefits of pest management, embracing ecosystem services also provides an incentive to preserve and protect environments that provide these and other essential services needed in agriculture and the world around us. While not every pest problem will be immediately or totally solved by natural systems, this work will help lay a foundation for identifying ways to better manage the services that are or could be available when properly managed. By understanding the interactions critical to managing production systems and opportunities to link with ecosystems services, the lessons learned in this project should have broad applicability well beyond cucurbits and cassava.

Animal Health Component

60%

Research Effort Categories

Basic

40%

Applied

60%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	1420	1130	25%
211	1455	1130	25%
215	3120	1070	25%
215	3110	1070	25%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 215 - Biological Control of Pests Affecting Plants;

Subject Of Investigation
3120 - Spiders, mites, ticks, and other arthropods; 1455 - Cassava (or manioc); 3110 - Insects; 1420 - Melons;

Field Of Science
1130 - Entomology and acarology; 1070 - Ecology;

Keywords

pest management

biological control

ecosystem services

natural enemies

cucurbits

cassava

insects

mites

Goals / Objectives
The overall goal of this project is to measure the biological control ecosystem services provided by natural enemies in cucurbit and cassava crop production systems. These services depend on the crop, pest complex and nature of the associated natural enemies, as well as associated microbial communities.Specific objectives are as follows:Characterize the natural enemy and associated microbial communities found in cucurbit and cassava crop production systems.Measure the biological control ecosystem services being rendered by natural enemies.Identify characteristics of biological control services with broader implications.

