Things are not always what they seem in this place…

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I often bring in accidental travelers when I gather leaves to feed my silkworms.  I get leaf hoppers, the occasional spider or caterpillar… and so I don’t worry too much when I notice something crawly coming out of my leaf bags.

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Today’s immigrant seemed not-quite-right somehow.  It’s a tiny little ant – or is it?  It runs like an ant… it wiggles its little antennae like an ant – but then every once in a while, its disguise slips.  It seems just a little too happy to be an ant alone – and it just didn’t move quite right.  It was hard to tell, because it’s so small and moves so fast – but eventually I got it to declare itself – I tipped my hand sideways, and it promptly caught itself mid-fall with a rapelling rope and climbed back up.

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He is SO a spider.  Perfect mimic – I really did have to catch him in the act to be sure. I’m guessing, with a brief Google search and a flip through BugGuide.net, that it’s a jumping spider called Peckhamia picata.  I think theirs is bigger, though – mine is maybe 2 mm long.

I kept him in a little plastic container so I could get some photos and to show Chris.  You can see how he built himself a little web nest:

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Voltinism

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Voltinism refers to the number of broods that a silkmoth strain (or species) will have per year.  Most of the silkworm strains in cultivation are univoltine (or monovoltine) – meaning they have one brood per year, and the eggs laid by the moths of that brood will go into diapause to hatch the next year.  Some strains are bivoltine, and have one generation that overwinters, and one that has non-diapausing eggs.

This strain from Thailand is multivoltine, meaning that it has multiple generations per year.  This makes sense in a region that has a very mild winter, and allows rearers to take advantage of the long growing season.  The first generation in spring lays eggs which hatch without diapause, and they continue to do so until the light cycle tells the worms that summer is drawing to a close, and then the moths will lay diapause eggs.  Some strains never diapause, like the Cambodians – but because of that, I wasn’t able to keep up with the strain.  I don’t have fresh mulberry in December.

The non-diapause eggs don’t mature the same way that diapause eggs do.  Instead of turning from pale yellow to brown and then gray, they stay pale yellow.  The only indication that they are fertile (and about to hatch!) is when you can see the head of the developing silkworm through the eggshell; it’s called “blue eye stage,” and it usually means you have a day or two before hatch time.

Fortunately, these moths are beginning to get the feel that summer is fading – they are laying some diapause eggs amongst the non-diapause.  I think that this is actually the work of multiple moths, one laying diapause eggs and one laying non-diapause eggs, but I wasn’t segregating them and can’t be sure.

The diapause eggs are tan colored, and will shift to dark gray, indicating they’re developed and in diapause – at that point, they can be refrigerated for storage until spring.