[For explanations and definitions see here. Almost all of the data here is derived from NBN Atlas and the species information from Steven Falk's Flickr and the HRS website]

Another big month for hoverflies. For the first time in the year, more species are past their peak than not - but many of those species are still around in good numbers. 71 species peak this month, but only 3 reach 10%opa for the first time. The 84 species that peaked last month are still around, of course!

July is the best month to see....

...Anasimyia lunulata (46,-98%)

This Anasimyia is very similar to A interpuncta, a clear view of the markings on T3-4 (especially at the sides), and a side view of the face profile will help to separate them. Its distribution has apparently been decreasing, and records from the last ten years are restricted to Devon/Cornwall and Wales, especially the north west and Anglesey. There are early 21st century records from around Godalming and Norfolk. It is a species of bogland, perhaps associated with sphagnum mosses and bog-bean. Falk's pics

*TOP TARGET*

...Cheilosia proxima (21,-97%)

In general with Cheilosia it really is a case of 'the more angles the better'! With proxima the underside of the abdomen should be heavily dusted, it is also useful to capture the bristles on the scutellum, the side profile of the face and the colours of the legs - but that view of the underside of the abdomen is particularly valuable.

The larvae are known to develop in the rosettes of marsh thistle, but Falk states that it is likely they also develop in other thistles, since this is also a common species in dry grassland where marsh thistle is not present. Falk's pics. A ubiquitous species, only becoming somewhat rarer north of Dundee.

*TOP TARGET*

...Pyrophaena granditarsus (7,-93%) and P. rosarum (15,-90%)

Very distinctively marked species - still regarded as Platycheirus by many. Male P. granditarsus have remarkable hooked modifications of both the front and middle tarsi. These species are ubiquitous in distribution. They are found in wet grassland and often hover around tall vegetation such as rushes and reeds, and it may be productive to look for them on the stems. They visit a wide range of flowers.

...Paragus haemorrhous (18,-97%) and Paragus tibialis (70,-100%)

So it's a bit ambitious to put these here, but given how common P. haemorrhous is, I think it's worth it. These are tiny flies: only males are really distinguishable. Firstly though, especially if you are near the Thames estuary/North sea coast of Kent, it is worth getting a very good picture of the eyes - vertical bands of hair in the eyes indicate the critically endangered P albifrons. If there are no bands of eye hairs, males can be distinguished from the underside of the abdomen, by the size of the genitals, and the shape of the pregenital sternites. (Although tibialis should only be encountered in the south from Lyme Regis to London, it has been recorded in western Wales.)

The following species were discussed in June's 'First month you may find', but they peak now:

Cheilosia scutellata (36,-77%), Chrysogaster cemiteriorum (29,-90%), Lejops vittatus (67,-100%)

The following species were discussed in May's 'First month you may find', but they peak now:

Chrysotoxum elegans (51,-97%), Eupeodes bucculatus (63,-100%), Eupeodes nitens (69,-100%), Lejogaster tarsata (36,-97%), Parhelophilus consimilis (55,-100%), Parhelophilus versicolor (33,-100%)

The following species were discussed in April's 'First month you may find', but they peak now:

Neoascia interrupta (56,-96%)

The following species were discussed in March's 'First month you may find', but they peak now:

Eristalinus aeneus (30,-51%), Syrphus torvus (13,-68%)

Other species that peak in July [species in square brackets usually require microscopy to identify]:

Blera fallax (77,-100%)
Cheilosia illustrata (7,-29%), [C ahenea (95,-100%), C. longula (50,-100%), C. velutina (76,-100%), C. vernalis (21,-100%)]
Chrysogaster solstitialis (12,-52%)
Chrysotoxum bicinctum (10,-31%), C. festivum (27,+63%), C. verralli (46,+23%)
Didea alneti (87,-100%)
Epistrophe grossulariae (13,-8%)
Eristalinus sepulchralis (14,-67%)
Eristalis horticola (10,-56%), E. intricaria (6,-43%), E. nemorum (9,-24%)
Eupeodes corollae (6,+39%)
Helophilus groenlandicus (100,-100%)
Heringia senilis (92,-100%)
Leucozona laternaria (25,-56%)
Megasyrphus erraticus (58,-88%)
Melangyna sexguttata (=compositarum) (49,-94%)
Melanogaster aerosa (58,-100%)
Melanostoma mellinum (3,-88%)
[Myolepta dubia (71,-74%), M. potens (92,-100%)]
[Neoascia geniculata (39,-98%), N. tenur (5,-99%)]
Parasyrphus lineola (57,-73%)
Pelecocera tricincta (66,-55%)
Pipiza lugubris (68,-93%)
Pipizella maculipennis (90,-100%)
Platycheirus albimanus (1,-71%), P. aurolateralis (88,-100%), P. clypeatus (8,-99%), P. nielseni (37,-100%), P. occultus (29,-99%)
Scaeva pyrastri (7,+18%)
Sphaerophoria loewi (85,-100%), S. rueppellii (44,-64%), S. scripta (5,+25%), [S. fatarum (58,-96%), S. interrupta (14,-98%), S taeniata (65,-100%)]
Syritta pipiens (2,-37%)
Syrphus ribesii (3,-38%)
Volucella pellucens (4,+78%)
Xanthandrus comtus (41,-69%)
Xanthogramma stackelbergi (71,-15%)
Xylota florum (48,-95%), X. sylvarum (17,-41%), X. tarda (68,-100%)

July may be the first month you see...

*TOP TARGET*

...Triglyphus primus (59,-100%)

46%opa in July. A Pipizine notable because the abdomen is dominanted by T2+3, with T4 hardly visible. A view of the face will help clarify that it is a Pipizine, not a Cheilosia. The upper-outer cross vein meets the marginal at an acute angle, like in Pipiza, Heringia and Neocnemodon. The legs are partly pale, and not thickened.

This small species is associated with waste ground and urban brownfield sites as well as other thermophyllic environments like dry meadows and heathland. The larvae appear to be specific predators of the Mugwort Gall Aphid (Cryptosiphum artemisiae) that forms galls on Common Mugwort (Artemisia vulgaris). So look out for this plant! T. primus occurs in England south of York and through the Midlands, becoming rarer south west of a line from Worcester to Brighton.

Other species exceeding 10% of peak abundance (%opa) for the first time in July are [species in square brackets usually require microscopy to identify]:

Sericomyia superbiens (27,-68%) 19%opa
Volucella inanis (18,+309%) 52%opa

Posted on February 8, 2024 07:30 AM by matthewvosper