Petite Genus Micromus brown lacewing
This week’s crawly is another prime example of “good things come in small packages.”
Meet the petite Genus Micromus brown lacewing.
At just about one-quarter of an inch in length these voracious predators and crop and garden protectors can easily go unnoticed.
Micromus lacewings are so teeny you could fit just about one and one-half of a micromus lacewing on top of one of our typical green lacewings.
In other words, they really nailed it with the “Micromus” scientific moniker.
While all species of lacewings are highly beneficial insects who devour a lot of “pest” soft-bodied arthropods during their (relatively) brief lifespans, micromus are particularly impressive for their “size to diet” ratio.
Micromus specialize in feeding on acarines (mites), scale insects, psyllids (plant lice), aphids, thrips and the eggs of lepidopterans and whiteflies.
They are so good at…well, being good, that the species Micromus tasmaniae has been mass-bred for biological pest control in Australia.
Once again, aren’t we lucky to have these awesome arthropods right here in our own backyards?
We may or may not have many of them. Of the 9,000 micromus sightings on iNaturalist, only 25 of them are in Oregon. However, at a glance micromus look a lot like the smaller caddisfly species – such as net spinning caddis.
In fact, when I first spotted our pictured micromus it was about a foot away from a net spinner and even I assumed it was “just another small caddisfly.”
Because you really have to look sharp (and possibly even through a magnifying glass or macro lens!) to identify micromus just laying about it’s a pretty safe bet we have many more than have been recorded.
Pro tip: If you see what looks like a teeny caddisfly munching down on an aphid – it’s a micromus! Caddisflies are not carnivores in their adult form.
All that said, micromus definitely fall into the “a rare and delightful find” category. Recall, there are only 9,000 recorded sightings in the United States, compared to 69,000 recorded sightings of micromus’ verdant cousins green lacewings.
There are only eight species of micromus in North America, but they can be found in all the contiguous United States.
It’s quite possible micromus may begin to become more populous in the US as word of their wicked effectiveness as biological control agents spreads.
Here are some fun facts on just how effective micromus are at dealing with aphids:
● Both adults and larvae are predatory
● They aren’t fussy eaters and will dine on all species of aphids
● They can handle the cold so have longer lifespans than green lacewings (and many other beneficial insects)
● Female micromus lay a large number of eggs over their lifespan
● They play well with other lacewings, that is to say lacewings won’t predate each other, but will find their own patch as a rule
But really, how beneficial can a teeny, tiny predator be? These delicate beauties have the appetite of a grizzly bear! A single adult micromus will eat up to 100 aphids – per day! Growing baby micromus need even more food and will consume up to 130 aphids per day.
Our amazing wee lacewing neighbors may have green eyes and warm red-brown lacy wings, but they are absolutely worth their weight.