Thank you so much for your writings. Hey, how long are they attached? How long from then till she lays the eggs and then how long until they hatch? As Spock would say, fascinating!
Thanks for the questions, Michael — and the opportunity to write yet more on these moths. So:
- Duration of Copulation — It varies by species, and perhaps other factors like ambient temperature (or even intruding biologists like me), but probably hours (rather than minutes). I believe that among many of these winter moths, the female copulates only once (or very few times) and the male may have multiple copulations over a course of a few days.
- Egg-laying — I'm not sure on this one, but typically in Lepidoptera the females don't wait long at all. In the case of winter moths, she might walk a way to find a spot to lay her eggs near leaf buds. But egg-laying is mostly the same day, often within minutes or hours.
- Eggs overwinter, then hatch in spring to spring to coincide with bud break and fresh leaves for feeding. They generally prefer tender, new leaves over older, hardened leaves (which over time might even build up higher chemical defenses against herbivory)
Thank you for the regional info on winter moth species and the details on the constraints of evolutionary pressures. (Change is coming. Our warming climate is a challenge for chickadees and others. Hard for me to face.)
Mixed benefits there and I share your sentiment. Warming will hurt some species by forcing them northwards (and hopefully they can literally move as fast as the change- most trees won't. But other species may prosper by the extension of their current range as well as population declines in their predators ( pine bark beetles may move north leaving southern pines to celebrate. Bears may move north, leaving the caterpillar grubs they feed on to multiply and consume the grain crops in the Breadbasket states, which plants will resent that mightily. Evolution (assisted by our own genetic engineering) will sort it all out eventually one hopes. But climate crash possibilities can't be ruled out and then it will be rough sledding for all of us.
Ultra-light body and large wings still seems to me to fall short of an explanation for the ability of any ectothermic animal to operate in the middle of winter. I'm surprised on looking it up that their range extends into really cold regions of Europe. Is there some habitat specificity that helps out? (Meadow or open areas on the western edge of forests where they might get some warming from winter sun, etc?) Some sort of metabolic hack to go along with the aerodynamics?
Your skepticism is warranted, Timothy. These moths do fly at temps just below freezing. But not much lower. And, yeah, they aren't as abundant in mid winter as they are now.
I'd need to read more work on the thermal physiology involved here. But there is some evidence (in vitro) that metabolic activity (your well-put "thermal hack") doesn't differ much between winter-flying geometrid moths and other winter- or summer-flying moths. But this warrants more scrutiny. I can dig up a paper for two for you on this. Most of the flight, the research suggests, comes from low wing loading in these species. That Marden paper (1995) cited below will have more on this. But I'll poke around in the literature I have.
And, yeah, outside of their peak flight periods, especially in January or even February, flight is probably more circumstantial -- coinciding with warmer, sunnier days, for example, or generally mild winters or, often the case, porch lights.
I wonder if Sue Cloutier might have anything to add in this regard.
Dec 21, 2023·edited Dec 21, 2023Liked by Bryan Pfeiffer
What this brings to mind is a favorite author and his book on insect thermodynamics;
Bumblebee Economics by Bernd Heinrich. It is on my bookshelf but my memory of the details have vanished from my fading memory. His writing is based on science yet is very accessible for the common reader.
Oh, Bernd's book. Right. I might have it! :-) (When he was emeritus, Bernd and I used to share an office at UVM -- he was never there, always outside!)
This is really interesting--the thought that even a very small tweak in body/wing design might enable flight on a tight energetic budget is really intriguing. I would guess combining this with your other observations--that the male moths are essentially climatic opportunists who take advantage of winter variance (a few warm days, days with abundant sunlight if low air temperatures, etc.) and who can confine flight largely to mate-seeking. (Makes me wonder if they also have really restricted range, e.g., that there's something that clusters the wingless females and males in relatively small microenvironments so the males don't have to do a lot of surplus flying to try and find the females.)
Makes me wonder also if they aren't essentially an Ice Age-adapted holdover. If they aren't physiologically maladapted to a warmer winter, they might find that over time, warming conditions in the Anthropocene bring some unwanted competitors and predators into their private winter retreat.
