Progress 10/01/14 to 09/30/17
Outputs
Target Audience:Over the three years of funding for this project, the target audience for this project have included mostly one PhD student (Ricardo Perez), who has been spearheading this project, another PhD student that is now a postdoc in the lab and a former postdoctoral associate that was in the lab and is currently and assistant professor at Virginia Tech. New to the project this year is the graduate student that is currently a postdoc (Heather Grab) who was widely influenced by the work done by Ricardo and who has been aiding the project through her great statistical skills and her knowledge of insect traits in ecosystem services. 10 undergraduate students have been involved in this project, most of them helping with various aspects of the research. However 1 undergraduate student, Anthony Polyakov, has stood out as he has expanded our initial goals to better understand the community composition of carabid beetles that are important natural enemies in the cabbage system we have been studying. All undergraduate students have received formal and informational training in research techniques in the field and in the lab and results also have been presented during lectures and discussions in my Ecology of Agricultural Systems classes. Ricardo has done extension work with farmers, mostly the 12 farmers where the plots where located. Informal meeting with the farmers discussing the goals of the project happened at each farm, but formal pamphlets were also delivered at the end of each season to inform the farmers about the goals accomplished and give them information about the diversity of natural enemies on their farm. The PhD and postdoctoral students involved have all gained ample experience mentoring undergraduate students through organizing research teams, paper discussions, data analysis and even paper writing or preparation of oral presentations of posters. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?As mentioned before most of the training and professional development from this proposal was for one graduate student and one undergraduate that have been intensively working on this project. The whole research training and professional development for the graduate student was through this project. He also got exposed to being an incredible mentor for the 10 undergraduates working in this project, but mostly to our long-term undergraduate Anthony Polyakov, that engaged in research and was interested in identifying and characterizing carabids. Ricardo and Anthony have worked together performing field work, identifying beetles, measuring body size traits, analyzing data and writing results. Anthony has also presented a poster of his work at an Annual Entomological Society of America meeting, which Ricardo helped him prepare. How have the results been disseminated to communities of interest?The results have been disseminated through conference talks and posters, and also through informal pamphlets prepared for each grower that has been part of the project. Results have also been disseminated through field farmers days and extension programs in the Entomology Department such as Insectapalooza. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
During the course of the whole project, we accomplished the first 3 specific objectives presented on our proposal. Although we could not accomplish the 4th objective, given that our data suggest that the control by Spined Soldier bugs is too context dependent to be an effective control tool in all landscapes, we added an objective where we are investigating the effects of landscape complexity of the indirect (fear) response of Colorado Potato Beetle to natural enemies in potato crops in NYS. We decided to switch the system since there is enough evidence that suggests that CPB will respond to natural enemies not just through consumptive, but also through non-consumptive effects. We wanted to test how context dependence this response is and the potato-CPB system was a better system to test this than the cabbage system. Overall in the 3 years of the project we found that: 1) Landscape simplification (more agricultural area around a farm) reduces natural enemies overall, but has a positive effect on the community of carabid beetles 2) Different pests respond differently to the effect of natural enemies. The complex of lepidoptera pest is controlled by natural enemies, mostly parasitoids that do decrease with landscape simplification. Flea beetles are not effectively controlled by the natural enemies found in our study and are influenced by the amount of pastures at the landscape scale. With more pastureland in the landscape, flea beetle abundance on cababge increases and affects its productivity. 3) Augmentative biological control with spined soldier bugs and ladybeetles increases biocontrol in complex but not in simple landscapes. The effect trickles down to the biomass produced by the cabbage head and has therefore consequences for productivity. 4) Colorado potato beetles reduce feeding on potato plants as a response to fear of predators in a landscape-context manner. In complex landscapes with more natural enemies, CPB populations are more likely to exhibit "fear" responses and to offer its progeny trophic eggs to stimulate the growth of the larvae.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Poveda K., H. Grab, & R. Perez Alvarez. Advantages from natural habitats for yield: how landscape simplification can affect yield through arthropod-mediated ecosystem services and disservices. Ecological Society of America Meeting. Ft. Lauderdale, FL, USA. August 11, 2016.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Perez, R., B. Nault & K. Poveda. Effects of landscape composition on crop yield mediated by specialist herbivores. Annual meeting of the Entomological Society of America, Minneapolis, MN, USA. Contributed Presentation. November 16th 2015.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2018
Citation:
Perez-Alvarez, R., B.A. Nault & K. Poveda. Contrasting effects of landscape composition on crop yield mediated by specialist herbivores. Accepted in Ecological Applications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Perez-Alvarez, R., B.A. Nault & K. Poveda. Delivery of pest control services is mediated by the functional composition of predator communities. Annual meeting of the Entomological Society of America, Minneapolis, MN, USA. Contributed Presentation. November 5-8th 2017.
