Progress 03/01/18 to 02/29/20
Outputs
Target Audience:The target audiences reached by my efforts this past year were researchers working with predatory and pest mites through talks at the National and Regional Entomological Society of America Meetings. I spoke with growers this year at our field day at the Coastal Research Station. I also presented to scientists at the USDA USVL in a special seminar. Attendees included land managers, farm managers, extension agents, and the general public in an extension talk with the Cultivate SciArt Initiative. Changes/Problems:I anticipate the four papers listed in the accomplishments to be submitted by December 2020. Two are already in draft form, and the other two require data analysis and manuscript writing. Because some of these analyses are not completed yet, the data management plan has not been completely fulfilled, nor have all physical specimens (mites) been completely curated as of January 2020. The data management plan will be completed by the time of manuscript submission, December 2020. Physical specimens will be curated and housed by March 2020. What opportunities for training and professional development has the project provided?I trained with USDA plant pathologist Chandrasekar Kousik, on how to culture cucurbit powdery mildew in order to raise mites in the Tarsonemidae that are prey for predatory mites. Additionally, I have participated in diagnosing tomato diseases with Clemson plant pathologist, Dr.Tony Keinath, in fields where graduate student projects are being conducted on Clemson CREC farm. I continued my mentorship relationships with graduate students Paul Bergeron and Danielle Lewis, formerly graduate students of Rebecca Schmidt-Jeffris. I mentored Paul Bergeron, now a student at Washington State University, on writing of publications and his thesis. I also mentored him in the preparation of presentations for the Entomological Society of America Annual Meeting. I was a member of the graduate committee of Danielle Lewis. In the absence of Schmidt-Jeffris, I was her entomological advisor at the research station where she conducted the second year of her master's research in the summer of 2019. I mentored her in preparation for her thesis defense and her presentation to the Entomology Department at Clemson. As mentioned previously, as a part of my extension training, I met with growers at the Clemson CREC Field Day and was able to get feedback on the materials I presented by both my co-mentors, Drs. Keinath and Cutulle. This included an information sheet, a field presentation, and my question and answer session. How have the results been disseminated to communities of interest?Results have been disseminated to communities of interest in the following ways: 1. Personal meetings with growers - During visits to survey growers' fields, I took the opportunity to meet with them personally to give them my assessment of the pest and natural enemy communities in the field from the previous visit, and if there was anything suspicious or concerning during the current visit. 2. Communications with county extension agents - I have been in communication with Zack Snipes, the Charleston County Extension Agent in the Lowcountry to provide him with informal scouting reports of pest pressure, but also fields where there is control from predatory mites. I have also done some identification work for Delaware Extension Agent David Owen, who I have advised on the ecological niches of his predatory mite community, which is remarkably similar to that in the Lowcountry of South Carolina. 3. I contributed to a reference publication for growers on Brassica pests, and led the development of a new reference publication on mite pests and mite natural enemies with entension agents Zack Snipes and Juston Ballew. 4. Presentations to other acarologists studying phytoseiids to communicate to their extension agents - I have been able to meet with the most eminent phytoseiid specialists this past November in St. Louis, MO for the Ecological Society of America symposium on recent acarological research. I was able to share my findings on the effects of non-prey resources (pollen) on the survival and reproduction capabilities of Proprioseiposis mexicanus. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Develop skills in agricultural ecology experimental methodology, in both conventional and organic cultivation and management of pests. In 2019, I accomplished multiple tasks to acquaint myself with typical growing practices of cucurbits conventionally and in small-sustainable ororganic fields. I led the preparation and planting of two experimental watermelon fields to test the effects of companion planting on predatory mite communities. I continued my education in knowledge of pesticide ingredients, safety, and application by attending two workshops for pesticide applicator credits. Additionally, I attended an all-day workshop for women in agriculture on the topics of soil health, pesticide application, small engine (chainsaw) safety, fire ant removal, and tractor safety. Develop proficiency in extension methods and communication (extension efforts), including publications and presentations. In 2019, I gave a short talk to the growers at the Charleston Co. pre-plant meeting. I also spoke at the Clemson CREC Field Day on a field experiment of my own that investigated the effects of companion planting on the abundance of phytoseiis mites in a watermelon field. My mentors were present and have given feedback to Schmidt-Jeffris. At the beginning of 2019, I contributed to a Clemson University reference publication for