EXPO update on SWD parasitoid releases – Good Fruit Grower

—by Matt MilkovichThe invasive noticed wing drosophila can devastate cherries and blueberries in Michigan, the place scientists are rearing and releasing two of the pest’s native enemies, the samba wasp and ronin wasp, in hopes they’ll set up populations. (Photograph illustration courtesy Martin Cooper)On Day 2 of the 2024 Nice Lakes Fruit, Vegetable and Farm Market EXPO, Michigan State College tree fruit entomologist Julianna Wilson advised a “story of two biocontrol brokers” — the samba wasp and ronin wasp.Julianna WilsonWilson spoke in the course of the morning Cherry session. She stated the samba wasp (Ganaspis brasiliensis) and ronin wasp (Leptopilina japonica) are each parasitoids of the noticed wing drosophila (SWD), the invasive fruit fly that may devastate North American fruit crops, particularly soft-skinned cherries and blueberries. Populations of each wasps, native to Asia, had been delivered to U.S. Division of Agriculture services a decade in the past and studied beneath quarantine. The samba wasp, which parasitizes SWD completely, was authorised for mass rearing and launch in 2021. The ronin wasp was not allowed to be launched, as a result of it additionally parasitizes different drosophila flies. The ronin wasp has been discovered within the wild in Michigan and different states, nonetheless, and researchers at the moment are allowed to mass-rear and launch the parasitoid as an SWD biocontrol agent, Wilson stated. “The excellent news is we’ve got each species right here, and we’re sustaining colonies of every,” Wilson advised the EXPO viewers. Each wasps parasitize SWD by laying their eggs inside SWD larvae which might be creating in fruit. The wasp larvae enable the SWD larvae to grow to be pupae, then eat them and use the pupae case to guard themselves whereas they grow to be adults. MSU researchers reared and launched a small variety of samba wasps in 2022. The wasps had been launched in “postharvest eventualities” within the wooded edges of cherry and blueberry plantings, the place SWD typically take refuge and the place researchers hoped the wasps would set up populations, she stated.They didn’t get well any samba wasps in 2022, however they launched 37,000 wasps at 30 websites the next yr and recovered wasps from 5 of them (none of them cherry websites, nonetheless), she stated. SWD infestation was “horrible” in Michigan in 2024, however researchers hoped the silver lining could be better institution of the pest’s pure enemies. They launched extra samba wasps that yr, however at fewer websites. They hadn’t recovered any samba wasps by Dec. 11, however they had been nonetheless processing samples, Wilson stated.They had been nonetheless processing samples from ronin wasp releases, too, however had already discovered wasps in two out of 14 cherry websites, she stated. “That’s actually thrilling,” Wilson stated. “It looks like it’s build up in quantity.”MSU entomologists will proceed to rear and launch the 2 biocontrol brokers, and can proceed to watch their inhabitants institution. They hope to see some impacts on SWD populations finally, but it surely’s going to be a long-term effort, Wilson stated. 



Source link