Location: Invasive Species and Pollinator Health
Project Number: 2030-22300-032-017-A
Project Type: Cooperative Agreement
Start Date: Sep 1, 2020
End Date: Jan 31, 2022
Objective:
1) Collect and maintain candidate stinkbug species for non-target testing and improve rearing protocols as needed; and 2) Test the host specificity two bagrada bug parasitoids, Gryon gonikopalense and Trissolcus hyalinipennis.
Approach:
To provide candidate species for non-target testing, 5-6 stinkbug species will be collected in locations throughout Northern California. Insect cultures will be maintained year-round. Host specificity testing will be measured in two phases, first using ‘no-choice’ testing followed by ‘choice’ tests. During the first phase the parasitoid will be exposed to just one species of egg. Those non-target stink bug species successfully attacked by the candidate parasitoid will be subjected to ‘choice tests,’ whereby the parasitoid is exposed simultaneously to eggs of two stink bug species: bagrada bug and one of the non-target stink bugs. For these tests, clusters of fresh stink bug eggs (<24 h old) will be glued onto card stock strips using drops of Gorilla® glue and placed in glass vials. For no-choice tests, one mated female parasitoid will be released into each vial and removed after 24 hours. The placement of egg strips in choice tests will mimic natural conditions; bagrada bug eggs will be placed on sand on the cage floor and eggs of non-target species will be elevated 6cm from the cage floor on leaves of their preferred host plant. Eggs will then be monitored (for choice tests, egg strips from the target and non-target stink bug species will be placed in separate vials after exposure to parasitoids), and numbers of emerging parasitoids (by sex) and days to parasitoid emergence will be recorded. Eggs without emerging stink bugs or parasitoids will be dissected to record numbers of parasitoid larvae that failed to complete development. This information will help determine the suitability of the different stink bug species as hosts for the parasitoids.