cabbage and other brassica growers on larval pest-Lepidoptera. At the end of 2019, I led the writing and design of a small reference publication for growers on mite pests and mite natural enemies intended for use in the field. That was recently published by Clemson Extension in December 2019. Gain experience mentoring early-career researchers In the past 12 months, I assisted in the mentoring of two Masters students, Danielle Gray Lewis and Paul Bergeron, both students of Schmidt-Jeffris. I mentored Lewis in community ecology field sampling techniques and conceptual frameworks in relation to the research in her agricultural ecosystem, as well as preparation for required exams and meetings related to the completion of her degree. She graduated with her M.Sc. in the fall of 2019. I helped Paul Bergeron in his preparations for presenting at the Acarological Society of America (ASA) annual meeting in November 2019, held concurrently with the Entomological Society of America Meeting. Hepresented and was awarded second place for Outstanding Student Presentation at the ASA sponsored talks. I will continue to mentor Bergeron at WSU where he is continuing his research for his doctorate degree in association with Schmidt-Jeffris. Objective 1: Investigate phytoseiid biodiversity and the management factors impacting phytoseiid abundance in tomato and watermelon. I continued my investigation of the the diversity of phytoseiids and their abundances in watermelon fields in the summer of 2019. Since 3 individuals were collected total from tomato fields in 2018, watermelon was the primary focus in 2019. I surveyed 8 fields (8 growers) repeatedly this summer and collected 6 species: • Athiasia greenae: 3 individuals total • Euseius obispensis: 20 individuals total • Neoseiulus reticulatus: 3 individuals total • Phytoseiulus persimilis: 86 individuals total • Proprioseiopsis mexicanus: 64 individuals total • Typhlodromips arenillus: 8 individuals total The majority of these species were collected from small conventional growers. Objective 2: Examine the use of common vegetable pathogens as alternative food sources for phytoseiids, focusing primarily on oomycetes and fungi responsible for powdery (Podosphaera xanthii) and downy mildew (Pseudoperonospora cubensis) in Cucurbitaceae. In 2018-19, only cucurbit powdery mildew was observed in watermelon fields with any frequency. Cucurbit downy mildew was not detected in fields I surveyed. In 2019, I observed cucurbit powdery mildew in association with the most frequently collected phytoseiid species in my survey, P. mexicanus and a small fungivorous tarsonemid mite. I examined if P. mexicanus will consume cucurbit powdery mildew, the fungivorous tarsonmid, or both. I conducted an experiment with 30 eggs to examine their development on P. xanthii and found that once egs hatched, they developed to the protonymph stage and then individuals died, meaning they were not able to consume P xanthii. P. mexicanus was able to consume the fungivorous Tarsonemidae, however. Females developed in 3.2 days on average (SD +/- 0.6). The time between introduction of a male and oviposition was 2.2 days on average (SD +/- 0.8). Both of these are comparable to the best performing plant pollend for the same life history parameters (C. lanatus, D. cooperi, and T. incarnatum). On average, females laid 1.8 eggs (SD +/- 0.4), which is comparable to the Cucurbita spp. pollens we tested for the same life history parameters. We also found that when given a standard amount of tarsonemid mites in a timed feeding experiment, that P. mexicanus consumed 6.5 tarsonemids on average per hour (SD +/- 2.4). This is relevant because there are herbivorous tarsonemids that are economically important pests of ornamentals, such as broad mite (Polyphagotarsonemus latus) and cyclamen mite (Phytonemus pallidus). Additional experimental research conducted in 2019 My largest research effort of 2019, and one that we are the most excited about, is a set of feeding experiments intended to test the quality of non-prey resources that P. mexicanus may be using in field of watermelon (C. lanatus, three Cucurbita spp., T. incarnatum (Crimson clover), plus a few well researched pollen supplements that are either written about in literature (D. cooperi) or are commercially available (Typha sp.). These are the results of a one-way ANOVA of developmental time, time to oviposition once a male is introduced, and number of eggs laid per day (based on a 4-day time period): Table I. ANOVA results of P. mexicanus performance on pollen and prey combination food resources. Averages with the same letter do not differ from each other by p = 0.05 or less. Developmental time (days+/-S E) Time to oviposition (days; SE) Eggs per day (eggs; SE) C. lanatus 2.9; 0.20 a 1.5; 0.16 a 3.5; 0.21 a C. maxima 3.8; 0.25 ab 2.0; 0.20 ac 2.0; 0.24 bc C. moschata 4.1; 0.19 bc 2.3; 0.20 ac 0.69; 0.20 e C. pepo 3.7; 0.21 ab 1.9; 0.22 ac 2.0; 0.32 bd T. incarnatum 3.5; 0.20 ab 1.6; 0.17 ab 3.4; 0.23 a D. cooperi 3.0; 0.25 a 1.8; 0.20 ac 3.0; 0.26 ab T. urticae + Typha 3.9; 0.11 b 1.9; 0.21 ac 1.4; 0.24 cde T. urticae 4.2; 0.20 bc 2.5; 0.20 bc 0.88; 0.21 de Typha sp. 5.0; 0.26 c 2.6; 0.22 c 1.0; 0.27 cde Both developmental time and time to oviposition were shortest on C. lanatus and T. incarnatum pollens. This is of particular interest because these plants are always or often part of a watermelon agroecosystem previous to or as a part of transplant. These findings suggest a reason for why P. mexicanus is the most commonly collected predatory mite in watermelon agroecosystems (Farfan, unpublished).
