Male European Wasp (Vespula germanica). Scale bar = 5 mm.
Two species of the exotic wasp genus
occur in Tasmania. The European or German Wasp
(F.), was first found in a Hobart suburb in 1959 and has since spread to all parts of the State. By contrast the English or Common Wasp,
, is a relative newcomer to the state, where it is believed to have arrived around 1995. Both species are also present on the mainland.
European Wasp and English Wasp appear extremely similar and are difficult to tell apart, but currently the former species is more common and widespread in the state. Both species have similar life cycles and behaviour. Vespid wasps are the most troublesome outdoor insect pest found around homes, in gardens, fruit orchards and especially where sweet foods, fruits or liquids are present. With their yellow and black stripes they are familiar to most Tasmanians.
Male Flower Wasp (Thynnus zonatus). Scale bar = 5 mm.
However, European or English Wasps are sometimes confused with a native species
, or Flower Wasp. This species is found in coastal areas in Tasmania. It is longer and more slender than the vespid wasps and only the males are winged. These wasps do sting but are not attracted to meat like the introduced vespids and are a solitary species that do not form nests. Flower Wasps are not regarded as pests as they do not interfere with outdoor eating or attack fruit like the introduced wasps.
Vespid wasps are swift, strong fliers and are likely, particularly in autumn, to become aggressive when interfered with. When wasps are close by, you should avoid sharp movements because these will attract their attention and may excite them so that they sting. They are capable of inflicting a severe sting. Unlike a bee, each wasp can sting repeatedly.
Wasps are social insects and live in nests where adults rear the young. New nests are begun by young queens, which leave the old nest in autumn, seek a warm protected place to spend the winter and begin making the new nest in spring. After finding a suitable space, the young queen constructs a few cells of a grey papery material made from saliva mixed with chewed wood fibres. The cells are attached to the roof of the cavity or space selected for the nest and one egg is laid in each. The queen tends the first brood of grubs through to maturity, but thereafter the workers take over the gathering of food and the rearing of grubs, leaving the queen to lay eggs.
The grubs are fed on insect and animal matter obtained by the workers. In this regard the wasps may be beneficial since they prey on many harmful insects, including flies and caterpillars. However their predatory activity, when intense, has been shown to severely diminish native insect fauna in some areas and has a detrimental effect on biodiversity.
Towards the end of summer the colony reaches its full size, and the workers forage for sweet materials much more than previously. Similarly their search for protein-based foods intensifies and often switches from insects to meat scraps,such as pet food or picnic food, to feed the rapidly increasing number of grubs. The wasps become more aggressive as their numbers increase and they are most troublesome during autumn.
Mating flights occur on fine, warm days in the autumn, after which the new queens seek over-wintering sites. The colony then declines and usually perishes, although in Tasmania some nests are maintained throughout the winter and are further enlarged in the following season.
Wasps attack a wide range of damaged, ripe fruit. In general they are unable to damage sound fruit and thus are rarely a problem in clean, commercial apple orchards. Sometimes the wasps will damage ripe grapes directly by entering the fruit where it joins the stalk. Thin-skinned fruits such as raspberries, peaches and apricots may also be subject to direct attack when they are ripe and particularly when they are overripe.
When in high numbers, wasp presence can interfere with outdoor activities.
Occasionally wasps may be seen in large numbers about pine or gum trees. They are attracted to the sweet secretions of scale insects, aphids or plant exudates.
Wasps will sometimes enter beehives in search of food, and persistent attacks may weaken the hives. Restricting the hive entrance to a width of 4-6 cm during the winter has been found to assist the bees in keeping wasps out. The hive can be protected further by placing a sheet of glass about 35 cm x 10 cm against the front of the hive with its top edge leaning against a 6 mm piece of wood or a short twig. Bees pass through the gap at the top, but wasps are more likely to enter through the open ends, and are more easily repelled by the bees. In hives of reasonable strength, the glass may rest on two 6 mm pieces of wood but if the hive is weak the glass may rest on the board.
Wasp nests should be treated with extreme caution as disturbance may provoke wasps to attack and multiple stings can be life threatening. Let someone know where you are and what you are doing if you are attempting to control European wasps. Registered pest controllers are recommended to locate and destroy wasp nests.
In instances where European wasp nests cannot be located or reached, the following updated chemical control permit conditions are now in place:
- APVMA Permit Number – PER89402 (‘Permit to allow minor use of an unregistered AgVet chemical product for control of European Wasp’).
Department of Primary Industries, Parks, Water and Environment (DPIPWE)
165 Westbury Road, Prospect, TAS, 7250
This permit valid until 31 March 2025.
Updated Permit Conditions
This updated permit allows for control of European wasps using meat based baits containing Fipronil as the only active constituent, within vineyards, horticulture crops, public parks and reserves, outside eating areas and residential areas.
In support of industry, DPIPWE continues as the permit holder, however the updated permit removes DPIPWE as the approved supplier and distributor of wasp baits in Tasmania. This permit allows the following groups to undertake the baiting:
- licensed Pest Control Operators,
- State and Local Government employees, and
- primary producers who are suitably qualified and are experienced in the application of agricultural chemicals.
The use of the baits in urban residential areas is restricted to licensed Pest Control Operators and State/Local Government employees trained for this use. Licenced pest controllers are automatically deemed suitably qualified and experienced in the application of agricultural chemicals to use the product under the permit.
State and Local Government employees and primary producers will need to have successfully completed training in the use of agricultural chemicals. The currently available training units are AHCCHM304 (Transport and Store Chemicals) and AHCCHM307 (Prepare and apply chemicals to control pest, weeds and diseases), or equivalent such as ChemCert.
For full permit details, including other critical permit considerations, appropriate preparation and storage of baits (including permitted commercial Fipronil products), safety considerations for users, positioning and labelling of bait stations, completion of the baiting program, reporting adverse effects on any person or the environment and required record keeping, click here:
For more information on the appropriate use of agricultural chemicals and the relevant training opportunities please email email@example.com
or call Biosecurity Tasmania on 03 6165 3777.