What to look out for: October to February

The 'off season' for hoverflies really begins toward the end of October and continues into early March. (see the end for a list of species still above 10%opa in October). Using data from NBN atlas and excluding those marked 'larva', only 2% of all hoverfly records occur in the months Nov-Feb. Nevertheless, that is some. I do not believe any species achieve 10%opa from November to January, the only species to do so in February is Melangyna quadrimaculata - see March's article for information about that.

Some 46 species have records from January (I excluded larvae from the search but I can't guarantee that none of the results are 'undeclared larvae!'). It must be said though that you are considerably more likely to see adult hoverflies in the winter in the south.

The most likely species to see are Eristalis tenax, Eristalis pertinax, Eristalinus aeneus (near the coast), Episyrphus balteatus, Meliscaeva auricollis, and Melanostoma species. These may actually overwinter as adults. I have personally seen Eristalis tenax and Episyrphus balteatus on New Year's Day before!

It is worth therefore looking for hoverflies basking in sunlight on mild winter days. It may be possible to attract them by spraying foliage with a solution of sugar in water. In late winter, catkins (especially Salix) and early flowering Prunus species may be useful hunting grounds.

Another way to see hoverflies in winter is by looking for their larvae...

Larvae can most easily be found by searching through leaf litter. In the winter most larvae will be in a state of diapause (a sort of hibernation, if you will). Diapause often involves a change from bright to dull colours (green larvae often go brown). There is a separate project specifically for UK hoverfly larvae that also feeds into the HRS. Rotheray's guide to larvae is still very useful and can be found here. Many larvae can be identified to genus, and some even to species.

The following species remain over 10%opa in October
Didea fasciata 14%opa
Eristalis abusiva 12%opa, E. pertinax 20%opa, E. tenax 34%opa
Eupeodes luniger 22%opa
Helophilus pendulus 17%opa
Melanostoma scalare 11%opa
Neoascia podagrica 21%opa
Platycheirus albimanus 21%opa, P. manicatus 10%opa, P. scutatus 11%opa
Sericomyia silentis 16%opa, S. superbiens 15%opa
Syrphus ribesii 14%opa, Syrphus torvus 22%opa
Xanthandrus comtus 13%opa

Posted on February 8, 2024 10:06 AM by matthewvosper