Nature Notes – September 2016
Several times at this time of year a neighbour has been in touch to report a caterpillar of one of our spectacular Hawkmoths. This year it was one of the largest, a Privet Hawkmoth, which grows up to 4 inches long! All the species can be recognised as hawkmoths by the large curved spine at the tail end of the body. This one is a bright green, with a striking row of narrow diagonal stripes, purple and white, along its body. As its name suggests, it feeds on the leaves of Privet, and I have sometimes found it on the leaves of wild privet, but in gardens it may feed on Lilac and possibly other plants. Towards the end of August the fully grown caterpillars come to the ground where they may sometimes be found, and work their way deep into the soil, where they pupate and pass the winter. The adult emerges in the following June. Although active at night, these may occasionally be seen sitting out during daylight. They are enormous moths, the wings clouded pale and chocolate brown, but with bright pink and black striped body showing when the wings are opened.
Last year it was an Elephant Hawkmoth that I was shown. This caterpillar is a little smaller, about 2 ½ inches and less colourful (grey with black blotches). Its most obvious feature is two pairs of black and white eye spots on the sides of the body. These, with the narrow head and thorax make the front end look astonishingly like a miniature elephant’s head and trunk. The adult is pink and pale green, and nothing like an elephant. Around Lime trees in this area there is also the Lime Hawkmoth, whose caterpillars are bright green with yellow stripes.
Along the Gull in Sweffling, in amongst the Hairy Willowherb I mentioned last month, is a different species of Teasel. This is called the Small Teasel, and is quite a scarce plant, growing in damp places – it probably occurs elsewhere along the river Alde. Despite the name it is as tall as the common Teasel; it is the flower heads that are small. Almost over by now, they are whitish, dying to round clustered seed heads just under an inch across. Look out for it.
Beside our house is a Tamarisk bush, large and unruly and with a mind of its own as to how it grows. It does have masses of feathery pink blossom in spring, which very soon fade to a brown mess. However, we value it most for the way it attracts small birds in August and September. These include a number of the summer visiting warblers like Chiffchaff, Blackcap and Whitethroat. What they are finding there, whether seeds or small insects, I do not know, nor do I know whether they are birds which have bred nearby or are departing migrants passing through on their way south. But each year they are there. The one I most like to see is the Lesser Whitethroat. All these birds are small and often hard to see clearly, but this one is quite distinctive. It is a very small warbler, grey with a white chin and a dark patch through its cheek. Soon they will be leaving, travelling via northern Italy or perhaps Greece, to cross the Mediterranean and the Sahara Desert, to winter around Sudan and Ethiopia.