Interesting topic. I think this Marden paper is the best fit to Timothy Burke's question about a metabolic hack. Both the biochemistry (enzyme, muscle temperature optima) and mechanical traits (stroke length, etc.) are part of what allow flight within a characteristic range of temperatures. Note that the ranges of both summer and winter moths are limited and only partly overlapping. This is in keeping with what we know about enzyme activity vs. temperature. Muscles are enzymes too, in effect--- they cleave ATP to achieve filament movement, and evolution can adjust the temperature optimum for this to happen. To cite an example from a different group of animals, antarctic ice fish and hot springs fish are both able to move and behave "normally" at the range of temperatures to which they and their enzymes are adapted. Transfer each to the other's environment, and I don't think the outcome would make either one smile. Another topic not touched on is that insect flight muscle is entirely aerobic, with some really cool anatomic and behavioral mechanisms for supplying the oxygen.
Thanks much for the supplemental perspective, Walter. You and Timothy will no doubt drive me to more literature — and perhaps a follow-up post.
Overall, the dialogue that follows many of my posts on Chasing Nature makes me appreciate Substack even more, and has made it all the more easier to abandon social media. It's tough even to read comments following my (non-controversial) essays in The Boston Globe.
I am ever grateful for the intelligence of the readers here, including those who don't agree with me. I hope it makes me a better writer.
Bryan: Thanks for this one. It and the solstice arrived on the first weekday morning in a long while when I have almost no work emails to deal with. Which gave me ample time to read and reflect. Flightless females and active winter insects reminds me of a story I was researching this time last year — on fireflies.
Bryan, you always have delightful surprises in store for me. I'm going to be at a hot springs this solstice, where if I'm lucky I might be able to see the stars (it's overcast here for weeks at a time in winter, which gets a lot of people down). But now I'm going to keep an eye out for moths. Happy Solstice!
I didn’t see stars or moths but did finally get some moonlight! Took my kid the long way home through the Bison Range (20,000 acres managed by the Confederated Salish & Kootenai Tribes) and saw a cluster of buffalo, a kestrel in flight, and four very active bald eagles. Love that place.
Love this one! Over at my rag we have an entomologist PhD who would love this essay! I learned more about moths in this one piece than I had from all my previous reading- All hail moths and the Insecta in general. They've got the lumbering tetrapodia beat all hollow!
And all hail the return of the light, my own favorite day of the year!
Dec 22, 2023·edited Dec 22, 2023Liked by Bryan Pfeiffer
Yes we are clumsy and won't be around for all that long, but at least we meant well and gave the world some neat inventions like Ziploc bags and electric toothbrushes. Yes, all hail the Insecta and especially the Ants, true rulers of this planet, good for another billion years at least!
How wonderful. What a lyrical and beautiful piece that manages to be quite educational too. I loved it! And couldn’t help but note the metaphor that many humans might find true of our motherhood, ultimate blessing though it may be: “it is the females that more often exchange their wings for the greater good.” Not always, of course, but there’s a bit of truth ringing there. Happy Solstice!
The author was of course speaking of insect females, when he wrote the quoted phrase. You may be referring to that. If you were speaking in the (metaphorical) context of human females, however, I’d argue that, given we (fortunate members of certain human societies) can consciously decide whether or how frequently to reproduce, we are thus capable of making childbearing decisions that we view as benefitting the greater good (whatever that may mean to us individually) rather than in service of our own reproductive fitness.
Indeed, I was referring to the insect female. The question of the common good among humans is really fraught, so I was not referring to it, even metaphorically.
Thanks, Rebecca. There is so much to explore on this topic. I'm no evolutionary biologist (mostly I'm just a guy with binoculars, an insect net, a pencil and notebook, and a few ideas). But I do hope to write more on female roles and burdens in reproduction. In some ways, this post on aphids is a rare example of females really running the show: https://chasingnature.substack.com/p/males-need-not-apply
Wow! The photos on that post are incredible - I've never seen anything like that mass of wooly aphids. Do they secrete this waxy, cottony cover for themselves en masse? And then emerge from it to go their separate ways in a different season? Or is this a structure they may build at any time of year?
And also fascinating to learn of this (potentially) female-directed reproductive life cycle. Nature is so cool.
In the 1970s, a naturalist living in the Panamint Valley of California, Derham Giulinani, brought a flightless, strap-winged female moth to the entomologists at the University of California, Berkeley. Giuliani had collected the active moth in mid-winter on the sand dunes of Deep Spring Valley in the eastern Sierra Nevada. Subsequently, several UC entomologists spent 4 years on expeditions under icy winter conditions, finally collecting a total of 17 more, largely using pitfall traps because the females are flightless. You can find one of their papers here: https://images.peabody.yale.edu/lepsoc/jls/1990s/1994/1994-48(1)8-Powell.pdf.
