A BEGINNER'S EXCURSION INTO ENTOMOLOGY JOAN A . PLANT
ONE wet Sunday morning in the summer of 1972 my husband came in from the garden to enquire what it was that he had found on the linen post. Lying in a box were two very bedraggled Privet Hawk Moths, they were mating and, having taken photographs, I put them with some privet leaves into a large box covered with muslin. T h e moths stayed together until the Monday night, then in a few days eggs were laid on the leaves and the sides of the box and the parents were freed. Now the fun started, eggs were given to friends and, as a result, I hope there are now more Privet Hawks in Ipswich, Playford and Leiston. T h e remaining eggs hatched after eight or nine days, there were about twenty stränge little pale green caterpillars, each with a black horn at the tail, longer than their bodies. These were transferred with the aid of a paint brush to privet twigs stuck into a jar of wet peat. Very soon the caterpillars started to grow rapidly, and purple and white stripes appeared on their sides. When they had grown to about two inches long, they were transferred to a large box with about an eight-inch depth of soil in which were stuck privet twigs, the whole being covered with muslin to prevent the caterpillars wandering off to pupate elsewhere. By this time these magnificent creatures were eating voraciously, and the food needed renewing three or four times daily, as they stripped the twigs. T h e growth of the caterpillars varied slightly and, as they reached maturity, they made their way to the soil where some burrowed leaving a hole to indicate their point of entry, whilst others remained on the surface where they changed from bright to dull green with reddish brown shading. At the same time they shrank slightly, appeared more rigid and, in between restless periods, they became torpid and eventually shed their skins as brown papery shrivelled shells, thus revealing the typical dark brown shiny pupa with the raised part containing the tongue. Dßring the period of hibernation the box was kept cool on the floor of the conservatory. However, I found dampness under the box in the spring, and this, no doubt, caused some of the pupae to die, as they were found to be rotten at the time that their luckier companions emerged. Some eggs were laid and the beautiful moths were released. Unfortunately the eggs were sterile. There the story might have ended except for the help of friends who had obtained eggs after giving their moths the freedom of a shed. But they had only kept a few caterpillars, having put
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the surplus on their hedge. I managed to get them to let me have four caterpillars, there are now four pupae carefully tucked away. So, who knows? I may be lucky this year. I hope the experts will bear with this very amateur report on the life cycle of Sphinx ligustri and my attempt to increase the species where I was told it had not recently been observed. This experience has been very instructive, I have colour slides of the various stages of development, except the eggs. This oversight I hope to remedy this year. What next? Perhaps I can try a similar experiment with the fantastic Puss Moths whose caterpillars eat the Balsam poplars at the bottom of the garden, or perhaps there may be a Death's Head Hawk Moth among the potatoes. Joan A. Plant, 56 Linden Road, February, 1974.
Aldeburgh.
Note July, 1974 T h e Puss Moths seem to have deserted the poplars and, with the realisation that I have much to learn about the Privet Hawk, here are this season's observations:— T h e moths emerged a little earlier than last year, probably due to unusually mild weather earlier on. Possibly for the same reason, plus the excessive dryness, one had deformed wings. There was one female, but, as they seemed loth to mate, I let them go. I was given more eggs on June 22nd, these hatched on July Ist and 2nd about a week earlier than last year. I noticed some emerging caterpillars appeared to eat egg shell, others I was not sure about. Is it possible that the shell contains nutrients which accounted for the robustness of some caterpillars? Were the weaklings those who did not eat shell? One died, I intend to watch the hatching very closely next year. In the meantime there are eight pupae in a box raised off the ground in a cool part of the greenhouse. Next year, when the moths emerge they will be put in a shed as the more airy conditions seem to be conducive to mating and the production of fertile eggs.