Back in the late 60's, as a child, I remember seeing lots of the enchanting glow worms in our back garden every evening, and while living in the Hill Country of Texas, USA during the mid 80's, again, they were ubiquitous, however, that's the last time I've seen them. Are they still around?, and if not, what's the reason for their demise? thanks

Post's pictures

109_6178.JPG, 78.28 kb, 1024 x 768

Without knowing anything of the American fauna for 'glow-worms' (which may or may not be related to European 'glow-worms'), I would speculate that the most likely reason is habitat change or habitat loss (most of the declines in abundance and / or range for species we have good data for tend to be habitat specialists). Modifying, even subtly, an organisms habitat can dramatically effect the chances of breeding, mating or even surviving to adulthood. In the UK, our 'glow-worm' (Lampyris noctiluca) is a beetle, predominantly of hard limestone / chalk grasslands, where there are plentiful numbers of small snails for the larvae to feed on. The loss of these grasslands in terms of absolute size, linkage and quality are reasoned to explain, at least in part, the possible decline of this species (and many other, more surveyed species, like moths and butterflies).

There are, obviously, many other possible explanations that may work independently or in conjunction with the above (these things are usually a combination of fectors that are complex to unravel) but as I don't know anything about the species to which you refer, its life history or the region, I'm afraid that I can't speculate much further.