Many different species of flying insects are found near gardens. Some types of bees and wasps live in nearby burrows below the ground. They benefit from living near gardens because they can collect pollen and nectar as well as feed on live insects. Some wasps and bees deliver a painful sting if they are provoked, but others are both harmless and beneficial.
Cicada Killer Wasps
Cicada killer wasps are large solitary wasps that live underground. They are large--nearly 2 inches in length--and they have black and yellow bodies with reddish heads and light brown wings. Their colouring closely resembles that of a yellowjacket wasp. According to the Ohio State University Extension, these wasps spend the winter as larvae beneath the soil and emerge fully grown in June or July. They often build their burrows in home lawns or near gardens because they feed on nectar. The wasp larvae, however, feed on cicadas. A female wasp stings a cicada and drags it back to her burrow, where she places the insect in a cell. She lays an egg in the cell and then seals the entrance. The larval wasp hatches several days later and feeds off the cicada's body. Cicada killer wasps can sting, but they usually choose to ignore people unless they are disturbed.
Some mining bees look a great deal like honeybees, while others are metallic green or brightly striped. These solitary insects live underground in lawns, gardens and other areas with flat surfaces and good drainage. A female mining bee digs multi-chambered burrows beneath the surface of the ground. The chambers are for her eggs. She stocks the chambers with nectar and pollen that she collects from flowers and then deposits an egg on the surface of the food supply. When the egg hatches into a larval bee, it eats the nectar and pollen. The larva morphs into an adult underground and overwinters in its burrow. It emerges in the spring to continue the life cycle. According to the University of Delaware, these bees are not aggressive and do not sting even when provoked.
Scoliid wasps have blue-black bodies, purplish-black wings, and two yellow stripes on either side of their abdomens. These solitary wasps live below the ground. According to Ralph Mitchell, county extension director for the Charlotte County Extension Service, scoliid wasps are considered beneficial because they control the beetle grub population in lawns and gardens. The adult wasps feed on nectar, but their larvae feed on white grubs. A female wasp stings the grub to paralyse it and takes it back to her nest. She lays an egg on the paralysed but still living grub. When the egg hatches, it feeds on the grub for about two weeks. Scoliid wasps will sting if they are grabbed, but they are generally not aggressive.