The Backyard Arthropod Project

An extractive metallurgist attempts to answer your entomology questions!

OK, like most people who have web sites, I check the access statistics for the pages from time to time. And one of the things that the statistics program tells me, is what search terms people have used that found these pages. A lot of these search terms are phrased in the form of questions. So, even though I wasn’t explicitly asked any questions to my face, I figure, what the heck, I was *sort of* asked them, so I might as well take a stab at answering. And even though I am an extractive metallurgist by profession, not an entomologist, I have picked up a lot of information and can answer a lot of the more basic stuff. I’m making a good faith effort to be correct, but anytime you see that I’m making a mistake, please feel free to leave a comment to correct me. So, anyway, here goes!

1. How does a click beetle escape predators?
They have a joint in the middle of their thorax that they can “cock” to store energy, then when they release it they pop vigourously and are really hard to hold onto. A picture of one is here.

2. What does a funnel web spider look like?
The funnel web spiders in North America are blackish-brown, moderately hairy spiders with bodies up to a centimeter long. The males wander around a lot, while the females hang out in their webs, which look like a white silk sheet curled into a cone at one end. The funnel web species in North America are harmless, and completely unrelated to the Australian funnel web spiders (aside from both being spiders, that is).

3. Why are mites arachnids?
According to the introductory entomology book I have here (Fundamentals of Entomology, by Richard J. Elzinga),the identifying traits of an arachnid are:
(a) eight legs (four pairs of legs)
(b) their mouthparts consist of ”chelicerae” and ”pedipalps”
(c) their bodies are divided into two portions (the cephalothorax and the abdomen)
(d) they have no antennae.
Mites have all of these traits, and are therefore arachnids.

4. Aside a spider, what animal belongs to the arachnid family?
Mites, ticks, scorpions, pseudoscorpions, harvestmen, whipscorpions, sunspiders, sea spiders, and similar animals. Spiders are by far the most commonly-seen arachnids, though.

5. What are assassin bug wanted for?
Murder! They prey on a lot of insects that we consider to be pests. For example, there are species of assassin bugs that eat bedbugs. Some assassin bugs sometimes also bite humans (and some southern species actually live on mammal blood), so sometimes you *don’t* want them.

6. Why can’t humans adapt to pesticides as quickly as insects?
Two reasons: (1) insects have a lot more offspring than humans, a single pair of insects could have hundreds or even thousands of offspring, so even if a small fraction of those have pesticide resistance, they can rapidly breed the population back up. (2) they breed a lot *faster* than humans. Some extreme cases, like fruit flies and aphids, can have a generation every few weeks, compared to about one generation every 25 years for humans. And every generation swaps around and spreads any genes for pesticide resistance, so they can evolve very fast if necessary.

7. How do harvestmen breed?
Well, there are over 7000 species of harvestmen, who probably all do it somewhat differently, but there is a description of how the common Striped Harvestman does it here. Basically it involves a lot of prodding each other and wrestling.

8. Can funnel webs live on windows in Australia?
I don’t see why not, lots of other spiders do, although I expect that they’d be most likely in the corners of the windows or underneath the windowsills.

9. Is the male funnelweb more dangerous?
If you mean the Australian funnel web, then yes, but only because you are more likely to encounter the males. They wander around looking for females, while the females pretty much stay put. So, the males are the ones that might, say, crawl into a pile of clothing or a shoe.

10. Can mites get in your brain?
Urgh. I hope not! They mostly infest skin and hair follicles, but I suppose there could be some species that get inside the body and infest the brain. I’ll have to look into that.

11. How many have been bit by a funnel spider?
Probably a lot fewer than the number of people who think they have. According to this Australian Government site, only 13 people have died from Australian funnel-web bites, and there have been no deaths since the antivenom was developed in 1981. They don’t say how many people have been bitten and survived, probably nobody knows for sure. There is a tendency to notice a wound that looks kind of bite-ish, see a spider somewhere around, and say “Hey, that spider must have bit me!” Then the panic starts.

12. Where do funnel web spiders live?
There are at least two distinct families of spiders that build funnel-shaped webs, but the two groups are not actually related. The non-poisonous funnel webs live all over the world. The poisonous ones only live along the east coast of Australia.

13. Are crickets and grasshoppers the same thing?
No, although they are related. Crickets tend to be fatter, softer, and more inclined to live in caves and under rocks, while grasshoppers mostly live, well, out in the grass, hopping about.

14. Why arthropods are scarce in the oceans?
They aren’t. Crustaceans, like lobsters, crabs, and shrimps, are all arthropods, and they seem to be pretty common in the oceans.

15. Varroa mite can they kill people?
Um, no. They only bite honeybees. Unless you rounded up, say, 100,000 of them and used them to choke somebody to death, but I suppose that isn’t what you meant. Or if they kill all of a beekeeper’s honeybee colonies, driving him to bankruptcy, thus causing him to commit suicide in despair, but that probably isn’t what you meant either.

16. Why is the funnel web so poisonous?
I don’t know. Just lucky, I guess.

17. Where can a harvestman bite you at?
Probably nowhere. They don’t have much in the way of biting apparatus, and I doubt they can even leave a mark, let alone break the skin. And I believe that they have no venom in any case. The harvestmen I have played with over the years were pretty inclined to shed a leg or two and get away, but never really made any attempt at biting.

18. What is the name of the continent that spiders don’t live in ?
That would be Antarctica. Practically nothing lives on land in Antarctica, so that isn’t very surprising. Although, there are “sea spiders” in the ocean *around* Antarctica, does that count?

So, that’s what I have for now. I’ll add more as they come up. And, if someone wants to formally ask me a direct question, I’m game if you are.