Publications
- Type:
Book Chapters
Status:
Published
Year Published:
2019
Citation:
Farfan, M. A. and Schmidt-Jeffris, R. A. 2019. Biodiversity of Phytoseiidae (Acari: Mesostigmata) of annual specialty crop systems: the current state of knowledge worldwide and the need for study in the U.S. Contemporary Acarology 2017. eds. H. J. Hutcheson, M. Skvarla, and R. Ochoa.
- Type:
Other
Status:
Accepted
Year Published:
2019
Citation:
Farfan, M. A. Natural communities of predatory mites (Phytoseiidae) in two specialty annual cropping systems in South Carolina: Contributing to IPM through food web ecology. USDA Vegetable Laboratory, Charleston, SC. 1 May 2019.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2019
Citation:
Farfan, M. A. and Schmidt-Jeffris, R. A. The diversity and potential food web of Phytoseiidae in two annual specialty crops in South Carolina. Entomological Society of America Southeastern Branch Meeting. Mobile, AL. 5 March 2019.
|
Progress 03/01/19 to 02/29/20
Outputs
Target Audience:The target audiences reached by my efforts this past year were researchers working with predatory and pest mites through talks at the National and Regional Entomological Society of America Meetings. I spoke with growers this year at our fieldday at the Coastal Research Station.I also presented to scientists at the USDA USVL in a special seminar. Attendeesincludedland managers,farm managers, extension agents, and the general public in an extension talk with the Cultivate SciArt Initiative. Changes/Problems:Because the data analysis and manuscripts based on this research were delayed in favor of more data acquisition, I have requested a no-cost extension to be able to have funding for publishing the forthcoming manuscripts in 2020. This is the only change requested. I anticipate the four papers listed in the accomplishments to be submitted by December 2020. Two are already in draft form, and the other two require data analysis and manuscript writing. Because some of these analyses are not completed yet, the data management plan has not been completely fulfilled, nor have all physical specimens (mites) been completely curated as of January 2020. The data management planwill be completed by the time of manuscript submission, December 2020. Physical specimens will be curated and housed by March 2020. What opportunities for training and professional development has the project provided?I trained with USDA plant pathologist Chandrasekar Kousik, on how to culture cucurbit powdery mildew in order to raise mites in the Tarsonemidae that are prey for predatory mites. Additionally, I have participated in diagnosing tomato diseases with Clemson plant pathologist Tony Keinath, in fields where graduate student projects are being conducted on Clemson CREC farm. I continued my mentorship relationships with graduate students Paul Bergeron and Danielle Lewis, formerly graduate students of Rebecca Schmidt-Jeffris. I mentored Paul Bergeron, now a student at Washington State University, on writing of publications and his thesis. I also mentored him in the preparation of presentations for the Entomological Society of America Annual Meeting. I was a member of the graduate committee of Danielle Lewis. In the absence of Schmidt-Jeffris, I was her entomological advisor at the research station where she conducted the second year of her master's research in the summer of 2019. I mentored her in preparation for her thesis defense and her presentation.to the Entomology Department at Clemson. As mentioned previously, as a part of my extension training, I met with growers at the Clemson CREC Field Day and was able to get feedback on the materials I presented by both my co-mentors, Drs. Keinath and Cutulle. This included an information sheet, a field presentation, and my question and answer session. How have the results been disseminated to communities of interest?Results have been disseminated to communities of interest in the following ways Personal meetings with growers - During visits to survey growers' fields, I took the opportunity to meet with them personally to give them myassessment of thepest and natural enemy communities in the field from the previous visit, and if there was anything suspicious or concerning during the current visit. Communications with county extension agents - I have been in communication with Zack Snipes, the Charlestoncounty extension agent in the Lowcountry to provide him with informal scouting reports of pest pressure, but also fields where there is control from predatory mites. I have also done some identification work for Delaware extension agent David Owen, who I have advised on the ecological niches of his predatory mite community, which is remarkably similar to that in the Lowcountry of South Carolina. I contributed to a reference publication for growers on Brassica pests, and led the development of a new reference publication on mite pests and mite natural enemies with entension agents Zack Snipes and Juston Ballew. Presentations to other acarologists studying phytoseiids to communicate totheir extension agents - I have been able to meet with the most eminent phytoseiid specialists this past November in St. louis, MO for the Ecological Society of America symposium on recent acarological research. I was able to share my findings on the effects of non-prey resources (pollen) on the survival and reproduction capabilities of Proprioseiposis mexicanus. What do you plan to do during the next reporting period to accomplish the goals?I will concentrate my next year on data anaylsis and completion of publications having to do with this research. These were originally planned to be completed by the expiration of the grant, but due to the extended timetable of the surveys and the additional food resources we added to the planned laboratory experiments, these remain to be completed in 2020. Four are planned: Farfan, M. A., Coffey, J., Schmidt-Jeffris, R. A. Analysis of developmental time and reproduction of Proprioseiopsis mexicanus (Acari: Phytoseiidae) on potential prey and non-prey food resources in cucurbit agroecosystems in South Carolina, U.S.A. Farfan, M. A., Coffey, J., Schmidt-Jeffris, R. A. Minute fungivores link aboveground and belowground food webs in cucurbit agroecosystems in South Carolina: Potential in management of herbivorous tarsonemids. Farfan, M. A, Coffey, J., Miller G., and Schmidt-Jeffris, R. A. Residual activity ofmiticides for controlling Tetranychus urticae in watermelon and impacts on residentpredatory mites. A paper on the communities of phytoseiids on watermelon and associations with weed communities and environmental factors.** ** This is a critical paper to the dissemination of results of my postodctoral fellowship research. I have requested a no-costextension to be able to continue to access funding for publication fees necessary for all these papers to be open-access.
