Giant Insect Spotted in Texas Hill Country

As you might imagine, I get all manner of emails. To say these messages cover a wide range of topics would be an understatement. Earlier this month, I received an email from a reader that touched on something I’ve never discussed on the site before. This reader recounted his encounter of a giant and unusual insect of some sort in the Texas Hill Country. Following is the reader’s email to me:

“Hello, I hope this e-mail finds you well. I'm a XXXX resident, and a follower of your blog for the past two years or so. During that time I’ve thought of contacting you once or twice to get some input on something that happened about six years ago while I was living in Fredericksburg, out in the hill country. I don't know why, but today is the day I'm finally writing that e-mail. I’m sure you're besieged with stuff like this on a weekly basis, so I'll try to keep it brief.

Back in Fredericksburg, i was working the night shift at a pizza hut on Main Street (or 290, as it's known to the rest of the state) and was out in the back area behind the restaurant smoking a cigarette. Earlier that evening one of the waitresses had come in from break a little shaken up saying that she'd seen some kind of large insect while taking out the trash - being a lifelong Texas native in a relatively rural part of the state, I didn't think much of it - after all, we've got some big bugs here in Texas. Sure enough though, about halfway through my cigarette, I caught sight of something I, to this day, cannot explain. Hanging out on the wall of the building just under a security light was a gigantic insect of some sort.

It was very awkward in shape, something I've attributed in hindsight to the possibility that it might have actually been two insects mating - but even dividing the size of what I saw in half, each one of these things would have to be at least 6 inches - and that's probably a conservative estimate. It had exposed wings which were folded back, the backs of the wings were a molted brown and black pattern much like a moths, but had a very pronounced membrainage like a cicada. It's body was hidden under the wings, but the glimpse I caught of it as it took flight was slender - like a lacewing - but huge. The most prominent feature, and the one that keeps me coming back to the memory time and time again, was a pair of pretty sizable pincher like mandibles - very reminiscent of the kind you see on large tropical beetles. Of course, Fredericksburg, being as small and uneventful as it is, my first response was to grab everyone I could from inside and show them. Shortly afterwards, amid a chorus of 'gross' and 'eww' the whatever-it-was flew off.

No, it's not a very exciting story at all but it's one that's stuck with me over the years. Me and my roommates at the time, both of whom were also there to see it, tried a few times to identify it via the internet but never came up with anything that looked similar. I know it's probably a shot in the dark, but I was wondering if you'd ever come across reports of similar sightings from the Fredericksburg area, or anywhere else for that matter - or if you might know of a species that fits the description. I watch a lot of David Attenburough, but I'm admittedly no entomologist or wildlife expert, so this could be a pretty common species. I just figured that if there was anyone to ask it'd be you. “

I very much appreciated this reader’s faith in me but I’m no entomologist either, I’m afraid. So, what to do? I was intrigued by the description of this large insect as it sounded nothing like anything I was familiar with but didn’t really know where to start. I have all manner of books on mammalian and reptilian species but nothing on insects. I decided that, before I started blindly searching through Google for Texas insects, I would pick the brain of some of my friends and contacts who know a whole lot more about just about everything than I do. They did not let me down.

It was suggested that the insect in question might have been a dobsonfly. There are over 200 species of Dobsonfly and they are found all over the world. Both male and females can reach lengths in excess of five inches. The wingspans of these large insects are often twice the length of their bodies and are lined with intersecting veins. These insects also have very long segmented antennae, which make them appear even larger.

Of all the unique features, it is the sharp mandibles these insects possess that seem to catch the attention of any who spot them and rightfully so. The mandibles of the male are quite menacing looking and can be in excess of one inch in length. While large and scary looking, these mandibles are quite harmless to humans. Males can’t generate much leverage with them and use them only to clasp onto females when mating. These mandibles do add to the frighteningly prehistoric appearance of the creature to be sure. While the male dobsonfly can’t deliver much of a bite, the female, which retains the short and powerful mandibles of their larval stage, certainly can. The female dobsonfly would be more than capable of delivering a painful bite to a human. Both sexes will put on an intimidation display when threatened. They will raise their heads and spread their jaws in a menacing fashion. This display is mostly a bluff. Their last real line of defense is an irritating and foul-smelling liquid they spray from their anal region.

If you’ve never heard of a dobsonfly you aren’t alone. You may be more familiar with what they are called during their larval stage: hellgrammites. Hellgrammites live in rivers, lakes, and creeks. They prefer to linger under rocks and feed on the larvae of other insects. Both males and females possess short and sharp pincers at this stage. Hellgrammites typically reach lengths of two to three inches and remain in this stage of development for 2-3 years before crawling up onto shore to pupate. Typically, the hellgrammite will remain in its cocoon over the winter months and emerge as a fully formed dobsonfly in the spring.

Adult dobsonflies don’t usually venture far from the body of water from whence they emerged. The species is mainly nocturnal and is attracted to bright lights (The reader mentions the insect was positioned under a security light. I would be curious to know if there was a creek or stream in the immediate vicinity as well). Once out of its cocoon, the dobsonfly has only seven days to mate and deposit its eggs near a water source before dying. The fact that they spend most of their lives under water in the larval stage as hellgrammites, don’t venture too far from water sources (which often feature heavily wooded shorelines), and live only seven days once they reach adulthood prevent them from being well-known to most people.

I can’t say for sure the reader who emailed in saw a dobsonfly. I sent a reply email to the reader with a photo of this insect attached but have not yet heard anything back. I do feel the dobsonfly is a good candidate for what this reader witnessed in the Hill Country.

While I am familiar with hellgrammites, I have never seen an adult dobsonfly. After looking into the matter a bit, I can see why running into one would be a bit startling. They are truly intimidating, prehistoric-looking creatures. I was stunned to know insects of this size and appearance make Texas their home.

It is good to know there are still surprises out there in the Lone Star State... even for an old dog like me.