Project Methods
Objective 1 Characterize the natural enemy and associated microbial communities found in cucurbit and cassava crop production systems.Cucurbits - This work will be implemented as complementary research to a regional effort led by Purdue University to evaluate tradeoffs between commercial cucurbit pest management and pollinator health best practices. Cooperators in Indiana, Ohio and Michigan received a USDA SCRI grant to address similar tradeoff concerns between different cucurbit production systems. The Indiana team will work on the disruptive effects of pesticides on watermelon pollinators, and the efforts on natural enemies are outlined below. This research will be done in paired fields of watermelons planted using commercial practices. Each field will be surrounded by corn that has either been treated or not with neonicotinoids. These paired combinations will be replicated in five locations across the state.Natural enemy community - Representative guilds of predators (e.g., coccinellids, carabids, spiders, hemipterans), parasitoids (e.g., tachinids and braconids) and pathogens (nematodes and fungi) found associated with striped and spotted cucumber beetles, the most common arthropod herbivore pests of watermelon, will be characterized in terms of abundance, diversity and species richness from population samples taken each week using plant counts, soil core samples, pitfall trap and sticky traps throughout the production season. This will be done in watermelon fields surrounded by either treated or untreated corn subjected to either intensive or integrated pest management (IPM) practices, and in the surrounding corn fields.Pesticide risk - Selected natural enemies representing different guilds, e.g., predators, parasitoids, pathogens, and different functional groups, e.g., natural enemies found on plants, on the ground or in the soil will be evaluated for their exposure to pesticides in both corn and watermelon field plots as described above. Corresponding plant and soil samples will also be collected and evaluated. Samples will be collected periodically during the cucurbit growing season. Pesticide residues will be analyzed by liquid chromatography-mass spectrometry (LC-MS) using an Agilent 1200 LC interfaced to a Thermo-LTQ mass spectrometer at the Proteomics Facility of the Bindley Bioscience Center.Microbial associations - A subsample of natural enemies collected for pesticide risk will also be screened for associated microorganisms. The results will provide a baseline of microbe/host associations necessary for understanding consequential interactions between species and communities. The total gut bacterial community will be characterized with a targeted amplicon approach using the16S rRNA gene for bacteria- and ITS for fungi. Basic bioinformatics approaches will be used, e.g., Mothur Bioinformatics Pipeline (https://www.mothur.org) to characterize the microbial community diversity, composition and abundance. The results will provide a baseline of microbe/host associations necessary for understanding consequential interactions between species and communities.Cassava - This work builds on a longstanding campaign to control the exotic cassava green mite on cassava in Africa. Among the mite predators in the family Phytoseiidae introduced in the 1980s and 1990s, Typhlodromalus aripo, has become a consequential biological control agent with considerable potential impact throughout much of the African cassava belt.Cassava green mite natural enemy database - During the cassava green mite campaign, a better understanding was needed of the mite fauna found on cassava. This prompted a continent-wide inventory of mites found on cassava and associated crops, selected weeds and native plants throughout the cassava belt in Africa. These data will be captured in a georeferenced database with links to agrometeorological and vegetation data to better characterize the site records and help define biotic and abiotic limits to the distributions evident in the data.Objective 2 Measure the biological control ecosystem services being rendered by natural enemies.Cucurbits -Biological control services - The services provided by natural enemies will be measured by monitoring pests, natural enemies and plant performance in a series of field experiments. Cucumber pests and natural enemies on watermelons plants that have been manipulated to allow or repel natural enemies will be enumerated throughout the growing season in the field. The number of pests and natural enemies found per plant in each cage will be counted each week from the time the cages are established in the field until the crop is harvested. Additionally, plants in each cage will be scored for pest damage, e.g., leaf size, leaf area damaged, length of branches and fruit weight, and related to plot yields that will be measured separately in the same field.Food webs - The numerical relationships observed between natural enemies and the prey they presume in the field will be confirmed by examining predator gut content. DNA analysis of gut content will provide a quantitative snapshot of the interactions between cucumber beetles and members of their predator community and help identify key linkages within the cucurbit food web. Samples will be taken periodically during the growing season from representatives of specific predator guilds, e.g., piercing-sucking vs chewing, aerial vs ground, high vs low vagility, social vs solitary, and their guts will be analyzed using DNA extracted from field samples followed by cloning and sequencing PCR amplicons using high-throughput next generation sequencing (Pompanon et al. 2012).Cassava -Impact of exotic phytoseiid predatorsPersistence of T. aripo and corresponding densities of M. tanajoa - Field surveys will be done in selected countries to determine the long-term persistence of T. aripo and measure corresponding pest densities of M. tanajoa. This information will fill gaps in knowledge about the establishment, spread and persistence of the introduced predator, and verify whether the corresponding pest densities continue to remain below population densities have changed from historical levels since the release of exotic predators.On-farm impact of T. aripo on cassava production - Cassava production trials done in Benin and Nigeria over several seasons in multiple locations to measure the impact of T. aripo on cassava yield in plants with and without the predator will be analyzed, reported and compared across time and space with new productions trial results. T. aripo inhabit cassava shoot tips during the day, which makes it easy and effective to selective remove this predator by applying a pyrethroid pesticide drench only to the shoot tips (Onzo et al., 2014).Economic impact of biological control on cassava - this will require the collaboration of a production economist to help measure the net present value of the biological control campaign using current cassava production data and market prices. The goal would be to document the impact of the campaign and publish the results in the scientific literature.Objective 3 Identify characteristics of biological control services with broader implications.The scientific literature will be reviewed and combined with the results from this project for a meta-analysis of successful biological control services. The objective will be to identify general principles that can be applied to promote biological control as an ecosystem services in crop production systems.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The primary audience for this project is the scientific community, as well as crop production stakeholders including farmers, crop and pest consultants, and policy makers. Because of the coronavirus pandemic, most meetings were cancelled or postponed. Changes/Problems:COVID-19 pandemic significantly disrupted plans, activities, workforce support What opportunities for training and professional development has the project provided?A master's student, a second postdocs, an undergraduate student and an international student intern were all trained as part of this project in 2020. All of these individuals got experience with field research, while the intern, graduate student and postdoc contributed to data analysis, and preparing and presenting talks at stakeholder venues and scientific meetings. Ultimately, they will take the lead in developing manuscripts and drafting scientific publications. How have the results been disseminated to communities of interest?The primary audience for this project is the scientific community, as well as crop production stakeholders including farmers, crop and pest consultants, and policy makers. Because of the coronavirus pandemic, most meetings were cancelled or postponed. What do you plan to do during the next reporting period to accomplish the goals?Cucurbit production system: Finish data analyses Present results at scientific meetings Draft manuscripts Cassava production system: On hold until COVID-19 pandemic allows for international travel

