The flowers are cross-pollinated primarily by various bees, including Andrenid bees (Andrena spp.), bumblebees, and honeybees. Both nectar and pollen are available as floral rewards. The pollen is released from the anthers in response to the "buzz pollination" of the bees (high frequency vibration of the thoracic muscles). In addition to these floral visitors, many insects feed on the foliage, stems, and other parts of blueberry shrubs. For example, the larvae of two beetles, Oberea myops (Rhododendron Stem Borer) and Oberea tripunctata (Dogwood Twig Borer), bore through the twigs of these shrubs, while the larvae of two flies, Dasineura cyanococci and Dasineura oxycoccum (Blueberry Gall Midge), form galls on the buds or developing flowers. Other insect feeders include the leaf beetles Altica sylvia and Tricholochmea vaccinii, the larvae of Rhagoletis mendax (Blueberry Fruit Fly), Clastoptera saintcyri (Heath Spittlebug), Limotettix vaccinii (Blunt-Nosed Leafhopper), and Mesolecanium nigrofasciatum (Terrapin Scale). The caterpillars of two butterflies, Callophrys augustinus (Brown Elfin) and Callophrys henrici (Henry's Elfin), feed on the flowers and developing fruits of blueberry shrubs. In addition to these insects, the caterpillars of such moths as Hemaris gracilis (Slender Clearwing), Sympistis dentata (Blueberry Cinder), and Xestia dilucida (Reddish Heath Dart) also feed on these shrubs (see the Moth Table for a more complete listing of these species). Blueberries fruits are an important source of food to many vertebrate animals. These species include the terrestrial turtles, Clemmys insculpta (Wood Turtle) and Terrapene carolina (Eastern Box Turtle); such birds as the Ruffed Grouse, Wild Turkey, Blue Jay, American Robin, Yellow-Breasted Chat, Wood Thrush, and Eastern Bluebird (see the Bird Table for a more complete listing of species); and such mammals as the Black Bear, Red Fox, Raccoon, Striped Skunk, Opossum, Red Squirrel, Eastern Chipmunk, Jumping Mouse, Deer Mouse, and White-Footed Mouse. In addition to the fruits, the White-Tailed Deer and Cottontail Rabbit also browse on the foliage and twigs. Because Lowbush Blueberry is a densely branched shrub that often forms large colonies, it provides significant protective cover for ground-nesting birds and other wildlife.