Insect Larvae Guides?

What with the lockdown in the UK, like a lot of the country I’m currently doing a lot more gardening! Realistically though, this means taking photos of bugs…!

One group which I’m finding a lot of but I’m not very good at identifying are insect larvae (this one, for example: It’s not something I’ve ever really come across, and I’m at a loss as to how even to narrow the ID down! Butterflies, moths and ladybirds are mostly ok, but beyond that I’m lost.

Does anyone have any resources that can help with larvae identification? Maybe websites or field guides?

Thanks very much!


I would recommend putting up observations, and go as far as you can with ID. Then when it gets IDd to species level, ask those who can ID that far what they use or can recommend as far as guides or literature go. Often there will be guides specific to your part of the world, and perhaps have a search through your local library catalogue via their website. They might be closed for loans, but searching their stocks are likely to reveal resources of local applicability…


Ooh that’s a good shout. I’ll have a look around the local libraries. Thanks @kiwifergus!


You’re welcome!

Kia kaha, stay safe…!


Some general larval insect guidelines I picked up from iNaturalist users:

  • No legs = flies
  • 3 pairs of true legs and 3-5 pairs of prolegs = lepidoptera (butterflies/moths)
  • 3 pairs of true legs and more than 5 pairs of prolegs = sawflies
  • 3 pairs of true legs and no prolegs: beetles
  • 3 pairs of true legs, massive mandibles, no prolegs = probably lacewings, antions or owl flies
  • 3 pairs of true legs, massive mandibles, almost lice-like body shape, in water = probably dragonfly/damselfly
  • 3 pairs of true legs, no mandibles, almost beetle-like body shape but the wings are short = stinkbugs/shield bugs/true bugs

Thanks! Great tips. Now if someone could turn this into a manga I’d remember it even better. Visual learner here.


If you find a fly larva on a plant with aphids on it, it’s likely a hover fly from the subfamily Syrphinae. They often have patterning, and can also by found in early spring under leaf litter before they come out of hibernation. There’s a guide for the UK here, and I’ve been working on collecting images for North America here.


“Larvae At Work”? :stuck_out_tongue_closed_eyes:

You can view them visually by going to one of those taxon’s pages, then the photo gallery for that taxon and filtering on life stage.


Yeah, and sometimes they look really cool! All slug-like and partially translucent.
I’ve yet to view one myself, though.

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Here are some mentions of guides of diptera larvae in UK.

UK Syrphid larvae guide

UK Barkfly key (those larvae are less caterpillar-like, though)


I can’t recommend any specific books but Buglife have an online shop which has some books. There are even more books if you search the whole NHBS site

Buglife also have an “identify a bug” page. I’ve not tried it though.

Naturespot has caterpillars of butterflies, moths & sawfly (though it doesn’t include all species).


“Larvae at Work” delightful title. Good reminder, I use the taxon pages for caterpillars, but I should use them to discover beetles, bugs, and other mysterious larva.

Visual examples using filters in the photo galleries


There’s also body positions and movement: Eg., some sawfly larva hold their bodies in “S” positions (with their butts in the air), geometroid moth caterpillars have an “inchworm” walk, and antlion larva will scoot backwards


Yes some of them can really move. Here’s a sawfly dance troupe I observed.


I’m not good with larvae at all, but I do know that Noctuid larvae (cutworms) are very difficult to identify, even to Genus. And many of them have never even been recorded. Just for your information. Good luck!


After two decades working as an entomologist, I still struggle with identifying insect larva. They can be tricky, and I often require some time with a microscope and a good key to even get them to the order and family levels (I use Immature Insects, Frederick Stehr, but it is a very expensive set of books). Identifying larvae further than that is often beyond my ability and I have to send specimens to qualified specialists. While teaching undergraduate entomology classes for non-entomologists I discovered a great webpage for Dr. John Meyer’s general entomology class at North Carolina State University:

His class includes an insect collection, and his website has a great beginning key for insect Orders for both adults ( and larvae ( Hope this helps, and happy exploring.


For the visual learners, here’s a neat guide -



These guides are great. Are any wikis aggregating these?

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That’s just what I needed! :smile: