Date of Award


Degree Type


Degree Name

Master of Science in Biological and Environmental Sciences (MSBES)


Plant Sciences and Entomology

First Advisor

Nathaniel Mitkowski

Second Advisor

Lisa Tewksbury


Two species of invasive swallow-worts (Vincetoxicum nigrum and V. rossicum) have become problematic in unmanaged areas and agricultural settings in the Northeastern United States. Traditional methods of mechanical and chemical control are inadequate or unfeasible to implement so in 2017, the defoliating moth Hypena opulenta was approved for release in the United States for biological control of swallow-worts. Since 2017 the URI Biocontrol Lab has been releasing and studying the establishment of the species in Rhode Island, Massachusetts, and Connecticut. In 2018 a fungal pathogen was observed infecting V. nigrum plants at H. opulenta release sites. To investigate the fungal pathogen, a modified Koch’s postulates protocol using inoculum from fresh tissue was employed and strongly supports an identification of Amycosphaerella africana. To investigate the potential impact on H. opulenta establishment, a no-choice development experiment was conducted using diseased V. nigrum foliage. To investigate the potential for interaction, disease phenology was documented at an H. opulenta release site in Charlestown, RI and the factors influencing the timing of spring emergence for established H. opulenta were examined to predict possible phenological overlap of the two species on V. nigrum. Diseased V. nigrum foliage did not affect larval growth, however, development time was significantly slower for larvae fed diseased foliage. The first signs of the pathogen were recorded in July in both 2022 and 2023 in Charlestown RI. Temperature appears to be more important in predicting spring moth eclosion, meaning the timing of larval activity could vary year to year; however, due to photoperiod triggered diapause initiation for H. opulenta it is unlikely that many larvae will be feeding after mid-July on infected foliage. Due to this temporal separation, it is therefore unlikely fungal disease is a factor impacting establishment in southern New England.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.



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