Hylotrupes bajulus
In 3 days ~10% in a week ~20%
Hylotrupes is a monotypic genus of woodboring beetles in the family Cerambycidae, the longhorn beetles. The sole species, Hylotrupes bajulus, is known by several common names, including house longhorn beetle, old house borer, and European house borer. In South Africa it also is known as the Italian beetle due to their introduction to the environment by way of infested packing cases that had originated from Italy. Hylotrupes is the only genus in the tribe Hylotrupini.
This species, originating in Europe, and having been spread in timber and wood products, now has a practically cosmopolitan distribution, including Southern Africa, Asia, the Americas, Australia, and much of Europe and the Mediterranean.
Hylotrupes bajulus can reach a body length of about 8–20 mm (0.31–0.79 in), while mature larvae can reach 30 mm (1.2 in). These beetles are brown to black, appearing grey because of a fine grey furriness on most of the upper surface. On the pronotum two conspicuously hairless tubercles are characteristic of the species. On the elytra usually there are two whitish pubescent spots. Females do not have a real ovipositor, only a little more elongated telson... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Sierra de Guadarrama National Park | 🇪🇸 Spain |
Rare
Under 5% of wildlife watchers report a House Longhorn sighting in Prague on a given day, based on 6 verified sightings from GBIF citizen-science data. It is the 594th most-seen of the 724 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 House Longhorn in Prague on a given day, against under 5% in August to June, the lowest months. That is one of Prague's wettest months, with about 80 mm of rain against 30 mm in February.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most House Longhorn sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 cities where we can rate House Longhorn sightings, Prague ranks 3rd at under 5%, level with the leaders once rounded. The best odds are in Porto (Portugal, under 5%) and Vienna (Austria, under 5%).
Same family: Cerambycidae
The closest relatives of the House Longhorn that you can see in Prague (family Cerambycidae, Longhorn Beetles) are Fairy-Ring Longhorn Beetle (about 10%), The Tanner (about 10%) and Spotted Longhorn Beetle (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the House Longhorn is recorded against all the insects logged in Prague (6 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.
