This is a call to prepare for pest invasions with an eye to proactive biocontrol written by Mark Hoddle in a recently published article in the journal BioControl:
A new paradigm: proactive biological control of invasive insect pests
Invasive insect pests are a significant and accelerating threat to agricultural productivity, they degrade wilderness areas, and reduce quality of life in urban zones. Introduction biological control, the introduction, release, and establishment of host-specific efficacious natural enemies, is an effective management tool for permanently suppressing invasive pest populations over vast areas, often to levels that may no longer cause economic or environmental damage. However, introduction biological control programs are reactive: they are only initiated after an invasive pest has established, spread, and is causing damage that requires mitigation. Host specificity and host range testing of natural enemies for use in an introduction biological control program against an invasive pest can take years to complete. During this time, the target pest population continues to increase, invades new areas, and inflicts damage.
Proactive biological control research programs identify prior to their establishment pest species that have high invasion potential and are likely to cause economic or environmental damage once established. Natural enemies are selected, screened, and if sufficiently host-specific, approved for release in advance of the anticipated establishment of the target pest. Following detection of the target pest and determination that incipient populations cannot be eradicated, natural enemies already approved for release are liberated into infested areas.
This proactive approach to introduction biological control could significantly reduce project development time post-invasion, thereby lessening opportunities for pest populations to build, spread, and cause damage.
Tamarixia radiata wasp for Asian Citrus control
Scientists use samba wasps to manage the invasive spotted-wing drosophila, a key pest of small andstone fruit worldwide
By Vaughn Walton
Recently, spotted-wing drosophila (Drosophila suzukii, SWD) has appeared in fruit production areas worldwide. This invasive pest that resembles a vinegar fly, is highly damaging to berries and stone fruits. This fly infests these fruits as they ripen, costing half a billion dollars of crop damage annually in the USA. Affected crops include strawberry, raspberry, blackberry, blueberry, cherry, and wine grape.
Most vinegar flies attack overripe fruit laying eggs in the soft fruit. Spotted-wing drosophilhas a saw-like ovipositor, and can lay its eggs into ripening, susceptible fruit. The saw-like ovipositor allows SWD to cut into the firm outside of fruit and push its eggs in. These eggs are laid directly under the fruit surface area and immediately, sometimes even within hours, start to hatch. Hatching larvae will start feeding on the pulp of the affected fruit. Within two or three days, feeding larvae soft-en the pulp and provide entry to microorganisms, resulting in unacceptably soft and spoiled fruit. Within a one-week period, under ideal conditions, larvae will emerge from fruit. Emerging SWD larvae can pupate either in fruit or outside, after which adults emerge to repeat the life cycle. The life cycle can be completed within as little as ten days, with up to ten generations per season, resulting in explosive pest populations.
Scientists are researching control measures for SWD. One possibility for control includes the release of insect predators. In Oregon, USA, during summer of 2022, scientists are releasing a parasitoid wasp, also called the samba wasp (Ganaspis brasiliensis) as a predator, to combat the highly damaging and invasiveness, spotted-wing drosophila (Drosophila suzukii, SWD). Samba wasp releases in the Willamette Valley are part of a worldwide bid to help manage SWD. Samba wasp is also being evaluated by Kent Daane at UC Berkeley, so keep your eye on what's going on in California, as well.