Impacts
What was accomplished under these goals?
Develop skills in agricultural ecology experimental methodology, in both conventional and organic cultivation and management of pests. In 2019, I accomplished multiple tasks to acquaint myself with typical growing practices of cucurbitsconventionally and in small-sustainable or organic fields. I led the preparation and planting of two experimental watermelon fields to test the effects of companion planting on predatory mite communities. I continued my education in knowledge of pesticide ingredients, safety, and application by attending two workshops for pesticide applicator credits. Additionally, I attended an all-day workshop for women in agriculture on the topics of soil health, pesticide application, small engine (chainsaw) safety, fire ant removal, and tractor safety. Develop proficiency in extension methods and communication (extension efforts), including publications and presentations. In 2019, I gave a short talk to the growers at the Charleston Co. pre-plant meeting. I also spoke at the Clemson CREC Field Day on a field experiment of my own that investigated the effects of companion planting on the abundance of phytoseiis mites in a watermelon field.My mentors were present and have given feedback to Schmidt-Jeffris. At the beginning of 2019, Icontributed toa Clemson University reference publication for cabbage and other brassica growers on larval pest-Lepidoptera. At the end of 2019, I led the writing and design of a small reference publication for growers on mite pests and mite natural enemies intended for use in the field. That was recently published by Clemson Extension in December 2019. Gain experience mentoring early-career researchers In the past 12months, I assisted in the mentoring of two Masters students, Danielle Gray Lewis and Paul Bergeron, both students of Schmidt-Jeffris. I mentored Lewis in community ecology field sampling techniques and conceptual frameworks in relation to the research in her agricultural ecosystem, as well as preparation for required exams and meetings related to the completion of her degree. She graduated with her M.Sc. in the fall of 2019. I helped Paul Bergeron in his preparations for presenting at the Acarological Society of America (ASA) annual meeting in November 2019, held concurrently with the Entomological Society of America Meeting. He did present and was awarded second place for Outstanding Student Presentation at the ASA sponsored talks. I will continue to mentor Bergeron at WSU where he is continuing his research for his doctorate degree in association with Schmidt-Jeffris. Objective 1: Investigate phytoseiid biodiversity and the management factors impacting phytoseiid abundance in tomato and watermelon. I continued my investigation of the the diversity of phytoseiids and their abundances in watermelon fields in the summer of 2019. Since 3 individuals were collected total from tomato fields in 2018, watermelon was the primary focus in 2019. I surveyed 8 fields (8 growers) repeatedly this summer and collected 6species: Athiasia greenae: 3 individuals total Euseius obispensis: 20individuals total Neoseiulusreticulatus: 3individuals total Phytoseiulus persimilis: 86individuals total Proprioseiopsis mexicanus: 64 individuals total Typhlodromips arenillus: 8individuals total The majority of these species were collected from small conventional growers. Objective 2:Examine the use of common vegetable pathogens as alternative food sources for phytoseiids, focusing primarily on oomycetes and fungi responsible for powdery (Podosphaera xanthii) and downy mildew (Pseudoperonospora cubensis) in Cucurbitaceae. In 2018-19, only cucurbit powdery mildew was observed in watermelon fields with any frequency. Cucurbit downy mildew was not detected in fields I surveyed. In 2019, I observed cucurbit powdery mildew in association with the most frequently collected phytoseiid species in my survey, P. mexicanusand a small