Source: UNIV OF MINNESOTA submitted to NRP
BIOLOGICAL CONTROL OF INVASIVE INSECTS: PRINCIPLES AND IMPLEMENTATION
Sponsoring Institution
State Agricultural Experiment Station
Project Status
ACTIVE
Funding Source
STATE
Reporting Frequency
Annual
Accession No.
1027215
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 9, 2021
Project End Date
Jun 30, 2026
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIV OF MINNESOTA
(N/A)
ST PAUL,MN 55108
Performing Department
Entomology
Non Technical Summary
I will continue work on biological control of the soybean aphid in Minnesota, focusing mainly on the introduced parasitoid Aphelinus certus. The emphasis will be on understanding overwintering strategies, and how overwintering of this beneficial insect can be improved. I will also continue studies of the hyperparasitoids of A. certus, focusing on whether they pose a serious threat to biological control. In a second objective, I will begin studies on the possible 'spillover' of biological control services from agricultural to natural settings. I will investigate the hypothesis that polyphagous plant pests that have been controlled through biological control releases yet that disperse from agricultural to natural settings are controlled by the same natural enemies in the natural settings. This could be an important mechanism by which native plant diversity is protected from invasive herbivorous insects.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1360510113025%
2111820113075%
Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 136 - Conservation of Biological Diversity;

