These tiny insects give birth to generations of all-female offspring. Until autumn, when they also produce males — a remarkable case of female reproductive autonomy.
This is alluded to indirectly in your essay, but a major advantage of parthenogenetic production of females is that it more or less doubles the population growth rate. Only females can contribute to the future population because only females can produce more aphids. Males are a waste in this context. Because aphids are everybody's favorite lunch, this extreme population growth rate, in effect, outruns mortality by predation (think aphid lions, parasitic wasps, ants, fly larvae, etc).
I don't know if woolly aphids do this, but in some aphid species, crowding induces the development of wings in some of the parthenogenetic offspring. These winged females then fly off to found new colonies.
As you showed for woolly aphids, aphids in general are really fantastic creatures, unendingly interesting and surprising.
This is great, Walter. Thanks so much. I so wanted to write this, but the post was getting long. (So I opted for the plasticity angle.) But, yeah, this is fundamental to aphid biology. And I could write another 1500 words on the developmental biology going on inside these females. Then the ants! Very cool stuff. Thanks again!
That's an awesome question, Linda. I didn't really get into the reproductive developmental biology. But it's fascinating. I have a paper on that. I'm gonna send it to you (and I'll read more of it). But, basically, no, these are female clones of the adult female that develop inside her, then she pops them out like babies. Crazy for even an insect to do this.
I adore this essay. You have such a gift for making science and life in general both fascinating and discernible. The first time I ever saw these in large numbers was the first Covid year when I took the dog for her evening walk. They came up as a topic of "WTF are these?" during my recent Master Naturalist course, at which point I was introduced to them as "you mean those tiny little insects with blue tutus?" So now they're also Tiny Tutu Bugs in my neighborhood. Assuming they're the same beings. (The only thing I regret from that course is the implantation of the ever-present question "But is that a TRUE BUG?")
Unrelated: I seeded milkweed two weeks ago! Spent a day clearing thistles and quack grass out from all along the raspberry bed and put them in there. The sunflowers did well there this year, so I have hopes. 🤞🧡🌻(why no milkweed emoji?)
I am SO GLAD you've seen these. (I had a feeling you had.) So I'll compile a list of their names. Tiny Tutu Bugs is AWESOME! And, yeah, that "true bug" thing kinda erupts from time to time — almost like righteousness over the Oxford comma. 😀
I've not only seen them, I think I've eaten a fair amount. When they're around, they're AROUND. There are worse things to be made of, stardust and Tiny Tutu Bugs. I wish I could take a picture of them but that would be a real feat. I love the ones you got.
Bryan, maybe I’m missing something obvious, but if only females hatch in the spring, and they only produce more females, where the males that mate with the females in the fall come from?
No worries, Brian. Lots to follow here. So those males come now as part of the seasonal switch from asexual (clonal) to sexual reproduction. The shorter days trigger the sisterhood of females to produce females AND males in the fall. And either males or females (or both) have wings in this generation -- so they disperse on the winds and find mates (and don't necessarily mate with their siblings).
Thank you Bryan. I have seen the airborne fuzzballs, grabbed a few to view closely. What an interesting and enlightening story! One more reason to appreciate the wonder and diverse lives of insects that live around us.
Outstanding to read. We had these in our yard in Seattle and I wondered about them. Of course, way more interesting than one would think at first glance. Thanks. David
Glad you're seeing them, David. Yeah, this time of year I get reports from all over the continent, including the Pacific Northwest. I suspect they'll be flying there into November or December or so.
A fantastic article--thanks Bryan! I had no idea that the fuzzy blue-butts were flying aphids. I knew a little bit about aphid reproduction from Oleander Aphids--I've spent a lot of time with milkweed--which have similar reproductive cycles. I remember reading that once one generation is born the next is generation gets birthed almost simultaneously. It all happens so fast. Each generation has the next generation already formed in their bodies. Wild stuff these aphids. Thanks again!
Thanks so much, Nina. Yep, that's aphid reproductive biology -- we can have multiple generations existing together. I recall reading somewhere something to the effect that an aphid "giving birth" at the base of a plant stem can be a great grandmother by the time she ascends to the top of the stem. Something like that. They are indeed prolific -- and indeed prey to other insects and vertebrates.
Find them all over my Tuscan kale, which bums me out every year. I have a new found respect. If you have tips for reducing their infestation on kale, I would love them.
This is alluded to indirectly in your essay, but a major advantage of parthenogenetic production of females is that it more or less doubles the population growth rate. Only females can contribute to the future population because only females can produce more aphids. Males are a waste in this context. Because aphids are everybody's favorite lunch, this extreme population growth rate, in effect, outruns mortality by predation (think aphid lions, parasitic wasps, ants, fly larvae, etc).
I don't know if woolly aphids do this, but in some aphid species, crowding induces the development of wings in some of the parthenogenetic offspring. These winged females then fly off to found new colonies.
As you showed for woolly aphids, aphids in general are really fantastic creatures, unendingly interesting and surprising.
