National Insect Week

Despite my long absence, I haven't given up on this yet. I've been alternating between lazy, depressed, and high the last three weeks, but luckily I've stumbled across a good incentive to get back to it and maybe even finish a few partial posts rotting in the backlog.

This week (21-27) is apparently National Pollinators Week in the US. Well, pollinators don't really do much for me, but luckily England has done one better, and declared this National Insect Week. Obviously I'm nearly too late, but I see it as an excuse to write one or two posts at least.

I have much to say on spiders, particularly regarding my newest acquisition Latrodectus variolus, the Northern Black Widow spider. This is the most venomous species found in Canada (albeit rarely) -its native status meaning it is fully legal for me to keep. I'm on the hunt for a male, now.

But enough on spidery-goodness, we're here to learn about bugs! Bugs are pretty cool critters all around, and my admiration only grows with the more I learn. For the interested, "Life in the Undergrowth" is probably one of the most astounding documentaries -or even films- ever. The critters found therein are exemplary of the reasons I disdain people's need to believe in religious/supernatural experiences; our fellow lifeforms kicking around earth are so goddamn interesting.


Without further rambling, I bring you the horned worm, Manduca sexta. Despite having a giggle-inducing latin name, horned worms are great due to their large size and vibrant colours. Rare indeed is the bearded dragon or leopard gecko that will turn down a hornworm, and there are simply no bearded dragons who are too big for horned worms. These catterpillars commonly grow to 4", and like silkworms they do so quickly.

In the wild hornworms feed on either tobacco or tomato leaves, depending on their subspecies: tomato hornworms are restricted to tomato, while tobacco hornworms relish either plant. Unfortunately this makes them toxic to our reptiles, and so when bred as feeder insects, M. sexta are raised on a prepared diet similar at a glance to silkworm chow. Instead of being made up nearly entirely of mulberry leaves, the hornworm's diet is a complicated blend of agar, nutrients, and vitamins.

2L DI Water
40 grams agar
0.4 grams streptomycin sulfate
8 grams ascorbic acid
40 ml 10% formalin
8 ml pure linseed oil
20ml vitamin solution (see below)
one dry pack(see below)
Dry-Pack Ingredients:
160 grams wheat germ          32 grams Brewer’s yeast
72 grams Casein                   64 grams sucrose
24 grams salt mixture W        7 grams cholesterol
4 grams sorbic acid               2 grams methyl p-hydroxybenzoate
Vitamin Solution Ingredients:
450 mg nicotinic acid           105 mg folic acid
225 mg riboflavin                 9 mg biotin
105 mg thiamine                 105 mg pyridoxine
450 ml DDI water 

Hornworm chow: Not for the casual hobbiest. (by Purdue University)

Fortunately for those like me, with a borderline obsession of culturing insects, M. sexta chow is priced comparably with silkworm chow. The reason hornworms are so much pricier than silks is partially due to the fact that they eat so much more (having to reach a larger size in roughly the same amount of time), and also due to their more complicated breeding, which I'll delve into right this second!

When you decide to breed silkworms, you only have to show a little restraint. Let a few of them get large enough to cocoon, and presto! Hornworms are a little more specific in their requirements for getting it on. To a hornworm, weaving a cocoon out in the open, or even wedged into a corner, does not seem like a good idea. Hornworms know (not really, I'm anthropomorphising. Hopefully you already knew that) that a cocoon sitting out in the open is just a bird snack, so they dig. Dropping from their delicious tomato, they burrow a few inches into the soil and surround themselves with a translucent shell. A few weeks after pupating the moths will emerge. If the moths have adequate room, they will climb a vertical surface and dry their wings, enabling them to fly and feed. If the container is too small (only a few feet in volume) and the moths are cramped, they will not dry their wings, and will not fly or be able to feed independently. This inability to eat is because hornworm moths are flight-feeders. They lap up nectar with a super-long proboscis while hovering in front of a flower (or hummingbird feeder). If the moth is not able to fly, it must be hand fed (!) by uncurling the proboscis with a fine-tipped paintbrush or toothpick, and placed into a sugar/water solution.

Needless to say, my attempt at culturing these will be with a large cage for the moths.

After filling up on sugar water, the moths will get it on, and the female will deposit her eggs on the underside of a host plant (tomato/tobacco). In our world of culturing, those eggs will be collected and removed  from the leaves to hatch 4-5 days later (a much faster turnaround than silks, which often require a few weeks in the fridge to stimulate hatching). A little over a month later and those hatchlings will be ready to pupate themselves!

This is a project I'll likely be getting into at the store, as I don't have the space at home for a container more than 2'x2'x3', but it is one I'll be getting to before the end of the summer: once the hornworm supply dries up, I'll hopefully still be producing them.

For some more in-depth info, the Manduca Project has great some stuff for extending your hornworm knowledge.

Next up: Vermiposting, a post that's been languishing in my drafts for months.

1 comment:

  1. Ziggy says: NOM NOM NOM HORNWORMS!!!