Tuesday, July 30, 2013

Diversity in conformity: Meet the Hologram Moth

Green-backed Looper by day, Hologram Moth by night
Learning a new group of insects is always a challenge, but some groups are easier than others. Moths are a special challenge because there are so many of them. As of 2010, Greg Pohl and his coauthors have documented 2367 species of Lepidoptera in Alberta and more are added each year. The vast majority of these are moths, but 175 or so are butterflies.
Flash-induced iridescent 'hologram' style Diachrysia balluca Geyer, 1832
Like all living organisms, moths show individual variation within a species, some genetic, some the result of developmental or ecological experiences. Many moths also seem to exhibit a general convergence in patterns among various species and genera.
A pair of 'Carpet Moths', mystery moth on left, Dysstroma hersiliata (Guenée, 1858) on right
This is particularly striking in the many species of moths with forewing patterns that seem to break up their outlines and allow them to blend into the background where they rest during the day - on tree trunks and limbs, among lichens or dead leaves, on the ground, or in a shadow somewhere. Presumably much of the variation in colour and patterns in the wings results from natural selection that improves the survival of moths with patterns appropriately cryptic for the places they like to rest.
Also known as the Large Brassy Plusia, another Diachrysia balluca under the black light
Bird predation is known to have been a primary factor in the classic example of the Peppered Moth (aka Pepper & Salt Geometer) becoming the Carbon Black Moth in industrial England. As the smoke from coal fires coated the bark and branches of light-coloured trees, the white & black patterned Peppered Moth populations became dominated by melanistic forms - dark as coal dust. More impressively, as clean air laws and the change to other fuels resulted in a drastic reduction in particulate pollution, the Peppered Moth morph again became the more common. Such switching between two morphs is easy to understand, but the seemingly random variation in patterns is less so.
A Green-Arches resting on a grill - probably not its natural resting place
These BugGuide Green Arches Anaplectoides prasina (Denis & Schiffermüller, 1775) are a nice example of variations within a theme. No two moths are exactly the same, yet the underlying patterns are all similar. I'm guessing these moths like to rest on lichen covered surfaces, but it is hard to think like a bird, and perhaps they see it differently. Not much seems to be known about where moths hang out during the day; however, the preponderance of grey to brown to buff patterns resembling bark and lichens among the mid to larger moths seems suggestive.
Aposematic Virgin Tiger Moth Grammia virgo (Linnaeus, 1758)
Not all moths are cryptic, of course, but often the reason for being bold is clear. The Virgin Tiger Moth above, for example, is positively shouting "Do't eat me: I taste badddd!", although that probably wouldn't help much in the dark and one wonders what a bat would think? Spicy?
What is this Hologram Moth trying to tell me?
And I wonder what birds and bats think about the Green-backed Looper? I know what I think - if you are going to use a flash to take pictures of this moth, you will need a flash diffuser. Other than that, though, I find this looper confusing. It is very large for a Plussine, so presumably would make a good meal for a bird or bat. Having now seen the moth resting during the day (picture at the top), however, I'm guessing it may like to hide among dying or damaged leaves. I've got no idea why it has such a strange hairdo though.
Party time at the black light

Grant BS. 1999. Fine tuning the Peppered Moth Paradigm. Evolution 53: 980-984. http://bsgran.people.wm.edu/melanism.pdf

Majerus MEN. 1998. Melanism - Evolution in Action. Oxford University Press, NY. http://www.amazon.ca/Melanism-Evolution-Michael-E-Majerus/dp/0198549822

Miller K. The Peppered Moth - An update. http://www.millerandlevine.com/km/evol/Moths/moths.html

Pohl GR, Anweiler GG, Scmidt BC & Kondla NG. 2010. An annotated list of the Lepidoptera of Alberta, Canada. ZooKeys 38: 1–549.