Read the Samba Story. Images supplied by Vaughn Walton
UCCE & UCR Argentine Ant & Citrus Pest Management Field Day
Get Down with Argentine Ants
November 1 – Redlands, CA
November 2 – Saticoy, CA
Overview of Biocontrol Methods for ACP in Southern California, Mark Hoddle, Entomology and Extension Specialist at UC Riverside, Director of Applied Biological Control Research,
Overview of ACP/HLB Area-wide Spray Programs in Southern California, Sandra Zwaal, Citrus Pest & Disease Prevention Program, ACP/HLB Grower Liaison San Diego, Riverside, San Bernardino, and Ventura Counties,
Then out to the field to see:
Argentine Ants in Citrus at designated stations in small groups
- Discussions and demonstrations of use of hydrogel beads for Argentine ant control and we would cover aspects of ant biology/ecology/behavior/other control options at this station, Ivan Milosavljevic, UC Riverside
- Discussion and demonstration of monitoring programs for Argentine ants with a focus on using infra-red sensors, visual sampling, sugar-water saturated cotton wool balls, and liquid monitoring vials, Mark Hoddle & Michael Lewis, UC Riverside
- Enhancing natural enemies in citrus orchards with the use of cover crops. This station will cover possible species that could be used, aspects of flowering plants that make them good candidates for use in conservation biological control, the types of generalist natural enemies that will respond to these floral resources, and benefits and drawbacks of using cover crops. Nicola Irvin, UC
- The potential for hydrogels across regions, ant species, crops, and active ingredients. Discussion about major ant groups, resources to identify ants, a little about ant biology in the context of making hydrogels work, and then give an update on the results of trials funded by DPR to evaluate hydrogels against different ant species in different crops across California using five different active ingredients. This station will include the Ant ID mini station. David Haviland, UC Cooperative Extension, Kern County
REGISTRATION Acknowledgment Reply will include agenda and directions for the different sites
Contact: Ben Faber, email@example.com, 805-645-1462
November 1 Location: Carriage House Prospect Park, 1399 Prospect Dr, Redlands CA 92373
November 2 Location: 2641 SP Milling Rd, Saticoy, CA, follow the signs to Rancho Santa Clara del Norte, which is at the end of the road. Watch at turn to SP Milling Rd for traffic on Hwy 118/Los Angeles Ave./span>
Biological control is the management of pests and their damage by the beneficial action of parasites (parasitoids), pathogens, and predators. These beneficial organisms, collectively, are named natural enemies.
Conserving (or protecting) and releasing natural enemies are important components of integrated pest management (IPM). In most situations, employing practices that conserve natural enemies is more effective, and less expensive and time consuming, than purchasing and releasing them.
Learn about the specific situations where purchasing and releasing parasites and predators can increase the effectiveness of biological control. Before purchasing natural enemies, consult the University of California (UC) IPM Pest Management Guidelines for that crop to learn whether UC research has shown that releasing them is effective. Some natural enemies on the market have never been demonstrated to effectively control any agricultural pest in California.
Obtaining Natural Enemies
Natural enemies can be purchased directly from various producers (companies that rear them) and suppliers (companies that purchase from producers and repackage and resell them). Some sources of parasites and predators are members of the Association of Natural Biocontrol Producers (ANBP). All ANBP members formally agree to a code of ethics and standardized methods.
Natural enemies purchased by users are commonly delivered via shipping services. Purchase parasites and predators only from in-state providers. It is illegal to obtain insects and other arthropods outside of California and carry or have them shipped across state lines without a permit from agricultural officials. Some pest control advisers and pest scouts will procure and release natural enemies as a service for growers.
Methods for Releasing Natural Enemies
Two methods for releasing natural enemies are inoculation and inundation:
- Inoculation—relatively few natural enemies are released. The offspring of these natural enemies provide biological control, not the individuals released.
- Inundation—large numbers of natural enemies are released, often several times over a growing season. The natural enemies released, and possibly their offspring, provide biological control.
The mealybug destroyer is an example of a natural enemy that is only released through inoculation—at relatively low numbers once per year early in the growing season. Aphytis melinus and Trichogramma parasites are released by inundation—at regular intervals over the growing season—to control California red scale and eggs of pest moths, respectively. Both inoculation and inundation can be used with predatory mites, depending on the situation.
Releasing Natural Enemies Effectively
Releasing natural enemies is most likely to be effective in situations where: 1) University of California researchers or other pest management experts have previously demonstrated success and 2) some level of pests and their damage can be tolerated in that crop. Desperate situations are not good opportunities for releasing natural enemies. Pests or their damage may already be too widespread for any release of parasites or predators to prevent economic loss of crop quality or quantity.
