Egle concomitans (Pandelle, 1900)

Michelsen, Verner, 2009, Revision of the willow catkin flies, genus Egle Robineau-Desvoidy (Diptera: Anthomyiidae), in Europe and neighbouring areas, Zootaxa 2043 (1), pp. 1-76 : 14

The Egle concomitans section

This section was proposed by Griffiths (2003) to include the widespread Egle concomitans ( Pandellé, 1900) , European E. myricariae Grossmann, 1998 and two northern Chinese species E. longirostris ( Stein, 1907) and E. anthomyioides (Fan in Jin et al., 1981). Two further, undescribed species have been reported from northern Pakistan (D.M. Ackland in litt.).

Species of this section, in particular E. concomitans , appear in some respects more plesiomorphic than other species of Egle and were actually until recently assigned to the genus Lasiomma Stein (e.g., Hennig 1972, Jin et al. 1981, Fan et al. 1988). Hennig (1976) found his own earlier generic assignment questionable, but made no alternative proposal. The present combination with the genus Egle was first suggested by Michelsen (1988) based on synapomorphies of the male terminalia. Corroboration of this assignment came with Grossmann (1998) who reported the larval habits of E. myricariae to be essentially the same as those of typical Egle except that its host plant was German tamarisk, Myricaria germanica (Tamaricaceae) rather than species of Salix or Populus (Salicaceae) . The small bisexual flowers of Myricaria form tight inflorescences superficially resembling the catkins of willow. Both have their developing seeds embedded in hair for subsequent wind dispersal.

Morphological support for the monophyly of the overall plesiomorphic Egle concomitans section is somewhat tenuous and has the implication that the projecting lower face and extended mouth parts have arisen through homoplasy in this section. However, certain male characters: (1) very prominent setose processes between bases of posterior lobes of sternite V; (2) accessory sclerites in membranous genital pouch; and (3) complex surstyli with spinous setae on inner apical lobe(s) might represent genuine autapomorphies. It also seems that the two undescribed Pakistani species mentioned above to some extent bridge the morphological gap between E. concomitans and the E. longirostris species group (D.M. Ackland in litt.).