Source: UNIVERSITY OF MISSOURI submitted to NRP
INDIRECT EFFECTS OF DROUGHT ON THE BIOLOGICAL CONTROL OF APHIDS BY PARASITIC WASPS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1019547
Grant No.
2019-67011-29729
Cumulative Award Amt.
$116,859.00
Proposal No.
2018-07775
Multistate No.
(N/A)
Project Start Date
Jun 1, 2019
Project End Date
Aug 31, 2020
Grant Year
2019
Program Code
[A7101]- AFRI Predoctoral Fellowships
Recipient Organization
UNIVERSITY OF MISSOURI
(N/A)
COLUMBIA,MO 65211
Performing Department
CAFNR
Non Technical Summary
Drought is known to affect plants in a negative way by disrupting the physiology and quality of the plant. Herbivorous insect feeding may be affected by the decrease in plant quality. The effect of drought on the quality of herbivores as prey may indirectly affect predators. Aphids are a common pest in agricultural commodities, and their populations can be controlled by the use of parasitic wasps. Parastoids lay eggs and develop inside of a host, eventually killing it. It is unclear whether aphids feeding on drought-stressed host plants are better or worse hosts for parasitoids. The goal of this project is to determine if the ability to locate aphid hosts, egg-layingpreference (stinging), and wasp development are affected by water limitation in the plants the aphids are feeding on. Understanding how droughts may indirectly affect biological control is important for predicting and monitoring future pest outbreaks in agriculture.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
21515421130100%
Knowledge Area
215 - Biological Control of Pests Affecting Plants;

Subject Of Investigation
1542 - Soft red wheat;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
The goal of this predoctoral proposal is to elucidate the mechanism(s) underlying the differential impact of plant water availability on pest control. My objectives are to determine if plant water availability affects the ability of the wasp to locate aphids, wasp acceptance of aphid hosts for oviposition, and the development of the wasp within the aphid host. The study is novel in that we utilize a range of drought-stressed host plants to evaluate insect response. This project will advance the Farm Bill Priority Area of Plant health and Production by expanding our knowledge of biological control services under drought conditions to mitigate the impacts of climate change on food production. Through my mentorship by Dr. Finke, I will complete professional development activities to improve my abilities in teaching/mentoring, leadership, and science communication to gain transferable skills for a career in agricultural science research.
Project Methods
Objective 1: Does drought affect the ability of wasps to locate aphids in the environment?We will offer individual wasps the choice of four different treatments within a four-arm olfactometer. Wasps will be offered volatiles from whole plants with three different levels of water availability (well-watered, mild and severe stress) each with 30 aphids, and a well-watered control plant without aphids. Preference will be recorded as the first arm of the olfactometer in which the wasp travels >5cm. If the wasp has made no choice after 10 mins, the wasp will be deemed unresponsive and excluded from the study. The assay will be replicated 20 times and blocked for time. For each replicate, wasps will be replaced, the arena cleaned with acetone, the plants switched out, and the treatments randomly assigned to arms. A G test will be used to detect differences in the response profiles of wasps to the 4 plant water treatments (SAS version 9.4). Objective 2: Does drought affect wasp acceptance of aphid hosts for oviposition?Parasitoid host assessment will be determined through behavioral bioassays as previously done in our lab (de Oliveira et al., 2014). One female wasp will be offered 5 aphids from one of the three host-plant water treatments (see "Methods: Aphid Colony"), and wasp behaviors will be monitored during 10 minute observations. Duration of time spent walking around the enclosure (foraging), and frequency of antennal contact and stings with the ovipositor will be recorded using event-recording software (Observer XT 8.0; Noldus Information Technology, Leesburg, VA). This experiment will be replicated 15 times in a randomized complete block in time. Aphids that are stung by the wasp will be dissected to determine if oviposition occurred. The effects of host-plant water status on wasp antennal contact with the aphid, number of stings, and time spent foraging will be evaluated using ANOVA (PROC MIXED) with block as a random factor in the model. Oviposition per stung aphid will be assessed using logistic regression.Objective 3: Does drought affect the development of the wasp inside the aphid host?Wasp development will be evaluated through daily observations of stung aphids within individual cages in a greenhouse setting. One female A. colemani wasp will be offered 5 aphids from one of the three host-plant water treatments and stinging events will be observed over 10 minutes. This process will be repeated sequentially for each treatment using a new wasp for each assay until 15 replicates are obtained, blocking for time. Stung aphids will be separated and placed individually on treatment host plants in cages and their status will be monitored daily to assess time to wasp pupation and time to adult wasp emergence, and percent of wasp emergence from pupae. The effect of water stress treatment on parasitoid development time will be evaluated using ANOVA and the percent of successful adult wasp emergence will be evaluated using logistic regression.Water Treatments:Wheat plants are grown in pots under well-watered conditions for 14 days before water treatments are applied. At 14 days, soil is watered to saturation and allowed to drain overnight. The weight of each pot the following morning is considered 'field capacity' and serves as the reference weight for creating water treatments. Water is withheld as plants dry down to a percent of their weight at field capacity to create a mild-stress treatment (75% of field capacity) and a severe stress treatment (50%), while the well-watered plants are maintained at field capacity. Once the target weight is reached, pots are watered daily to maintain this weight. Whole plant water potential measurements are obtained at the conclusion of each experiment, as well as aboveground plant biomass to verify the plants are experiencing stress.Aphid Colony: All aphids used will be genetically identical (i.e., clonal). Twenty aphids will be placed on each of 45 wheat plants (15 plants per well-watered, mildly-stressed, or severely stressed treatment) for two weeks before experiments begin. Each set of aphids offered to wasps per replicate will be reared on a different host plant to ensure independence.