|
Progress 10/01/15 to 09/30/16
Outputs
Target Audience:The target audience for this project have included one PhD student and a postdoctoral associate that have both received training and have been doing research in this project. They have also done some extension work with the farmers, where they are performing their work, by telling them about the project and the preliminary data we are getting. The PhD student has gained ample experience mentoring undergraduate students and at least 2 undergraduate students have gained research experience working on this project. One undergraduate student is performing independent research that will probably result in a publication. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided mostly training for one graduate student that is developing his dissertation on this topic. This year of experience in the field definitively have generated a change in knowledge for the PhD student, the postdoc and the 2undergraduates involved in the program. It has also provided the PhD and the postdoctoral student the opportunity to mentor undergraduate students, who are learning about alternative management strategies and how landscape complexity can affect the effectiveness of different management systems. The new discovery that landscape complexity is changing the morphological traits of species is a new and exciting direction this project is taking. How have the results been disseminated to communities of interest?Until now we have been in close contact with participating farmers, who have received information about the natural enemies that are found on their farm and in the region. We also inform them how the use of natural enemies in their farm can be useful for to control cabbage pests. What do you plan to do during the next reporting period to accomplish the goals?We are in the process of finalizing one paper on the effect of landscape complexity on pest pressure in cabbage fields. Another paper showing the landscape-dependent effects on augmentative biological control still needs some data analysis and writing. From a data-generating point of view we will continue working on the changes in the morphological traits of natural enemies along the landscape gradient to better understand how pest control can be influenced not just by the abundance of natural enemies, but by changes in its size.
Impacts
What was accomplished under these goals?
Until now we have been able to address the first 3 objectives of the proposed work. Our work until now provides a comprehensive assessment of how landscape composition affects biocontrol services provided by both augmented and naturally occurring predators. Our results show significant positive effects of augmentative releases of predators on biocontrol of lepidopteran larvae. Effects of augmentative releases on pest control and plant damage were influenced, as expected, by differences in landscape composition. Contrary to our expectations, augmentative releases of predators presented the strongest potential for reducing lepidopteran larvae, under conditions of high landscape complexity. Importantly, our data also suggest that naturally occurring predators such as ground beetles, harvestmen, and lady beetles can also enhance biocontrol of lepidopteran pests in cabbage fields. Current work also shows that landscape complexity does not just affect pest control by resident natural enemies through changes in numbers and richness, but that it can affect the size of the same species of natural enemy. Our current data suggest that the size of the natural enemy community is a better predictor of pest control than species richness and abundance, indicating that more attention needs to be placed on this interesting and still unexplored metric.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
*Perez, R., B. Nault & K. Poveda. Testing the intermediate landscape complexity hypothesis for augmentative biological control. XXV International Congress of Entomology. Orlando, FL, USA. Contributed Presentation. September 28, 2016
|
Progress 10/01/14 to 09/30/15
Outputs
Target Audience:The target audience for this project have included one PhD student and a postdoctoral associate that have both received training and have been doing research in this project. They have also done some extension work with the farmers, where they are performing their work, by telling them about the project and the preliminary data we are getting. The PhD student has gained ample experience mentoring undergraduate students and at least 2 undergraduate students have gained reseatch experience working on this project. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has provided mostly training for one graduate student that is developing his dissertation on this topic. This year of experience in the field definitively have generated a change in knowledge for the PhD student, the postdoc and the 2 undergraduates involved in the program. It has also provided the PhD and the postdoctoral student the opportunity to mentor undergraduate students, who are learning about alternative management strategies and how landscape complexity can affect the effectiveness of different management systems. How have the results been disseminated to communities of interest?Until now we have been in close contact with participating farmers, who have received information about the natural enemies that are found on their farm and in the region. We also inform them how the use of natural enemies in their farm can be useful for to control cabbage pests. What do you plan to do during the next reporting period to accomplish the goals?We are in the process of analyzing data and planning one further field season to see if the patterns that were found in 2015 will hold over different season. With those two years of data we will be able to address our third objective of designing local management strategies that take into account the surrounding landscape.
