Lesley Smitheringale Fine Art

Garden Guests Diary - Native Paper Wasps [14 Jan 08]

When wandering around my garden today I discovered at least two of these paper wasp colonies and after looking at the close-up photographs I took, I have immense respect for these industrious builders and protectors of their young.  Paper wasps form small colonies and make paper nests under tree branches and the eaves of houses. The nests are shaped like inverted cones, and consist of a cluster of hexagonal cells made from wood fibre mixed with saliva. The wasp larvae are maggot-like and develop inside the papery cells of the nest. These nests are a work of art and must take ages to build.  You can see the hierarchal order of the new eggs which are larger and more developed towards the centre and top of the colony.

The milky white eggs, which can be seen suspended within the cells, develop into paper wasp larvae. Workers feed these grubs on chewed up caterpillars of other insects and, when fully fed, the larvae spin a silken cocoon about themselves in which they develop into adult colony members.

Life Cycle and Habits

Paper wasps and hornets are social insects, living in colonies containing workers, queens and males. Colonies are annual with only inseminated queens overwintering. Fertilized queens occur in protected places such as houses and other structures, hollow logs, in stumps, under bark, in leaf litter, in soil cavities, etc. Queens emerge during the warm days of late April or early May, select a nest site and build a small paper nest in which eggs are laid. One egg is laid in each cell. As she adds more cells around the edge, eggs are deposited. Larvae in the centre are older with the younger larvae further out. It is the cells at the rim of the nest which contain eggs. After eggs hatch, the queen feeds the young larvae. When larvae are ready to pupate, cells are covered with silk, forming little domes over the individual openings. Larvae pupate, emerging later as small, infertile females called “workers.” By mid-June, the first adult workers emerge and assume the tasks of nest expansion, foraging for food, caring for the queen and larvae and defending the colony. Remember with paper wasps, the nest is the work of a single female, has a single layer or “tier” of cells and is not enclosed by envelopes. In hornets, the nests usually consist of a number of stories or “tiers,” one below the other and completely enclosed by spherical walls. Each cell may be used for two or three successive batches of brood.

Adult food consists of nectar or other sugary solutions such as honeydew and the juices of ripe fruits. Paper wasps and hornets also feed on bits of caterpillars or flies that are caught and partially chewed before presenting to their young. Hornets may be seen almost any summer day engaged in their winged pursuit of flies.