Progress 06/01/19 to 05/31/21

Outputs
Target Audience:The insight gained during this reporting period has reached scientific colleagues at research conferences and through publications. The project has also reached undergraduate students, the general public, and children through outreach efforts. Changes/Problems:The project has ended very early due to a job oppportunity. Therefore, one of the research objectives was unable to be completed, and the PD was unable to attend the Preparing Tommorrow's Leaders for Science workshop. Further, the PD meeting was canceled in 2019, and I was unable to attend. What opportunities for training and professional development has the project provided?An undergraduate was mentored by the PD for 4 months in 2019. One research technician was employed to assist with completing experiments. The PD attended the Preparing Future Faculty program for the Fall of 2019. The PD completed all requirements to recieve a Minor in College Teaching in Spring 2020. Completed 1 Extension event and 7 Outreach events to disseminate scientific information to the public The PD successfully defended their PhD dissertation. The PD recieved an offer for a postdoctoral position (hence the end of the fellowship) How have the results been disseminated to communities of interest?Results from the experiments were presented at 2 conferences. The poster presentation given by an undergradaute mentored by the PD was awarded 3rd place in an undergraduate research competition, and the conference talk given by the PD was awarded 1st place in a national graduate student presentation competition.This specific work has resulted in a paper that is in prep for submission to Environmental Entomology. In total, the fellowship has funded my writing to produce 5 first person manuscripts (1 in press, 1 in revision, 1 in review, and 2 in prep) in addition to 2 co-authored papers (1 published, 1 in review). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Experiments were completed to address how plant water limiation influences wasp acceptance of aphid hosts for oviposition. PD was awarded Graduate Student Leadership Award from the College of Graduate Studies at MU

Publications

  • Type: Journal Articles Status: Awaiting Publication Year Published: 2020 Citation: Nalam, V., Issacs, T., Moh, S., Kansman, J., Finke, D., Albrecht, T. and P. Nachappa. 2020. Diurnal Feeding as a Potential Mechanism of Osmoregulation in Aphids. Insect Science. doi: https://doi.org/10.1111/1744-7917.12787.
  • Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Kansman, J., Nalam, V., Nachappa, P., and D. Finke. Plant water stress intensity mediates aphid host choice and feeding behavior. Ecological Entomology.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Finke, D.L. and J. Kansman. Plant primacy in the effects of drought on aphids and their natural enemies. XXVI International Congress of Entomology, Helsinki, Finland.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Hermann, S., and J. Kansman. Management through manipulation: improving biological control while considering abiotic and biotic stressors. Annual Meeting of the Entomological Society of America, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Kansman, J., Ward, M., and D. Finke. Say yes to the host: Examining consequences of drought for aphid and parasitoid wasp interactions. Annual Meeting of the Entomological Society of America, St. Louis, MO.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Ward, M., Kansman, J. and D. Finke. Say yes to the host: The effects of drought on parasitoid wasp behavior. University of Missouri Life Sciences Week, Columbia, MO.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Kansman, J. and D. Finke. Sweating the small stuff: Effects of drought for aphid performance and behavior. Annual Meeting of the North Central Branch of the Entomological Society of America, Cincinnati, OH.


