Moths as Pollinators

When I was younger, I often wondered
“How is it that there are (and especially in Australia) so many more species of moths than there are butterflies, and yet when I look at flowers at night, I rarely see moths?”

Later, I found several satisfactory explanations including ‘very few moths feed as adults (but may drink dew)’ and that it is mostly Sphingids and Noctuids seen at flowers. Most moths’ energy needs are met by the intensive feeding of the larva.

However, I recently read this article (also published on many other major news websites) which made me question this again:
https://www.bbc.com/news/science-environment-52630991

What do you think? I would also love to see your observations of moths on flowers!

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Here is an photo I took of a moth on a flower in Kosciuszko National Park, New South Wales, Australia.
I was volunteering in a collection trip for research on alpine pollinators. Anecdotally, I noticed a high proportion of flies and day-flying moths pollinating in that alpine area. Unfortunately we didn’t net at night (but tricky), but there was some light sheet trapping.
https://www.inaturalist.org/observations/25983620

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I had an interesting experience regarding this late last summer. The goldenrod meadow near my house was full of butterflies, bees, beetles, flies and a few moths during the day, but I went out on one warm night and realized that the goldenrod flower heads were buzzing with moths of a couple dozen species that I was unable to identify. It made me wonder how much the moths are responsible for the pollination of these plants in comparison with their more easily seen diurnal counterparts.

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And perhaps very dependent on temperature, wind, moonlight etc!

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There has been limited research on topic over time, and it is good to see the coverage of the recent study.

There are a couple of projects on iNat that collect this kind of information. Here is a key one focused on North American leps: https://inaturalist.ca/projects/butterfly-moth-nectar-plants. It is definitely focused butterflies but there are quite a few moth observations. The field “Nectar plant” is the main resource for capturing the relationship, and it feeds into one of iNat’s external relationships with www.globalbioticinteractions.org. Here is one of my nectaring moth observations with the GloBI link in the bottom right, beside the GBIF link https://inaturalist.ca/observations/3391357.

I edit an atlas of moth observations for the province of Ontario and we have tried to capture this relationship and have 400 records of moths nectaring/possibly pollinating.

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I’ve seen many on flowers, so it’s just a matter of noticing certain species at the certain time.
https://www.inaturalist.org/observations/40128304
https://www.inaturalist.org/observations/20043279

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I suppose its because we don’t see them pollinating, with many species being nocturnal. When we turn on our moth trapping lights, thats serves more as a distraction to them instead!

I have quite a few observations, enjoy:
https://www.inaturalist.org/observations/36256498
https://www.inaturalist.org/observations/29979800
https://www.inaturalist.org/observations/16961125
https://www.inaturalist.org/observations/10700169
https://www.inaturalist.org/observations/10358424
https://www.inaturalist.org/observations/9053942
https://www.inaturalist.org/observations/8926950
https://www.inaturalist.org/observations/8652444
https://www.inaturalist.org/observations/8203635
https://www.inaturalist.org/observations/7553520
https://www.inaturalist.org/observations/7553810
https://www.inaturalist.org/observations/7552840

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Thanks @dkaposi, @melodi_96 and @robotpie for the great observations. I will have to keep a sharper eye out. I’m still interested in seeing some pollination after dark.

@dkaposi, can anyone join the lepidoptera nectar plants project? Or is it restricted to N. America? I’ll have to look for something similar near me. But will definitely look at adding more data in the Observation Fields

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yes, it’s an open project, feel free to join
It started as a North American project but many non-NA observations are now included, so join up!

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I’m not convinced “most moths nonfeeding” is true. I often see a diverse array of crambids, geometrids, noctuids, and assorted unidentifiable micros bombing certain native and nonnative garden flowers en masse; I see sphingid Hyles lineata infrequently, most nectarers I observed are of relatively low popularity and drab colors. Other flowers are largely ignored, these tend to be stereotypical “prim and proper lawn garden” things like roses, pansies, etc.

I suspect “most moths nonfeeding” is more precisely “most Charismatic Megafauna moths nonfeeding”, since the big fat well-known things are mostly Saturniidae (Actias, Hyalophora, Attacus, Eacles, Dryocampa, Citheronia, Automeris), the domesticated and thus widespread Bombyx mori, and big swarmy conspicuous pests like Lymantria and Malacosoma, with Sphingidae being the major Charismatic taxon with functional tongues (some sphingids are nonfeeding though).

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I think you are probably exactly right with the charismatic moths.

Do you know of any resources on which families/subfamilies have mouthparts? I wondered this when I found a poorly moth and thought it could use some energy, then found out many Hepialids cannot feed as adults.

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I quickly assembled a list of major aphagous families from bits of research papers I read.

  • Psychidae
  • Saturniidae
  • Bombycidae, Apatelodidae
  • Dalceridae, Megalopygidae, Limacodidae
  • Epipyropidae, Cyclotornidae
  • Cossidae
  • Lymantriinae (not a family right now but it used to be)
  • Tineidae

Some families only have a handful of aphagous-adult taxa and these are not included in the list above. Note that recent studies have shown certain reduced-proboscis taxa to be still capable of feeding, although older research still claims such taxa do not take calories; Gluphisia puddles for hours to harvest sodium (I highly doubt any saturniids and bombycids with functional tongues will be found, I have observed Plodia interpunctella slurping honey though).

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