Category: parasitic wasps

nanonaturalist:

I was finally able to ID some of my mystery observations on iNat! I always love finding “evidence” like this but having absolutely no idea what they are. I had guessed that the top one (bright lime green) was an insect cocoon, and the bottom one (white cottony fluffy mass attached to a stalk of grass) was a collection of eggs.

The top photo was taken at Southeast Metropolitan Park outside of Austin in late January. iNaturalist Observation [link] is here. Turns out all I had to do was google “texas lime green cocoon” and viola! These are spinybacked orbweaver eggs! Spinybacked orbweavers are one of my favorite Texas spiders–they are so much fun to watch and I find them everywhere. Below are just a few of the ones I have seen recently–each photo is a unique individual.

image

The bottom two photos were taken in my backyard, also in late January. iNaturalist observation [link] is here. This one really had me stumped. I have seen several of these but just couldn’t figure out what they were. Nobody on iNat offered suggestions. I noticed the first ones towards the end of summer/early fall, and I assumed that they were likely eggs or a cocoon from one of the common insects/spider I find in my yard. I looked up what the eggs/cocoons for various species looked like, but nothing was even close. I had pretty much given up. 

Then last night, I was at the bookstore trying to find some African bird books for my November trip to Malawi and had no luck, so I consoled myself by leafing through the Texas Nature books to see if any were worth buying. I found one that was about Texas Bugs, and was an interesting guide of the most common arthropods you find here. Lo and behold, in the braconid wasp section, there was a photo that looked EXACTLY like this. 

In case you are not familiar, braconid wasps are the parasitic wasps that grow on caterpillars. You may be familiar with the Microgastrinae that have individual pupas hanging off caterpillars (photo taken at a bioblitz in east Texas in May 2015, observation posted here [link]):

image

It seems that other species in this family make super fluffy pupae–so fluffy that you can’t see the poor caterpillar underneath them. I had considered dissecting one of these fluffy masses, but decided against it for some reason. Now I really wish I had! If I’d seen a caterpillar in there, I would have known it was braconid wasps!

Another fun post to come across! I posted this in March 2017. I did eventually come across some more of those super fluffy cocoon piles, but the host was always long gone by the time I had found it. Braconids do not exclusively prey on caterpillars! I have seen some that will make their cocoons away from what they had presumably used as a host, so it seems there is no “right” way to be a parasitic wasp! 

I like this post because it shows where my learning curve really started to take off. Spring 2017 was the point in time when I started to CONSUME entomology content like it was malt vinegar and sea salt potato chips (and I have a bit of an addiction…). I also like that it shows that sometimes you learn through intelligence (my google abilities), and sometimes you learn just by pure luck (flipping through a book at a bookstore). And really, you need both!

Reposted July 14, 2019

bogleech:

While I love seeing people sympathize with insects, I’ve noticed an increasing trend in the insect groups of people who think killing their natural predators is a good thing to do. Come on! I don’t think these folks would advocate shooting a lion to protect a gazelle.

One particularly unfortunate example I keep seeing are people putting caterpillars “out of their misery” for being covered in parasitic wasp cocoons. It’s well meaning on paper, but what it really means is that a bunch of baby insects just died instead of only one, and those baby insects were a plant’s most important line of defense against the caterpillar.

Empathizing with living things is important, but you can’t play favorites or treat some as “bad guys” for fulfilling their whole purpose!

I need to dig through my photos to find the ichneumon wasp that emerged from a sphinx moth pupa I had. Absolutely gorgeous. I loved her. The pupa had become a different shape, and the inside is iridescent. She was perfect. Meeting her was so special because I had no idea who she would be. A true gift.

June 30, 2019

Somehow, a cuckoo wasp found her way into my house and got stuck. I did the “catch her with a cup!” trick, but she didn’t get mad or try to escape… because the cup still had some juice residue in it 😂 You can see her lapping it up. 

I don’t know too much about these wasps besides they got the name “cuckoo” based on their parasitic nesting behavior (like cuckoo birds who will lay eggs in other birds’ nests and take off), and that they are way too pretty 😍 

She flew away happily when I took her outside. I think she appreciated the snack! 

 August 29, 2018

Stunning Fossils Show Ancient Parasitic Wasps Still Inside Their Unfortunate Hosts:

thelepidopteragirl:

HOLY SHIT THIS IS SO COOL

Aaaaaahhhhhhhh!!!!!!!!!!!

I found a tussock moth caterpillar around my house with the wasp casings still attached. The weirdest part was that it was very active and it seemed almost normal despite the "rice grains." I didnt know that they lived at all after the wasps emerge so I was surprized to say the least.

I saw something like this recently as well (and I still have no idea what the things actually were). This is on an American Dagger Moth caterpillar:

image
image

I can’t remember if I actually touched them, but I seem to recall that they felt hard and rigid. And this caterpillar was still alive and active, happily munching away at boxelder leaves. I really have no idea what these things are, so if anybody knows (or has some crazy guess), PLEASE tell me!

By contrast, my poor Vine Sphinx baby didn’t really move after the braconid larvae popped out. He stopped eating and didn’t walk at all, but I know he was still alive because he would occasionally shift a little in how he was holding onto his stem, and sometimes would twitch a little. 

Caterpillar anatomy is a little weird though (well, all insect anatomy is weird). If the caterpillar only has a few wasps, and if the wasps didn’t eat through any essential organs, the caterpillar very well could live for a while without too much consequence. I have no idea if they can fully recover and pupate after parasitization though!

Photos from May 16 at the Colorado River in Austin, TX / Posted July 11, 2018

The braconid wasps that parasitized one of my Vine Sphinx caterpillars were “born” recently. This was my first time witnessing the whole process first hand, and I was horrified to see that even after the adult wasps emerged, the poor caterpillar was STILL alive, and for lack of a better host, it seems this generation of wasps planned to parasitize it again. I ended up putting the entire enclosure into the freezer. Seemed the kindest thing to do.

Still, really interesting. Nature can be pretty disturbing, huh?

July 10, 2018

Oh no! One of the Vine Sphinx moth caterpillars has parasitoids! This caterpillar looked perfectly normal last night, but today it was covered in braconid wasp cocoons. In the gifs, you can actually see some of the bare larvae (white wormy things) spinning their cocoons.

Unfortunately, these wasps will kill the caterpillar. In the top photo, you can see a white spot towards his head, in his side in front of his first proleg. That spot is a larvae digging its way out of the caterpillar.

I’ve seen the cocoons on some small caterpillars before, but I’ve never seen this in progress, especially not on a large caterpillar! It’s a little sad, but wow, so interesting. Can’t wait to collect the wasps!

July 5, 2018