Rearing Lepidoptera

SUFFOLK

129

BUTTERFLIES

and released ; of these 33 were Essex Skippers. It is hoped that more work will be done in order to determine the relative numbers of the two species in the county, and also to determine more accurately the distribution of the Essex Skipper.

It would seem, therefore, that although there have been some losses during the last 33 years, there have also been some gains, and that we need not be too despondent about the butterfly life of our county. Some of the old records give no indication that a particular species, now rare, was common in those days ; it is probable that the records may have referred only to a few stray specimens that had wandered from their normal home. It must not always be assumed that a butterfly is breeding in a certain area just because it is seen in that particular part. Again, there must be many areas in the county that have not been thoroughly searched. We are all perhaps inclined to go to the same places year after year, to note that a species is less numerous there than it has been, and to come to the conclusion that the species is therefore dying o u t ; while it is quite possible that, for some reason the species has changed its headquarters and is now occurring in another area from which it was previously absent and which, for that very reason, had not recently been visited.

S.

BEAUFOY.

NOTES ON REARING LEPIDOPTERA, 1953.

BUTTERFLIES: T h e S C O T C H A R G U S , Erebia aethiops Esp. Of the four larvae which entered hibernation (Trans, viii, p. 79), only one survived the winter. This fed slowly on Poa annua, hiding by day low down in the grass stems. In July, the larva spun a few silk threads around itself, as it lay on the ground at the base of the grass stems. It pupated inside this slight web, and a female emerged on 8th August.

Fifteen more ova were received from the north this summer.

All have hatched and it is hoped that a larger number of butterflies will result next year.

The P U R P L E E M P E R O R , Apatura iris Linn.

Of the five larvae sleeved out last autumn (Trans, viii, p. 79), one died before hibernation ; two spent the winter at the fork of a twig with the main stem (the usual position for hibernation) ; one wintered

NOTES ON REARING LEPIDOPTERA 130 at the tip of a leaf which the larva had previously fastened witk silk threads to the stem to prevent the leaf's falling in the winter ; and the fourth on a piece of string which secured, inside the sleeve, the base of the sleeve to the main stem of the sallow sapling.

All four larvae survived the winter, but one died soon afterwards.

The remaining threeflourished,producing two males, one on 2nd July, the other on 3rd July, and a female on 7th July.

I now have six larvae from ova laid in SufFolk. The resulting butterflies will be released in the wood where the ova were found.

SMALL BLUE, Cupido minimus Fuessly. This species spends the winter as a fully grown larva, and for many years I had failed to get any to survive. Last winter, I succeeded. Females had deposited on thefloweringheads of kidney vetch and the plant, when the larvae were fully grown, was covered with netting but was left out of doors, unprotected from the elements. In April, two larvae were seen crawling around. They pupated at the beginning of May,firstsuspending themselves between a blade of dead grass and a stem by a silk girdle. The pupae are remarkable for their tufts of long hairs. A female emerged on 8th June ; the second pupa dried up.

The PALE CLOUDED YELLOW, Colias hyale L. and C. calida Verity. I have been fortunate in being able to rear from their earlier stages both Colias hyale and the recently discovered C. calida. In the autumn of 1952, I was given a few young larvae of each, and I attempted to " force " both species. The C. hyale larvae, which feed on lucerne, continued to feed and produced butterflies at the end of October. The C. calida larvae, whose foodplant is horse-shoe vetch, refused to feed and did not eat again until the spring. Butterflies emerged from the chrysalids at the end of May. It is not always easy to distinguish between the two species in the imaginal stage, but the larvae are quite distinctive. Those of C. calida have prominent yellow and black marks down the back which are not present in the larvae of C. hyale.

S.

BEAUFOY.