Tapered Drone Fly

Eristalis pertinax

Eristalis pertinax is a hoverfly in the family Syrphidae. It was first described by Giovanni Antonio Scopoli in 1763 and is found in Asia and Europe. Like Eristalis tenax, the larvae of E. pertinax are rat-tailed maggots living in drainage ditches, pools around manure piles, sewage, and similar places containing water with high organic load and low oxygen concentration. Source

Where it is now

In the last 8 weeks this insect was recorded 118 times across 7 areas (each area is a 5 degree square).

See the Tapered Drone Fly on the live map

Movement and weather

Each season it is first heard regularly where daytime highs are around 11°C (typically 10 to 12°C, from 5 areas). That holds across 15° of latitude, which suggests its timing follows temperature more than the calendar.

Arrival dates

The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.

Download every area as CSV

Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.