fungivorous tarsonemid mite. I examined if P. mexicanus will consume cucurbit powdery mildew, the fungivorous tarsonmid, or both. I conducted an experiment with 30 eggs to examine their development on P. xanthii and found that once egs hatched, they developed to the protonymph stage and then individuals died, meaning they were not able to consume P xanthii. P. mexicanus was able to consume the fungivorous Tarsonemidae, however. Females developed in 3.2 days on average (SD +/- 0.6). The time between introduction of a male and oviposition was 2.2 days on average (SD +/- 0.8). Both of these are comparable to the best performing plant pollend for the same life history parameters (C. lanatus, D. cooperi, and T. incarnatum).On average, females laid 1.8 eggs (SD +/- 0.4), which is comparable to the Cucurbitaspp. pollens we tested for the same life history parameters. We also found that when given a standard amount of tarsonemid mites in a timed feeding experiment, thatP. mexicanus consumed 6.5 tarsonemids on average per hour (SD +/- 2.4). This is relevant because there are herbivorous tarsonemids that are economically important pests of ornamentals, such as broad mite (Polyphagotarsonemus latus) and cyclamen mite (Phytonemus pallidus). Additional experimental research conducted in 2019 My largest research effort of 2019, and one that we are the most excited about, is a set of feeding experiments intended to test the quality of non-prey resources that P. mexicanus may be using in field of watermelon (C. lanatus, three Cucurbita spp., T. incarnatum (Crimson clover), plus a few well researched pollen supplements that are either written about in literature (D. cooperi)or are commercially available (Typha sp.). These are the results of a one-wayANOVA ofdevelopmental time, time to oviposition once a male is introduced, and number of eggs laid per day (based on a 4-day time period): Table I. ANOVA results of P. mexicanus performance on pollen and prey combination food resources. Averages with the same letter do not differ from each other by p = 0.05 or less. Developmental time (days+/-S E) Time to oviposition (days; SE) Eggs per day (eggs; SE) C. lanatus 2.9; 0.20 a 1.5; 0.16 a 3.5; 0.21 a C. maxima 3.8; 0.25 ab 2.0; 0.20 ac 2.0; 0.24 bc C. moschata 4.1; 0.19 bc 2.3; 0.20 ac 0.69; 0.20 e C. pepo 3.7; 0.21 ab 1.9; 0.22 ac 2.0; 0.32 bd T. incarnatum 3.5; 0.20 ab 1.6; 0.17 ab 3.4; 0.23 a D. cooperi 3.0; 0.25 a 1.8; 0.20 ac 3.0; 0.26 ab T. urticae + Typha 3.9; 0.11 b 1.9; 0.21 ac 1.4; 0.24 cde T. urticae 4.2; 0.20 bc 2.5; 0.20 bc 0.88; 0.21 de Typha sp. 5.0; 0.26 c 2.6; 0.22 c 1.0; 0.27 cde Both developmental time and time to oviposition were shortest on C. lanatusand T. incarnatum pollens. This is of particular interest because these plants are always or often part of a watermelon agroecosystem previous to or as a part of transplant. These findings suggest a reason for whyP. mexicanusis the most commonly collected predatory mite in watermelon agroecosystems (Farfan, unpublished).
Publications
- Type:
Book Chapters
Status:
Published
Year Published:
2019
Citation:
Farfan, M. A. and Schmidt-Jeffris, R. A. 2019. Biodiversity of Phytoseiidae (Acari: Mesostigmata) of annual specialty crop systems: the current state of knowledge worldwide and the need for study in the U.S. Contemporary Acarology 2017. eds. H. J. Hutcheson, M. Skvarla, and R. Ochoa.
- Type:
Other
Status:
Accepted
Year Published:
2019
Citation:
Farfan, M. A. Natural communities of predatory mites (Phytoseiidae) in two specialty annual cropping systems in South Carolina: Contributing to IPM through food web ecology. USDA Vegetable Laboratory, Charleston, SC. 1 May 2019.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2019
Citation:
Farfan, M. A. and Schmidt-Jeffris, R. A. The diversity and potential food web of Phytoseiidae in two annual specialty crops in South Carolina. Entomological Society of America Southeastern Branch Meeting. Mobile, AL. 5 March 2019.