Increase the likelihood that natural enemy releases will be effective by
- Accurately identifying the pest and its natural enemies.
- Learning about the biology of the pest and its natural enemies.
- Releasing the appropriate natural enemy life stage and species.
- Releasing when the pests' vulnerable life stage(s) are present and at numbers that can be controlled by natural enemy releases.
Natural enemies are unlikely to be effective when released as if you were applying a pesticide. Instead, anticipate pest problems and begin making releases before pests are too abundant or economic damage is imminent.
- Remember that natural enemies are living organisms that require food, shelter, and water. Protect them from extreme conditions. For example, release them at night or early in the day during hot weather.
- Avoid applying broad-spectrum, residual (persistent) insecticides and miticides, and in some situations certain systemic or other pesticides, before or after releasing natural enemies. When needed, use pesticides selectively. For example, spot spray only where pests are abundant but localized.
Common reasons for the lack of satisfactory biological control after releases include the
- Application of broad-spectrum, residual insecticides, or in some situations systemic or other pesticides, prior to or after a release.
- Incorrect timing of release.
- Release of the wrong natural enemy for the pest situation.
- Release of a natural enemy species that is known to be ineffective.
For information on the use of biological control, see the UC IPM Pest Management Guidelines for your crop and specific pests. Most crops have a table called “Relative Toxicities of Insecticides and Miticides to Natural Enemies and Honey Bees” in the “General Information” section. Use these resources to guide pesticide selection to conserve natural enemies and improve biological pest control.
- Association of Natural Biocontrol Producers, Clovis, CA
- Grower Guide: Quality Assurance of Biocontrol Products (pdf), Vineland Research and Innovation Centre, Ontario
- Insectary Plants
- Natural Enemies Gallery
- Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control
- Protecting Natural Enemies and Pollinators
- UC IPM Pest Management Guidelines
This Page is duplicated from the UC Integrated Pest Management website - https://www2.ipm.ucanr.edu/agriculture/natural-enemy-releases-for-biological-control-of-crop-pests/
Photo of predatory" mealybug destroyer" or Cryptolaemus
How ants can be “good” in ag production systems
By: Madison Sankovitz, UCR Entomology, Ph.D. Candidate, Purcell Lab, UC Riverside
Ants are often underappreciated in the United States for their natural benefits to agriculture. Organized as predatory superorganisms, ants often play an important role in pest management. Further, their influence extends beyond their pest control abilities; many ants live in soil and play a crucial role in maintaining soil fertility. Although recognized for their aphid-protecting tendencies and thus disliked by many growers, many traits of ants make them not only beneficial insects in agricultural settings but possibly a significant solution for sustainable food production moving forward.
The ability of ants to suppress pest species in an efficient way has been known since the year 300 A.D., and farmers continue to conserve and promote ant populations in agricultural systems in many regions of the world (Drummond & Choate 2011). They eat the larvae and eggs of pests and also disturb them during feeding and oviposition (e.g. López & Potter 2000). Weaver ants Oecophylla spp. (which live throughout Asia and Australia) are arguably the most well-documented ant genus used in biological control, but similar effects may occur in ants worldwide. Weaver ants share beneficial traits with nearly 13,000 other ant species and are unlikely to be unique in their properties as control agents (Offenberg 2015). For example, all ants can store protein in the form of trophic eggs and brood that can be cannibalized (Nonacs 1991), making their colonies stable and predictable service. Similar social and morphological traits in other ant species suggest great potential for the use of native California ants in the control of arthropod pests, weeds, and plant diseases in orchards and arable crops.