This is great, Walter. Thanks so much. I so wanted to write this, but the post was getting long. (So I opted for the plasticity angle.) But, yeah, this is fundamental to aphid biology. And I could write another 1500 words on the developmental biology going on inside these females. Then the ants! Very cool stuff. Thanks again!
Wow. Love this essay, Bryan.
Is there any chance the zygotes (or whatever aphids have that are zygote-esque) change gender very early in this process,?
That's an awesome question, Linda. I didn't really get into the reproductive developmental biology. But it's fascinating. I have a paper on that. I'm gonna send it to you (and I'll read more of it). But, basically, no, these are female clones of the adult female that develop inside her, then she pops them out like babies. Crazy for even an insect to do this.
Thanks!
I adore this essay. You have such a gift for making science and life in general both fascinating and discernible. The first time I ever saw these in large numbers was the first Covid year when I took the dog for her evening walk. They came up as a topic of "WTF are these?" during my recent Master Naturalist course, at which point I was introduced to them as "you mean those tiny little insects with blue tutus?" So now they're also Tiny Tutu Bugs in my neighborhood. Assuming they're the same beings. (The only thing I regret from that course is the implantation of the ever-present question "But is that a TRUE BUG?")
Unrelated: I seeded milkweed two weeks ago! Spent a day clearing thistles and quack grass out from all along the raspberry bed and put them in there. The sunflowers did well there this year, so I have hopes. 🤞🧡🌻(why no milkweed emoji?)
I am SO GLAD you've seen these. (I had a feeling you had.) So I'll compile a list of their names. Tiny Tutu Bugs is AWESOME! And, yeah, that "true bug" thing kinda erupts from time to time — almost like righteousness over the Oxford comma. 😀
I've not only seen them, I think I've eaten a fair amount. When they're around, they're AROUND. There are worse things to be made of, stardust and Tiny Tutu Bugs. I wish I could take a picture of them but that would be a real feat. I love the ones you got.
You know the Oxford comma saves lives, right? 🤗
I'm a slow convert to Team Oxford Comma (a refugee from Team AP Style dogma).
I am steeped in Chicago Manual of Style. 😀
My undying favorite argument for the Oxford comma: https://languagelog.ldc.upenn.edu/nll/?p=3438
Why no monarch emoji!?!? Both would be awesome though!
Mind blown, thank you!
Thanks, Jackie. Mine as well!
Bryan, maybe I’m missing something obvious, but if only females hatch in the spring, and they only produce more females, where the males that mate with the females in the fall come from?
No worries, Brian. Lots to follow here. So those males come now as part of the seasonal switch from asexual (clonal) to sexual reproduction. The shorter days trigger the sisterhood of females to produce females AND males in the fall. And either males or females (or both) have wings in this generation -- so they disperse on the winds and find mates (and don't necessarily mate with their siblings).
Ah. Ok. Got it now. So much going on there. Amazing.
Inspirational. Thank you. You explain well how important it is to appreciate the small things.
... and so many of those small things out there! 😀💜
Taking the matriarchy to a whole new level! 💙
Yeah, I wish I had used "matriarchy" in the essay!
I learn so much from you, Bryan. Thanks for doing the research and putting it all together. You be the best!!
No YOU are the best!!! (And I added one more exclamation point that you did.) 😆
Feel the hug, man. Feel the hug.
Thank you Bryan. I have seen the airborne fuzzballs, grabbed a few to view closely. What an interesting and enlightening story! One more reason to appreciate the wonder and diverse lives of insects that live around us.
Yay! I'm so glad you got up close and personal with them, Gayle! (I need to get better photos of them.) Send my regards to the gang!
Thankful to learn all this - I'm often speechless at the beauty of it. Grateful for your sharing.
Almost as wonderful as birds, huh, Jo? 🤣
Outstanding to read. We had these in our yard in Seattle and I wondered about them. Of course, way more interesting than one would think at first glance. Thanks. David
Glad you're seeing them, David. Yeah, this time of year I get reports from all over the continent, including the Pacific Northwest. I suspect they'll be flying there into November or December or so.
This is...wonderfully weird.
Ha! (I'll bet you've seen them in the gardens!)
Yes, I am hooked
A fantastic article--thanks Bryan! I had no idea that the fuzzy blue-butts were flying aphids. I knew a little bit about aphid reproduction from Oleander Aphids--I've spent a lot of time with milkweed--which have similar reproductive cycles. I remember reading that once one generation is born the next is generation gets birthed almost simultaneously. It all happens so fast. Each generation has the next generation already formed in their bodies. Wild stuff these aphids. Thanks again!
Thanks so much, Nina. Yep, that's aphid reproductive biology -- we can have multiple generations existing together. I recall reading somewhere something to the effect that an aphid "giving birth" at the base of a plant stem can be a great grandmother by the time she ascends to the top of the stem. Something like that. They are indeed prolific -- and indeed prey to other insects and vertebrates.
So cool! Thanks again! ;)
Find them all over my Tuscan kale, which bums me out every year. I have a new found respect. If you have tips for reducing their infestation on kale, I would love them.
I'm no gardener. Sorry, Mary!
Wow, amazing. Thank you for writing this!