Exploiting tools for manipulating insect diapause

Abstract

Tools that could be used to subvert the insect diapause response offer potential for insect pest management as well as for the experimental manipulation of insects and the facilitation of mass rearing procedures. In some cases, it is desirable to break diapause on demand and in other cases, it may be attractive to exploit diapause for long-term storage of biocontrol agents or valuable experimental lines. This review highlights some of the diapause disruptors reported in the literature, as well as chemical and physical manipulations that can be used to extend diapause or even induce diapause in an insect not programmed for diapause. The insect hormones are quite effective agents for breaking diapause and in some cases for extending the duration of diapause, but a collection of other chemical agents can also act as potent diapause disruptors, e.g. organic solvents, weak acids and bases, carbon dioxide, imidazole compounds, LSD, deuterium oxide, DMSO, ouabain, cholera toxin, cyclic GMP, heavy metals, and hydrogen peroxide. Physical manipulations such as artificial light at night, anoxia, shaking and heat shock are also known diapause disruptors. Some of these documented manipulations prevent diapause, others terminate diapause immediately, others alter the duration of diapause, and a few compounds can induce a diapause-like state in insects that are not programmed for diapause. The diversity of tools noted in the literature offers promise for the development of new tools or manipulations that possibly could be used to disrupt diapause or manage diapause in controlled laboratory experiments and in mass-rearing facilities.

Histone acetylation is associated with pupal diapause in cotton bollworm, Helicoverpa armigera

“…Research indicates that hormones (juvenile hormone, ecdysone, and insulin) are the primary diapause regulators. 1 In this study, we used the pupal diapause of H. armigera as a model system to demonstrate that insect diapause is controlled by histone H3 acetylation, an epigenetic modification. First, we demonstrated the down-regulation of histone H3 acetylation in the diapause-type pupae.…”

“…Studying the molecular processes of diapause offers fresh insights into the discovery of possible therapeutic targets in pest management. Research indicates that hormones (juvenile hormone, ecdysone, and insulin) are the primary diapause regulators 1 . In this study, we used the pupal diapause of H. armigera as a model system to demonstrate that insect diapause is controlled by histone H3 acetylation, an epigenetic modification.…”

“…Diapause, an environmentally preprogrammed period of arrested development, is common among insects and has helped the Class insect a succeed by bridging unfriendly environments. 1 Complex physiological traits accompany diapause, such as slower development, longer lifespan, and lower metabolism. 2,3 As insects enter diapause, their adaptability to the environment and stress resistance are enhanced, which is vital for their survival and population growth.…”

“…Diapause, an environmentally preprogrammed period of arrested development, is common among insects and has helped the Class insect a succeed by bridging unfriendly environments 1 . Complex physiological traits accompany diapause, such as slower development, longer lifespan, and lower metabolism 2,3 .…”