Impacts
What was accomplished under these goals? We discovered a pest assemblage in cucurbit production dominated by cucumber beetle pests that fluctuate seasonally, geographically and annually with a closely linked and extensive natural enemy community that provides essential biological control services when not disrupted by the unnecessary use of insecticides. The cucurbit pest assemblage and associated natural enemies in this cropping system have now been quantified and characterized as a function of a typical growing season under commercial-scale production practices. We identified specifics members of these communities, and once again in another cropping system, measured and confirmed the disruptive impact that some production practices, specifically the over use of pesticides, can have on these communities, particularly on the ecosystem services provided by local natural enemies. The ecosystem services provided by these natural enemies maintain cucumber beetle pests below economic thresholds throughout the season in most locations over multiple years when Integrated Pest Management (IPM) best practices are followed. This pest management approach results in a greater abundance and higher diversity of natural enemies, fewer pests reaching economic threshold, and less money spend on unnecessary insecticides with no measurable reduction in crop yields. Characterize the natural enemy and associated microbial communities found in cucurbit and cassava crop production systems. While most of the data have been summarized and the preliminary statistical analyzes completed, aggregating the results into functional feeding guilds and examining community-level and landscape effects is still in progress. A representative sample of the results being prepared for all the targeted taxa and functional feeding guilds are presented here. These include data from the foliage strata featuring cucumber beetles and coccinellid predators, and from the soil for collembola as alternate prey. While data were collected from both watermelon and the surrounding corn, only a selection of results mostly from watermelon are ready and reported here. Cucumber beetles - Cucumber beetles are the primary insect pest of concern to commercial watermelon growers and were the principle pest target in this trial. The three main species in our trial were the striped (Acalymma vittatum Fabricius), the spotted cucumber beetles (Diabrotica undecimpunctata howardi Barber), and the western corn rootworm, (Diabrotica virgifera virgifera LeConte). Cucumber beetles were counted every two weeks on plants and from sticky cards after a week in the field located in the same fields. Striped cucumber beetles were the most common and dominant cucumber beetle on plants and sticky cards in watermelon plots where counts were highly correlated. Spotted cucumber beetles were much less abundant, and rarely found on plants and only occasionally on sticky cards in watermelon plots. The western corn rootworm was almost exclusively found on corn where other cucumber beetle species were either absent or rare. Results from plant counts reflected most observations from sticky cards - more arthropods on watermelon than corn, more arthropods on watermelon in 2019 than 2018 - but without the diversity resolution found from sticky cards. Similar patterns in abundance and seasonality was observed in the targeted taxa - striped cucumber beetles on watermelon, western corn rootworms on corn, coccinellids and spiders on both crops, and with only a few differences between location, which probably reflected the collecting method. Significantly greater number of cucumber beetles, regardless of species, were found in the IPM field plots, but abundance did vary significantly between locations, seasons and years. The pattern for location was cucumber beetle specific, while counts on watermelon generally increased during the season across taxa, and the overall abundance was again significantly greater in 2019 compared to 2018, again across sampling methods and taxa. Coccinellids - Coccinellids in watermelon on plants showed a significant positive response to the fixed effects of location, treatment and season, while from sticky cards, coccinellids responded significantly to year, location and season; treatment effects were not significant. More coccinellids were found on sticky cards in 2018. Coccinellids counts on plants and sticky cards varied between locations, but were similar in their rank order. Coccinellids on plants were significantly more abundant in the IPM plots, but similar in abundance from sticky cards. Peak abundance was significantly greatest mid-season. In corn, coccinellids on plants approached significance for location, while on sticky cards, they responded significantly to location and season. Year and treatment were not significant for either sampling method. Coccinellids on plants and sticky cards varied similarly, but not identically, between locations with the observations in watermelon. The peak early to mid-season was significant only from sticky cards. Collembola -The arthropods found in the soil from watermelon and corn plots were similar in diversity, but varied in abundance and response to the fixed effects of the field trial. The community was dominated by collembola at nearly 80% of the total observed arthropods. Beetles (adults and larvae) and diplurans along with the collembola comprised more than 90% of the total arthropods. Other taxa observed in both crops included millipedes, fly larvae, spiders, webspinners, hymenopterans, centipedes, immature hemipterans, symphylans, thrips and worms. Collembola in watermelon were significantly affected by year (greater in 2018), location, treatment (greater in IPM vs CPM plots) and season (fewer early with a distinct peak mid-season in 2018, while similar for mid and late season in 2019). Measure the biological control ecosystem services being rendered by natural enemies. In the 2018 season, the mean proportion predation of waxworm larvae and spotted cucumber beetle eggs in watermelon was significantly higher in plots managed with IPM vs CPM. The interaction of Treatment*Prey was statistically different in watermelon, and there was no difference between prey type. In the 2019 season, the mean proportion predation of waxworm larvae and striped cucumber beetles in watermelon plots was significantly higher in plots managed with IPM vs CPM treatments. Mid and late season predation was significantly higher than the early season. The mean proportion predation was significantly affected by treatment and season in both type of preys (e.g., striped cucumber beetle and waxworm larvae), but there was an effect by location only for waxworm larvae. Identify characteristics of biological control services with broader implications. The indiscriminate use of insecticides as a pest management strategy can diminish the impact of natural enemies and reduce the availability of non-pest prey like collembola essential for the ecosystem services that promote economically viable crop production. Consequently, growers who adopt pest management strategies like IPM that rely on the biological control services of natural enemies should also consider the effects of local abiotic factors in combination with the surrounding landscape on insect abundance and prey availability when managing on farm and in the larger agroecosystem.