This is brilliant and fascinating, Bryan. You have a talent for narrating exotic couplings... We have winter moths (Operophtera brumata) in abundance here in the midcoast. Seems safe to assume that the flurry of moths attracted to the porch lights in December are the unwanted (if still fascinating) brumata? Are the Bruce Spanworms likely to be at the lights in November? Not sure if it's worth trying to "control" the invasive winter moths by dealing with those at the lights, and certainly don't want to harm any of the spanworms, but some favorite trees were munched pretty thoroughly last summer. Your thoughts?
Well, you know, to be honest, I wonder if we know for certain that they're O. brumata. I'll need to double-check, but I think it requires dissection to tell brumata from bruceata, which does indeed fly earlier (November) but is done flying here in Vermont by December. Even so, I wonder whether bruceata flies later on the midcoast.
I'm not sure we can trust all iNaturalist records on these two species -- even "Research Grade" records. Not only that, I wonder whether Alsophila pometaria was causing your tree damage. (Turns out that I did have a sentence in the essay about some of these geometrids being insect "pests" but struck it.) Which tree species got munched?
It might take a Maine forest entomologist who's spent time collecting and dissecting these moths to be certain exactly what you've got. But I'll ask around a bit.
Oh, yeah -- no (a "yeah-no"), I wouldn't defer to my knowledge. I was just about to email you to say that I did some poking around to find that all three of those species I mentioned are in Maine and can be pests. Bruceata do come to lights, but I've never seen them in big numbers. I hadn't known that brumata was sometimes such a problem in Maine! Yikes!
I'll always defer, Bryan, but will offer up little bits of info that come my way...
I'm willing to harass the winter moths at the light if it seems a rational, very local way to control them, i.e. in the yard at least. But I don't know whether those at the light represent enough of the population to bother with.
But let's not let this conversation descend into such matters. Enjoy the holidays, Bryan, and may the new year bring you more moths and memories.
Back atcha with moths and memories. I frankly don't know a thing about controls, but I suspect (as you do) that lights won't help, in part because the females obviously won't come to the lights and, I suspect, enough males will still be out and about ... you know ... being males.
Thank you so much for your writings. Hey, how long are they attached? How long from then till she lays the eggs and then how long until they hatch? As Spock would say, fascinating!
Thanks for the questions, Michael — and the opportunity to write yet more on these moths. So:
- Duration of Copulation — It varies by species, and perhaps other factors like ambient temperature (or even intruding biologists like me), but probably hours (rather than minutes). I believe that among many of these winter moths, the female copulates only once (or very few times) and the male may have multiple copulations over a course of a few days.
- Egg-laying — I'm not sure on this one, but typically in Lepidoptera the females don't wait long at all. In the case of winter moths, she might walk a way to find a spot to lay her eggs near leaf buds. But egg-laying is mostly the same day, often within minutes or hours.
- Eggs overwinter, then hatch in spring to spring to coincide with bud break and fresh leaves for feeding. They generally prefer tender, new leaves over older, hardened leaves (which over time might even build up higher chemical defenses against herbivory)
Wow! Thanks for the information. Just to think how all this evolved over geologic time if that's the right term. Like the song let's fall in love 🤣
Birds do it,....sloths do it........ Even educated winter moths do it!
Really appreciate it, Bryan.
Thank you for the regional info on winter moth species and the details on the constraints of evolutionary pressures. (Change is coming. Our warming climate is a challenge for chickadees and others. Hard for me to face.)
So we might even expect A. pometaria in Vermont in the not-too-distant future? You have them flying at your latitude? What about O. brumata?
I have had both at my lights in New Salem MA... north central MA.
Sue, if you're so inclined, see Timothy Burke's comment below -- and my reply. Maybe you'd have some insights.
Mixed benefits there and I share your sentiment. Warming will hurt some species by forcing them northwards (and hopefully they can literally move as fast as the change- most trees won't. But other species may prosper by the extension of their current range as well as population declines in their predators ( pine bark beetles may move north leaving southern pines to celebrate. Bears may move north, leaving the caterpillar grubs they feed on to multiply and consume the grain crops in the Breadbasket states, which plants will resent that mightily. Evolution (assisted by our own genetic engineering) will sort it all out eventually one hopes. But climate crash possibilities can't be ruled out and then it will be rough sledding for all of us.
i always learn something interesting from your blog.