Saturday, July 27, 2013

Bold-feathered Grass Moth, probably

A dizzy moth, perhaps the Bold-feathered Grass Moth 
If you've read this blog before, you know me for a whinger about the Alberta weather. You probably imagine me as a grouchy old wanker with nothing better to do than look out his window and feel sorry for himself. Well, there is something to that: I often look out my window and feel totally depressed by the weather (the climate is beyond my comprehension).
Herpetogramma pertextalis (Lederer, 1863), most likely
Still, I soldier on and find what I can to be positive about in this land in which I find myself imprisoned (my heroic aspect revealed). This weekend has been a tough one - pretty bloody miserable after a string of ordinary to miserable weekends all 'summer'. Still, I had a few hours last night with the blacklight before the massive thunderstorm hit about 3:40 am. 
Probably Herpetogramma pertextalis, but maybe Sitochroa chortalis 
This moth was one of the several interesting - oh why be coy - very cool moths that fluttered into the light between showers and downpours last night. Took me a long time to figure out its probable name because it looks so geometrioidy. But no, it is a Pyraloidea of one ilk or another, and quite possibly the rather rare (in Alberta) Bold-feathered Grass Moth.
Carpet moth, as yet identified
Should I brave the thunder and lightening again tonight or try to get some sleep? Well, when one sleeps one may, perchance, dream. Is a moth at the light worth a pleasant dream? Well, beats  a nightmare and we have all winter to sleep. My guess is that this is Dysstroma hersiliata (Guenée, 1858), the Orange-barred Carpet Moth, but a better picture would be nice and who knows what else may show up.

Friday, July 26, 2013

A Big Moth with a Mono-ocular gaze: Polyphemus

A big moth with that 'I'm looking at you' attitude
In Alberta, that too far north for comfort latitudinal range, one gets used to being biodiversity-challenged. If you went back in time a decade of thousand years - nada in geological time - you would have nothing living here except very cold-tolerant algae and bacteria. Still, that pallid and unreliable sun has been shinning with what passes for warmth here for more moth generations than one could easily count.
Antheraea polyphemus (Cramer, 1776) - as big as a mouse, but without the Hanta Virus
Gradually, solar cycles allowing, even Alberta will gradually integrate itself into the Greater North American Biome. Who knows, but maybe one day Grizzlies and Armadillos will frolic together beneath the shadows of the Rockies. Well, best not to expect too much from Mother Nature. To her a barren wasteland of ice or volcanic magma is just as natural as a rainforest. So, while we may, let us imagine a diversity of elegant and attractive moths fluttering around our wasteful nocturnal emissions.
A big, bad Polyphemus caterpillar eating my Mayday
Polyphemus is a big moth - wingspan of about 6 inches (15 cm) - not the biggest, Alberta can boast other giant silk moths such as Luna Moth (apparently a recent arrival) and Glover's Silk Moth - but the biggest that has come fluttering to my night lights. Personally, I welcome all and any additions to Alberta's fauna - as long as they come with their baggage of parasites and predators that not only add to our biodiversity, but keep any one species from being too, too common.
A dozen Polyphemus caterpillars in a Mayday is interesting, a thousand would be a disaster
In Greek legend and mythology Polyphemus was a big, bad cyclops. Although much spoken of in ancient times, today he and she are just big moths. Is there a greater thrill than having a mouse-sized moth walk on your hand? Well, yes, many, but it is still a very nice thing.

Wednesday, July 24, 2013

All moths are interesting, but some are more interesting than others

Two-spotted Looper outshines a Double Dart
Back on the Moth Farm the clouds continue their unending downpour. I huddle next to the wood stove and wonder if the gophers must be learning to swim. The moths, though, seem content to wing their way through the mists between showers and provide some colourful relief from the dreary doldrums of summer in Alberta. Well, some provide colourful relief, but others seem content to blend into the grey background. Compare these two Owlet Moths (Noctuidae): the brightly patterned Two-spotted Looper Autographa bimaculata (Stephens, 1830) and the dull as dishwater Double Dart Graphiphora augur (Fabricius, 1775).
Two-spotted Looper Autographa bimaculata
Bright silver spots, squiggles, scripts and autographs are characteristics of many Owlet Moths but especially those in the subfamily Plusiinae and subtribe Plusiina and are reflected in many generic names based on the Greek root grapho (= write) such as Anagrapha, Autographa, Megalographa, and Syngrapha. What the genus Plusia may refer to, however, is a mystery. 
Putnam's Looper Plusia putnami Grote, 1873
A mystery too is why the silver spots and squiggles? Since similar marking occur on unrelated moths, one might think they serve some function. Perhaps they reflect moonlight or sonar to dazzle bats. In any case, the clouds continue to scuttle across the sky, dropping rain, rain, rain and the moths flutter between squalls and hunker down during them.
The Hooked Silver Y Syngrapha alias (Ottolengui, 1902)

