Armyworm Moth

Armyworm Moth

Mythimna unipuncta

Daily sighting probability ~20% · Possible
at Porto

In 3 days ~50% in a week ~80%

234 Verified sightings at Porto
97 In all 8 parks From 2019 to 2026
November Best month
🌙 Nocturnal When it's spotted

About the Armyworm Moth

Mythimna unipuncta, the true armyworm moth, white-speck moth, common armyworm, or rice armyworm, is a species of moth in the family Noctuidae. The species was first described by Adrian Hardy Haworth in 1809. Mythimna unipuncta occurs in most of North America south of the Arctic, as well as parts of South America, Europe, Africa, and Asia. Although thought to be Neotropical in origin, it has been introduced elsewhere, and is often regarded as an agricultural pest. They are known as armyworms because the caterpillars move in lines as a massive group, like an army, from field to field, damaging crops.

The true armyworm has a distinct migration pattern in which they travel north in the spring and south in the fall to ensure that mating occurs in a favorable environment in the summer. While progressing through the life cycle stages of egg, larva, pupa, and adult, this species must avoid attack from predatory bugs, birds, wasp and fly parasitoids, and bacterial and fungal diseases. As polygamous insects, females release sex pheromones and choose multiple males as mates. The production and release of the pheromones are influenced by temperature, photoperiod, and the juvenile hormone. Hearing is an important sense for the true armyworm, necessary for mating and evading bat predation. Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Guadalupe Mountains National Park 🇺🇸 United States
~10%
2 Big Bend National Park 🇺🇸 United States
~10%
3 Pyrénées National Park 🇫🇷 France
~10%
4 Shenandoah National Park 🇺🇸 United States
~10%
5 Point Pelee National Park 🇨🇦 Canada
~10%
6 Cévennes National Park 🇫🇷 France
<5%
7 Acadia National Park 🇺🇸 United States
<5%
8 Cumbres de Monterrey National Park 🇲🇽 Mexico
<5%

Cities Where Found

# City Country Daily sighting probability
1 Porto 🇵🇹 Portugal
~20%
2 Austin 🇺🇸 United States
~20%
3 Turin 🇮🇹 Italy
~10%
4 Chicago 🇺🇸 United States
~10%
5 Dallas 🇺🇸 United States
~10%
6 Sacramento 🇺🇸 United States
~10%
7 Boston 🇺🇸 United States
~10%
8 San Antonio 🇺🇸 United States
~10%
9 Puebla 🇲🇽 México
~10%
10 Milan 🇮🇹 Italy
~10%

Before you go

What are the chances of seeing an Armyworm Moth in Porto?

Possible

About 20% of wildlife watchers report an Armyworm Moth sighting in Porto on a given day, based on 234 verified sightings from GBIF citizen-science data. It is the 10th most-seen of the 498 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.

When is the best time to see an Armyworm Moth in Porto?

November

In that month about 40% of wildlife watchers report an Armyworm Moth in Porto on a given day, against about 10% in January–March, June and September, the lowest months. That is one of Porto's wettest months, with about 140 mm of rain against 15 mm in July.

What time of day is best to see an Armyworm Moth?

Between 9 pm and midnight

Across all the parks we cover, that three-hour window holds the most Armyworm Moth sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.

Is Porto the best place to see an Armyworm Moth?

Yes

Of the 34 cities where we can rate Armyworm Moth sightings, Porto has the highest daily chance: about 20%. Next come Austin (United States, about 20%) and Turin (Italy, about 10%).

Which relatives of the Armyworm Moth live in Porto?

Same genus: Mythimna

The closest relatives of the Armyworm Moth that you can see in Porto (genus Mythimna) are The Delicate (about 10%), Mythimna riparia (about 10%) and Mythimna sicula (about 10%), with each one's daily chance of a sighting.

Where does the Armyworm Moth sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Armyworm Moth is recorded against all the insects logged in Porto (234 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.

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