HORTICULTURAL ENTOMOLOGY Host Status of Blueberry to Invasive Tephritid Fruit Flies in Hawaii

Forced infestation studieswere conducted to determinewhether northern or southern highbush blueberries, Vaccinium corymbosum L., are hosts for the invasive tephritid fruit ßies in Hawaii. Fruit were exposed to gravid female ßies of Bactrocera dorsalis Hendel (oriental fruit ßy), Ceratitis capitata (Wiedemann) (Mediterranean fruit ßy), or Bactrocera cucurbitae Coquillet (melon ßy) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal and adult emergence. The number of puparia, number of puparia per gram, and percentage of adult emergence on ÔBluecropÕ blueberry were signiÞcantly higher for B. dorsalis and C. capitata than B. cucurbitae; B. dorsalis, C. capitata, and B. cucurbitae produced an average of 1.06, 0.60, and 0.09 pupae perg fruit andhad50.8, 54.1, and12.7%adult emergence, respectively. ÔBerkeleyÕ blueberriesproduced an average of only 0.06, 0.02, and 0.0 pupae per g fruit for B. dorsalis, C. capitata, and B. cucurbitae, respectively. Similarly, six blueberry cultivars were harvestedweekly for 10wk, exposed toBactrocera latifrons (Hendel) in cages, and held for pupal and adult emergence on either sand or artiÞcial diet. In total, 2,677 blueberries were exposed to 2,681 B. latifrons and held on sand, and no pupariation or adult emergence was observed. Small numbers of B. latifrons puparia and adults emerged from the artiÞcial diet treatment in all cultivars. Results from rearing on sand and diet indicate that blueberry is an acceptable oviposition host for B. latifrons but not an adequate developmental host. These data suggest blueberry is potentially a good host for B. dorsalis and C. capitata, and an adequate host for Bactrocera cucurbitae, but that there may be signiÞcant variation in resistance among cultivars. Blueberry seems to be a nonhost for B. latifrons.