Dragonflies out and about

MANY people are commenting on the unusual abundance of dragonflies this season.No doubt the large dragonfly numbers are due largely to the spring and summer rainfall, although I am surprised that populations increased so quickly.Dragonflies, and the smaller but similar damselflies, begin life in the water. Dragonfly nymphs are known as mudeyes. Most species spend a year or two as mudeyes before emerging as adults, so I cannot explain how they are suddenly so numerous.However, they have certainly had ideal conditions during the last few months, with warmth, good underwater shelter, plenty of small insects for food and probably fewer predators than usual.The colour of these insects is amazing. Locally we have several “tiger” dragonflies, as well as an attractive powder-blue one and a red one.Damselflies are generally more colourful, although smaller and more delicate. Local damselflies are often found in a handsome colour combination of enamel-blue and black, but there are many other colours.Dragonflies feed on flying insects. Flies and mosquitoes are favourites, so we have every reason to be thankful for the abundance of dragonflies when we have so much water for mosquito breeding. I recently watched numerous dragonflies around a lake at dusk. They were gathered there to feed on midges. These they caught readily with sudden darts and turns. Not only can they twist and turn acrobatically; they can actually fly backwards for short distances when they need to.Dragonflies normally hold their four wings outspread, but damselflies hold theirs folded above their slender bodies.Damselflies tend to live in more sheltered places and their flight is not as strong as that of the larger, more powerful dragonflies.Although they breed in lakes, swamps, creeks and dams, and they are most often found close to these places, the adults can also occur a long way from water.Many of them are territorial, patrolling their own territories and defending them. Close observation of them will often reveal territorial skirmishes.Swallowtails going or goneWith extra sightings from such places as Ballarat North, Ballan, Mt Helen and Wendouree, the Ballarat region was well-covered during the recent visit of orchard swallowtail butterflies.The reports have almost ceased with only a couple from February. With the first sighting on January 15 and the last on February 9, they visited us for almost four weeks.As well as receiving reports from across the Ballarat region, we have also heard of orchard swallowtails near the coast at Skene’s Creek.Egg-laying has been reported. A Mt Clear resident has sent photographs of the caterpillars on her lemon tree and she believes she now has a chrysalis. Other readers have reported female butterflies showing definite interest in their lemon trees, so these citrus owners will have to decide whether to prioritise their trees or their caterpillars.The caterpillars are brown and white with large heads in their young stage, but change to green with a few dark bands and a long white stripe when a bit older.Later they turn a brighter green with white diagonal bands and a white stripe. At all stages they have several soft spines.PigweedA SUCCULENT, fast-growing summer weed has the name of pigweed or purslane. Its status as a native Australian plant is rather complicated.The Flora of Victoria says pigweed is found in all Australian states, as well as in most of the world.It then goes on to say that it is “doubtfully native anywhere in Victoria, but apparently native in central and northern Australia”.Furthermore, this prostrate, reddish-stemmed weed is “a variable species, possibly containing several native and exotic components which may be worthy of formal recognition.”Whatever its status, it is common here in summer and autumn in open places, gardens and wasteland, where it grows readily on bare ground.It is an edible plant and has been eaten for thousands of years without any preparation. Its “vegetable” taste is not dissimilar to that of silver beet and the leaves have a pleasant succulent texture.However, some people regard them as slimy. They can also be steamed and have been used in pickles. The tiny seeds are said to be highly nutritious; they were used as food by the Aborigines.The five-petalled flowers are golden-yellow.The botanical name of this plant is Portulaca oleracea.Nature QueriesWe have been enjoying watching great crested grebes at Lake Wendouree and we have noticed they are still nesting. Is this late for them to be nesting?B.B., Sebastopol.This is getting late for them, but the summer rains have extended the good conditions for them. However, we cannot expect nesting to continue for much longer this year, because most of the grebes will leaves us by April.We have had what we identified as a bird-dropping spider in our garden. It is common in Ballarat? T.S.Bird-dropping spiders are found in small numbers each year in summer and autumn, but are not particularly common. However, they are probably more numerous than we realise, because of their excellent camouflage.