Heterostylum robustum
In 3 days ~10% in a week ~20%
Heterostylum robustum, the bomber fly, s a species of bee fly belonging to the Bombyliidae family. It is found in southwestern Canada, most of the western United States, and Mexico. It is a bomber fly, parasitizing bees and wasps by launching its eggs into their nests. It is the principal parasite of the alkali bee Nomia melanderi, an important alfalfa pollinator across Washington, Oregon, Idaho, and Wyoming. Other hosts of the fly include solitary bees such as Nomia nevadensis bakeri, Dieunomia triangulifera, Calliopsis anthidia, Nomia scutellaris, and Halictus rubicundus.
The eggs of H. robustum are 1.2 mm long, 0.7 mm wide, oval-shaped, and tapered on each end. They have a coating of mucus to which soil particles adhere. In the laboratory, the eggs take between about 8 and 11 days to incubate. Like the eggs of ground-nesting bees, they are laid by adults emerging in spring before the beginning of winter.
The development of the larvae of H. robustum proceeds through four moults. First stage larvae are nearly-white planidia, very active and about 1.6 mm long. They have three pairs of thoracic bristles, one long pair of caudal... Wikipedia →
| # | Park | Country | Daily sighting probability |
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More parks will be added in future updates.
Rare
Under 5% of wildlife watchers report a Bomber Fly sighting in San Diego on a given day, based on 10 verified sightings from GBIF citizen-science data. It is the 463rd most-seen of the 693 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.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Bomber Fly in San Diego on a given day, so our monthly data shows no clear season.
Among the best
Of the 2 cities where we can rate Bomber Fly sightings, San Diego ranks 2nd at under 5%, level with the leaders once rounded. The best odds are in Phoenix (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Bomber Fly is recorded against all the insects logged in San Diego (10 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.
