I would like to introduce you to my little friends, the soldier bugs.
These little buggers have been a wonderful insect to learn how to rear. For one thing, as predators, they are highly responsive when displayed. Like goldfish, when you feed them little scooby snacks, they tend to feed on what you feed them right away. Even as young nymphs, they seek out food and stick their proboscis into their prey and get down to business without much ado.
As young nymphs, they are happy to receive soft-bodied aphids. As they mature, though, their palate becomes more sophisticated, and they will only respond to larger prey such as small caterpillars, housefly maggots, and hide beetle larvae.
For some unknown reason, they did not feed on earthworms that I gave to them; it appears as though the earthworm skin may be too tough for them to penetrate. I suspect that the earthworms might have been prone to crawling too much. And who wants to your meal to squirm? However, I did not try to feed them young earthworms.
Unfortunately, these little predator-buggers are damn expensive to buy as eggs through a bio-control supplier. If you are one of the rare people who actually wants to rear them, I recommend waiting until they can be collected in the summer. I personally have never wild-collected Podisus, but I’ve had good luck collecting and rearing wild-collected assassin bugs (a close relative). Both species are usually readily available in flowery meadows, and they can be reared using similar methods and host species.
Another place you might find soldier bugs is in a garden where fine cabbages are grown.
If you can’t obtain them yourself, let me at least tell you a thing or two about this delightful insect. Soldier bugs are true bugs, meaning they belong to the Order Hemiptera, or “half-winged”. Like other hemipterans, they do not enter a complete metamorphosis. In other words, they do not create a cocoon or a chrysalis. All they need do to become winged adults from wingless mature nymphs is shed their skin. It’s actually kind of spooky. One day I had wingless nymphs, and the next day I had winged adults that looked totally different from each other, and I thought that the petri dish had been infiltrated somehow.
Soldier bugs will teach you a lot about how insects are able to capture and dominate different insects at different stages of their development. For example, soldier bug nymphs feed readily on green peach aphids that feed also on cabbages. As the nymphs grow larger, though, you can introduce them to more “difficult” foods such as fruit fly maggots, young hide beetle larvae, and of course cabbage butterfly caterpillars.
In petri dishes, though, you must be careful to separate the nymphs or else they will cannibalize each other.
Beyond life cycles
One of the reasons I am so fond of the soldier bug is because it is one of the first species that showed me the direct connections between food consumption and food production. If I didn’t have enough cabbage, I couldn’t produce enough cabbage butterfly caterpillars. Without sufficient caterpillars, it was near impossible to sustain a soldier bug colony because you need copious amounts of caterpillars (i.e., protein) to coax the females into laying viable eggs which, bby the way, are worth 60 cents an egg by typical biocontrol supplier standards.