Anasa tristis
In 3 days ~20% in a week ~30%
Anasa tristis is a species of bug in the family Coreidae. It is a major pest of squash and pumpkins, found throughout North America, and is a vector of the cucurbit yellow vine disease bacterium. These bugs can emit an unpleasant odor when disturbed. It is commonly known as the squash bug but shares this name with certain other species.
The adult A. tristis is a greyish-brown, somewhat flattened insect reaching a length of about 1.5 cm (0.6 in) and a width of 0.75 cm (0.3 in). There is often a row of alternate brown and gold spots along the margin of the abdomen. Adults survive for three or four months.
Anasa tristis can be found on various members of the gourd family Cucurbitaceae, but most often occurs on pumpkins and squashes. Some varieties and cultivars are more susceptible to attack than others. Research has shown that nymphs can grow to adulthood with varying degrees of success on different host plants; 70%, 49%, 14%, 0.3% and 0% survived to maturity on pumpkin, squash, watermelon, cucumber and cantaloupe melon respectively. Nymphs can develop from the first instar to the second instar when fed on pumpkin, cucumber, or even water alone, but... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Portland | 🇺🇸 United States | |
| 2 | Salt Lake City | 🇺🇸 United States | |
| 3 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 4 | Dallas | 🇺🇸 United States | |
| 5 | Philadelphia | 🇺🇸 United States | |
| 6 | Phoenix | 🇺🇸 United States | |
| 7 | Baltimore | 🇺🇸 United States | |
| 8 | Sacramento | 🇺🇸 United States | |
| 9 | Denver | 🇺🇸 United States | |
| 10 | Washington | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Squash Bug sighting in Portland on a given day, based on 48 verified sightings from GBIF citizen-science data. It is the 128th most-seen of the 507 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
July to October
In those months about 10% of wildlife watchers report a Squash Bug in Portland on a given day, against under 5% in November to June, the lowest months. Those are among Portland's driest months, with about 55 mm of rain a month against 250 mm in December.
Yes
Of the 15 cities where we can rate Squash Bug sightings, Portland has the highest daily chance: about 10%. Next come Salt Lake City (United States, under 5%) and Minneapolis [Saint Paul] (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Squash Bug is recorded against all the insects logged in Portland (48 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.
