(continuing discussion of the Battles et al. journal article)

In 25 years of monitoring in Delaware starting in 1998, light-trap catch averages declined from about half as many moths as pheromone traps in the first 5 years to less than 5% as many moths by the end of the period. A similar pattern was observed over a shorter 10-year period of sampling in New Jersey. On the other hand, a 15-year period of sampling in Minnesota showed no difference in the efficacy of the two trapping methods.

The causes of this decline in light trap efficacy are uncertain. Competition from light sources in the area is one possibility, but the data on competing light sources is poor and no statistically significant results are found. The researchers speculate that the more likely cause is that rapid evolution has decreased the flight-to-light response of this species. The paper notes that the Corn Earworm seems particularly susceptible to rapid evolutionary change as it has multiple generations per year and high dispersal rates: it cannot survive winter temperatures in Canada and the northern US and migrates each spring from the southern US.

Overall, this is not good news for moth observers. Perhaps other means of trapping may need to be explored, such as bait, pheromones or suction traps. On the other hand, it remains to be seen whether this finding is applicable to other species as well.

A new study produces evidence showing that light traps for moths are becoming less effective over the past 25 years. They use data on one pest species, the Corn Earworm (Helicoverpa zea), for which the moth's prevalence over time has been monitored using light traps (using fluorescent black-light bulbs) and pheromone traps operating in close proximity.

The paper is publicly available: Ian Battles et al., “Moths are less attracted to light traps than they used to be” Journal of Insect Conservation, published 19 April 2024 (https://link.springer.com/article/10.1007/s10841-024-00588-x ). New York Times subscribers may also wish to read commentary on the article in the April 19, 2024 issue (Veronique Greenwood, “Like Moths to a Flame: We May Need a New Phrase”).

This is an exciting new study providing an original and seemingly convincing explanation of this age-old puzzle. The idea is that insects are not attracted to a light source but come to it because of navigation errors. The title is "Why flying insects gather at artificial light." The publisher has posted a great 7-minute video explaining the study:
https://www.nature.com/articles/d41586-024-00261-y

Here is an excerpt from the Abstract of the study:

"Contrary to the expectation of attraction, insects do not steer directly toward the light. Instead, insects turn their dorsum toward the light, generating flight bouts perpendicular to the source. Under natural sky light, tilting the dorsum towards the brightest visual hemisphere helps maintain proper flight attitude and control. Near artificial sources, however, this highly conserved dorsal light-response can produce continuous steering around the light and trap an insect. Our guidance model demonstrates that this dorsal tilting is sufficient to create the seemingly erratic flight paths of insects near lights and is the most plausible model for why flying insects gather at artificial lights."

The full research study is posted at:
https://www.nature.com/articles/s41467-024-44785-3

This website also contains, as supplementary information for the study, 7 additional videos showing the behavior of various flying insects around light sources.

I received my copies last week.

This is the first volume to be published of a planned four-volume series which will cover every species recorded in Ontario. Volume 4, the first to be published, covers the macro-moth families Noctuidae, Euteliidae and Nolidae. It is called volume 4 as these are the last families of moths in the taxonomic ordering.

The authors are David Beadle (co-author of the Peterson Field Guide to Moths of Northeastern North America), Michael King and Phillip Holder.

It is spiral-bound, so it lies flat on the desk. It is 143 pages. Species are listed in order of their P3 numbers. Most pages include six species, with one photo of each. Each species is illustrated with a photo of the adult moth in its natural resting position. with the common name just below the photo. Text below the photos covers the P3 number, scientific name, flight period, description, range and foodplants. More than one photo is provided where the species has significant variation.

For sample pages and ordering, go to:
https://mattholderfund.com/product/ontario-moths-volume-4/

A new moth book has been written by David Beadle (co-author of the Peterson Field Guide to Moths of Northeastern North America), Michael King and Phillip Holder:

ONTARIO MOTHS: A PHOTOGRAPHIC GUIDE, VOLUME 4
Hawk Owl Publishing
They are taking pre-publication orders at a discounted price until August 15, 2023.
For sample pages and ordering, go to:
https://mattholderfund.com/product/ontario-moths-volume-4/

This is part of a projected four-volume series that is to cover, if possible, all moth species recorded in Ontario. By comparison, the Peterson Field Guide covered only about half of these species (since it was only one volume).

The first volume to be published, which covers Noctuidae and a few odds and ends, is called "Volume 4" because the species in the book are last in the normal taxonomic ordering. It covers 643 species and includes 800 colour photographs. Moths are shown in natural resting positions.

Today I learned from Greg Pohl of the sudden passing of Ian Toal (@mamestraconfigurata), who was one of the most prolific identifiers of Ontario moths on iNat -- 15,000 observations in all. He provided a valuable service to so many, and taught us so much. Sad. An obituary appeared in the Winnipeg Free Press ( https://passages.winnipegfreepress.com/passage-details/id-309457/TOAL_IAN ). His LinkedIn profile shows his wide interests and his experience inside and outside of entomology ( https://ca.linkedin.com/in/ian-toal-74697b86 ).

Also today, Chris Schmidt of Agriculture Canada provided a full identification for the Imperial Moth specimen observed by David Okines near St. Williams (Norfolk County) on July 19. Chris says it is subspecies imperialis, which has not been seen in Canada since the early 1980s (subspecies pini is the one widely observed in Ontario and western Quebec). A truly amazing find. This raises many questions. Was it there all along, but just not observed, or is this a recolonization from moths flying in from other areas? And is subspecies imperialis to be found anywhere else in southwestern Ontario?

Alan Macnaughton

This article in the Journal of the Entormological Society of Ontario documents Geoff Pekor's (@sneak-e) discovery of a new moth (and a new family!) for Canada. There is a very small link to a free pdf halfway down the page.

Helpfully, all the early records are on iNaturalist, here is a the first observation: https://inaturalist.ca/observations/56085703
Other authors: @stevepaiero @jasondombroskie @tompreney @josh_vandermeulen @basilconlin

This journal post on iNaturalist was prepared by Chuck Sexton (@gcwarbler). He reviews the regional variations in Painted Lichen Moth (H. fucosa) and Scarlet-winged Lichen Moths (H. miniata). There appears to be less ambiguity in the Ontario records, but he presents some interesting variations across the continent.

Hypoprepia lichen moths: What a mess!

The Lepidopterists's Society annual meeting is online this year - consider it an upside of Covid. Members and non-members are welcome to participate for a small fee. The schedule is now available so that you can see if any of the sessions are of interest:

https://www.lepsoc.org/sites/all/themes/nevia/lepsoc/Lepsoc_2021_Schedule.pdf

The schedule for the combined annual meeting of the LEPIDOPTERISTS’ SOCIETY, SOUTHERN LEPIDOPTERISTS’ SOCIETY, ASSOCIATION FOR TROPICAL LEPIDOPTERA, and SOCIETAS EUROPAEA LEPIDOPTEROLOGICA has been posted on the Lepidopterists' Society website.

Registration information is available here:

https://www.lepsoc.org/content/2021-annual-meeting

While Ontario is suffering through a Gypsy Moth explosion, other regions have their own invasive moths. Maine and nearby states are suffering from a recurrence of the Browntail Moth. It was introduced to North America in 1890, then suffered a collapse and is now making a comeback.

The article is in The Atlantic, which does allow 3 free article per month:
https://www.theatlantic.com/science/archive/2021/07/maine-caterpillar-itchy-poisonous-browntail-moth/619376/