Come with me on a houseplant safari...

Imagine this scenario: you know so little about houseplants that you only have the vaguest idea that most of them possess leaves. You can probably identify a couple of species out of hundreds, at a push. This may be unthinkable for our beloved houseplants, but when it comes to the creatures that live on and around them, it is the norm. If you post a picture of any creature around your plants on social media, the response is often "KILL IT WITH FIRE!"

And yet, being able to correctly identify one species of fauna from another comes in extremely useful, whatever your level of houseplant expertise. That way you know the difference between species have the potential to harm plants and those that are either harmless or beneficial. It saves us treating plants unnecessarily, and allows us to pick the right solution to the creatures that we don't want living on our plants.

So, grab a hand lens and come with me on houseplant safari. Here are a few things you may spot along the way... 

Mites are tiny arachnids: there are thousands of species, each with their own unique habits and appearance. Some live in birds nests, on honey bees, and even on the bodies of slugs (have a look next time you see a big slug, you might be able to spot some scurrying about). Not to mention that there's a whole genus of mites that live on human skin. The mites we are most concerned with are those that live and around on plants, but not all of these cause harm, and some are used as biological controls for other houseplant pests. 

The red spider mite, aka the two-spotted spider mite (Tetranychus urticae), is the most familiar, and most feared, because it's a sap-sucking mite that will damage houseplants. The mite itself is too small to see with the naked eye, unless you have incredibly good vision: instead look for white grainy deposits on the undersides of the leaves, especially along the midrib, made of the shed skins of the mites. In severe infestations, webbing will be present (if things have reached that point, the plant is probably beyond saving). The mites themselves will be visible under 10x magnification or more, but they are usually not bright red: more of a rusty brown. (Here's a good video of their lifecycle, and I dedicated a whole podcast episode to this mite). 

If you don't have a lens to hand but still spot a scarlet red mite scurrying about, especially on terracotta pots that have been outside in the sun, you're most likely looking one of a suite of species known as the red velvet mite (pictured above, at great magnification). The good news is that none of them feed on plants. 

Spotted a mite with the naked eye that looks like a teeny white balloon on legs moving at speed across soil or plants? I'd bet you've seen a mould mite (Tyrophagus putrescentiae). As the name suggests, they feed on mould and will not harm your houseplants, although you may wish to control numbers if they set up home in your kitchen cupboards.

Turn your hand lens on the soil itself and you will probably spot some writhing translucent worms with black heads, just over half a centimetre long: these are the larval stage of the fungus gnat, from the family Sciaridae. The adults that end up floating around our plants surely count as the most annoying of all the creatures you'll meet on a houseplant safari: they are drawn to the carbon dioxide in your breath. 

You may also spot hypoaspis mites (Stratiolaelaps scimitus), a predatory mite used as a biological controls that's around 1mm long and pale brown in colour. Finally, if you lift up a nursery pot and find small, light coloured creatures that spring up when you touch them, you have a colony of springtails. These are part of the cleanup crew, subsisting on decaying plant material. I talk about these handy little creatures in On The Ledge podcast episode 167.

I have merely scratched the topsoil here, but I hope I've inspired you to think a little deeper about the houseplant biome and its occupants.

This blogpost was taken from The Plant Ledger, my twice monthly email newsletter about the UK houseplant scene. Subscribe here and get my free in-depth guide to fungus gnats.