Thanks for reading, Sandi!
Fascinating essay.
Thanks, Ray. Nothing like moth mating to stir the senses on the solstice! 😀
Ultra-light body and large wings still seems to me to fall short of an explanation for the ability of any ectothermic animal to operate in the middle of winter. I'm surprised on looking it up that their range extends into really cold regions of Europe. Is there some habitat specificity that helps out? (Meadow or open areas on the western edge of forests where they might get some warming from winter sun, etc?) Some sort of metabolic hack to go along with the aerodynamics?
Your skepticism is warranted, Timothy. These moths do fly at temps just below freezing. But not much lower. And, yeah, they aren't as abundant in mid winter as they are now.
I'd need to read more work on the thermal physiology involved here. But there is some evidence (in vitro) that metabolic activity (your well-put "thermal hack") doesn't differ much between winter-flying geometrid moths and other winter- or summer-flying moths. But this warrants more scrutiny. I can dig up a paper for two for you on this. Most of the flight, the research suggests, comes from low wing loading in these species. That Marden paper (1995) cited below will have more on this. But I'll poke around in the literature I have.
And, yeah, outside of their peak flight periods, especially in January or even February, flight is probably more circumstantial -- coinciding with warmer, sunnier days, for example, or generally mild winters or, often the case, porch lights.
I wonder if Sue Cloutier might have anything to add in this regard.
What this brings to mind is a favorite author and his book on insect thermodynamics;
Bumblebee Economics by Bernd Heinrich. It is on my bookshelf but my memory of the details have vanished from my fading memory. His writing is based on science yet is very accessible for the common reader.
The 2004 update is worth checking out. It has more research findings. I may purchase that one!
Which update? I can send you any lit you need.
Bumblebee Economics: With a New Preface Paperback – Illustrated, November 30, 2004
Oh, Bernd's book. Right. I might have it! :-) (When he was emeritus, Bernd and I used to share an office at UVM -- he was never there, always outside!)
Here's the Marden (1995) abstract:
The temperature-sensitivity of muscle performance in a
winter-flying ecotothermic moth (Operophtera bruceata)
was examined and compared with that of a summer-flying
endothermic hawkmoth (Manduca sexta). O. bruceata
muscle contracted over a temperature range of 1–28 °C,
whereas M. sexta muscle contracted at temperatures of
13–42.5 °C. Maximum (unloaded) contraction velocity
(Vmax) was greater in O. bruceata over most of the range of
temperatures where muscle from both species was
excitable (3–4 lengths s21 versus 0.6–3.6 lengths s21 at
13–28 °C), but M. sexta muscle achieved a much higher
Vmax at the temperature that this species maintains during
flight (10 lengths s21 at 40–42.5 °C). The capacity of O.
bruceata muscle to generate tension was approximately
twice that of M. sexta muscle (peak tetanic tension of 13.9
versus 7.0Ncm22). This greater force-generating capacity
in O. bruceata largely offset its lower shortening velocity,
such that maximum instantaneous power output was
equivalent in both species at temperatures below 35 °C
(approximately 100–120Wkg21). M. sexta muscle achieved
instantaneous power outputs of up to 202Wkg21 at
temperatures of 40–42.5 °C. Muscle activation and
deactivation (measured by times to peak tension and to
half-relaxation during isometric twitches) were most rapid
for O. bruceata at temperatures of 15–30 °C and for M.
sexta at temperatures of 30–40 °C.
Data for power output of flight muscle from these moths
are combined with estimates of induced power required for
flight in order to show how adaptations for thermal
sensitivity of muscle power output interact with
morphology (low wing-loading, high flight muscle ratio) to
allow O. bruceata moths to fly at extremely low body
temperatures, and to construct a model showing how the
fecundity of flightless O. bruceata females would decline if
they were to regain the ability to fly. Marginal flight over
a narrow range of temperatures for O. bruceata females
would require a 17 % reduction in fecundity; to fly over as
large a range of temperatures as do males would require
an 82 % reduction in fecundity.
This is really interesting--the thought that even a very small tweak in body/wing design might enable flight on a tight energetic budget is really intriguing. I would guess combining this with your other observations--that the male moths are essentially climatic opportunists who take advantage of winter variance (a few warm days, days with abundant sunlight if low air temperatures, etc.) and who can confine flight largely to mate-seeking. (Makes me wonder if they also have really restricted range, e.g., that there's something that clusters the wingless females and males in relatively small microenvironments so the males don't have to do a lot of surplus flying to try and find the females.)
Makes me wonder also if they aren't essentially an Ice Age-adapted holdover. If they aren't physiologically maladapted to a warmer winter, they might find that over time, warming conditions in the Anthropocene bring some unwanted competitors and predators into their private winter retreat.
Interesting topic. I think this Marden paper is the best fit to Timothy Burke's question about a metabolic hack. Both the biochemistry (enzyme, muscle temperature optima) and mechanical traits (stroke length, etc.) are part of what allow flight within a characteristic range of temperatures. Note that the ranges of both summer and winter moths are limited and only partly overlapping. This is in keeping with what we know about enzyme activity vs. temperature. Muscles are enzymes too, in effect--- they cleave ATP to achieve filament movement, and evolution can adjust the temperature optimum for this to happen. To cite an example from a different group of animals, antarctic ice fish and hot springs fish are both able to move and behave "normally" at the range of temperatures to which they and their enzymes are adapted. Transfer each to the other's environment, and I don't think the outcome would make either one smile. Another topic not touched on is that insect flight muscle is entirely aerobic, with some really cool anatomic and behavioral mechanisms for supplying the oxygen.
Thanks much for the supplemental perspective, Walter. You and Timothy will no doubt drive me to more literature — and perhaps a follow-up post.
Overall, the dialogue that follows many of my posts on Chasing Nature makes me appreciate Substack even more, and has made it all the more easier to abandon social media. It's tough even to read comments following my (non-controversial) essays in The Boston Globe.
I am ever grateful for the intelligence of the readers here, including those who don't agree with me. I hope it makes me a better writer.
Bryan: Thanks for this one. It and the solstice arrived on the first weekday morning in a long while when I have almost no work emails to deal with. Which gave me ample time to read and reflect. Flightless females and active winter insects reminds me of a story I was researching this time last year — on fireflies.
Oh, I want to see the firefly work!
Bryan, you always have delightful surprises in store for me. I'm going to be at a hot springs this solstice, where if I'm lucky I might be able to see the stars (it's overcast here for weeks at a time in winter, which gets a lot of people down). But now I'm going to keep an eye out for moths. Happy Solstice!
... and even if you don't see stars or moths, hey, you'll be in hot springs!
I didn’t see stars or moths but did finally get some moonlight! Took my kid the long way home through the Bison Range (20,000 acres managed by the Confederated Salish & Kootenai Tribes) and saw a cluster of buffalo, a kestrel in flight, and four very active bald eagles. Love that place.
Love this one! Over at my rag we have an entomologist PhD who would love this essay! I learned more about moths in this one piece than I had from all my previous reading- All hail moths and the Insecta in general. They've got the lumbering tetrapodia beat all hollow!
And all hail the return of the light, my own favorite day of the year!
All hail Insecta, indeed! What a privilege it is for this lumbering tetrapod to speak for the spineless.
Yes we are clumsy and won't be around for all that long, but at least we meant well and gave the world some neat inventions like Ziploc bags and electric toothbrushes. Yes, all hail the Insecta and especially the Ants, true rulers of this planet, good for another billion years at least!
What a beautiful and dramatic love story! (dying in the cold after love making!) 🤍
Glad to count on you, Sabrina, for highlighting the drama!
How wonderful. What a lyrical and beautiful piece that manages to be quite educational too. I loved it! And couldn’t help but note the metaphor that many humans might find true of our motherhood, ultimate blessing though it may be: “it is the females that more often exchange their wings for the greater good.” Not always, of course, but there’s a bit of truth ringing there. Happy Solstice!
Not to get too picky, but whatever exchange females make is for their own fitness, not for the greater good.
The author was of course speaking of insect females, when he wrote the quoted phrase. You may be referring to that. If you were speaking in the (metaphorical) context of human females, however, I’d argue that, given we (fortunate members of certain human societies) can consciously decide whether or how frequently to reproduce, we are thus capable of making childbearing decisions that we view as benefitting the greater good (whatever that may mean to us individually) rather than in service of our own reproductive fitness.
