CA Clarke, Breeding the Large Blue Butterfly in Captivity
Posted: Tue Jun 02, 2020 3:06 pm
This is a rather obscure paper that I discovered after it was referenced in the AES publication "Breeding the British Butterflies" by PW Cribb. It's available here: https://www.biodiversitylibrary.org/ite ... 8/mode/2up as a scan but I dont believe a transcription is available anywhere (apart from this one I made and the terrible OCR I based it off). The photos are all screenshots from the scan at the link above. I think this paper could be useful in a reintroduction project and I don't believe anyone has attempted to breed this species since.
Clarke, C.A. (1954) Breeding the Large Blue Butterfly in Captivity 1953–54. Ent. Rec. 66, 209–10.
In 1952-53 an attempt was made to rear the Large Blue (Maculinea arion L.) in a specially prepared 6 ft. X 4 ft. greenhouse, in the hope that the butterfly might be bred on a large scale. This was a failure, as also was the use of various glass observation nests. It was therefore decided in 1953-54 to try to breed a few individual butterflies by the "walnut" method described in detail by Purefoy in 1915 and recorded in Frohawk's Natural History of British Butterflies. This proved successful and the notes which follow indicate the special points of interest which arose during the experiment: —
1. The female arion laid readily on wild thyme and the eggs were placed in 1" diameter tins. Under a hand lens the eggs could be seen to darken after a few days and fresh thyme was then put in. When the larvae hatch they are so small that they are diflicult to find, disappearing into the thyme buds. The simplest plan for breeding, therefore, is to renew the food-plant every few days and never to throw anything away; by this means no caterpillars are lost. Frass in the tins can be detected about ten days after hatching, and when the larvae become salmon pink, after about a fortnight, they are more visible and can be seen in or around the thyme buds. When, after three weeks, the caterpillars leave the thyme, they crawl rapidly round the tin and are then ready to be transferred to the walnuts. Cannibalism is said to occur but we did not see any and on several occasions three or four larvae were found in different flowerlets on the same bud of thyme.
2. The most diflicult period was changing over from the wild thyme to the ants. The caterpillars were introduced into the "walnut" on a paintbrush, but a large number of them then disappeared. Whether they were eaten by the ants or whether they were drowned through entering the water seal is not known, but out of 30 or 40 caterpillars introduced into the nests only 7 successfully established themselves with the ants. Possibly we had too much earth both under and around the walnuts and the caterpillars may have burrowed into this and been lost. Very little earth (about ⅛") seems to be necessary. At no time did we witness the spectacle of "humping", nor did the ants appear to pay any attention to the caterpillars.¹
3. The "walnuts" (2½" × 1½") were hollowed out of wood and roughened inside. We used Myrmica rubra L. ( = M. ruginodis Nyl.) ants from Cheshire and these proved very satisfactory. Whether this is a new species of ant for arion is doubtful, since recent work suggests that ruginodis and M. laevinodis Nyl. are almost identical.² Nests are found chiefly under stones and the simplest way to remove them is to scoop them up with a spoon and to take the brood off the underside of the stone with a paintbrush. On return home the tin is emptied on to one of the little tables with a walnut and a water seal (see photograph) and the earth well broken up and spread out. The ants then quickly establish themseves under the "walnut". We fed the ants every two or three days with chopped mealworm, and a few drops of water were placed under the shell two or three times a week.
4. When established, the larvae grew quite quickly until hibernation in mid-October, fresh brood from new nests being added as needed. The caterpillars were inspected every day and were kept at room temperature throughout. Even during the winter they exhibited occasional activity but at no time did we see them actually eating. Two died during hibernation. Brood in Nature reappears about April and is then added to the nests. After the winter the remaining larvae grew very slowly and the first chrysalis was obtained on 10th June; before pupation the caterpillars dropped from the roof and lay as if dead for three or four days. The first one to do this was inadvertently destroyed as we thought it was, in fact, dead.
Butterflies emerged as follows: 1st July — male; 12th July — female; 17th July — male. The fourth pupa darkened but the insect never emerged.
We are very grateful indeed both to Mr. N. D. Riley and to the owner of the land for allowing us to take a few arion females from a protected colony; also to Mr. Wilfred Lee, University of Liverpool, for the photographs which illustrate this paper.
¹Since writing this paper young larvae of Maculinea alcon, a continental Lycaenid, with myrmecophilous habits similar to arion, have been studied. M. rubra ants have been observed to carry the alcon caterpillars on many occasions, particularly when the "walnuts" have been disturbed. The ants appear to deal with the larvae exactly as they do with their own brood, picking either up before escaping from the light.
²Dr. John Carthy (personal communication) states that M. rubra L. (=ruginodis) and M. laevinodis Nyl. can be distinguished biometrically but many individuals are indistinguishable. Rubra is a dimorphic species but it seems as though laevinodis should be absorbed into rubra L. as Linnaeus first said.
REFERENCE.
FROHAWK, F.W., M.B.O.U., F.E.S., etc., Natural History of British Butterflies.
Hutchinson & Co., 1914.
Clarke, C.A. (1954) Breeding the Large Blue Butterfly in Captivity 1953–54. Ent. Rec. 66, 209–10.
1. The female arion laid readily on wild thyme and the eggs were placed in 1" diameter tins. Under a hand lens the eggs could be seen to darken after a few days and fresh thyme was then put in. When the larvae hatch they are so small that they are diflicult to find, disappearing into the thyme buds. The simplest plan for breeding, therefore, is to renew the food-plant every few days and never to throw anything away; by this means no caterpillars are lost. Frass in the tins can be detected about ten days after hatching, and when the larvae become salmon pink, after about a fortnight, they are more visible and can be seen in or around the thyme buds. When, after three weeks, the caterpillars leave the thyme, they crawl rapidly round the tin and are then ready to be transferred to the walnuts. Cannibalism is said to occur but we did not see any and on several occasions three or four larvae were found in different flowerlets on the same bud of thyme.
4. When established, the larvae grew quite quickly until hibernation in mid-October, fresh brood from new nests being added as needed. The caterpillars were inspected every day and were kept at room temperature throughout. Even during the winter they exhibited occasional activity but at no time did we see them actually eating. Two died during hibernation. Brood in Nature reappears about April and is then added to the nests. After the winter the remaining larvae grew very slowly and the first chrysalis was obtained on 10th June; before pupation the caterpillars dropped from the roof and lay as if dead for three or four days. The first one to do this was inadvertently destroyed as we thought it was, in fact, dead.
¹Since writing this paper young larvae of Maculinea alcon, a continental Lycaenid, with myrmecophilous habits similar to arion, have been studied. M. rubra ants have been observed to carry the alcon caterpillars on many occasions, particularly when the "walnuts" have been disturbed. The ants appear to deal with the larvae exactly as they do with their own brood, picking either up before escaping from the light.
²Dr. John Carthy (personal communication) states that M. rubra L. (=ruginodis) and M. laevinodis Nyl. can be distinguished biometrically but many individuals are indistinguishable. Rubra is a dimorphic species but it seems as though laevinodis should be absorbed into rubra L. as Linnaeus first said.
REFERENCE.
FROHAWK, F.W., M.B.O.U., F.E.S., etc., Natural History of British Butterflies.
Hutchinson & Co., 1914.