Agonopterix alstroemeriana
In 3 days ~10% in a week ~20%
The hemlock moth (Agonopterix alstroemeriana), also known as the defoliating hemlock moth or poison hemlock moth, is a nocturnal moth species of the family Depressariidae. Of Palaearctic origin, it was first found in North America in 1973 when it was accidentally introduced. The moth is widespread throughout the northern half of the United States, southern Canada, northern Europe, and, more recently, New Zealand and Australia. The larval form grows to around 10 mm, while the adults wingspan is between 17 mm and 19 mm.
It is best known for its use in biological control of the lethal poison hemlock (Conium maculatum), which is eaten by its caterpillars (larvae). The toxicity of its host plant may actually benefit the caterpillar because it helps females recognize locations for oviposition. This species also uses the leaves of its host plant (C. maculatum) to form protective tubes around the caterpillar.
This species was first described in 1759 by Carl Alexander Clerck and originally named Phalaena alstroemeriana. Adult moths are pale brown, almost tan, with a lighter colored area near the bottom of their wings and a few darker spots found near the edges... Wikipedia →
| # | Park | Country | Daily sighting probability |
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More parks will be added in future updates.
Rare
Under 5% of wildlife watchers report a Poison Hemlock Moth sighting in Portland on a given day, based on 12 verified sightings from GBIF citizen-science data. It is the 316th most-seen of the 507 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
July
In that month about 10% of wildlife watchers report a Poison Hemlock Moth in Portland on a given day, against under 5% in August to June, the lowest months. That is one of Portland's driest months, with about 10 mm of rain against 250 mm in December.
Among the best
Of the 7 cities where we can rate Poison Hemlock Moth sightings, Portland ranks 3rd at under 5%, level with the leaders once rounded. The best odds are in London (United Kingdom, under 5%) and Auckland (New Zealand, under 5%).
Same order: Lepidoptera
The closest relatives of the Poison Hemlock Moth that you can see in Portland (order Lepidoptera, Butterflies and Moths) are Large Yellow Underwing (about 20%), Gray Hairstreak (about 20%) and Western Tiger Swallowtail (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Poison Hemlock Moth is recorded against all the insects logged in Portland (12 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
