Ημερολόγιο της/του antonva
Unfortunately, they can only be identified through genitalia, there is a recent recent study with a key to tell them apart, but only one species can be identified without genitalia (P. minutulus, which has one less segment than the rest).
The article: https://zookeys.pensoft.net/article/37816/element/2/15//
This are the species of the genus Phlegra found in Spain:
-P. blaugrana
-P. bresnieri
-P. cinereofasciata
-P. fasciata
-P. lineata
-P. sierrana
P. bresnieri has been observed in Galicia, which has thinner bands than the rest in the opistomsome.
A taxonomic key to the European species can be found here: https://araneae.nmbe.ch/specieskey/261/Phlegra
There is a key (K) to the Eristalis flies of the West Paleartic region which describes 20 species. Iberfauna (I) list 11 in Spain, and 9 of them have observations in iNat (N). There is also one observation of the American species E. stipator.
-E. alpinus (K) (I)
-E. arbustorum (K) (I) (N)
-E. cryptarum (K) (I)
-E. horticola (I) (N)
-E. intricaria (K) (I) (N)
-E. jugorum (K) (I) (N)
-E. nemorum (I) (N)
-E. pertinax (K) (I) (N)
-E. rupium (K) (I) (N)
-E. similis (K) (I) (N)
-E. tenax (K) (I) (N)
I will adapt the key to Spain:
Bumble bee like species; thorax with dense pile which obscures the base color: E. intricaria
-Bee like species; thorax with pile which does not obscure base color: 2
Antenna orange yellow. All tibiae orange: E. cryptarum
-Antenna brown to brownish black. At least tibia of fore and hind legs partly black: 3
Face with pale pollinose (worn specimens may have a narrow trace of a shiny medial stripe on lower half): E. arbustorum
-Face with a shiny black medial stripe: 4
Medial stripe of face very wide, up to 1/3 of width of the face. Eye in the middle with a dorsoventral band of denser and generally darker pile. Katepimeron hairy: E. tenax
-Medial stripe narrower than 1/3 of the face. Katepimeron bare: 5
Tarsi of fore and mid legs entirely yellow: E. pertinax
-Tarsi of fore and mid legs party or entirely dark: 6
Arista long haired; the longest hairs about as long as 1/3 the length of the arista. Pterostigma very long, about six times as long as broad: E. similis
-Arista hairs shorter than 1/3 the length of the arista, but several times as long as the arista at the base. Perostigma also shorter: 7
Hind femur somewhat swollen and arcuate, more so in the male. Anterior half of mesonotum dulled by greyish patterned pollinosity. Wings with a more or less obvious cloud across the middle: E. alpina
-Hind femur slender and straight. Anterior half of mesonotum not dulled by greyish patterned pollinosity: 8
Face yellow with a distinct black median stripe sharply separated from the yellow base. Pterostigma longer than broad. Face deeply anteroventrally produced, in profile about as much as the width of an eye. Hind femur normally black at the base: E. jugorum
-Face black or only obscurely yellow at the sides. Pterostigma long, 3-3.5 times longer than broad. Hind metatarsus orange-yellow. Female with tergites 2-4 brightly shining, without dull traverse bands. (also distinctive male genitalia visible in the key): E. rupium
Unfortunately, the guide considers E. jugorum, E. nemorum and E. horticola as synonyms, so I don't know about the accuracy of the last question. Seeing pictures of E. jugorum, it doesn't even sheem to have a yellow face. Some notes on those 3 species from observing the pictures in iNat: all three have abdomens with light transversal stripes, and two orange blotches at the sides of the first abdominal segment. in E. jugorum and E. horticola these blotches seem roundish, but in E. nemorum they are more fang-like. In males of E. arbustorum, these same blotches are also distinctive, giving the central black region an hourglass shape. E. horticola and E. jugorum have distintive black wing markings.
A couple observations with interesting commentary on E. horticola and E. jugorum:
https://www.inaturalist.org/observations/54184998
https://www.inaturalist.org/observations/19252915
https://www.inaturalist.org/observations/51623799
The abdomens of E. similis and E. pertinax have a tapered look, at least in some cases, but the tarsi have different colors (yellow/orange in pertinax, at least partially black in similis)
Link to the West Paleartic key: https://www.researchgate.net/publication/269928346_The_West_Palaearctic_species_of_the_genus_Eristalis_Latreille_Diptera_Syrphidae
Species listed in Spain: http://iberfauna.mncn.csic.es/showficha.aspx?rank=T&idtax=49175
As described in this article (http://sea-entomologia.org/IDE@/revista_60.pdf) and dicussed in this observation (https://www.inaturalist.org/observations/151817873)., there are 4 species of Panorpa Scorpionflies in Spain:
-P. communis
-P. germanica
-P. meridionalis
-P. vulgaris
P. meridionalis seems to be the most widespread species, while P. vulgaris may be restricted to the Pyrenees, so it probably cannot be found in Galicia.
