THE objects pictured were collected in summer underneath a cypress tree near the North Gardens wetlands at Lake Wendouree.The largest is approximately 16mm across. Their size can be gauged by the pencil in the photo.These are gastroliths, or "yabbie stones", or "yabbie buttons".They are a mineral supply in the stomach of a yabbie, absorbed eventually by the yabbie when it needs to moult into a new hard shell.Yabbies and other crustaceans must moult their outer skin to allow for growth. They have the new, soft skin underneath and this new skin must expand before it hardens.Just before moulting, the yabbie develops reserves of calcareous matter. These dissolve after the old skin is shed. The minerals in the "stones" are necessary for the hardening of the new skin.If the yabbie dies just before or soon after moulting, the gastroliths remain. The supply of these under a tree indicates that a bird such as an ibis, heron or cormorant had perched up above and regurgitated them onto the ground below. I think the likely predator would be a white ibis.It is likely that one yabby would have just one stone at a time, so a supply of many of them on the ground would indicate a successful bird or a long-term perching place.Chirping beetleMost beetles are silent creatures, so it was a surprise to pick up a fairly large black specimen that made distinct chirping sounds.It made a short noise every couple of seconds while it was being held. Its abdomen swelled noticeably with each rasping chirp.The glossy beetle was one of the scarabs. Scarab beetles belong to the same group as the "Christmas beetles".It was on a gravel road, and was picked up for inspection and for its own safety on the road.The sound was apparently a defensive one, probably used to distract or deter potential predators.Some other beetles make similar defensive noises, but we seldom hear them.Such sounds might be heard more often if we handled more beetles.Black nightshadeBlack nightshade is just one of many weeds that have grown prolifically over summer because of the higher-than-usual rainfall.It is always a common weed of gardens and sheltered or shady places, but this year it has become very numerous and widespread.It is often wrongly known as deadly nightshade, but the true deadly nightshade is a very different plant that is not found in Victoria. Black nightshade is not poisonous.Not only is black nightshade abundant, it is growing taller than usual. Some plants have reached more than a metre tall and have become woody.The plant itself is well-known to local people, but it is often known by the wrong name.It is a large-leaved plant with white flowers. Berries are at first green and hard, then inky-black and soft when they are ripe.They are readily eaten by blackbirds and probably other birds. The soft fruity part is digested, but the seeds pass through the birds and are thus dispersed.These seeds are obviously very hardy, and probably long-lived. Both these features are advantageous for the plant’s survival.The plants themselves are also hardy, germinating in many inhospitable situations and able to survive there with very little water.This common nightshade plant is also known as blackberry nightshade, because of its black berries. This name is probably a better one than black nightshade, which could imply that the whole plant is black.The true deadly nightshade is a different plant, although it is in the same family as the black nightshade. Its botanical name is Atropa belladonna. Black nightshade is Solanum nigrum.Butterfly bushThere are few better shrubs for attracting butterflies than the Buddleia, which is often commonly known as butterfly-bush.The sweet-scented flowers attract numerous butterflies, especially common browns.There is another shrub that is useful for butterflies.It is the glossy abelia, Abelia x grandiflora. This one has numerous white flowers and it attracts butterflies and moths.A butterfly that seems to be particularly attracted to our specimen is the wood white, or red-spotted jezebel.As a bonus, the plant attracts moths in the evening. Its evening-perfumed flowers bring the remarkable hawk moths.These large buzzing moths hover in front of the tubular flowers, inserting their long "tongues" in search of nectar.Unfortunately these are evening moths, so it is difficult for us to get a good look at them. Sometimes our abelia bush has had seven or eight of these moths fluttering around it after sunset.Our plant is around two by two metres in size. The bronze or reddish leaves are a feature of the shrub, which has proved very hardy and drought-tolerant in recent years.It flowers for most of the summer and autumn, so it is a valuable plant for nectar-feeding insects of many species.