Progress 06/01/19 to 08/31/20

Outputs
Target Audience:The insight gained during this reporting period has reached scientific colleagues at research conferences and through publications. The project has also reached undergraduate students, the general public, and children through outreach efforts. Changes/Problems:The project has ended very early due to a job oppportunity. Therefore, one of the research objectives was unable to be completed, and the PD was unable to attend the Preparing Tommorrow's Leaders for Science workshop. Further, the PD meeting was canceled in 2019, and I was unable to attend. What opportunities for training and professional development has the project provided?An undergraduate was mentored by the PD for 4 months in 2019. One research technician was employed to assist with completing experiments. The PD attended the Preparing Future Faculty program for the Fall of 2019. The PD completed all requirements to recieve a Minor in College Teaching in Spring 2020. Completed 1 Extension event and 7 Outreach events to disseminate scientific information to the public The PD successfully defended their PhD dissertation. The PD recieved an offer for a postdoctoral position (hence the end of the fellowship) How have the results been disseminated to communities of interest?Results from the experiments were presented at 2 conferences. The poster presentation given by an undergradaute mentored by the PD was awarded 3rd place in an undergraduate research competition, and the conference talk given by the PD was awarded 1st place in a national graduate student presentation competition.This specific work has resulted in a paper that is in prep for submission to Environmental Entomology. In total, the fellowship has funded my writing to produce 5 first person manuscripts (1 in press, 1 in revision, 1 in review, and 2 in prep) in addition to 2 co-authored papers (1 published, 1 in review). What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Experiments were completed to address how plant water limiation influences wasp acceptance of aphid hosts for oviposition. PD was awarded Graduate Student Leadership Award from the College of Graduate Studies at MU

Publications

  • Type: Journal Articles Status: Awaiting Publication Year Published: 2020 Citation: Nalam, V., Issacs, T., Moh, S., Kansman, J., Finke, D., Albrecht, T. and P. Nachappa. 2020. Diurnal Feeding as a Potential Mechanism of Osmoregulation in Aphids. Insect Science. doi: https://doi.org/10.1111/1744-7917.12787.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Hermann, S., and J. Kansman. Management through manipulation: improving biological control while considering abiotic and biotic stressors. Annual Meeting of the Entomological Society of America, Orlando, FL.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Kansman, J., Ward, M., and D. Finke. Say yes to the host: Examining consequences of drought for aphid and parasitoid wasp interactions. Annual Meeting of the Entomological Society of America, St. Louis, MO.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Ward, M., Kansman, J. and D. Finke. Say yes to the host: The effects of drought on parasitoid wasp behavior. University of Missouri Life Sciences Week, Columbia, MO.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Kansman, J. and D. Finke. Sweating the small stuff: Effects of drought for aphid performance and behavior. Annual Meeting of the North Central Branch of the Entomological Society of America, Cincinnati, OH.
  • Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Kansman, J., Nalam, V., Nachappa, P., and D. Finke. Plant water stress intensity mediates aphid host choice and feeding behavior. Ecological Entomology.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Finke, D.L. and J. Kansman. Plant primacy in the effects of drought on aphids and their natural enemies. XXVI International Congress of Entomology, Helsinki, Finland.


Progress 06/01/19 to 05/31/20

Outputs
Target Audience:The insight gained during this reporting period hasreached scientific colleagues at research conferences and throughpublications. The project has also reached undergraduate students, the general public, and children through outreach efforts. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Anundergraduate was mentored by the PDfor 4 months in 2019. One research technician was employed to assist with completing experiments. The PD attended the Preparing Future Faculty program for the Fall of 2019. The PD completed all requirements to recieve a Minor in College Teaching in Spring 2020. Completed 1 Extension event and 7 Outreach events to disseminate scientific information to the public How have the results been disseminated to communities of interest?Results from the experiments were presented at 2 conferences. The poster presentation given by an undergradaute mentored by the PDwas awarded 3rd place in an undergraduate research competition, and the conference talk given by the PDwas awarded 1st place in a national graduate student presentation competition. A manuscript pertaining to the research is currently in preparation. What do you plan to do during the next reporting period to accomplish the goals?Complete the remaining objectives and submit themanuscript for publication Present this data at 1-2 additional conferences

Impacts
What was accomplished under these goals? Experiments were completed to address how plant water limiation influences wasp acceptance of aphid hosts for oviposition.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Nalam, V., Issacs, T., Moh, S., Kansman, J., Finke, D., Albrecht, T. and P. Nachappa. 2020. Diurnal Feeding as a Potential Mechanism of Osmoregulation in Aphids. Insect Science. doi: https://doi.org/10.1111/1744-7917.12787.
  • Type: Journal Articles Status: Under Review Year Published: 2020 Citation: Kansman, J., Nalam, V., Nachappa, P., and D. Finke. Plant water stress intensity mediates aphid host choice and feeding behavior. Ecological Entomology.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Kansman, J. and D. Finke. Sweating the small stuff: Effects of drought for aphid performance and behavior. Annual Meeting of the North Central Branch of the Entomological Society of America, Cincinnati, OH.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Kansman, J., Ward, M., and D. Finke. Say yes to the host: Examining consequences of drought for aphid and parasitoid wasp interactions. Annual Meeting of the Entomological Society of America, St. Louis, MO.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Ward, M., Kansman, J. and D. Finke. Say yes to the host: The effects of drought on parasitoid wasp behavior. University of Missouri Life Sciences Week, Columbia, MO.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Finke, D.L. and J. Kansman. Plant primacy in the effects of drought on aphids and their natural enemies. XXVI International Congress of Entomology, Helsinki, Finland. *postponed to July 2021