|
Progress 03/01/18 to 02/28/19
Outputs
Target Audience:The target audiencesreached during the first year of my postdoctoral fellowshipresearchwere vegetable growers of South Carolina including, but not limited to, 12watermelon and tomato growers. Some of the growers who participated in this research, and received direct knowledge regarding natural enemies and pest pressure intheir fields in the Lowcountry of SC, are Gullah, a local minority group of descendants of colonial era slaves. This work alsotargeted county extension agents in South Carolina who advise growers in all parts of South Carolina on management strategies based on the results of my research. I was able to be in contact withthem through personal discussions, trips for field scouting,and field day talks. Changes/Problems:During the course of this research, three tasks that moved me toward my objectives require amendment due to both promising findings and the unexpected results of weed and phytoseiid surveys: Due to the diversity and abundances of phytoseiids observed from sampling watermelon fields, I will add an additional season of field surveys to be completed in 2019 in order to evaluate the consistency in diversity and abundance, and the timeframe for phytoseiid appearance in a field. I will survey eight fields total. Seven of these will be conventional, and one will be in the small-sustainable category. The sampling method will follow the exact protocol from 2018. I will not complete a full sampling of tomato fields as last year, however, because the data from 2018 revealed that there are very few phytoseiid mites in tomato fields. I will instead ask country extension agents to alert me to any tomato fields in their areas experiencing an outbreak of spider mites and target these for sampling. Because I decided to continue the surveys of watermelon fields in 2019, the publication originally planned to disseminate the results of this data will occur in October/November 2019. Six species of phytoseiid mites were collected over the 2018 field season. Of these, Proprioseiopsis mexicanus was collected in an order of magnitude above any other species (< 150) and is a clearly dominant taxon in most natural communities in South Carolina. Additionally, the next two most abundant species, N. fallacis and P. persimilis have well-known resource requirements and are even produced commercially. Given this, I will change these feeding studies to focus solely on P. mexicanus and test additional alternative food resources for survival and reproduction. In addition to Curcurbita maxima, C. pepo, and C. moschata, I will test the following for survival and fecundity of P. mexicanus: Ice Plant (Delosperma cooperi) pollen - Ice Plant pollen has been mentioned in the literature as an alternative resource for culturing mites in addition to T. urticae. I will investigate whether this is a sufficient food resource for survival and reproduction. Nutramite® Willow (Typha spp.) pollen - This pollen is commercially available and marketed as a nutrient additive for predatory mites released in a greenhouse setting. I will investigate whether this can be the sole resource for survival and oviposition. Tarsonemidae - I observed tarsonemid mites (the family of mites that both the Broad mite, Polyphagotarsonemus latus, and the Cyclamen mite, Phytonemus pallidus,in association with both cucurbit powdery mildew and P. mexicanus. I suspect that the tarsonemid mites are feeding on the powdery mildew and the P. mexicanus are feeding on the tarsonemid mites, but this remains a point in need of clarification to understand the role of P. mexicanus in crop systems. This is a perfect opportunity to test the powdery mildew and the fungivore separately to see if this pathogen plays a direct or indirect role, or both, as a food resource to P. mexicanus. Thrips - During the preparation of cultures of P. mexicanus for use in the alternative-resource feeding studies, the lima bean plants used to rear T. urticae became infested with thrips from our greenhouse. P. mexicanus was observed on multiple occasions feeding on thrips in the cultures. Given that my primary mentor, Dr. Schmidt-Jeffris, collected P. mexicanus from the blossoms of a cucurbit in 2017, it is possible that the typical diet for P. mexicanus is pollen and thrips, which are known to consume parts of flowers. Crimson Clover (Trifolium incarnatum) pollen - This legume is used in many fields on the CREC farm, and by my growers, as a cover crop to increase N availability for the next crop-plant. From my observations, these fields have predatory mites earlier in the season, so investigation of Crimson Clover pollen as an alternative food resource is justified. 3. Of the plant pathogens observed in growers' fields in 2018, only cucurbit powdery mildew (Podosphaera xanthii) was observed with frequency. Downy mildew (Pseudoperonospora cubensis) was only observed on the CREC experimental farm, which excludes it from my survey. This is not a surprising result because opposing environmental conditions propagate these pathogens. Therefore, I have been investigating plants with powdery mildew more intensely for predatory mite presence, and its role as a resource for predatory mites. 