The prospects for cryopreservation of noctuid eggs in the mass production of Trichogramma spp

• Published in: BioControl (Dordrecht, Netherlands) Netherlands), 2021-12, Vol.66 (6), p.753-764
• Main Authors: Paixão, Magda F., Takahashi, Tamara A., Sassaki, Guilherme L., Foerster, Luís A.
• Format: Article
• Language: English
• Subjects: Agriculture; Animal Biochemistry; Animal Ecology; Behavioral Sciences; Biological control; Biomedical and Life Sciences; Butterflies & moths; Cryopreservation; Eggs; Entomology; Females; Freezing; Insects; Lepidoptera; Life Sciences; Liquid nitrogen; Low temperature; Maltodextrin; Mass production; Metabolites; New records; Nitrogen; NMR; NMR spectroscopy; Nuclear magnetic resonance; Nutritive value; Parasitism; Plant Pathology; Species; Spectroscopy; Spectrum analysis; Trehalose; Trichogramma; Wheat
• ISSN: 1386-6141; 1573-8248
• DOI: 10.1007/s10526-021-10109-3

Successful long-term cryopreservation of lepidopteran eggs for the mass production of parasitoids of the genus Trichogramma Westwood (Hymenoptera: Trichogrammatidae) requires a more tolerant species to withstand ultra-low temperatures. We compared the viability of eggs of Anticarsia gemmatalis Hübner (Lepidoptera: Erebidae) and Mythimna sequax Franclemont (Lepidoptera: Noctuidae), cryopreserved in liquid nitrogen, and evaluated the viability of M. sequax eggs to support the large-scale production of high-quality Trichogramma species. The presence of anti-freezing metabolites in lepidopteran eggs was detected and quantified by 1 H nuclear magnetic resonance (NMR) spectroscopy. Parasitism by Trichogramma pretiosum Riley of M. sequax eggs stored for 30 days was significantly higher (84.2%) in comparison to A. gemmatalis (6.7%). The 1 H NMR spectrum showed that the amounts of anti-freezing metabolites maltodextrin and trehalose were greater in M. sequax eggs, a possible explanation for their suitability to cryopreservation in comparison to A. gemmatalis . Eggs of M. sequax cryopreserved for up to 12 months maintained a mean rate of parasitism between 80 and 90% by Trichogramma atopovirilia Oatman and Platner and T. pretiosum, the latter declining to 79% after 12 months. Both Trichogramma species can exploit long-term storage of M. sequax eggs at ultra-low temperatures, without any apparent fitness penalty to the first generation. This is the first record of eggs of a noctuid species being cryopreserved for up to one year and remaining susceptible to parasitism by Trichogramma species. This procedure should enable large-scale production of hosts with high nutritional quality, and the production of parasitoids that is synchronized better with their use as biological control agents in annual crops.