zdufran's Journal

This journal entry is to draw attention to observations from a few friends who encountered some wonderful moths on recent travels to South America.

First, Steve Davis (https://www.inaturalist.org/people/spdavis81) and a few other local birders I know went on a group birding trip to Ecuador in early March. At several of the eco lodges where they stayed the hosts had setup a white sheet and light overnight to lure in insects which would serve as a buffet to birds in the morning. This has become common practice at many such eco lodges that cater to birders. I'm conflicted on this practice, since it is surely detrimental to the insect numbers in the area. On the flip side, it is bringing some awareness of insect biodiversity to a group of people (birders) who are already naturally inclined to care. Maybe the awareness will lead to some positive changes to help insects. Some of these birders have become enamored with the late night insect show as much as the morning birding that it attracts. Steve took photos of some of the insects and has uploaded them to iNaturalist here: https://www.inaturalist.org/observations?place_id=7512&taxon_id=47157&user_id=spdavis81&verifiable=any

(By the way, on the rare occasions that I leave my sheet setup and light on overnight, I am careful to get up early to check the sheet and shoo away the insects before the birds come for breakfast.)

Second, my friends Rosario (https://www.inaturalist.org/people/argonauta) and Mike Douglas went on an incredible 28-day cruise from Miami, down through the lesser Antilles, and then up the Amazon River to Manaus, Brasil. They are avid naturalists with keen interest in plants and birds. Mike has been giving nature talks on cruise ships for the past few years and was doing so on this cruise ship. While their cruise ship moved up the Amazon River within view of the forests on the river bank, many insects (mostly moths) were attracted to the lit walkways of the ship and landed on the walls and walkways. Mike and Rosario have been coming to moth nights with me for the past few years and were already inclined to pay attention. Mike started to show photos of the insects at his nature talks on the boat, especially to highlight the concept of biodiversity. After that, people started joining Mike and Rosario for their evening insect surveys. Perhaps others have made insect observations while floating down a river like this, but it seemed pretty novel to me, and a great way to do a transect of the Amazon Rainforest. "Moth Nights on the Amazon" really puts my local moth nights to shame! :)

Mike has added a page to his website with a narrative and photos of the insect activity and some of the fellow passengers who joined in the appreciation. He talks a little about photography, about mimicry, crypsis, and then breaks the moths down by families. There are some truly astounding and beautiful specimens. Please check it out here:
https://thetravelingnaturalist.org/miami-to-manaus-28-day-cruise/

Meanwhile, Rosario has been posting the observations to iNaturalist and getting identifications. Here are their observations from the Amazon leg of the journey:
https://www.inaturalist.org/observations?nelat=1.9913868074126604&nelng=-49.069248611170785&place_id=any&subview=map&swlat=-6.344814000687892&swlng=-65.50479548617079&user_id=argonauta&verifiable=any

Who wants to sign up for a 28 day cruise with me!?! :)

Yesterday I learned that there is a PhD student at Penn State working on a revision of the gall wasp genus Antistrophus and that he needs collections of galls on Pyrrhopappus. I volunteered to help look for them, having seen some in the past.

While I was at work today I went for a walk down the street, as is my habit. I noticed plenty of Pyrrhopappus along the side of the road, so I began looking. I found quite a few, and collected about a dozen.

As I was walking along and inspecting the flowers I noticed one of my favorite little elusive moths, Schinia mitis, which hosts on this plant. The moths visit the flowers in the morning, lay their eggs in the center and then fly away or snooze in the flower as it closes for the day. The caterpillars eat the flowers and then, I assume, they pupate in the soil or inside the spent seed head on the ground. Since I was looking closely at each of these flowers I started coming across a few mating pairs of Schinia mitis, which was a first for me.

A lot of these moths would dart as soon as I would get close. Combined with the wind and their small size I would quickly lose them. However, the mating pairs would stay in place, even when I used my hand to steady the flowers in the wind. Because of the flighty nature, I was videoing each flower that I could tell had an occupant, not knowing if it would be a single moth that quickly disappeared or a mating pair that would stay in place. In one of these cases I came upon a mating pair where one of the two moths was much more vividly colored than the other. At the time I chalked this up to sexual dimorphism or natural variability.

However, when I returned to my desk at work I started looking at my photos a little more closely. If the other pairs demonstrated sexual dimorphism it was on a much more subtle scale than this pair. Furthermore, this one vividly colored moth looks identically like another species in the genus, Schinia bina.

The moth in question has a deep raspberry basal third, moderately pink median, and yellow terminal third. Also, the three sections are separated by two narrow and scalloped bands of white. The ventral sides of the wings are patterned. All of these characteristics are consistent with S bina and not with S mitis.

S mitis has a tan wing superimposed with magenta or brown V mark in the basal half of the wing and a diagonal mark in the lower half of the wing. The ventral sides of the wings are dark and solid, not patterned.

A final observation: when the wind blew the wings of the moth in question the abdomen was exposed and it appears to be quite large, which leads me to believe this was the female of the pair. I don't know if that has any implications, but I presume it might. For instance, if the female is the one who emits the pheromones among Schinia moths, then perhaps she was in the wrong place (the host plants of a different species) at the right time to make this pairing happen. Rather than a male S bina having traveled to this location after having sensed the pheromones of a different species.

I have shared the photos with Chuck Harp (@cehmoth), who specializes in Schinia and other Heliothinae.

I don't know how common interspecies mating or hybridization are among moths or specifically those of this family, but it's not something I have witnessed before. I also did a little searching today and have not come across many examples online. (one example)

IF this truly was a case of interspecies breeding, does this imply something about their phylogeny? Could they be related closely enough that their pheromones are similar?

I do note that Schinia bina's host plants are a bit of a mystery. It has been recorded on Verbesina encelioides during the late summer brood, but this spring brood that is in flight in April must be using a different plant. Could they be using Pyrrhopappus?

I did not collect any of these moths, although now I am sort of wishing that I had. I will be watching for this moth again, and also be looking for the caterpillars. Perhaps one flower will have some odd looking caterpillars that don't match the normal red and white striped caterpillars of Schinia mitis...

For reference, here are the MPG pages for each species.
Schinia mitis
Schinia bina