|FORBES, ANDREW - UNIVERSITY OF IOWA|
|FEDER, JEFFERY - UNIVERSITY OF NOTRE DAME|
Submitted to: The Canadian Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/23/2019
Publication Date: 1/1/2020
Citation: Yee, W.L., Forbes, A.A., Feder, J.L. 2020. Eclosion and adult longevity traits of Rhagoletis tabellaria (Diptera: Tephritidae) and Utetes tabellariae (Hymenoptera: Braconidae) in the laboratory. The Canadian Entomologist. 152(2):145-158. https://doi.org/10.4039/tce.2019.74.
Interpretive Summary: The ecology of fruit flies in the genus Rhagoletis has been well studied, but most of the information gathered has been based on only six species out of over 70 species. Rhagoletis tabellaria is a fly that attacks dogwood and has been implicated as a pest of some commercial fruit. Personnel at USDA-ARS in Wapato, WA, University of Iowa, and the University of Notre Dame determined the effects of chilling on emergence of R. tabellaria and its major parasitic wasp as well as fly and wasp longevity. When chilled, flies emerged earlier than wasps in accordance with when fly stages are available for attack, but when not chilled, flies did not emerge while wasps did, suggesting different physiological responses to cold by host and parasite. Flies survived longer than wasps in accordance with the short period when susceptible fly stages are available for attack. Results are important in that they expand our knowledge of Rhagoletis flies and their coevolution with their parasites.
Technical Abstract: The effects of duration of chilling on eclosion for Rhagoletis tabellaria (Fitch) (Diptera: Tephritidae), a fly that attacks red osier dogwood (Cornus sericea L.) (Cornaceae), and its parasitoid wasp Utetes tabellariae (Fischer) (Hymenoptera: Braconidae) along with fly and wasp longevity were determined in the laboratory. Female flies, male flies, and female and male wasps reared from fly pupae chilled for 195 d at 4.8°C and then held at 23.2°C eclosed as adults after an average of 22.6, 21.4, 39.6, and 34.3 d, respectively. Flies eclosed significantly earlier from pupae chilled at 2.7°C for 150 d (23.3 d; sexes combined) than 120 d (24.7 d), but wasp eclosion from the two treatments did not differ significantly (35.0 and 38.6 d, respectively). Fly eclosion rates from 195-, 150-, and 120-d chill treatments were 80.0%, 74.8%, and 51.0% while rates for pupae producing adult wasps were 10.7%, 10.7%, and 9.0%, respectively. No fly eclosed from non-chilled pupae held at 20–22°C, but at least 18.8% of non-chilled wasps eclosed. At 22.9°C, female and male flies on average survived longer (52.1 and 83.3 d, respectively) than wasps (females, 37.7 d; males, 28.7 d). Our findings suggest that diapause and developmental traits of R. tabellaria are more dependent on chilling durations and less flexible than those of U. tabellariae. As U. tabellariae apparently only parasitizes members of the tabellaria species complex, wasp eclosion timing and longevity may be adapted to attacking tabellaria flies and differ from those of wasps attacking Rhagoletis in other species complexes.