Four-Spurred Assassin Bug

Four-Spurred Assassin Bug

Zelus tetracanthus

Daily sighting probability <5% · Rare
at Denver

In 3 days ~10% in a week ~20%

12 Verified sightings at Denver
59 In all 6 parks From 2019 to 2026
August Best month
☀️ Diurnal When it's spotted

About the Four-Spurred Assassin Bug

Zelus tetracanthus, the four-spurred assassin bug, is a species of assassin bug in the family Reduviidae. It is found in the Caribbean Sea, Central America, North America, and South America. Adults are brown, black, or gray and have a body length of 10–16 mm. Their antennae and legs are long and slender. They have a row of four spurs across their thorax. Both adults and nymphs use a sticky secretion to capture prey. Wikipedia →

Global Distribution

Parks Where Found

# Park Country Daily sighting probability
1 Death Valley National Park 🇺🇸 United States
~10%
2 Saguaro National Park 🇺🇸 United States
~10%
3 Joshua Tree National Park 🇺🇸 United States
~10%
4 Grand Canyon National Park 🇺🇸 United States
~10%
5 Big Bend National Park 🇺🇸 United States
<5%
6 Cumbres de Monterrey National Park 🇲🇽 Mexico
<5%

Cities Where Found

# City Country Daily sighting probability
1 Ciudad Juárez 🇲🇽 México
~10%
2 Mesa 🇺🇸 United States
~10%
3 Las Vegas 🇺🇸 United States
~10%
4 Phoenix 🇺🇸 United States
~10%
5 Salt Lake City 🇺🇸 United States
~10%
6 Austin 🇺🇸 United States
~10%
7 Dallas 🇺🇸 United States
<5%
8 Portland 🇺🇸 United States
<5%
9 San Antonio 🇺🇸 United States
<5%
10 Philadelphia 🇺🇸 United States
<5%

Before you go

What are the chances of seeing a Four-Spurred Assassin Bug in Denver?

Rare

Under 5% of wildlife watchers report a Four-Spurred Assassin Bug sighting in Denver on a given day, based on 12 verified sightings from GBIF citizen-science data. It is the 246th most-seen of the 461 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.

When is the best time to see a Four-Spurred Assassin Bug in Denver?

August

In that month about 10% of wildlife watchers report a Four-Spurred Assassin Bug in Denver on a given day, against under 5% in September to July, the lowest months. That is one of Denver's wettest months, with about 50 mm of rain against 15 mm in January.

What time of day is best to see a Four-Spurred Assassin Bug?

Between noon and 3 pm

Across all the parks we cover, that three-hour window holds the most Four-Spurred Assassin Bug sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.

Is Denver the best place to see a Four-Spurred Assassin Bug?

12th of 22

Of the 22 cities where we can rate Four-Spurred Assassin Bug sightings, Denver ranks 12th at under 5%. The best odds are in Ciudad Juárez (México, about 10%), Mesa (United States, about 10%) and Las Vegas (United States, about 10%).

Where does the Four-Spurred Assassin Bug sighting chance come from?

GBIF citizen-science records

It is estimated from how often the Four-Spurred Assassin Bug is recorded against all the insects logged in Denver (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.

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