Berkeley Home Biology Lab: Silkworm Sex


While the rest of the world reacted to today’s Supreme Court health care decision, we were witnessing the miracle of insect sex here in North Berkeley. To wit: Kate has been raising silkworms as part of her science teaching. We had a little plastic storage container that has become home to about a dozen silkworm cocoons, and today, silkworm moths emerged from two of them. Amazingly, or perhaps because these creatures have evolved to give themselves the best chance of procreating (or both), the two emergees were a male and female who immediately found each other and went to work mating. We’ll have some exciting video later (the picture above catches me shooting Kate recording the event with her iPad), but I have to say how impressive it is to see how quickly, purposefully and efficiently these pale, flightless creatures attended to their business. The male, the smaller of the two moths, fumbled around a little amid bouts of love grappling, but then hooked up (literally, it looks like) with his female friend (the female is at left in the photo below). Now, about an hour later, they’re quiet but still connected.


5 Replies to “Berkeley Home Biology Lab: Silkworm Sex”

  1. We are doing the same project here in Brooklyn with Cecropia and Polyphemus moths which are large silkworms. It is quite fascinating and the point, among other things, is to show the kids an example of the life cycle of a particular species.

  2. John, I had no idea those Cecropia and Polyphemus moths were silkworms, too. One of the striking things about these moths is how un-striking they really are and how utterly dependent on human intervention they are; I wonder if they’ve had flight bred out of them.
    Interesting species, Bombyx mori:
    One of the things that seemed “obvious” watching the moths yesterday was that the male (very active) was reacting or homing in on some cue it was getting from the female (very passive). It turns out that the pheromone the female emits, bombykol, was the first insect pheromone to be discovered (in 1959, by a German who also did pioneering work on isolating human sex hormones in the 1930s).

  3. Yeah, your guys don’t exist in the wild. They are entirely the product of thousands(?) of years of domestication. Amazing to think about. They (the silk producers)go through some incredible amount of mulberry leaves every year.

  4. By way of an update, I have something like fifty Cecropia caterpillars bred from the ones we raised last year. Will keep you posted.

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