Insect Horror Movie Idea

Today I’m going to take a little detour from my usual blog posts.  This one’s not going to be a true story about entomology or educational in any sense of the word, so be prepared for pure entomological fluff! It’s also going to be 100% text as my attempts at drawing the necessary images failed miserably.

A reader sent me an e mail last weekend asking if I’d seen the movie
The Monster on the Campus.  Sadly, I have not seen this movie, but given my love for bad insect horror movies it is definitely going on my list of things I must watch.  Thinking about any sort of insect monster movie, though, makes me think about my idea for an insect horror movie.  I threatened to share this idea with you in a past blog post, and today I’m finally going to do it.  Today, I give you my plot for Hellgrammite!  Let’s set the stage…

Act One: The Monster in the River

Two fishermen are fishing a river, ideally a reasonably deep one that runs through the mountains, perhaps something in the Pacific Northwest.  The two fishermen are shooting the breeze while they catch trout, but one needs to go “take care of some business” and wanders off on his own into the bushes.  A minute later, the other fisherman hears a scream and runs over to where his companion went, only to find that he’s gone without a trace.  He makes a report to the sheriff saying he thinks his friend, who had been drinking after all, fell into the river and drowned.

Cut to a scene in a local diner where the old timers are telling stories, and a couple of them get into a heated debate about whether there’s something dangerous lurking in the river…

The obligatory amorous teenager scene comes next.  A pair of frisky teens heads down to the river for a late night “picnic” and spread a blanket out along the shore.  They’re just getting down to business when the girl says she hears something.  The guy, of course, tells her it’s nothing, but she won’t be dissuaded.  She’s just about to get really angry at him for not believing her when he’s pulled away by some unseen assailant.  She runs screaming away from the water, but she doesn’t have the keys.  A few days later, she stumbles out of the woods, bloodied and muddy, in front of a car.  She tells the sheriff what happened as her wounds are treated at the town clinic.

Act Two: The Investigation

At this point, the sheriff starts to worry that something going on at the river and goes to investigate.  He discovers something troubling, a large “skin” with long tendrils coming off the side and huge jaws.  He brings in a biologist to consult, an aquatic entomologist (of course!) who happens to be doing her research in the area.  (We need more intelligent female scientists in this type of movie, so my entomological hero is a woman.)  She decides it looks like a giant hellgrammite, but can’t understand how it could possibly get so big.  She starts to investigate.

Act Three: The Source of the Trouble

In her investigations, the entomologists makes a horrible discovery: the feed lot upstream is illegally dumping wastes into the river!  She tests the water and sure enough – growth hormones!  They must be what’s caused the oversized hellgrammite…

Act Four: Discovery of the Hellgrammite!

Up until this point, none of the entomologist’s/sheriff’s team have seen the monster, but they soon get an up-close look at it.  One of the teammates (this person absolutely must wear a red t-shirt) is standing by the river when an ENORMOUS 8 foot long hellgrammite explodes out of the water and takes the hapless redshirt down with him, in spite of frenzied attempts by his companions to pull him out of the hellgrammite’s jaws.  You see a stream of red moving down the river a few moments later, and the sheriff and his guys try to shoot the hellgrammite as it quickly disappears upstream.

In an attempt to find and kill the monster, the entomologist looks at maps and satellite images of the river (she should probably be a GIS expert too – these hero types need multiple skills, right?) and finds a few places where the hellgrammite might be hiding.  It would have to be in the area near where the growth hormones are being released into the river, but would also have a nice, big boulder that the hellgrammite could call home.  She finds a likely place and they gear up to conquer the beast.

Act Five: Death of the Hellgrammite

This is the part I haven’t worked out to my complete satisfaction yet (I will happily accept any alternative death scene ideas for the hellgrammite in the comments below!), but the entomologist, the sheriff (who’s fallen in love with the entomologist at this point), and their team head to the place where they expect to find the hellgrammite.  There are signs that it is living in the area – more shed exoskeletons, bones of its human and other victims washed up on shore.  The entomologist sends a little remote-controlled submersible into the cavern under the boulder she’s identified as the likely home and we see the hellgrammite inside.  They’ve confirmed this is where the giant hellgrammite is living and they prepare to kill it…  Somehow…  I think the death needs to involve some completely ridiculous combination of electroshocking to knock it out (though it would have to be one hell of an electroshocking unit!), dragging it up on shore, and then flash freezing it with liquid nitrogen to kill it.  Yeah, that sounds about right.

The monster is dead!  The nearby town is safe!  The entomologist and the sheriff kiss and you know everything will be alright.  Or will it?  What’s that on the shore, off under that fallen log near the hellgrammite’s home?  Is that…  Is that a hellgrammite pupa?

Coming soon! The sequel to Hellgrammite!: Dobsonfly!

If anyone wants to actually make my movie for me, please feel free to do so.  I’d be happy to act as a consultant on a script or help out in any way I can, but I certainly don’t want to make it myself.  I think this would make a great cheesy insect monster movie though, so who wants to make my movie for me?  I’ll be the first person in line to see it!  :)


Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth


We had an insect trading session in the class I’m TAing this semester, so everyone brought in extra insects they had in their collections to trade for things they didn’t have.  I’m going to discuss some of my observations about the trading session in an upcoming post (I was fascinated!) but today I’m g0ing to focus on the specimen I was most excited about: a live hellgrammite.