Indeed, I was referring to the insect female. The question of the common good among humans is really fraught, so I was not referring to it, even metaphorically.
Thanks, Rebecca. There is so much to explore on this topic. I'm no evolutionary biologist (mostly I'm just a guy with binoculars, an insect net, a pencil and notebook, and a few ideas). But I do hope to write more on female roles and burdens in reproduction. In some ways, this post on aphids is a rare example of females really running the show: https://chasingnature.substack.com/p/males-need-not-apply
Wow! The photos on that post are incredible - I've never seen anything like that mass of wooly aphids. Do they secrete this waxy, cottony cover for themselves en masse? And then emerge from it to go their separate ways in a different season? Or is this a structure they may build at any time of year?
And also fascinating to learn of this (potentially) female-directed reproductive life cycle. Nature is so cool.
In the 1970s, a naturalist living in the Panamint Valley of California, Derham Giulinani, brought a flightless, strap-winged female moth to the entomologists at the University of California, Berkeley. Giuliani had collected the active moth in mid-winter on the sand dunes of Deep Spring Valley in the eastern Sierra Nevada. Subsequently, several UC entomologists spent 4 years on expeditions under icy winter conditions, finally collecting a total of 17 more, largely using pitfall traps because the females are flightless. You can find one of their papers here: https://images.peabody.yale.edu/lepsoc/jls/1990s/1994/1994-48(1)8-Powell.pdf.
Thanks, Walter. Downloaded and now in my pile of reading.
This is brilliant and fascinating, Bryan. You have a talent for narrating exotic couplings... We have winter moths (Operophtera brumata) in abundance here in the midcoast. Seems safe to assume that the flurry of moths attracted to the porch lights in December are the unwanted (if still fascinating) brumata? Are the Bruce Spanworms likely to be at the lights in November? Not sure if it's worth trying to "control" the invasive winter moths by dealing with those at the lights, and certainly don't want to harm any of the spanworms, but some favorite trees were munched pretty thoroughly last summer. Your thoughts?
Well, you know, to be honest, I wonder if we know for certain that they're O. brumata. I'll need to double-check, but I think it requires dissection to tell brumata from bruceata, which does indeed fly earlier (November) but is done flying here in Vermont by December. Even so, I wonder whether bruceata flies later on the midcoast.
I'm not sure we can trust all iNaturalist records on these two species -- even "Research Grade" records. Not only that, I wonder whether Alsophila pometaria was causing your tree damage. (Turns out that I did have a sentence in the essay about some of these geometrids being insect "pests" but struck it.) Which tree species got munched?
It might take a Maine forest entomologist who's spent time collecting and dissecting these moths to be certain exactly what you've got. But I'll ask around a bit.
Well, I certainly defer to your knowledge, but there are known populations of winter moth up and down the coast here (https://www.researchgate.net/figure/Winter-moth-Operophthera-brumata-outbreak-areas-estimated-for-2014-in-coastal-Maine_fig4_331382712) and there are efforts to control them (https://www.pressherald.com/2017/11/29/south-portland-joins-the-battle-against-winter-moths-in-maine/). Do bruceata appear in great numbers like brumata? Last winter my brother and his wife walked through a plague-sized cloud of the moths as they came up to my folk's place (in Boothbay). And are bruceata as drawn to porch lights?
Oh, yeah -- no (a "yeah-no"), I wouldn't defer to my knowledge. I was just about to email you to say that I did some poking around to find that all three of those species I mentioned are in Maine and can be pests. Bruceata do come to lights, but I've never seen them in big numbers. I hadn't known that brumata was sometimes such a problem in Maine! Yikes!
I'll always defer, Bryan, but will offer up little bits of info that come my way...
I'm willing to harass the winter moths at the light if it seems a rational, very local way to control them, i.e. in the yard at least. But I don't know whether those at the light represent enough of the population to bother with.
But let's not let this conversation descend into such matters. Enjoy the holidays, Bryan, and may the new year bring you more moths and memories.
Back atcha with moths and memories. I frankly don't know a thing about controls, but I suspect (as you do) that lights won't help, in part because the females obviously won't come to the lights and, I suspect, enough males will still be out and about ... you know ... being males.
Fascinating!
A cracking good discussion, mates! Where else but on Substack?!
What a gift to be joined by readers smarter than me.