Lonchaea helvetica MacGowan

This species with its bare eyes, single row of subvibnssal setae, partly yellow tarsi, bare
scutellar disc, single stigmatical bristle and long antennae clearly belongs to the laticorms
group amongst the genus Lonchaea This group has been recently revised by MacGowan &
Rotheray (2000) who added a further three previously combined under the name L laticorms
Meigen and by MacGowan (2000) who added a further species, L ibenca MacGowan, 2000
from Spam.
Lonchaea helvetica differs from the other members of the laticornis group m the structure of
the male termmaha In particular the surstylus has a greatly extended and recurved posterio  ventral process and the aedeagus has a long, sinuous apical section This species shows

closest affinities with L mallochi MacGowan & Rotheray, 2000 and L serrata MacGowan
& Rotheray, 2000 both of which are species which as larvae are almost exclusively confined
to deciduous trees Neither of these species however has the recurved tip to the surstylus or
the long, sinuous apical segment to the aedeagus The other member of this group which is
apparently confined as a larvae to conifers is L caledonica MacGowan & Rotheray, 2000
which occurs in western Europe It however is easily distinguished from L helvetica by its
relatively massive, square shaped cerci and by the rounded posteno ventral process to the
surstylus. In the female the apical segment of the ovipositor m L helvetica has a lateral
fringe of short hairs which is a character not present m other females of the laticorms group
The related L obscuntarsis Collin, 1953 which, m the male, does have the combination of
a longer, more smuous, apical segment of the aedeagus and a rather hooked tip to the surstylus,
is separated from this species by the presence of hairs on the dorsal surface of the scutellum,
hairs posterior to the strong bristle on the katepisternum and hairs on the orbital plates