The wing patterns are quite variable, so they may not be a good trait to use in identification. One trait that can be useful to ID the males are the markings on the male's reproductive capsule (the one that looks like the stinger), which in the case of P germanica are broad an straight, and in the other species thinner and converging.
Another character that can be useful is the color of occiput (top-back of the head), which in this region should always be black in P. communis, and brown-redish in P. meridionalis.
There are only 3 species:
-Trichius fasciatus
-Trichius gallicus
-Trichius sexualis.
T. fasciatus is the most widespread species and its range overlaps the other two species, but it's easily identifiable in most cases: all 3 species have 3 pairs of black markings on the elytra, and in T. fasciatus the most anterior marks touch the anterior margin of the elytra.
In the other 2 species there is a separation between the margin and the markings. These two have mostly separate distributions: T. gallicus can be found in Western Europe and T. sexualis in Eastern Europe. However, there are some exceptions, like this observation of T. sexualis in France (https://www.inaturalist.org/observations/164617047) and this one from Western Austria (https://www.inaturalist.org/observations/189154121), which may indicate that there may be some individuals of T. sexualis incorrectly assigned to T. gallicus in that region.
There are only three species:
-S. ribesii
-S. torvus
-S. vitridipennis
S. torvus can be IDed because in both sexes it has hair on its eyes. Under direct sunlight, this makes white reflections, but seems difficult to see otherwise.
As for S. ribesii and S. vitridipennis, the males are practically identical (other than genitalia and micropilosity of the wings), but the females are different because in S. vitridipennis 3/4 of the hind femora are black, and in S. ribesii yellow.
Sources:
https://en.wikipedia.org/wiki/Syrphus_ribesii
https://www.mapress.com/zt/article/view/zootaxa.4216.5.1
There probably are 2 species of Microdon in Galicia:
-M. analis
-M. mutabilis
-M. myrmicae
M. analis is easy to identify because it's the only one for which the hind margin of the scutellum is black. The other two, on the other hand, are cryptic species, as shown here: https://biblio.naturalsciences.be/associated_publications/societe-royale-belge-dentomologie-koninklijke-belgische-vereniging-voor-entomologie-1/srbe-145-2009/van-de-meuter-et-al-bulletin-145-vii-xii-116-120-2009.pdf
Three species have been reported in Galicia, and one more has been reported nearby:
-S. dignota
-S. pyrastri
-S. selenitica
-S. albimaculata (nearby)
S. pyrastri is easy to identify: the markings in the abdomen are almost white and not very curved, while S. albimaculata has squarish spots, and the other two species have heavily curved yellow markings.
S selenitica and S. dignota are difficult to distinguish: males are possible to ID by the angle that the eyes make when they meet in the front of the head: 90-106 degrees for S. dignota and 120-136 in S. selenitica. Females are tricky, and multiple traits should be used. They are described in this article: https://www.researchgate.net/publication/262917841_Scaeva_dignota_RONDANI_1857_Diptera_Syrphidae_-_first_records_in_Poland
Two Xylota species have been reported in Galicia, and two more nearby. For sure:
-X. segnis
-X. xanthocnema
Nearby:
-X. ignava
-X. sylvarum
The all look similar (black slender flies, with enlarged femurs for males), but they can be divided in two groups. X. xanthocnema and X. sylvarum are black with the last segments of the abdomen yellow, but the first has all yellow hind tibiae, and X. sylvarum partially black.
X. segnis and X. ignava have most of the abdomen orange, with black tip, but X. ignava has hind tibiae with yellow tips and yellow hind tarsi. Also, deeper red abdomen
Further ID help for X. ignava:
https://www.inaturalist.org/observations/180417146
Big, striking yellow and black hoverflies. Somewhat similar to Chrysotoxum, but these have long protruding antennae.
There are three species:
-X. citrofasciatum
-X. dives
-X. pedissequum
X. citrofasciatum is very easy to distinguish becuase it has orange legs, but the other two species are really similar. Here is a guide on how to tell them apart: https://www.inaturalist.org/posts/38160-xanthogramma-species-in-europe