Subject Of Investigation
1820 - Soybean; 0510 - Wilderness;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
Goals/Objectives1. Biological control of soybean aphid by Aphelinus parasitoidsBased on our previous work on Aphelinus certus as a biological control agent of soybean aphid, we will focus on a continuation of overwintering dynamics with an increased focus on strategies to improve overwintering survival. We will also continue our work quantifying the effect of A. certus on suppression of soybean aphid, as well as on hyperparasitoids of this and other parasitoids of soybean aphid.2. Biological control of agricultural pests in natural areasMany non-native agricultural pests are polyphagous and feed not only on crop plants but on native plants in their introduced geographical range. When these pests are controlled through the importation of biological control agents, there is a chance that the biological control agents will 'spill over' into natural habitats, attack the invasive pest there, and thereby protect native plants from herbivory. I will identify such pest/natural enemy systems in Minnesota and formulate research goals to test the hypothesis that introduced biological control agents are protecting native Minnesota plants from invasive agricultural pests that have infiltrated natural ecosystems.
Project Methods
Project Outline and MethologiesObjective 1. Biological Control of Soybean Aphid using Aphelinus parasitoids1.1. The effect of tillage practices on overwintering survival of A. certus. Our data to date suggest that A. certus mummies overwinter within soybean fields, and preliminary studies have shown that mummies that emerge beneath 2 inches of soil have a very low chance of emerging from the soil. Based on these observations, we hypothesize that overwintering success of A. certus will be higher in untilled than in tilled soybean fields. We will conduct a series of in-field manipulative experiments and comparisons of unmanipulated fields to test this hypothesis. The manipulative experiments will compare aphid densities and emergence rates of A. certus mummies seeded into fields in sites with various levels of tillage in an experiment-station setting in a randomized field setting. Similar comparisons will be made in farmer fields with various levels of tillage.1.2. The role of corn in the dynamics of A. certus. A. certus is a generalist aphid parasitoid that readily attacks various aphid pests of corn, including the corn leaf aphid Rhopalosiphum maidis and the bird-cherry-oat aphid R. padi. Since corn and soybean are frequently rotated in Minnesota and other states in the North-Central U.S., our finding of A. certus overwintering within soybean fields suggests that these parasitoids will emerge into corn fields. We therefore hypothesize that aphids attacking corn are particularly vulnerable to attack by A. certus. Indeed, the linkage between corn and soybean habitats may be a key to understanding the overall dynamics of A. certus in the agricultural landscapes of Minnesota and surrounding states. We will begin investigations of this linkage by sampling R. maidis, R. padi and other grain aphids on corn from field corn and sweet corn sites in fields following soybean on experiment-station land. If these surveys indicate parasitism of corn-infesting aphids, we will plan additional experiments and observations to determine the fate of A. certus that emerge in corn fields that follow soybeans. Methods for these studies are pending on finding such experiments. Whether or not such parasitism is found, one purpose of these investigations will be to determine whether the corn habitat represents a sink for A. certus (i.e. a habitat with high immigration of A. certus but low survival) or a source of A. certus (i.e. a habitat with high survival and reproduction from which parasitoids colonize soybean).1.3 Hyperparasitoids of A. certus. As noted above, we have discovered seven hyperparasitoids attacking A. certus throughout Minnesota, with the most common species being in the genus Alloxysta. One of these species - A. curta - is thelytokous (i.e. all-female) but able to produce males when treated with antibiotics. This suggests infection by the endosymbiotic bacterium, Wolbachia, which is known to cause thelytoky in various hymenopteran parasitoids. We will test the hypothesis that thelytoky in A. curta is caused by Wolbachia by using PCR to identify Wolbachia in lines of A. curta that are either sexual (cured) or asexual (uncured). We will also continue to sample hyperparasitoids in all of our field-sampling studies, and incorporate a hyperparasitism module into our existing matrix model of A. certus-soybean aphid interactions to investigate the potential role of hyperparasitism in impacting population dynamics of soybean aphids.2. Biological control of agricultural pests in natural areas Many non-native agricultural pests are polyphagous and feed not only on crop plants but on native plants in their introduced geographical range. When these pests are controlled through the importation of biological control agents, there is a chance that the biological control agents will 'spill over' into natural habitats, attack the invasive pest there, and thereby protect native plants from herbivory. Although this phenomenon is not well studied, a scenario suggesting that it could be important has played out in the Galapagos Islands with the introduction of the infamous Cottony Cushion Scale, Icerya purchasi, which is a polyphagous insect native to Australia that is known mainly as a pest of citrus throughout the world. The scale insect invaded the Galapagos Islands the 1980s and greatly endangered a number of native and endemic plants there. The biological control agent Novius (= Rodolia) cardinalis was introduced in 2002 and provided near-complete control of the Cottony Cushion Scale there, saving various endemic plants from likely extinction.While the control of Cottony Cushion Scale in Galapagos does not represent a case of spillover of biological control from agricultural to natural settings, N. cardinalis has been introduced against the scale insect in citrus in over 50 countries to great success. I hypothesize that native plants have been protected from this herbivore associated with many of these introductions and I have a sabbatical leave planned in 2022 during which I will test this hypothesis with colleagues in Israel and Italy. I am also the co-convener of a Working Group of the International Organization of Biological Control that is focused on this question, not only for Cottony Cushion Scale, but for non-native pests that are under control by introduced agents in general. This Working Group will help in identifying other cases of polyphagous insect pests under biological control throughout the world, and the potential for spillover-mediated protection of native plants. Upon my return from sabbatical in early 2023, I will begin a search for such pest/natural enemy systems in Minnesota. The first will be the imported cabbageworm, Pieris rapae, which feeds on a number of brassicaceous plants, including North American natives, and is under successful biological control by two parasitoid species in Minnesota. In order to maintain a focus in these investigations, we will focus on pests such as P. rapae, which are under successful importation (= 'classical') biological control.

Progress 10/01/21 to 09/30/22

Outputs
Target Audience:Soybean farmers Soybean extension agents Soybean pest control advisers Biological Control Specialists Entomologists Ecologists Evolutionary biologists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Invited presentationduring reporting period: 3/2022. G.E. Heimpel. Biological control of soybean aphid: the parasitoid Aphelinus certus. Invited presentation: Strategic Farming 2022; University of Minnesota Extension (virtual). Submitted presentationduring reporting period: 3/2022. J. Dregni, K. Welch, J. Kaser, R. Kochand G.E. Heimpel. Parasitismofsoybeanaphid byAphelinus certusfrom 2011 to 2021 in Minnesota. Entomological Society of America, North Central Branch, Minneapolis, MN. Poster presentation. What do you plan to do during the next reporting period to accomplish the goals? Soybean aphid biological control: determine effect of tillage on soybean aphid biological control, and the risks and benefits of the parasitoid Aphelinus certus to native insects in Minnesota. Effect of biological control on native biodiversity in Minnesota. Explore systems withing which to explore this question.

