Eristalis, Latreille, 1804

Campoy, Andrés, Pérez-Bañón, Celeste, Nielsen, Tore R., Rojo, Santos & Cibio, Research Institute, 2017, Micromorphology of egg and larva of Eristalis fratercula, with an updated key of Eristalis species with known third instar larvae (Diptera: Syrphidae), Acta Entomologica Musei Nationalis Pragae 57 (1), pp. 215-227 : 222

Key to third instar larvae of known species of genus Eristalis

The following key is based on the keys of HARTLEY (1961) and DOLEZIL (1972), but with additional species and the amendment of several characters previously considered diagnostic but later shown to be shared among several species. The key has been updated to include the morphological studies of this paper. All known larval descriptions of Eristalis species are listed in Table 1.

1 Cuticle on dorsum with reticulate or mesh-like pattern of brown patches. ....................... .......................................................................................... E. nemorum (Linnaeus, 1758)

– Cuticle without reticulate or mesh-like pattern of brown patches. ................................ 2

2 Primary crochets strong, broad, markedly bent, their length scarcely exceeding their widthat base; distal 2/5 of crochets darkly pigmented (see HARTLEY 1961: Fig. 74).. ..... ................................................................................................. E. tenax (Linnaeus, 1758)

– Primary crochets long and thin, slightly bent, almost twice as long as their width at the base; distal 1/4 (exceptionally 1/3) of crochets more or less pigmented (see HARTLEY 1961: Fig. 73). ................................................................................................................ 3

3 Long spicules located in the upper margin on the lateral lips branched ( Figs 5–6 ). ......... ....................................................................................... E. fratercula (Zetterstedt, 1838)

– Long spicules located in the upper margin on the lateral lips simple, not branched (see PÉREZ - BAÑÓN et al. 2013: Fig. 2A ). ................................................................................ 4

4 Pubescence of dorsal and lateral parts of abdomen more or less spinose, at least slightly pigmented brown (particularly at bases of spines). ........................................................ 5

– Pubescence of dorsal and lateral parts of abdomen more or less fine, longer, hairs pale, without pigmentation. ..................................................................................................... 6

5 Anterior spiracle light brown and shinning, spiracular plate about 1.5–2 times as long as wide, stout and shortly conical; with a broadly truncate apex (see HARTLEY 1961: Fig. 79). ................................................................................... E. intricaria (Linnaeus, 1758)

– Anterior spiracle brown, spiracular plate about 3.6–4 times as long as wide (see KUZNETSOV & KUZNETSOVA 1994: Fig. 34). ......................... E. rossica Stackelberg, 1958

Figures

Figs 2–7. Third instar larva of Eristalis fratercula (Zetterstedt, 1838). 2 – head and thoracic segments (pro- and mesothorax), ventral view; 3 – antennomaxillary organs; 4 – details of the cephalic region and lips; 5–6 – long branched spicules in the upper margin on the lateral lips; 7 – longitudinal grooves and anterior spiracles, dorsal view. Abbreviations: am – antennomaxillary organs; an – antenna; as – anterior spiracles; bs – branched spicules; dl – dorsal lips; es – extra pair of sensilla; ll – lateral lips; mp – maxillary palp; mtp – mesothoracic prolegs; ts – tuft of long setae; vl – ventral lips.