A wasp's tongue differs in structure from that of a bee. A bee's tongue is modified into a long sucking proboscis, while the wasp has to manage with a short flat tongue with attached feelers. The wasp can therefore feed on liquids that are easily reached but is unable to reach concealed or distant nectar.
These two wasp species can often be seen drinking from still water, especially when mud is not available for nest building. I have a water dish buried to ground level amongst my herbs for invertebrates and lizards to make use of.
An Orange Potter Wasp collecting water from the dish I replenish regularly.
A wasp's thorax and abdomen are joined by a slender waist (petiole), and these two wasp species have an extended petiole, as you can see in the next photograph. They have four transparent wings, large eyes and mandibles.
Although they might appear fearsome, these wasps are not aggressive and are unlikely to sting unless attacked or handled. In fact, they almost seem oblivious to the rest of the world as they go about the task of nest-building.
The slim extended waist (or petiole) is a distinctive feature of these two wasps.
Mud nest construction
Unlike bees, no workers are produced, so individual nests are constructed by females. It is a massive project with differences in construction style with each wasp species.
The Orange Potter Wasp assembles flattened circular brood chambers about 25mm wide leaving a hole in the centre. The common name of potter wasp characterises the neat clay-pot appearance of the individual chambers. Both wasps will attach nests to exterior walls of buildings or most surfaces that are protected from moisture. Open sheds are particularly popular building sites and they have been known to clog up motors or machinery that remain idle.
A Potter Wasp has filled a chamber with caterpillars.
In the top picture, you can see the wasp's large mandibles separating a blob of mud into workable sized portions. It's hard to imagine just how many trips to the mud puddle the wasp must make in order to complete 7 or 8 chambers and then render the nest with several more layers. If mud is not available, the wasp will collect water and then dig soil to make its own mud.
The nest pictured above was destroyed and raided by a black rat, the introduced Rattus rattus, the night after this photograph was taken. No doubt the wasp would have rebuilt elsewhere.
A Mud-dauber Wasp putting the finishing touches to a cell after completing and rendering three chambers the previous day
The Mud-dauber Wasp, Sceliphron laetum, builds long narrow breeding cells with an opening in one end. The wasp will temporarily seal the chamber if unable to fully stock it before nightfall, removing the capping when it returns to finish construction.
Feeding the young
The female wasp has a sting which she uses to render pray helpless. The potter wasp collects caterpillars, while the mud-dauber will collect spiders to stock the nursery cells. One egg is laid in each chamber and will feed upon the fresh caterpillars or spiders upon hatching. When the larva has grown sufficiently it will pupate and metamorphose into a wasp, then chew its way to daylight and leave the nest. The life cycle is complete and will start all over again.
A mud-dauber wasp backs into the chamber with the final spider upon which a single egg is laid
Industrious little creatures arn't they? As with bees, some people might be sensitive to wasp venom, but they are not aggressive, making stinging unlikely. And besides, they are reducing the spider and caterpillar population of your garden - a natural insect control!