A troubled tale

I have been in a state of maternal - or I suppose paternal - angst for the last two weeks as the saga of my hawk moth caterpillars unsteadily unfolds. Regular readers may recall that a clutch of seven eggs was left on the bulbholder of the moth trap on the night of Saturday, 5th August, as shown in the picture to the left.

The following week they hatched, all seven of them, into the tiny caterpillars which I described here on Saturday, 12th August, expressing my delight that although extremely small and new to the world, they already sported miniature versions of the tail horn which distinguishes hawk moth larvae from almost all other moth and butterfly examples. Here is one of them to the right.

They had their translucent eggshells as initial fare - see left - and so it was a case of So far, so good. But then things turned extremely bad. One by one, the poor little mites fell foul of some unknown hazard and one by one, I found them dead. 

My difficulty was that I did not know what they were. Their parent had left no calling card. But since the only candidate which is still putting in an appearance in the trap at the moment, and for the past month, is the Poplar Hawk, I went for that and gave them willow leaves, the species' secondary food in the absence of actual poplars which we don't have nearby. I added buddleia as a back-up which might appeal to a variety of species.

After the first death, I increased the menu, with willow-herb for Elephant and Small Elephant hawks, apple for Eyed Hawks and lime for Lime Hawks, the last involving a cycle ride to the churchyard which has the nearest limes.

There were moments of encouragement; caterpillar poos appeared - see right with one of the brood. But my worries about both correct diet and the possibility of poisoning the poor little things by tempting them with the wrong food increased as the death toll steadily rose. By the middle of last week I was down to two. And then finally, one.  I thought lugubriously of Wordsworth's poem We Are Seven, which you can read in full here.

But now, some relief. The parallels to the verse (and he wrote worse, including the famous reference to the stuffed owl in While Anna's peers and playmates tread, or that great opening line of To the spade of a friend: 'Spade! With which Wilkinson hath tilled his lands...') became closer in that I had a SURVIVOR!  And I still have, although he or she had a very narrow escape when rain flooded the muslin-topped container while I was out. I found the caterpillar browsing unconcerned on almost the only dry patch among the waterlogged, and in some cases actually floating, leaves. Here he is, just after that amazing escape. And his current picture tops this post.

Meanwhile, I have at least had my conscience eased by the great expert and co-author of the Moth Bible, Martin Townsend, who so kindly invited me to see the Death's Head Hawk moths which hatched in Kirtlington, a mile or two from here, back in October 2014 - see account here. I contacted him in my despair and he agreed with my Poplar Hawk diagnosis, which seems to be confirmed as well by the way in which - touch wood firmly - the lone cattie is now getting on.

Martin also answered my query about the reason for the horns, which I aired here last week.  He suggests:  

The horn is simply an extension of the cuticle and l think it just serves to break up the outline of the caterpillar and increase the resemblance to a leaf, i.e. it looks like a leaf stalk. You will notice that in many cases a pale diagonal line continues from the horn across the side of the body which emphasises this. As they grow larger you will start to see the effect. Sometimes people think it resembles a sting but I tend to think that’s a fallacy.

His point about the leaf stalk camouflage is illustrated by these pictures which I took this morning:

Sorry to have banged on, but it's been quite a saga. Here's hoping for calmer times henceforth, though there are many hazards which a growing caterpillar may face.