Xylota Meigen, 1822

Jeong, Soo-Hyun & Han, Ho-Yeon, 2019, A taxonomic revision of the genus Xylota Meigen (Diptera: Syrphidae) in Korea, Zootaxa 4661 (3), pp. 457-493 : 461-462

The genus Xylota Meigen

Xylota Meigen, 1822: 211 . (type species: Musca sylvarum Linnaeus, 1758 ), (unjustified new name for Heliophilus Meigen ).

Zelima Meigen, 1800: 34 . (type species: Musca segnis Linnaeus, 1758 ), (suppressed by I.C.Z.N., 1963: 339).

Eumeros Meigen, 1803: 273 . (type species: Musca segnis Linnaeus, 1758 ), (for discussion of nomenclatural problem see Wirth et al., 1965: 604).

Heliophilus Meigen, 1803: 273 . (type species: Musca sylvarum Linnaeus, 1758 ), (for discussion of nomenclatural problem see Wirth et al., 1965: 604).

Micraptoma Westwood, 1840: 163 . (type species: Musca segnis Linnaeus, 1758 ).

Diagnosis. The members of the genus Xylota can be distinguished from other syrphid taxa based on the combination of the following characters [modified from Thompson (1975) and Hippa (1978)]: 1) face concave; 2) arista longer than width of face; 3) metasternum short, pubescent, without long pile; 4) metafemur swollen with short spiny ventral setae; and 5) male metatrochanter with ventral calcar in varying length (from short tubercle to long spine). In addition, Thompson (1975) and Hippa (1978) also recognized the following aedeagal structures: 6) ejaculatory hood medially with furrow; 7) large, laterally flared, ventral lobe with a pair of lateral ejaculatory processes between which is the ejaculatory duct, and an enlarged dorsal lobe, which has its posterior surface flared so that the lateral lobes extend along the resultant groove; and 8) basal area of ejaculatory processes large, with indistinct basal and distal canoes.

Distribution. Over 130 species from all zoogeographical regions ( Pape & Thompson, 2013).

Biology. The members of the genus Xylota are saprophagous in larval stage, with their feeding habitats usually associated with wood ( Rotheray & Gilbert, 2011). Adult flies typically move in jerky zig-zag motion, and flit rapidly from leaf to leaf ( Rotheray & Gilbert, 2011). They rarely visit flowers, instead they feed on pollen grains that have fallen onto leaves with their large labella sweeping surface of the leaves ( Rotheray & Gilbert, 2011; van Veen, 2004).

Rotheray & Gilbert (2011) reviewed their breeding habit as follows. Many Xylota species stay close to their breeding sites. They are known for their high fecundity with as many as over 500 ovarioles per ovary. Low larval survival rate, as a compensation of such high fecundity, is unknown but if they have only to find proper feeding habitats for their larvae, it is successful for them to survive because of their concealed and protective saproxylic feeding habitat. Courtship behavior of the genus is not well known except that coupling of X. segnis may extend to several hours.

Nomenclatural remarks. The genus Xylota has an interesting nomenclatural history. Among the three senior synonyms of Xylota , the oldest Zelima became unavailable, when all the new names by Meigen (1800) were suppressed due to the duplication with many names by Hendel (1908) that had been already widely in use (I.C.Z.N., 1963: 339). Wirth et al. (1965) later suppressed the other two senior synonyms, Heliophilus Meigen, 1803 , and Eumeros Meigen, 1803 , due to the similarly spelled names that have been also widely in use at that time ( Helophilus Meigen, 1822 – Eristalini ; Eumerus Meigen, 1822 – Eumerini ).