Leucozona xylotoides (Johnson, 1916):80

The subgenus Leucozona s. str. differs by having abdomen oval, marginated; 2nd tergum mainly white, grey or pale yellow, with a medial lack vitta; 3rd and 4th terga black (sometimes anterior margin of 3rd tergum whitis); and wing with a medial dark macula. The subgenus Ischyrosyrphus has abdomen parallel-sided, mostly unmarginated (sometimes with very weak margin on terga 4th and 5th); tergum 2 black with pair of large subbasal subquadrate pale maculae, medially joined or not; 3rd and 4th terga with small pale maculae; wing without dark macula, except dark stigma.

Leucozona (Ischyrosyrphus) xylotoides (Johnson, 1916).

Johnson, C.W. (1916) Some New England Syrphidae. Psyche (Camb) 23, 75-80.

Adapted from Vockeroth (1992).

Species rather slender with pile of moderate length. Wing unmarked. Abdomen nearly parallel sided, with pale to submetallic, subquadrate or subrectangular maculae on terga 2-4.

Head: Face moderately to densely pollinose, dull yellow with narrow dark shining medial vitta, about one-fifth as wide as face. Eye with long dense pile.

Thorax: Scutum black; in some specimens with brownish or bluish tinge, subshining, yellow or gray pollinose laterally, only pale pilose. Scutellum dull yellow to brown, much darker on about anterior half. Ventral scutellar fringe sparse. Pleura black, with obscure or distinct grayish pollinosity on about dorsal half. Anterior anepisternum, meron, and katatergum bare. Dorsal and ventral katepisternal pile patches narrowly joined posteriorly, almost joined anteriorly. Metasternum bare. Wing unmarked except for dark brown stigma, microtrichose with bare areas on basal one-third: base of 2nd costal cell and most of anterior half of cell R without microtrichia. Legs: Metacoxa with or without posteromedial pile tuft.

Abdomen nearly parallel sided, unmargined, or with very weak margin on terga 4 and 5. Tergum markings pale dull yellow to submetallic gray; tergum 2 with pair of large subquadrate basal maculae, about 5/6 as long as tergum; terga 3 and 4 each with pair of subbasal subrectanguIar transverse maculae.

Synonyms:

Syrphus velutinus Williston, 1882: 314.

Ischyrosyrphus tricolor Bigot, 1884: 73.

Very similar to Leucozona (Ischyrosyrphus) velutina, but the lattest has scutum with many black pile behind transverse suture; wing membrane entirely microtrichose; and pale maculae of 2nd tergum at most 3/5 as long as tergite. L velutina is only known from Western Canada.

Body lenght: 10.0-11.8 mm (Vockeroth 1992).

Mengual et al. (2008) included in their analysis one species of each subgenus of Leucozona and they were resolved together as sister group of the two major groups of Syrphini sensu stricto, with the genera Dideoides, Eriozona, Dideopsis, Megasyrphus, Didea, Epistrophella, Xanthogramma, Chrysotoxum and Epistrophe forming one of those major groups. The second wass formed by Melangyna, Fagisyrphus, Meligramma, Dasysyrphus, Parasyrphus, Syrphus, Eupeodes, Lapposyrphus, Dioprosopa, Simosyrphus and Scaeva.

Nearctic species known from the East coast, ranging from Vermont and New Hampshire south to Virginia.