Large and later still

by Wilfrid George

After my reporting ('Large and Late') in our July 1998 newsletter, the activities of Large White larvae into December 1997, my favorite pest has struck again.

Beating easily my previous 'record' of three larvae on 9th December 1997, I found ten of them on 16th December 1998 - this time at work on my purple sprouting broccoli. It was 9°C, and at least two of them were nibbling away. This time I decided to be merciful - the broccoli will sprout in April anyway - let's see how long the caterpillars can last.

On the 22nd they were still munching away at only 1.5°C. Then they had their hot Christmas dinner (warmed up to 11°C) at noon on 25th. All the nines - nineteen ninety nine - saw more munching at 9.00 a.m. at 9°C. There must have been over nine larvae, because on 9th January at least ten larvae were feeding at 5°C. Numbers did seem to reduce, though on 20th January I could still locate six of them .

I will not bore the reader with the almost daily data which continued half way through February until the last caterpillar (which was definitely moving) was seen on 17th, at 7°C at 9.00 a.m. Since then - V nothing. It seemed to me that these larvae were about full-grown throughout, but that in such low temperatures they could only digest enough food to maintain themselves, but not to develop further. Two of them did appear to try to pupate, but they finished dangling upside down (like tortoiseshells, rather than whites) humped and bloated, but they never formed pupae. It seemed surprising that, in the middle of Winter, no bird seemed to fancy these very obvious tit-bits. Their black and yellow warning colouration must have been very effective.

'Larvae occur from early May to early December, very occasionally into January, with two, sometimes three, generations a year'.

From volume 7, part 1, of The Moths and Butterflies of Great Britain and Ireland. Ed.

Large White by Douglas Hammersley

A Duke or a Duchess

by Douglas Hammersley

My first encounter with the Duke of Burgundy (Hamearis Lucina} was at Noar Hill, near Selborne in Hampshire, where a large population of this species may be found. Watching their behaviour among the scrubby hummocks on the hillside, I soon realised that the majority of those that I was seeing were male Dukes because of the vigorous manner in which they were defending their individual territories. It was some time before I spotted what I guessed was a female. She had rather brighter orange patches on the upper surfaces of her wings than I had observed on the males. The difference was only slight. Indeed, I came to the conclusion that there was a little in the wing patterns to differentiate between the sexes. Then I remembered to look at their legs! The forelegs of the male are degenerate and lack the distal five tarsal segments. This makes them too short for use in walking, and the males have to stand on four legs. The females, however, have fully- developed forelegs and walk about on six legs.

My drawings illustrate this anatomical difference.