Friday 5: Milkweed Predators

A few weeks ago, I helped a coworker do a training workshop for the Monarch Larva Monitoring Project.  She’s been doing MLMP for multiple years, so she knows more about it than I do, but I’ve really enjoyed being a part of the project since my arrival in North Carolina.  It was a lot of fun teaching the workshop too!  The attendees seemed really happy to be identifying monarch caterpillars in the classroom, then doing it some more outside.  I think everyone went home feeling a sense of accomplishment, so I considered it a success!

The day following the workshop was a Saturday and, since my coworkers and I have to take turns doing weekend shifts, it was my turn to work the weekend.  When it came time to take a break, I did what I never had a chance to do during the workshop: I took my camera down to the milkweed where the attendees had found so many of their monarch larvae and shot some of them.  It was raining a little, but that didn’t deter me!  And I’m glad it didn’t because I saw a ton of great stuff on that milkweed, including several predatory species that were presumably eating the excessively abundant oleander aphids:


Oleander aphids galore!

These predators included…



Ladybug eating an aphid

This is THE classic eater o’ aphids, and here you can indeed see one happily munching on an aphid.  It certainly had a lot to choose from!  It’s fun to remember that although so many people think of ladybugs as cute and adorable little beetles, they’re also predators that mercilessly chow down on other insects.  Nom nom nom!

Hover Fly Larva

There were several of these syrphid larvae on the milkweed:

Syrphid larva with aphids

Hover fly larva with aphids

According to our milkweed insect field guide (because what do I know about terrestrial fly larvae?), these flies are predators of aphids.  Go little fly, go!  Eat those aphids!  The more you eat, the more milkweed there is available for hungry little monarchs.  That fly will, as I understand, metamorphose into one of those great little yellow and black flies that hover a few feet above the ground.  I love everything about this larva, including the fact that you can see its digestive tract right through the exoskeleton.  Super cool!

Lacewing Larva No. 1

Lacewing with aphids

Lacewing larva with aphids

This lacewing wasn’t shy about its role as a predator and went scurrying about the leaves in search of aphids to eat.  I saw it catch and eat one, though I was so fascinated that I forgot to take a photo.  Oops!  Just imagine that lacewing with a nice, fat aphid in its mouth as it sucked down the aphid juice.  They’re fantastic little predators!  If you’re a gardener, these insects should become your best friends.

Lacewing Larva No. 2

Lacewing with aphid husks

Lacewing with aphid husk attire

Unlike the lacewing No. 1, lacewing No. 2 apparently felt the need for a disguise. If you look carefully you’ll notice that all that junk up on its back is discarded aphid exoskeletons, aphid husks!  I wasn’t able to find one of them, but some of these lacewings were positively covered in aphid husks so that you would never even expect an insect to be tucked away in the pile.  I am not sure whether these eat the aphids and then throw the husks on their backs (a sort of less permanent prison tattoo indicating the number of inmates this lacewing has killed) or scoop them up off the leaves and chuck them up there.  Either way, this lacewing was meandering more slowly around the leaf as it sought an aphid to eat than the lacewing above.  It was really fun finding two lacewing species with two totally different personalities!

And finally…

Itsy, Bitsy Spider


This was one of the smallest spiders I’ve ever seen!  It’s smaller than the aphids, and MUCH smaller than my fingers (which look positively enormous in this shot!), but it seemed to be going after the aphids nonetheless.  I can’t tell you anything more about this spider except that it was darling.  Look how tiny it is!  Adorable.

Milkweed is positively crawling with insects!  Apart from the aphids and their predators, I also saw ants herding aphids, a variety of wasps that seemed to be attempting to parasitize the aphids, some predatory flies, and a bunch of true bugs that were eating the milkweed.  Who knew that milkweed was such a battleground where every insect is in a life and death struggle for survival?  If you have milkweed in your area, I encourage you to visit it.  You’re likely to see some really cool things!


Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth

22 thoughts on “Friday 5: Milkweed Predators

  1. I shared this on The Monarch Butterfly Crusader. Thanks for this. Sorry I didn’t do the direct link. I cut and paste before I noticed the facebook icon.
    The Monarch Butterfly Crusader

  2. I really liked the larvae photos. It will be interesting to look out for predators next time I see some aphids. Usually I wash them off straight away with soap solution if they are in the garden!

