BARBERRY CARPET MOTH Fourth Report C . W . PLERCE
about 300 ova and larvae of the Barberry Carpet Moth (Pareulype berberata Schiff.) were placed on the planted barberry bushes in the new site near Bury St. Edmunds in August, 1973, there remained 10 pupae and a few larvae of the captive colony. These were retained as an insurance against failure of the initial release. Between 17th April, when two females emerged, and 7th May a total of 10 females and seven males appeared and these were kept until it was clearly established that mating had taken place and egg laying commenced. AFTER
The first eggs were laid on 30th April and laying was still proceeding when all the imagines were set free on the new reserve on 1 Ith May. In the meantime about 300 eggs were left in the breeding cages, resulting in over 150 pupae. On 24th June five imagines appeared and more followed in the next few days so that it was possible to release well over 100 imagines among which were a roughly equal number of both sexes. Many of the females ha<i been impregnated and were indeed laying for a day ur two before release. The freshly laid eggs were placed on the barberry bushes as well as 20 pupae. Thus by 2nd July, the date of the final release, there have been three occasions when the insect in all its stages has been introduced to the reserve, the other two being in August, 1973, and May of this year. It is possible that by introducing this insect in this manner the chances of failure have been reduced, although there are two factors which may weigh more heavily against success. Firstly, all those insects released have descended from one impregnated captured female in 1970 and two more females taken in 1971. Secondly, and certainly the more serious, is the fact that the food plant had been planted only about six months before the first introduction and may not have grown enough to have supported a viable population. There is a third factor which may have some influence on the outcome. The appearances of both first and second broods have in successive years become progressively earlier. This has not been due to any pampering during the winter months. There are grounds for thinking that the cause lies in the inevitable inbreeding that has occurred. South states that 'the moth is out in May and early June, and again in August'. My own records suggest that the first brood seldom appears before 24th May or later than mid-June. The second brood rarely shows up earlier than the last week in July or later than the third week in August.
BARBERRY CARPET MOTU
It can be seen, therefore, that both broods appeared about one month earlier than normal in the wild and may, after release, be prone to attacks by predators. Moreover, if the last introduction is successful, it is possible that a third brood may appear and partially overlap the second brood from the earlier releases, although it would be impossible to establish if this does occur. In spite of the dry early summer, the majority of the plants appear to be doing well, although even under the most favourable conditions Berberis vulgaris is a very slow grower until well established. One rooted piece transplanted from Shaker's Lane to my garden remained stationary for the first two seasons when it started to shoot quite vigorously. Given a good spring and summer in 1975, there is reasonable hope that the plants put in in 1973 will make good headway. This will naturally be to the advantage of the new colony of the Barberry Carpet Moth if it survives the autumn and winter of 1974/5 reasonably free from predators. Reference Pierce, C. W . (1974). Barberry Carpet Moth. Natural History, 16, 316.
T h i r d Report.
C. W. Pierce, 14 Chalkeilh Road, Needham