Have been out and about in local (Gloucestershire) apple orchards recently examining their mistletoe for signs of overwintering mistletoe insects. Little is known about the biology of our six mistletoe specialist insects, and how they spend the winter, and how they emerge, is one of many mysteries. I reviewed current knowledge on these insects, and challenged some of the assumptions being made about them, in a recent paper – which, if you’re interested, is downloadable here)
Accepted wisdom says that the Mistletoe Marble Moth spends the winter as a young larva, within a tiny leaf-mine in mistletoe leaves. These mines are, so the accepted story goes, crescent- or comma-shaped. Well, I’ve been round lots of orchards this week, and examined (very) large numbers of mistletoe leaves, and the only tiny leaf-mines I’ve seen have been straight ones. Is that the moth? Or something else entirely? I don’t yet know…
The four mistletoe bugs shouldn’t be active yet – far too early. But how do they overwinter? And what were the instar (larval) bugs I’ve seen this week, already crawling, very rapidly, through the mistletoe?
And then there’s insect number 6 – the mistletoe weevil. Last summer I found that their habit (as larvae) of eating away the mistletoe stem, within the plant tissue, just below the terminal bud, often killed that bud. So, this week I’ve been looking out for dead terminal buds without an exit hole (a hole shows that the adult weevil has emerged). And I found several – which, on dissection (see pic left), provided me with a rather annoyed-looking weevil larva. So that’s how they over-winter – within their cosy little homes inside the stem…
And we mustn’t overlook the pollinating insects. Our mistletoe flowers now – February – and it is insect-pollinated. That might seem odd for February, but it seems to work, so it can’t be that peculiar! Again, conventional wisdoms say that it is pollinated by small flies, and certainly today, in the sunshine, there were several gnat-sized flies frequenting the mistletoe clumps.
But there were also bees – proper honey-bees (see pics below) – probably finding that mistletoe was one of the few plants available to them this early.
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I wonder what would mistletoe honey be like?
ooh yes that would be wonderful!! is this the first time you;ve seen bees pollinating mistletoe?? fantastic pictures!!
Hi Suzanne,
I’ve often heard about honey bees on mistletoe – but yes, this is the first time I’ve seen them properly. This was in an orchard close to some hives, which probably helped. Though today (Saturday) I was in another mistletoey orchard with bee-hives and there was no sign of the bees on the mistletoe – but they were foraging in a next-door garden on the Sarcococca. Does that mean they prefer that, or simply that they found that first and might switch to the mistletoe soon? As the mistletoe flowers are only just out maybe they’ll discover it in a day or two’s time.
Pleased that you like the pics. They are quite good aren’t they – though to judge them in context you need to see all out-of-focus ones where they got away…
(btw – I’ll have to miss the Mtoe fest mtg next week – will try to catch up later)