Publications

• Type: Theses/Dissertations Status: Other Year Published: 2019 Citation: Iv�n Grijalva. 2019. Ecosystem services provided by natural enemies in Midwest melon production. MS Thesis, Department of Entomology, Purdue University.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The primary audience for this project was the scientific community, as well as crop production stakeholders including farmers, crop and pest consultants, and policy makers. Changes/Problems:Cucurbit production system Efforts to identify a genomic sequencing center to process gut content samples was not successful in 2019. Centers that were contacted were not able to provide either the service or reasonable cost estimates before the postdoc leading this effort took a permanent position right at the end of the field season. A new postdoc was hired at the end of the field season to take over the project, so this activity will be reviewed in 2020, particularly in view of a recent publication that may make these plans redundant. Cassava production system Since this effort is largely based on the volunteerism of colleagues located around the world, it will continue at a slow, but deliberate pace. What opportunities for training and professional development has the project provided?A master's student, postdoc, 6 undergraduate students and an international student intern were all trained as part of this project. All of these individuals got experience with field research, while the intern, graduate student and postdoc contributed to data analysis, and preparing and presenting talks at stakeholder venues and scientific meetings. Ultimately, they will take the lead in developing manuscripts and drafting scientific publications. How have the results been disseminated to communities of interest?The primary audience for this project was the scientific community, as well as crop production stakeholders including farmers, crop and pest consultants, and policy makers. What do you plan to do during the next reporting period to accomplish the goals?Cucurbit production system Finish processing field samples Compile, summarize and analyze data Present results at scientific meetings Present recommendations at stakeholder meetings Draft manuscripts Prepare grant proposals to analyze predator gut content and develop Extension pest management training for Midwest cucurbit producers Cassava production system The project is currently based on the volunteer time and efforts of colleagues located around the world, consequently the effort will continue at a slow, but deliberate pace. Solicit field survey data and mite specimens from colleagues in a country in East and Central Africa, respectively. Likewise, solicit field survey data and mite specimens from colleagues in one or two countries in South America, and in a new country Asia where concerns about the arrival of CGM as a new exotic introduced pest remains high.

Impacts
What was accomplished under these goals? All activities this past year were focused on the first objective of the project, a prerequisite for objectives #2 and #3. Cucurbit production system - The field season ended a few weeks before the end of the reporting period for this year, and there are still samples being processed. Consequently, it is premature to report on results and impact. Cassava production system - A field survey was made of the persistence and spread of the introduced phytoseiid predatory mite, Typhlodromalus aripo, found on cassava in Kenya during 2019. Cassava fields were samples for the exotic cassava green mite (CGM), Mononychellus tanajoa, pest and their phytoseiid predators including the introduced predator, T. aripo in two separate surveys. A survey was conducted by a colleague from the Kenya Agriculture and Livestock Research Organization (KALRO) in the semi-arid foothills east of Machakos, followed by a second survey along the humid south coast of Kenya (Lunga Lunga to Likoni) down to the border with Tanzania. (click the link for survey site locations: https://goo.gl/maps/kGMFpCQQ7aFzB1G27). The first survey provided a location and mite specimens for subsequent taxonomic determination. The second survey along the south coast included an evaluation of CGM densities and presence or absence of associated phytophagous and predatory mites. In the 12 cassava farms surveyed along the south coast, CGM and T. aripo were both found in 11 fields, but not the same fields in every instance. The one location with no T. aripo was in a field with very young cassava, where the predator was found in a nearby adjacent field with older cassava plants. The field with no CGM was older cassava with plenty of T. aripo which can persist on a variety of alternate food, but require CGM prey for oviposition. In fields with CGM, pest mite incidence was <30%, leaf damage symptoms averaged just a fraction over 1 on a scale of 1 to 5 (with 1 being no damage and 5 being dried, dying or dead leaves) and pest densities were relatively low at < 20 mites per leaf. The incidence of T. aripo in those field was 54% of the plants sampled. These observations are in line with what was observed more than 20 years ago for fields with established predator populations. These result show that the introduced predator continues to persist and keep the target pest at population levels that generally do not cause significant cassava yield losses. Both sets of survey samples have been forwarded to a colleague at CIRAD in France where the mites will be barcoded and haplotyped to determine species and assess population variations. In addition, mite specimens were received from colleagues in Brazil, in South America, and China, Vietnam and Laos in Asia, then forwarded to a colleague at CIRAD in France for molecular identification. This material will be used to determine which phytophagous mites are present, and see if easy to use DNA barcoding protocols can be developed for species determination.