Tuesday, July 23, 2013

Three Elegant Moths

Diachrysia balluca Geyer, 1832 the Large Brassy Plusia or Green-patched Looper
In the Alberta summer one has to take their enjoyment of nature when they can amongst all of the rains, hail, lightening and strong winds. So far, it has rained two out of every three days in June and July and over 10 inches of rain have fallen in the Home Bug Garden (and much of that has flowed through the basement). However, Saturday night at Gopher Hill from midnight until 1:30 am the rains let up and the black light went out to see what might be roaming around the cloudy darkness.
Malacosoma disstria Hubner, 1820 adult of the Forest Tent Caterpillar
As usual when the black light works its magic here, the response of the nocturnal Lepidoptera overwhelmed all other insects. That's probably an Alberta thing too, at least compared to Queensland and other warmer lands in which I've gone night-lighting - where beetles, wasps, flies and bugs were often almost as diverse as the moths.
Sicya macularia (Harris, 1850) the Sharp-lined Yellow
So, here's a short tribute to just a few of the hardy moths that braved the cool, damp night to flutter around a black-light.

Sunday, July 21, 2013

Mothing between Storms: Once Married Underwing

Once-married  Underwing Catocala unijuga
The start to [Inter]national Moth Week late last night-early this morning was not salubrious in the extended Home Bug Garden. Actually, in the HBG per se it was even wetter and less mothopilic than in the remote site - about 2 km east of Elk Island National Park. Still, through a process of judiciously applied wine, napping, and radar-gazing, I was able to emerge from the cabin, black-light in hand, just after midnight this morning as the rains receded and start attracting moths (and frogs - rain and moths seem to meet with froggy approval).
Underwing in under position
As usual when the blacklight doesn't have to compete with moon or rain, the results were stunning. I hope to be able to share some of the extraordinary diversity of form with my readers later in the week - as one, by one, names are applied. In the meantime, though, here is the first Catocala of the season and the largest of this morning's visitors. I myself was once married, so the common name of this very large and attractive moth has some resonance beyond its beauty and imposing size.  But much more is in store in the coming week as the smaller, but no less elaborate ad lumina nigra are exposed.
Mystery Moth

Saturday, July 20, 2013

[Inter]national Moth Week: Wet Night One

Virgin Tiger (Grammia virgo) over flies a Sharp-angled Carpet Moth (Euphyia intermediata) as coyotes (Canis latrans) howl in the night
Well, the yanks are doing their National Moth Week again and we friendly neighbours to the north are ready to remind them that moths respect not borders. Last week the Environment Canada prediction looked like we would be starting Moth Week with sunshine and clear skies. Well, Edmonton did have on of its rare two days in a row without rain this week; but alas, such perversity is now passed and the clouds and rains have returned.
Haploa lecontei aka LeConte's Haploa, another Tiger Moth
Rain is not so good for mothing, but clouds have a silver lining - cloudy nights are best for blacklighting. So the next week's predicted dreary day after day after day of clouds casts no pall over nights of scaly wonder. As an added bonus, if you stay up late enough each night appreciating moths then you'll probably sleep through most of the dreary day anyway (of course, this could get you fired). With any luck, tonight's rains will have passed before the long northern summer day is done and the black light will once more call forth the amazing diversity of scale-winged beauties. If not, well, I've been saving up moths for you for a rainy night or even a rainy week.
Large Lace-Border Scopula limboundata

Monday, July 1, 2013

A Katydid for Canada Day

Young Broad-winged Bush Katydid
Alberta isn't known for its warm summer evening filled with the songs of insects, but we do have katydids such as this Scudderia pistillata Brunner, 1878. Later in the year the Northern Bush Katydids will be singing at a pitch too high for me to hear, but right now they are concentrating on eating and growing.
Katydid on a Wild Rose for Canada Day
This nymph seems to be inordinately fond of the Provincial Flower - the Wild Rose - and no wonder, roses are full of high protein foods (including male reproductive parts). 
Happy Canada Day from the Home Bug Garden