Plant genotype influences plant suitability to herbivores; domesticated plants selected for properties such as high fruit yield may be particularly vulnerable to herbivory. Cultivated strains of highbush blueberry, Vaccinium corymbosum L. can be high-quality hosts for larvae of the gregariously feeding notodontid Datana drexelii (Hy. Edwards). We conducted an experiment assessing D. drexelii larval survival and pupal weight when fed foliage from five blueberry cultivars: ‘Bluecrop', ‘Bluetta', ‘Blueray', ‘Lateblue', and ‘Jersey'. We complemented this experimental work with repeated bush-level surveys of a managed blueberry patch for naturally occurring D. drexelii larval clusters. Larval survival and pupal weight were significantly higher on ‘Lateblue' foliage than from the ‘Bluecrop', ‘Bluetta', and ‘Jersey' cultivars. The blueberry patch surveys found more D. drexelii larval clusters on ‘Bluehaven', ‘Collins', and ‘Darrow' bushes than on the cultivars ‘Earliblue' and ‘Jersey'. The low D. drexelii occurrence and performance on the ‘Jersey' cultivar suggests that this variety may be appropriate for areas where this pest is common; conversely, their high occurrence on ‘Bluehaven' ‘Collins’, and ‘Darrow’ suggests that these cultivars may be particularly vulnerable. Cultivar-level variation in herbivore vulnerability highlights how understanding plant–pest interactions can help manage agricultural species.