Not the best of summers to spot the butterflies
by Paul Cormacain
THERE were common blues, ringlets, large whites, small tortoiseshell, butterflies. Well, it is summer and you expect to see butterflies in the summer. But I am sure you have noticed that our days are not endless hours of sunshine, and when the sun goes the butterflies tend to follow.
So the appearance of our butterflies has been somewhat erratic, but sure is it not like that every year? Both the humans and the butterflies have to make the most of it. We had nearly a few- months of summer weather, when we had not too much rain, followed by more summer weather when the rain was not too far away. All summer weather. If you want sunshine all the year round, you could always go to Iran or Iraq, but take my word for it, after a time you would give your left leg for some rain. I nearly did.
So the butterflies are enjoying the summer weather. They just do not like coming out if it is too wet and windy. The common blues I used to regard as a rare, difficult-to-see breed, but there seems to be plenty of them about.
In fact, I have just been looking at a distribution map of them, and seem to be more of them in the east than in the west. Yet I tend to see them in the west more, but that is because I tend to have more free time there.
The thing to do is to be on the lookout for birds foot trefoil. This is the major larval food for the common blue, so the adults would never be very far away from it. The mature insect is now going into its quiet stage, while there may be ova, larvae, and pupae about. Towards the end of the month it will start to reappear again, and should be about August and a large part of September. Its breeding habits are such that you may easily see the adult through most of October.
The ringlet seems to one of our most common butterflies at this time. This could be something to do with the fact that you would normally see the adult only in the month of July, and through part of August.
The eggs are laid in July and August, naturally, and the food plant for the larvae are grasses. The larvae hang around all through the autumn, winter and spring. Early in June the pupation will commence, and after about a fortnight more adults will appear. That will be about the beginning of next July.
In the meantime we will have to show some tolerance towards our large white butterflies. Part of their scientific name is brassicae, the genitive plural for cabbage and similar plants, cauliflower, sprouts and others. The choice of this word scientifically shows that the creature likes his cabbage. Which can mean that some farmers and some gardeners may not like him.
One of my Lepidoptera books coyly says that the large white may be injurious to cabbage. I have certainly seen the larvae in large numbers on cabbage. In some summers it is not unusual for swarms of large whites to be in cabbage fields, and farmers try to shoo them away.
There has been a large increase in the use of artificial fertilisers, but this may have little effect on the fate of the large white. This tends to increase the growth of some plants at the expense of others. The "others" would be the larval food plants of butterflies, but I do not really think this would affect the large white. The use of pesticides could be a different story, and their use at the surrounds of fields could affect the large white. Tests have shown that even a low dosage of pesticide can have lethal effects on the large whites. As a matter of interest, the green veined white, the common blue and gatekeeper are not so badly effected by a similar dosage.
The small tortoiseshell must be one of our best known and best loved insects. As a matter of interest, when it was permissible to use dieldrin and DDT, these two poisons did not seem to effect the small tortoiseshell, although its effect on other forms of wildlife was pronounced. I wonder is that why we have so many tortoiseshell about?
This butterfly extends from the Atlantic coast of Europe as far as the Pacific coast of Asia, quite an impressive range. It is very plentiful in England, less so in Wales, with parts of Scotland and Ireland having not such a large population of the butterfly. In spite of those comparative generalisations there are still plenty of them about here.
COMING EVENTS
Saturday 24th July: Butterfly Outing to the Umbra, Castlerock, 1100, with Bob Leslie, more information from Butterfly Conservation on 028 - 9079 6979.
Open Day at Portmor Lough, more from RSPB on 028 9049 1547
Sunday 25th July: International Bog Day at Peatlands Park, phone the Environment Service on 028 3885 1102
Saturday 31st July: Moth Workshop at Castleward, more from Butterfly Conservation 028 9079 6979.
Saturday 31s July to Tuesday 3rd August:-The RSPB invites all to Rathlin to see the last, for this year, of the seabirds. Give it a call on 028 9049 1547
Saturday 7th and Sunday 8th August: Oxford Island Wildlife 2004. A huge range of events over the two days, contact the Island for more, on 028 3832 2205
Sunday 15th August: Butterfly Outing to Rostrevor Park, with Trevor Boyd, 1100. Why not phone him for details, 028 9185 2276.
Ulster Star
23/07/2004
