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Dormancy Management to Enable Mass-rearing and Increase Efficacy of Sterile Insects and Natural Enemies
Closed for proposals
Project Type
Project Code
D41025CRP
1972Approved Date
Status
Start Date
Expected End Date
Completed Date
27 March 2020Description
Biological control applications based on the use of sterile insects and natural enemies are sustainable and environment-friendly control methods that are increasingly being used against pest insects. Dormancy is an integral component of many insect life cycles, wherein insects enter a state of developmental or reproductive arrest to avoid adverse conditions and synchronize their populations with favourable conditions. Dormancy responses are an obstacle to the effective implementation of mass rearing in many cases. The ability to manage dormancy could facilitate the development of new pest control programs that are currently constrained by species dormancy characteristics. Dormancy management could also offer opportunities to carefully time the supply of mass-reared insects upon demand and to enhance product quality. Specifically, dormancy management could enable effective mass rearing of insects that require dormancy, the ability to stockpile and mobilize them upon demand, maintenance of the genetic integrity of strains, and mitigating the stresses of sterilization, product shipment, and release. However, there is a clear gap in knowledge of the roles and mechanisms of dormancy on life cycle synchronization or stress resistance in sterile insects and natural enemies. The objectives of this CRP are: 1) to generate new knowledge about the induction, maintenance, and termination of dormancy in insects, 2) to disseminate and apply that knowledge to improve the efficacy of current biological control programs using sterile insects or natural enemies, and 3) to develop new programs for select insect pest species where dormancy has been a barrier. Furthermore, understanding dormancy responses may lead to novel pest management tools, such as dormancy disruption in the field.
Objectives
The objective of the project is to understand and harness dormancy management, physiological conditioning, and cold-storage approaches to enable mass-rearing of insect species previously difficult to rear and enhancing current mass-rearing efforts for biological control, specifically using sterile insects and natural enemies as part of an environmentally friendly, area-wide integrated pest management approach.
Specific objectives
Assess whether dormancy responses, physiological conditioning, and storage conditions can be used to decrease shipping-related damage and enhance post-shipping performance.
Assess whether dormancy responses, physiological conditioning, and storage conditions can be used to reduce radiation injury and enhance sterile insect performance.
Develop and assess new methods to manage dormancy responses, physiological conditioning, and storage conditions to facilitate mass rearing.
Develop and assess new methods to use dormancy responses, physiological conditioning, and storage conditions to enable or enhance the shelf life of biological control agents, including sterile insects and natural enemies.
Develop and assess new methods to use dormancy responses, physiological conditioning, and storage conditions to maintain the genetic integrity of laboratory strains.
Develop methods to incorporate dormancy into phenological models to improve the timing of field releases.
Explore the potential for dormancy responses to generate novel approaches for inducing “ecological suicide”.
Explore the role of the microbiome on dormancy responses, physiological conditioning, and cold storage to enhance mass rearing and shelf life of biological control agents.
Impact
The key achievements of the CRP were: 1) We evaluated chemical, endocrine, and environmental means to terminate diapause and accelerate development in mass-reared insects. While it is possible to modify development at a research scale, there exist many challenges to scaling these approaches to mass-rearing. 2) We demonstrated that fluctuating temperatures have profound and positive effects on insect performance, and can significantly extend shelf life of insects. The barriers to utilizing fluctuating temperatures in mass production are engineering, rather than biological. 3) While a range of cryoprotectants are associated with low temperature survival and performance, Proline (and some other free amino acids) emerges as a particularly valuable molecule because it appears to be effective at relatively low concentrations and can be administered in the diet. Addition of proline to diet would be reasonably easy to implement in mass-rearing. 4) We explored the roles of plasticity of SIT-relevant traits to environmental stressors, and its interaction with responses to other stressors associated with irradiation, transport, and release. Harnessing plasticity to improve rearing, handling, and field performance of insects holds great potential to enhance the efficacy of existing programs and facilitate development of new programs.
Relevance
The specific objectives of the CRP were achieved: (a) we developed and assessed new methods to manage dormancy responses, physiological conditioning, and storage conditions to facilitate mass rearing; (b) we examined the genetic architecture of dormancy responses, physiological conditioning, and storage conditions; (c) we developed methods to incorporate dormancy into phenological models; (d) we explored the potential of dormancy responses, physiological conditioning, and storage conditions to enable or enhance the shelf life of biological control agents, including sterile insects, natural enemies, and other beneficial insects; (e) we assessed the interactions between dormancy responses, physiological conditioning, and storage conditions in reducing radiation injury and enhancing sterile insect performance; (f) we showed that dormancy responses and physiological conditioning decrease shipping-related damage and enhance post-shipping performance; (g) we characterized the role of the microbiome on dormancy responses, physiological conditioning, and low temperature biology in insects; (h) we laid groundwork for understanding the potential for dormancy responses to generate novel approaches for inducing “ecological suicide”; (i) we summarized the state of knowledge of low temperature biology in a format useful for risk assessors. An important next step will be to transfer these advances to colony and strain maintenance, mass rearing, and field application.