Publications

• Type: Book Chapters Status: Published Year Published: 2019 Citation: Toko M., P. Neuenschwander, J.S. Yaninek, A. Ortega-Betran, A. Fanou, V. Zinsou, K. Wydra, R. Hanna, A. Fotso, O.K. Douro-Kpindou. 2019. Identifying and managing plant health risks for key African crops: cassava. In, Critical Issues in Plant Health: 50 Years of Research in African Agriculture. Neuenschwander, P.N., M. Tamo (editors), Burleigh Dodds Scientific Publishing, UK .
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Grijalva, I., A. Skidmore, R. Foster, J.S. Yaninek. 2019. Effects of watermelon pest management practices on pest predation, Indiana Academy of Sciences, Indianapolis, Indiana, March 30, 2019 (poster).
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Skidmore, Amanda, Jacob Pecenka, Iv�n Grijalva, Christian Krupke, Laura Ingwell, Rick Foster, Steve Yaninek, Ian Kaplan. 2019. Ecosystem service bundling: integrating predator and pollinator responses to insecticides in Midwest cropping systems. Entomological Society of America North Central Branch meeting, Cincinnati, Ohio, March 17-20, 2019 (invited presentation).
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Grijalva, Iv�n, Amanda Skidmore, Rick Foster, Steve Yaninek. 2019. Effects of watermelon pest management practices on pest predation. Entomological Society of America North Central Branch meeting, Cincinnati, Ohio, March 17-20, 2019 (poster).
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Parrado, Luisa M., Amanda Skidmore, Steve Yaninek. 2019. Neonics and Nematodes: investigation of pest management practices on entomopathogenic nematodes in Indiana corn and watermelon production systems. Entomological Society of America North Central Branch meeting, Cincinnati, Ohio, March 17-20, 2019 (poster).
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Skidmore, Amanda, Jacob Pecenka, Iv�n Grijalva, Christian Krupke, Laura Ingwell, Rick Foster, Steve Yaninek, Ian Kaplan. 2019. Ecosystem service bundling: integrating predator and pollinator responses to insecticides in Midwest cropping systems. Entomological Society of America North Central Branch meeting, Cincinnati, Ohio, March 17-20, 2019 (invited presentation).
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Grijalva, I., A. Skidmore, A., R. Foster, J.S. Yaninek. 2019. Predation of insect pests in watermelon under conventional vs IPM management, Indiana Small Farm Conference, Hendricks County Fairgrounds, Danville, IN, February 28-March 2, 2019.
• Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Skidmore, A. and J.S. Yaninek. 2019. Arthropod Food Webs in Watermelon, Indiana Small Farm Conference, Hendricks County Fairgrounds, Danville, IN, February 28-March 2, 2019.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Grijalva, Iv�n, Amanda Skidmore, Rick Foster, Steve Yaninek. 2018. Predation of insect pests in watermelon under conventional vs. IPM management. Great Lakes Expo Fruit, Vegetable & Farm Market, Grand Rapids, MI, December 4-6, 2018 (poster).
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Parrado, Luisa M., Amanda Skidmore, Steve Yaninek. 2018. Impact of pest management on entomopathogenic nematodes (EPNs) incidence in corn and watermelon fields in Indiana. Great Lakes Expo Fruit, Vegetable & Farm Market, Grand Rapids, MI, December 4-6, 2018 (poster).
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Parrado, Luisa M., Amanda Skidmore, Steve Yaninek. 2018. Isolation of entomopathogenic nematodes (EPNs) from corn and watermelon and the impact of crop management practices. Ohio Valley Entomological Association, Indianapolis, Indiana, October 19, 2018 (presentation).
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Grijalva, Iv�n, Amanda Skidmore, Rick Foster, Steve Yaninek. 2018. Effects of watermelon pest management practices and surrounding landscapes on surrogate host predation. Ohio Valley Entomological Association, Indianapolis, Indiana, October 19, 2018 (presentation).