Pug moths (Eupithecia) are a large genus (about 1,400 species) of tiny moths in the Family Geometridae (geometer moths or inchworms). There are hundreds of described species from all continents except Antarctica. Some even live on Pacific islands like the islands of Hawai’i with species whose larvae are carnivorous and catch and eat other insects. North America north of Mexico hosts at least 160 species. There are probably many more species yet to be described.
Eighteen Eupithecia species have been recorded from Minnesota. Some are known from five or fewer sightings in the state. I haven’t found all eighteen yet but have gotten to one-third of that number and that includes some of the rarities. The most common one is Eupithecia miserulata, a small grayish species with a dark dot on each of its forewings, faint scalloped lines on the wings, and often two or three dark dots along the costa. This moth can be variable and it is easy to confuse it with other species. I often find the yellowish larvae in July and August feeding on the anthers of black-eyed susan (Rudbeckia hirta) flowers, cut-leaf coneflower (R. laciniata), and sunflower (Helianthus grosseserratus). The larvae of E. miserulata are also reported to feed on oak, willow, and juniper.
Larval host preferences are not known for the other Eupithecia I’ve found except for E. strattonata (alder and spiraea), E. absinthiata (mugwort, wormwood, yarrow), and E. ravocostaliata (willow, cherry, birch and other woody plants).
Below are the six species I’ve found and been able to identify.
CLASSIFICATION
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Geometroidea (Geometrid and Swallowtail Moths)
Family Geometridae (Geometrid Moths)
Subfamily Larentiinae
Tribe Eupitheciini
Genus Eupithecia
SOURCES
Not Very Far Away 
I’ve just looked to see if we have these in the UK. We do. But identifying and distinguishing them all seems an utterly thankless task.
LikeLiked by 1 person
Some species of pug moths are apparently found on both sides of the Atlantic. So many of them are difficult to figure out. I have another post in the works on the Acleris moths which are very “fun” to identify.
LikeLiked by 1 person