Comments

  1. PaulBC says

    We’re very nice to spiders around here, but they don’t help out with the roaches at all. I think the pandemic may have exacerbated the situation since we all do a lot more eating at home.

  2. microraptor says

    Roaches are awfully big for most house spiders. I try to live and let live with spiders that come into my apartment, but unfortunately my cat does not. Guess they’re about the biggest game she ever gets.

  3. BACONSQAUDgaming says

    They don’t seem to have much effect on the fruit fly population in my place.

  4. John Morales says

    @1,2: roach hatchlings start out quite small, and only grow to full size over time.

    Anyway. Me, I evict any and all insects I find inside my house.

  5. hemidactylus says

    The Seek app PZ promoted here kept calling winged bugs found in my house termites, though I got visually suspicious because the bent antennae and tight waistlines. I freaked out until I tweezered the wings off and then the app called them ants. I guess the ant war has entered a new phase with them developing an air force. Are the bait traps no longer effective? Should I bring in spiders from bushes outside as mercenary antiaircraft contingents?

  6. imback says

    I live near ground zero of this year’s Brood X 17-year-cicada paroxysm. (I for one welcome our intermittent insect overlords.) Anyway this morning I saw one got caught in a spider web on the outside of a window frame looking out over the back deck, and I took a picture from the inside. You can see the spider crawling on the bottom of the dead cicada. (It might have died from natural causes; we’re on the backside of the paroxysm as now I see more dead ones than live ones, but there still is plenty of very loud singing in the treetops.)

  7. davidc1 says

    @7 Seems a bit mad to spend 17 years underground ,does that mean that species is evolving 17 times slower than it should .
    There is a moth or Butterfly in the Artic that can’t can get enough food to enable it to turn into a pupae during one summer ,so it
    stops ,and carries on next year.

  8. blf says

    @9, It’s one of their defenses against predators, Cicadian Rhythms: Why Does the 17-Year Cicada Emerge Like Clockwork?:

    Lots of available prey generally stimulates predator reproduction, increasing predator populations. Cicada predators with life cycles that match the cicada life cycle would be at a great advantage. By having a long life cycle, cicadas can prevent predators from matching their reproductive timing. By having a life cycle that is a prime number (as are 13 and 17), they can also prevent predators from developing a life cycle that is a factor of that number. (For example, a 12-year cicada species could be wiped out by any predator species with a 2-, 3-, 4-, or 6-year life cycle because each cicada emergence would be met with a boom in the predator population). […]

    Another defense is they emerge all at essentially the same time — billions to trillions(!) of them — overwhelming predators. They simply cannot all be ate. Enough will survive, by sheer numbers, for another cycle to begin. “Cicadas are practically defenseless. They don’t bite or sting and they’re not poisonous.”

  9. stroppy says

    @9 re mad bugs.
    The explanation I heard was that the cycle is long and odd enough to prevent predators from adapting to and depending on their emergence.

    In evolutionary term, I would guess that on average 17 years isn’t all that significant, but I defer to wiser heads.

  10. imback says

    The cicada’s 17-year cycle foiling specialized predators and filling the bellies of regular predators seems to work, so far. But there are a couple of open questions, at least from my point of view.

    How did they evolve to this point? What were there intermediate integer number of years in their heritage? And how do they count so well underground? After 17 years, most of them come out within a few days of each other. Not too many of our own analog timepieces could do that. And the most common error they make is to come up after only 13 years. What does that tell us about how they do it? Do they count years by fours?

  11. blf says

    imback@13, “the most common error they make is to come up after only 13 years.”

    Citation, please(on the “most common error”).
    My understanding (see, e.g., the link in @10) are the 13-year cicadas are a different species: “There are seven species of periodical cicadas: four 13-year cicada species and three 17-year cicada species.”

    Premature emergences are known, albeit the number of confused cicadas is trivial compared to the cyclic emergences. E.g., Brood Awakening: 17-Year Cicadas Emerge 4 Years Early (which, ironically, are Brood X 17-years emerging after only 13 years in 2017). That short article does, b.t.w., hint at possible timing mechanisms (including, essentially, “count years by fours”, which apparently is the usual length of each stage of development, excepting the very first).

  12. imback says

    @blf, sorry I don’t know the citation. It was something I read 4 years ago when some Brood X cicadas appeared early. And you’re right the number of confused ones was relatively small. I had maybe a dozen appear in my yard in 2017 but hundreds of times that this year. When they have low numbers like in 2017, they don’t get a chorus going and don’t mate. This would keep the errors from propagating to years outside the cycle.

    PS either the spider on the window cut the dead cicada loose or it just fell free.

  13. imback says

    @blf, sorry I don’t know the citation. It was something I read 4 years ago when some Brood X cicadas appeared early. And you’re right the number of confused ones was relatively small. I had maybe a dozen appear in my yard in 2017 but hundreds of times that this year. When they have low numbers like in 2017, they don’t get a chorus going and don’t mate. This would keep the errors from propagating to years outside the cycle.

    PS either the spider on the window cut the dead cicada loose or it just fell free.

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