Impacts
What was accomplished under these goals? Biological Control of Soybean Aphid I was on sabbatical leave for the entirety of 2022 working on non-Minnesota objectives.During the last two months of 2021 (the fist two months of the reporting period), we worked on the data analysis for the submission of a paper on cold tolerance, which occurred during 2022. Biological control of agricultural pests in natural areas No additional research was done on this sub-objective in Minnesota during the reporting period.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Batista, M.C., G.E. Heimpel, M. Bulgarella & M. Venzon. 2022. Diet breadth of the aphid predator Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae). Bulletin of Entomological Research 112: 528-535.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Brito, A.G.V., J. A. Salas, G.E. Heimpel & M. Bulgarella. 2022. Use of artificial nest boxes by two species of small, arboreal mammals in Ecuadorian tropical dry forest. Neotropical Biodiversity 8: 108-111.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Casiraghi, A., J.S. Dregni, N.P. Hidalgo, J. Kaser, G.E. Heimpel, J. Selfa & M. Ferrer-Suay. 2022. Brachyptery analysis in Alloxysta (Hymenoptera: Figitidae): synonymy of A. curta as the brachypterous male of A. ramulifera in the Nearctic. Proceedings of the Washington Entomological Society 124: 1-12.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Monticelli, L.S., N. Desneux, A. Biondi, E. Mohl & G.E. Heimpel. 2022. Post-introduction changes of host specificity traits in the aphid parasitoid Lysiphlebus testaceipes. Entomologia Generalis 42: 559-569.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Ramirez, I.E., Causton, C.E., Gutierrez, G.A., Mosquera, D., Piedrahita, P., Heimpel, G.E. 2022. Specificity within bird-parasite-parasitoid food webs: a novel approach for evaluating potential biological control agents of the Avian Vampire Fly. Journal of Applied Ecology 59: 2189-2198.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Bulgarella, M., M.P. Lincango, P.L. Lahuatte, J.D. Oliver, A. Cahuana, I.E. Ram�rez, R. Sage, A.J. Colwitz, D.A. Freund, J.R. Miksanek, R.D. Moon, C.E. Causton & G.E. Heimpel. 2022. Persistence of the invasive Darwins finch parasite Philornis downsi in the Galapagos Islands: an age-grading approach. Scientific Reports 12: 2325.
  • Type: Journal Articles Status: Under Review Year Published: 2023 Citation: Kaesar, T., E. Wajnberg, G.E. Heimpel, I.C.W. Hardy, L. Shaltiel, D. Gottlieb, S. van Nouhuys. Dynamic economic thresholds for insecticide applications against agricultural pests: importance of pest and natural enemy migration. In revision: Journal of Economic Entomology.
  • Type: Journal Articles Status: Under Review Year Published: 2023 Citation: Stenoien, C.M., L. Christianson, K. Welch, J. Dregni, K.R. Hopper & G.E. Heimpel. Cold tolerance and overwintering survival of Aphelinus certus (Hymenoptera: Aphelinidae), a parasitoid of the soybean aphid (Hemiptera: Aphididae) in North America. In review: Bulletin of Entomological Research since 24 Aug, 2022.
  • Type: Journal Articles Status: Under Review Year Published: 2023 Citation: Heimpel, G.E., P.K. Abram, M. Coll, I.C.W. Hardy, M. Mangel & M. Segoli. A framework for risk-benefit analysis of biological control introductions. In review: Frontiers in Ecology and Environment since 12 Dec, 2022.


Progress 07/09/21 to 09/30/21

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Project is new. Nothing to report yet.

Publications