Blattella germanica
Silhouette: PhyloPic
In 3 days ~10% in a week ~20%
The German cockroach (Blattella germanica), colloquially known as the croton bug, is a species of small cockroach, typically about 1.1 to 1.6 cm (0.43 to 0.63 in) long. In color it varies from tan to almost black, and it has two dark, roughly parallel, streaks on the pronotum running anteroposteriorly from behind the head to the base of the wings. Although B. germanica has wings, it can barely fly, although it may glide when disturbed. Of the few species of cockroach that are domestic pests, it probably is the most widely troublesome example. It is very closely related to the Asian cockroach, and to the casual observer, the two appear nearly identical and may be mistaken for each other.
Previously thought to be a native of Europe, the German cockroach later was considered to have emerged from the region of Ethiopia in Northeast Africa, but recent evidence indicates that it actually originated in South Asia or Southeast Asia, and diverged from Blattella asahinai slightly over 2,000 years ago. The cockroach's sensitivity to cold might reflect its origin from such warm climates, and its spread as a domiciliary pest since ancient times has resulted from incidental human transport... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Parque Natural Metropolitano | 🇵🇦 Panama | |
| 2 | Table Mountain National Park | 🇿🇦 South Africa |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Kuwait City | 🇰🇼 Kuwait | |
| 2 | Tijuana | 🇲🇽 México | |
| 3 | Kyiv | 🇺🇦 Ukraine | |
| 4 | Zhuhai [Macau] | 🇨🇳 China | |
| 5 | São Luís | 🇧🇷 Brazil | |
| 6 | Nairobi | 🇰🇪 Kenya | |
| 7 | Astana | 🇰🇿 Kazakhstan | |
| 8 | Valencia | 🇪🇸 Spain | |
| 9 | Guatemala City | 🇬🇹 Guatemala | |
| 10 | Budapest | 🇭🇺 Hungary |
Rare
Under 5% of wildlife watchers report a German Cockroach sighting in Philadelphia on a given day, based on 13 verified sightings from GBIF citizen-science data. It is the 340th most-seen of the 632 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.
December and January
In those months about 10% of wildlife watchers report a German Cockroach in Philadelphia on a given day, against under 5% in February to November, the lowest months.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most German Cockroach sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
40th of 69
Of the 69 cities where we can rate German Cockroach sightings, Philadelphia ranks 40th at under 5%. The best odds are in Kuwait City (Kuwait, about 30%), Tijuana (México, about 10%) and Kyiv (Ukraine, about 10%).
Same order: Blattodea
The closest relatives of the German Cockroach that you can see in Philadelphia (order Blattodea, Cockroaches and Termites) are American Cockroach (about 10%) and Oriental Cockroach (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the German Cockroach is recorded against all the insects logged in Philadelphia (13 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.