Hellgrammites are the larvae of the insect known as the dobsonfly and they are fabulous (or at least I think so).  In their adult form, dobsonflies are pretty gnarly looking.  Males tend to have long, intimidating mouthparts:

Dobsonfly male

Dobsonfly male. Awesome photo by Jessica Lawrence, available at 419853/bgimage

Though the mouthparts look scary, they’re really pretty wimpy.  The males of most species can only inflict a minor pinch because the mouthparts are so large they can’t get any leverage on them.  But these giant mouthparts do have a purpose – and, as in most cases where insects have supersized body parts, it all comes down to sex.  Female dobsonflies size up potential mates according to the size of his mouthparts, and in the world of the dobsonfly, bigger is definitely better!  The males with the biggest mouthparts are the sexiest, most desirable males, so some dobsonflies have evolved truly massive ones.

So a male with giant mouthparts mates with a female with more reasonably sized mouthparts to produce eggs.  Those eggs then hatch and these crawl out:

Hellgrammite (Corydalus cornutus)


Now I love hellgrammites and find them completely fascinating.  I am always thrilled to find these in the streams I work in and I can spend hours watching them.  Even so, I’ll be the first to admit that these are some truly vile looking larvae.  They’ve got big, strong mandibles they use to rip apart their prey and they are formidable predators.  They’ve got a pair of hooks on each of two fleshy prolegs on the back end (more about these in a moment) that stick to your fingers or clothes like burrs.  They’re big larvae too.  The hellgrammite in the photo is nearly 3 inches long!  And then there are the long, spindly gills sticking off the sides of the abdomen that give them an alien look.  These do nothing to diminish their threatening appearance and I think it makes them look like big, aquatic centipedes.

But those hooks and gills are also part of why I love hellgrammites.  If you’ve kept up with my blog, you know that my research broadly involves respiratory behaviors of aquatic insects.  Judging from the adaptations hellgrammites display and the habitats they live in, they need a lot of oxygen to survive.  That’s where the hooks and the gills come in: they both help the hellgrammite get as much oxygen from the water as possible.

Let’s consider the hooks for a moment.  If you’re an aquatic animal that requires a lot of oxygen, there is a specific type of water that is best suited to your needs: cold, turbulent, fast flowing streams or rivers.  That’s exactly where you’ll find hellgrammites, clinging to rocks right out in the areas of the strongest flow in cool or cold streams.  However, a giant three-inch long larva, even a flat one like a hellgrammite, is going to have a hard time holding onto the rocks when there’s water slamming into it constantly.  So, they’ve got these:

hellgrammite hooks

Prolegs and paired hooks at the posterior end of a hellgrammite.

Those little hooks grab a hold of the rock so that they aren’t ripped off the substrate and washed downstream.  Hellgrammites are also usually found under big rocks in these fast flowing streams, so the currents they experience are weaker than those on the upper surface of the rock.  Those little hooks aren’t always enough to keep a large hellgrammite in place if they venture out onto the top of the rock.

Hellgrammites are highly adapted for collecting oxygen from the water as well.  If you recall from my post on aquatic insect respiration, insects living in turbulent, cold water maximize their opportunities to collect oxygen from the water.  If they expand their exoskeleton into gills, their surface area increases and they can absorb as much of that relatively abundant oxygen as possible.  Hellgrammites have a lot of extra surface area in their gills.  The feathery looking gills sticking off the sides are rather immobile and simply increase the surface area.  The other set of gills, the puffy dandelion fluff looking ones, have muscles attached to them.  When a hellgrammite become oxygen stressed, it can wave those gills around through the water:

Waving the gills around is a form of ventilation and allows the hellgrammite to extract as much oxygen from the water as possible, especially under less than ideal situations.  The gill movements stir the water around the hellgrammite, pushing deoxygenated water away from the body and bringing oxygen-rich water into contact with the gills so that it may be absorbed.  Behavioral ventilation of this sort is common in aquatic insects and gill movements like this have been recorded in several species, especially within the mayflies.  Still, I can’t help but marvel at just how beautiful the hellgrammite gill movements are!  I hadn’t ever seen this behavior before I noticed it in the insect trading session and I was amazed.  I found it shocking that something that ugly could also have such a stunning characteristic.  It was almost hypnotic watching the hellgrammite pulsing its gills and I could have watched it for hours.

But then I was snapped right out of my gill-inspired reverie when the hellgrammite started to swim around the jar:

I don’t know about anyone else, but I find this sort of abdomen flicking, backwards swimming kinda creepy.  Crayfish do it too and it’s just bizarre.  Doesn’t that look like rather inefficient way to maneuver around your environment?  I can’t easily come up with a reason why this sort of swimming would have developed, though I’m sure there’s a good explanation.

Yep.  Hellgrammites are appalling to look at, but they are amazing in so many ways that I have to love them anyway!  I hope I’ve given you at least a little taste of my appreciation for these monsters of streams and rivers.  I’ll probably describe my plan for making a horror movie called “Hellgrammite!” at some point in the future.  I am sure you are all eagerly looking forward to hearing all about it.  It’s going to be fantastic!  :)


Unless otherwise stated, all text, images, and video are copyright © 2010