Impacts
What was accomplished under these goals?
The first three objectives were addressed over the course of the 2015 field season by specifically addressing the following 2 aims: Determine the effects of landscape complexity mediated by natural enemy communities on lepidopteran pest control and cabbage yield. Examine the role of landscape complexity on the effectiveness of augmentative releases of predators for biological control of lepidopteran pests. METHODS To address these aims we set up experimental fields in 11 farms throughout the Finger Lakes Region in NYS. The farms were selected along a gradient of agricultural intensification, which was measured within a radius of 1000 m around our experimental plots. Landscapes ranged from simple, comprised primarily of cropland (73% cropland), to complex landscapes, characterized by a high proportion of semi-natural habitats (2% cropland). At each site, the abundance and diversity of arthropods were monitored by using pitfall traps, yellow sticky cards, and visual plant inspection. In addition, on each sampling date, ten randomly selected plants per plot were removed from the ground to determine pest abundance, overall insect damage and plant biomass (or yield at the very end). In each farm, we established two experimental plots separated by at least 200 m. One plot was used as a control (no biocontrol augmentation) and the other was used to release Podisus maculiventris and Hippodamia convergens. Predators were released three times during the growing season at biweekly intervals beginning 15 days after transplanting. To measure predation rates provided by resident and augmented predators, we used four types of sentinel preys: Trichoplusia ni larvae, T.ni eggs, Plutella xylostella pupae and mealworms. We also used a video camera to record predatory arthropods visiting sentinel eggs and pupae. PRELIMINARY RESULTS The overall abundance of ground-dwelling predators in our system was higher than that of the foliar-foraging predators. The most common ground-dwelling predators were Carabidae, Staphylinidae, Araneae and Opiliones. The most common taxa of foliar foraging-predators included Coccinellidae, Nabidae, Geocoridae, and Miridae. Only a few predator species, however, appeared in high enough numbers to have the potential to significantly affect populations of cabbage pests. These taxa included Coleomegilla maculata, Carabids (Stelenophus sp. and Bembidion sp.), and Opilions. Spiders seem to be important in pitfall traps, but their densities were low on sticky cards and plant samples. We also observed a large number of parasitoid wasps (Cotesia glomerata), but the relative importance of parasitoids differed greatly among landscapes. The density of caterpillar pests was relatively low during the whole sampling period (control plots: 0.39 ± 0.14 larvae/plant, predators' plots: 0.56±0.14 larvae/plant). The most common caterpillar pest during the trapping period was P. rapae, while P. xyllostella was recorded only in a few plots. Natural populations of T. ni were not observed through the sampling period. The analysis of the first two sampling periods indicated that the proportion of eggs and mealworms removed by predators was not significantly different between the control and the augmentative releases plots. By contrast, larval predation showed a twofold increase from 0.16 to 0.34 in the experimental plots where the predators were released. This effect was independent of both landscape complexity and sampling date.
Publications
|
|