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Index of Subjects Yes, attraction to street lights is one thing, but possibly not the explanation here. I don't think that anything is known specifically about belostomatids apart from the physiology of the photoreceptors. But another well-know, smaller, also predatory hemipteran in Europe, the backswimmer Notonecta glauca, was looked at earlier by Rudolf Schwind. There's a similar one in ponds here, maybe even the same species, though it looks smaller. Although they normally live and hunt from just below the surface film in fresh water ponds, they disperse from pond to pond by flying. Notonecta locates a new pond visually at short wavelengths, homing in on the plane polarized light (PL) reflecting up towards it when flying, from the flat surface of the pond. This is the same physical principle that you notice when driving, as the annoying light glare reflecting towards you from a wet road surface ahead, which is partially plane-polarized. The latter can be mitigated by wearing Polaroid-type sunglasses where the axis of the sunglasses' PL filter (vertical) is opposite to the major PL plane reflected from the road or water surface (predominantly horizontal), so the glare is partially blocked. In a number of insects (esp. bees, ants, flies) certain eye facets are specialized for PL detection with two sets of 'PL analyzers' oriented at 90° to one another (sort of like having two orthogonal sets of sunglasses but the implementation is different). These analyzers lie along the dorsal rim of the compound eye, normally point upwards, and are used for analyzing skylight PL. In Notonecta, unusually, it's the opposite: the specialized analyzer zone is in the ventral eye looking downwards, which makes sense if the bug is flying, searching for PL reflections coming up from a pond below it. The best guess would be that the 'giant electric light bug' has the same pond-locating visual specialization and that that's how it located this miniature pond. The ones in S.E. Asia, Lethocerus sp., are among (and probably actually are) the largest known insects and sometimes used to illustrate the limitation on size imposed on insects, particularly by the length of their respiratory systems. Years ago I saw 100s dried out in the sun displayed on tables, sold for food in the main market in Bangkok, but declined the offer. Steve (Halifax) Quoting Randy Lauff <randy.lauff@gmail.com>: > The bugs were likely attracted to your area by the parking lot lights of > the shopping centre; I've had a number of stories over the years of people > finding these bugs in such situations. > > I have one in captivity here...it caught and fed upon a Mummichog longer > than it was. > > Randy > > _________________________________ > RF Lauff > Way in the boonies of > Antigonish County, NS. > > > On 17 June 2013 23:39, Don MacNeill <donmacneill@bellaliant.net> wrote: > >> Hi Andrew. It is a contained pond, about 6' by 4'. I don't know how >> the water bug found it since there are no other water features in the area >> (by the Halifax Shopping Centre). I did get a couple of pictures but it >> moved surprisingly fast when I tried to push it with a matchbook to a flat >> rock for pictures. >> >> The Danios do swim around. They might not go to the surface unless I put >> food there. I take the fish out in the Fall and keep them in an aquarium >> over the winter. >> >> Don >> >> Don MacNeill donmacneill@bellaliant.net >> On 17/06/2013 10:32 PM, Hebda, Andrew J wrote: >> >> Technically speaking, the use their proboscis to feed on body fluids. >> >> Do the Danios stay in the open or remain in the vegetation. >> Andrew >> Is this a contained pond, or connected to a drainage? >> ------------------------------ >> *From:* naturens-owner@chebucto.ns.ca [naturens-owner@chebucto.ns.ca] on >> behalf of Don MacNeill [donmacneill@bellaliant.net] >> *Sent:* June-17-13 9:13 PM >> *To:* NaturenNS >> *Subject:* [NatureNS] Giant Electric Light Bug >> >> I just found a Giant Water Bug in my backyard here in Halifax city. It >> was about 2.25 inches long and looked like a Belostomatidae water bug. I >> noticed that my cat was circling something in the grass, a short distance >> from my small pond. I'm glad she didn't try to eat it as they have pincers >> and some venom. >> >> Now I'm worried because I've put some Zebra Danios in the pond to eat any >> mosquito larvae. Google says these water bugs eat small fish. >> >> Don >> -- >> Don MacNeill donmacneill@bellaliant.net
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