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Index of Subjects Thanks, Stephen, for explaining how these critters can survive in watery conditions. My take on the extinct St. Helena species is that all endemics are on the road to extinction. Having such specialized needs in a period of global warming does not bode well for their continued existence. Of course such are among the most rarest & most interesting creatures on earth. Thus we feel we must do everything to protect them. Unfortunately we can only mourn as each disappears into history. Angus At 01:57 PM 17/11/2009, you wrote: >Hi Angus & other dermaptophobes: Even in your likely role here as agent >provocateur, Angus, your nonchalance about the fate of the St Helena Giant >Earwig should raise a few eyebrows. It now appears to be extinct, and is not >being rescued by taxpayer ecodollars as far as I could make out from reading >some of the same sources as you (the last 3 searches for it by visiting >entomologists failed, on this small island -- surveying insects in unique >habitats is what some entomologists do professionally). > >Turning this around, would you have been equally unhappy if a small >part of some >state's funds were to be expended in an attempt to save the Great >Auk, the last >couple of which were clubbed to death for food by sealers as I recall, or the >Dodo, likewise? Birds, yeah, earwigs, nay? If this is your position, then >closer to home for the SHGE, are you equally unconcerned that the SHGE`s bird >predator, the now extinct St Helena Giant Hoopoe, may have coughed its last in >part because an important food source disappeared? The suspected cause of >extinction of the SHGE itself is destruction of the Gumwood Forest at one >end of St. Helena. So, perhaps clear-cutting -> SHGE extinction -> SHG Hoopoe >extinction, reinforcing the interconnection of living things in complex >ecosystems, and the need to avoid disrupting same where possible. > >As to how the particular (alien, unloved) earwigs here can survive under water >for a while, insects breath through lateral spiracles coupled to tracheae, >internal air tubes that run directly into the tissues. At least in some cases >well investigated like the cockroaches you mention, the spiracles have both >protective guard hairs and associated muscles so that they can be closed off >completely by the insect, and in addition the outer parts of the >tracheal tubes >are hydrophobic (unwettable), like the outer cuticle. Thirsty >roaches are quite >happy to submerge themselves for a while to drink. No doubt earwigs have >similar specializations permitting their dunking, but I'm sure they can't >actually live under water indefinitely. They certainly float and will swim >around in a toilet bowl, so the question would be how yours managed to get >under water in the first place -- presumably they didn't, but simply sank when >you pulled the plug and then hung on for dear life, to anything nearby (?). >Steve > > >Quoting Angus MacLean <angusmcl@ns.sympatico.ca>: >>Re recent discussion on possibly dwindling populations of earwigs, >>I would personally be pleased to see the day when they are on the >>endangered list. However, l liken earwigs to cockroaches in that >>they will be here long after humans are gone from this earth. >> >>In any case we had an interesting case of an earwig which was >>adaptable to another environment. We have a backyard pond in which >>are a number of goldish. We remove them from the pond for the >>winter. A few days ago my wife noted something on one of them when >>we took them out. It was an earwig !!) latched on to the goldfish. >> >>We have to partially drain the pond in order to net them so only >>about 3-4 ins of water is left. Although it is known that earwigs >>like wet conditions (try leaving a wet mop out overnight), there is >>no indication they can live in water. There must be an explanation but...?? >> >>Incidentally there is one earwig, the St. Helena Earwig, on the >>endangered list. It is the largest earwig in the world and recovery >>plans are already underway. How scarce resources and monies are >>wasted! (I expect a backlash re the latter statement). >> >>Angus > >
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