    • You might never get the same sort of diversity of predators that we do where I work because we don’t treat our aphids and they can go wild on our milkweed. There are probably billions of them out there in the priarie right now! I suspect that washing them off would mean that you’re less likely to get the diverse predators population we see, but it will be interesting to look and see if that’s the case.

  3. Oh I love Milkweed! I love to photograph the insects buzzing around the flowers too. I really enjoy your blogs. Are there any beginning entomology books for newbies you’d recommend? Most of my ID info on picts I get from the web.

    • Are you looking for a field guide sort of book? If so, my favorites are the Kaufmann Field Guide to Insects of North America by Eric Eaton and the Field Guide to Insects and Spiders of North America by Art Evans. Both are excellent books for the beginner. If you haven’t seen online though, you really should. It’s an incredible reference! And it has a hundred times the species listed that any field guide could ever hope to have. I highly recommend BugGuide! It can be a little hard to navigate at first, but you can upload photos for the volunteer identifiers to ID for you. It’s free and you usually hear back right away. If you’re interested in the insect on milkweed specifically, there’s a great book for that! You can find it here:

    • In addition to an ID book or two, you might look for “Practical Entomologist” by Rick Imes. It’s a good intro to insect lives, behavior, attracting them, rearing, collecting. It has some keys for ID, but also has a bunch of projects to try, such as running beetles through mazes and training bees to come to different shapes. Lots of good drawings and photos. I think it’s aimed at junior high level, but I found it as an adult, and it’s not patronizing at all. It’s been around for 20 years, so it should be easy to find a used copy.

      • Thank you for mentioning this book! That was actually one of the books I bought (new at the time!) that I used back when I first decided I wanted to be an entomologist to help me learn how to make a collection and identify insects. It’s a great book! Very well written and contains a lot of good information about a wide range of entomological topics.

      • oh that’s awesome! I’ll have to look for Practical Entomologist… sounds fun. I’ve got lots of insects here in my garden.

  4. Thank you, I had seen hover fly larvae and didn’t know what it was. It’s fun to use a hand lens to watch them consuming aphids. Of course, the aphids are cute when you watch them through a hand lens.

  5. I love reading your stuff…since August is here and wasps are agitated, do you think it is best to leave them alone? My dog Max received multiple stings as a result of loud barking in the proximity of our back yard nest…now I’m fearful about how to handle the situation. I took the advice of someone and hung a fake nest near-by…there’s the idea that they are territorial. Anyway, I want to know if they are beneficial to the overall health of my back yard garden. Thanks for your expertise.

    • Honestly, if your dog has been stung then it’s likely that you will be stung too. If their stinging continues, you might want to consider calling someone in to deal with them because it sounds like their colony has gotten quite large and aggressive. The wasps likely provide pollination services for your garden, but if a barking dog is enough to set them off, you’re risking your health and safety by allowing them to remain where they are. I normally don’t recommend extermination of insects, but wasps can be dangerous if there are enough of them, and it sounds like you might be at that point. You’d be better off putting out a native bee house and planting butterfly attractive flowers to attract pollinators to your garden than leaving a nest of aggressive bees there.

  6. I keep meaning to get Bug Eric’s Kaufman guide, I have to do that immediately. But I loved this article. It’s been harder to find aphid-clear milkweed for my caterpillars every day. do you know whether I should bother looking for clean milkweed? I didn’t want to introduce predators into my caterpillar house. I actually thought that the yellow dots were moth eggs until I saw my photograph in the computer. And the number of photos of the aphids are increasing on Google+. Hopefully, I’ll find my first life viewing of lacewings (in any stage) when I inspect the milkweed this week. So thank you a dozen more times!

    • Oh, Eric’s Kauffmann guide is great! You should definitely get a copy of his book – he’s a super nice guy who wrote a great field guide. As for bothering to look for aphid-free milkweed… I don’t know! I’m not a garden pest expert by any means and my knowledge is quite limited in this regard. My gut reaction, however, is that trying to avoid contaminating your space with aphids is probably a good plan. Once they infest an area, it can be difficult to remove them.

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