4. In addition to surveying weed composition and percent cover both inside and outside of growers' watermelon fields this year, I will also measure the distance between the crop plants and the nearest non-crop plant. I have informally observed that fields on the CREC farm and fields of growers that are allowed to become weedy tend to have more predatory mites and less pest pressure. There is reason to evaluate the connectivity between weeds in the environment and predatory mite abundance. What opportunities for training and professional development has the project provided?Diversity of natural communities of Phytoseiidae in two annual specialty cropping systems of economic importance in South Carolina, USA.at the 2018 Entomological Society of America Annual Meeting in Vancouver, BC in November 2018. Additionally, I co-organized two symposiaThe Legacy of James McMurtry: Current Research in Phytoseiid EcologyandSoil Mites: Minute Arthropods with a Monumental Role.I attended the concurrent Acarological Society of America (ASA) annual meeting and symposia and networked with professional entomologists in Plant-Insect Ecosystems science and acarologists in all areas. Additionally, I was elected the president-elect for the ASA for 2019 while in Vancouver and will serve as their president in 2020. How have the results been disseminated to communities of interest?Results have been disseminated to communities of interest in the following ways Personal meetings with growers - During visits to survey growers' fields, I took the opportunity to meet with them personally to give them myassessment of thepest and natural enemy communities in the field from the previous visit, and if there was anything suspicious or concerning during the current visit. Presentations to growers - I presented at both the Watermelon Field Day, Edisto REC, Blackville, SC,and at the CREC Field Day, Charleston, SC, this past year where I discussed the mite natural enemy communities in South Carolina, what they look like, and some of the associations between field management with abundance and diversity. Communications with country extension agents - I have been in communication with Zack Snipes, the Charlestoncounty extension agent in the Lowcountry to provide him with informal scouting reports of pest pressure, but also fields where there is control from predatory mites. I have also done some identification work for Delaware extension agent David Owen, who I have advised on the ecological niches of his predatory mite community, which is remarkably similar to that in the Lowcountry of South Carolina. Presentations to other acarologists studying phytoseiids to communicate totheir extension agents - I have been able to meet with the most eminent phytoseiid specialists this past November in Vancouver, B.C. for the Ecological Society of America symposium on the ecology of phytoseiids. I was able to share my findings on the diversity and abundance of this community and how different communities are shaped by weediness. What do you plan to do during the next reporting period to accomplish the goals?I will continue my extension training through the production of a video on pest mites and mite natural enemies in South Carolina in collaborationwith Charleston Co. extension agent Zack Snipes. A fact sheet and second video will be produced in 2019 on the alternative resources observed to be consumed by phytoseiid mites in the pollen and plant pathogen feeding trials that will be completed at the Clemson CREC facility. These extension materials will be evaluated/editedby both Drs. Keinath and Cutulle, and remotely by Dr. Schmidt-Jeffris. In addition to the above, I will be seeking opportunities to give PowerPoint-based extension talks on beneficial arthropods in agroecosystems in Washington following my move in August 2019. This will be facilitated by Schmidt-Jeffris's longstanding relationship with the grower community in that region. These presentations will be evaluated remotely by my co-mentors prior to presentation.
Impacts
What was accomplished under these goals?
In 2018, I accomplished multiple tasks to acquaint myself with typical growing practices of cucurbits and tomatoes both conventionally and in small-sustainable or organic fields. I participated in field preparation and planting or organic tomatoes at the CREC farm. Goal #1: As a member of the Schmidt-Jeffris lab, I participated in the experimentation on, and planting and harvesting of, crops common in South Carolina, and relevant to my project (watermelon, tomato, zucchini, pumpkin) on the CREC farm. Thisincluded the planting of cover crops, field preparation (including irrigation principles and ditch placement for remediation of flooding), and chemical and cultural management of pests. I have also interviewed growers in both conventional and organic systems about their management practices and participated in some of the management of these fields with growers. In the past year, I learned about pesticide ingredients, modes of action, application, pesticide regulations in South Carolina, and the process of obtaining a pesticide applicators license by studying for and obtaining a license myself. Goal #2:In 2018, I worked with co-mentors Tony Keinath and Matt Cutulle in the field to learn the identification of plant pathogens and weed species, respectively. I received practice in scouting of growers' fields and fields on the CREC farm with Dr. Keinath for both powdery and downy mildew. I participated in weed identification and cover assessments in an organic tomato field managed by the Schmidt-Jeffris and Cutulle labs. Additionally, I amlearning to culture powdery mildew on cucurbit leavesfrom USDA plant pathologist Chandrasekar Kousikto have a supply of conidia for the feeding studies planned for Year 2. Goal #3: To date, I have given two solo extension field talks (one for watermelon growers and one for agricultural educators),co-presented with Schmidt-Jeffris during the CREC Field Day,and co-presented a series of outreach talks to high school students. My mentors were present and have given feedback to Schmidt-Jeffris. I recently contributed toa Clemson University reference publication for cabbage and other brassica growers on larval pest-Lepidoptera. Goal #4: In the past 11 months, I assisted in the mentoring of two Masters students, Danielle Gray Lewis and Paul Bergeron, both students of Schmidt-Jeffris. I mentored Lewis in community ecology