In addition to pest control, ants are important soil agents in agricultural systems because they contribute to aeration and fertilization, leading to higher soil quality. Aeration is the creation of pockets of air in soil, which help nutrients, water, and fertilizers seep into the soil and reach a greater extent of root systems throughout an agricultural plot. Ants aid in this process by digging a labyrinth of tunnels within the soil. Furthermore, ants introduce outside nutrients (e.g. seeds and insects) to the aerated soil through their foraging; food sources brought into the nest by worker ants decay and fertilize the surrounding plants, especially in no-till plots (Lange et al. 2008). For example, one field experiment showed that ants and termites increase wheat yield by 36% from increased soil water infiltration due to their tunnels and improved soil nitrogen (Evans et al. 2011). This result suggests that ants and termites have similar functional roles to earthworms (often regarded as the most important agents of soil turnover in many regions of the world). Additionally, they may provide valuable ecosystem services in dryland agriculture, which will become increasingly crucial for agricultural sustainability in arid climates, as is the case in some parts of California (Evans et al. 2011).
Ants as Indicators
The presence of ants alone can be beneficial for growers; ants have been suggested as effective bioindicators of soil quality, especially in low-income areas that do not have access to expensive soil monitoring equipment (De Bruyn 1999). Growers are being pressured to rectify the issues of land degradation by reforming their management techniques; however, there are few tools to monitor soil health that can reliably inform farmers of the wholistic state of their soil. If ants could be further investigated as accurate bioindicators, they would be valuable tools for use in agricultural practices worldwide.
Through changes in management practices such as tillage and other manipulations of vegetation and crop structure, beneficial ant populations can be conserved in a variety of agroecosystems. However, there is still much research to be done to determine the extent of agricultural services ants provide. Some ant species succeed in defending specific cropping systems, whereas others are damaging and yet others play dual roles. A future challenge is to determine positive and negative ant–crop pairs and to develop management practices that facilitate the positives and remove the negatives. Another possibility for research is to focus on the development of barriers that keep ants in soil and off of crops; this would allow them to carry out their soil services while not tending phloem-feeding insects. Additionally, there is a need for better documentation of ant biodiversity in agricultural soils in many regions of the world, including California. This data will allow for evaluation of ants as bioindicators of soil quality and predictions of the vulnerability of ant species under future changes in land use and climate. If we can better understand species patterns and the multitude of roles ants play in agricultural systems, they can be utilized for more sustainable food production in the future.
De Bruyn, L. L. (1999). Ants as bioindicators of soil function in rural environments. In Invertebrate Biodiversity as Bioindicators of Sustainable Landscapes (pp. 425-441).
Drummond, F., & Choate, B. (2011). Ants as biological control agents in agricultural cropping systems. Terrestrial Arthropod Reviews, 4(2), 157-180.
Evans, T. A., Dawes, T. Z., Ward, P. R., & Lo, N. (2011). Ants and termites increase crop yield in a dry climate. Nature communications, 2, 262.
Lange, D., Fernandes, W. D., Raizer, J., & Faccenda, O. (2008). Predacious activity of ants (Hymenoptera: Formicidae) in conventional and in no-till agriculture systems. Brazilian archives of Biology and Technology, 51(6), 1199-1207.
López, R., & Potter, D. A. (2000). Ant predation on eggs and larvae of the black cutworm (Lepidoptera: Noctuidae) and Japanese beetle (Coleoptera: Scarabaeidae) in turfgrass. Environmental Entomology, 29(1), 116-125.
Nonacs, P. (1991). Less growth with more food: how insect-prey availability changes colony demographics in the ant, Camponotus floridanus. Journal of Insect Physiology, 37(12), 891-898.
Offenberg, J. (2015). Ants as tools in sustainable agriculture. Journal of Applied Ecology, 52(5), 1197-1205.
Rüppell, O., & Kirkman, R. W. (2005). Extraordinary starvation resistance in Temnothorax rugatulus (Hymenoptera, Formicidae) colonies: demography and adaptive behavior. Insectes Sociaux, 52(3), 282-290.