Agromyza pallidiseta Malloch, 1924

Lonsdale, Owen, 2021, Manual of North American Agromyzidae (Diptera, Schizophora), with revision of the fauna of the " Delmarva " states, ZooKeys 1051, pp. 1-481 : 1

Agromyza pallidiseta Malloch

Agromyza pallidiseta Malloch, 1924: 192. Frick 1952a: 375; Spencer and Steyskal 1986b: 58.

Description.

Wing length 2.3-2.4 mm (♀). Male unknown. Length of ultimate section of vein M4 divided by penultimate section: 0.6. Eye height divided by gena height: 1.6. Head as described for A. aristata except parafacial not as strongly projecting and ocellar seta 1/2 length of postocellar seta.

Chaetotaxy: As described for A. aristata , except there are four dorsocentrals (one presutural), not three.

Colouration: As described for A. aristata except as follows: setae yellow; first flagellomere yellow with basal 1/3 very pale; posterolateral corner of frons only dark to level of posterior (not anterior) ors.

Variation: Florida specimen (head mostly collapsed) with ocellar seta ~ 2/3 length of postocellar and fronto-orbital plate brown to base of anterior fronto-orbital.

Host.

Unknown - possibly Celtis occidentalis ( Ulmaceae ).

Distribution.

Canada: ON*. USA: DC, FL*.

Type material.

Holotype: USA. DC: Rock Creek Park, 29.v.1922, J.R. Malloch (1♀, USNM).

Additional material examined.

Canada. ON: Ottawa , Arboretum, adult on Celtis occidentalis , 27.v.2017, O. Lonsdale, CNC799468-799471 (4♀, CNC) . USA. FL: Torreya St. Park , 29.iv.1952, O. Peck, on wood mud flat, CNC352944 (1♀, CNC) .

Comments.

The grey pruinose notum, yellow setae and head of Agromyza pallidiseta make it an easily recognised, albeit uncommon, species in eastern North America, known only from the holotype, one Florida female and four Ontario females. The Ontario females were taken as adults on Celtis occidentalis .

The Californian female listed as Agromyza pallidiseta in Spencer and Steyskal (deposited in the USNM) is clearly not conspecific with the holotype, as it is 2 × as large (4.6 mm), has a longer ocellar seta and brown setae.