field sampling techniques and conceptual frameworks in relation to the research in her agricultural ecosystem, as well as preparation for required exams and meetings related to the completion of her degree. I also helped Lewis in her preparations for presenting at the ESA annual meeting in November 2018. I will continue to mentor Lewis from remote in community ecology and ecological processes at the Clemson CREC in 2019. She is currently at the Clemson campus completing coursework, and I mentor her remotely now in concepts relating to her current coursework in community ecology. I will continue to mentor Bergeron in person as he is transferring to WSU to continue his research in association with Schmidt-Jeffris in August 2019. Objective 1: Sampling of leaves from both tomato (10 fields) and watermelon fields (13 fields) to do enumerative sampling of phytoseiids and weed composition and cover was completed in the first 6 months of Year 1 as specified in the Project Plan of my application. I collected the majority of phytoseiids from watermelon, with only three phytoseiid individuals found in tomato fields. Six species were collected from watermelon fields and 3 species from tomato fields total after83 collection events in 2018. The most frequently collected species wasProprioseiopsis mexicanus(Garman, 1958): Conventional Tomato: Proprioseiopsis mexicanus (1 individual) Neoseiulusfallacis (1 individual) Phytoseiulus persimilis (1 individual) Small-sustainable tomato: Zero phytoseiids collected Conventional Watermelon: P.mexicanus (154individuals) N.fallacis (24 individuals) P.persimilis (5 individuals) Typhlodromips neoclavicus (5 individuals) Athiasia greenae (2 individuals) Small-sustainable watermelon: P.mexicanus(5individuals) N.fallacis(3individuals) P.persimilis(1individual) T.neoclavicus(4individuals) Athiasia morgani(1individual) I completed the collection of data from a stakeholder survey in December 2018. Eight of my 12 growers responded to this survey. Upwards of 13 different fungicides were used by my growers to control cucurbit diseases. Three of my growers of both tomato and watermelon did not spray any pesticides. One of these was a small-sustainable grower, and one was a certified organic grower. The fewest phytoseiids were collected from these last two growers' fields (six and zero, respectively). Objective 2: During the surveys in 2018, only cucurbit powdery mildew was observed in watermelon fields with any frequency. Cucurbit downy mildew was not detected in fields I surveyed. I observed cucurbit powdery mildew in association with the most frequently collected phytoseiid species in my survey, P. mexicanus. Therefore, I want to concentrate the pathogen portion of my proposed feeding study on powdery mildew exclusively. This will examine if P. mexicanus will consume cucurbit powdery mildew, and if they can survive and reproduce on only powdery mildew conidia. Objective 3: I completed weed surveys (composition and cover) of grower's fields that were also surveyed for phytoseiid mites. My findings were that of the three most common weeds, Wild Radish (Raphanus raphanistrum), Yellow Nutsedge (Cyperus esculentus) and Quackgrass (Elymus repens), two C. esculentus and E. repens, do not produce pollen in typical blossoms, and therefore are unlikely to be pollen resources for phytoseiids, or the foci for the pollen-feeding trial proposed in my application. Additionally, I observed Purple Cudweed (Gamochaeta purpurea) to have ahigh abundance of predatory phytoseiids residing on it in a grower's watermelon field, so it has become a focus of study as afood resource. I am currently rearing Purple Cudweed because it appears to be habitat for plant bugs in the Hemiptera, and juvenile stages of these bugs may be prey for P. mexicanus. Currently, in the literature there is no known association between phytoseiids and plant bugs. Current status in2019: Early in January 2019, I began the first part of the alternative resource feeding studies. This consisted of a life table study ofP. mexicanus, which has been collected from Delaware to South Carolina infields alongthe east coast but whose life history and ecology are unknown. The life table study serves as a "control" and represents the standard care regime we provide toP. mexicanusfor mass rearing:T. urticaeand Nutramite® Willow (Typhaspp.) pollenon leaves of Lima bean plants forT. urticaeto feed. With our standard of care, we observed the life cycle of 138 individuals by monitoring their development every 12 hours. Of the 138, 86were observed to reach adulthood (62.3%). Due to their very short development time, I was occasionally unable to observe an individual in the protonymph or deutonymph stage, therefore, I have full data on development times for 70 individuals. Fifty-one of these were female (72.9%) and 19 were male (27.1%). Female (average time per developmental stage and standarddeviation; n = 51): Egg to larva:1.32 +/- 0.32 days Larva toprotonymph:0.635 +/- 0.223 days Protonymph to deutonymph:1.38 +/- 0.676 days Deutonymph to adult:1.95 +/- 0.602 days Total development time on average: 5.29 days Average time for a female to lay an egg after a male had been introduced: 2.35+/- 0.847 (n = 16) Male (average time per developmental stage and standarddeviation; n = 19): Egg to larva: 1.51 +/- 0.398 days Larva toprotonymph: 0.616 +/- 0.218 days Protonymph to deutonymph: 1.90 +/- 0.638 days Deutonymph to adult: 2.31 +/- 0.897 days Total development time on average: 6.34 days
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2018
Citation:
Farfan, M. A. and Schmidt-Jeffris, R. A. Diversity of natural communities of Phytoseiidae in two annual specialty cropping systems of economic importance in South Carolina, USA. Entomological Society of America Annual Meeting. Vancouver, B.C. Canada. 14 November 2018.
|