Key to Monomorium queens of the New World

This key is based on: DuBois, M. B. 1986. A revision of the native New World species of the ant genus Monomorium (minimum group) (Hymenoptera: Formicidae). University of Kansas Science Bulletin. 53:65-119.

1

Head broadest at occiput; surface sculpturing greatly reduced; masticatory margin of mandible with fewer than 4 teeth . . . . . 11

Head broadest near compound eyes; at least some surface sculpturing near mandibular insertion; masticatory margin of mandible with 4 teeth . . . . . 2

2

return to couplet #1

Lateral profile of scutum and scutellum convex . . . . . 5

Lateral profile of scutum and scutellum flat or concave . . . . . 3

3

return to couplet #2

Scape with lateral fringe of erect setae; occurs in California, Nevada, and Utah . . . . . Monomorium wheelerorum (= Monomorium ergatogyna)

Scape lacking lateral fringe of erect setae . . . . . 4

4

return to couplet #3

Petiole emarginate; postpetiole not emarginate; head sculpturing reduced; occurs in Caribbean region . . . . . Monomorium ebeninum

Head of Monomorium ebeninum queen

Profile of Monomorium ebeninum queen

Petiole not emarginate; postpetiole emarginate; head sculpturing as in; occurs in central Mexico . . . . . Monomorium compressum

5

return to couplet #2

Mesonotum with notal furrow . . . . . 6

Mesonotum lacking notal furrow . . . . . 7

6

return to couplet #5

Metanotum not projecting to level of propodeum and scutellum; petiole and postpetiole not emarginate; occurs in central and north-central Atlantic coastal states . . . . . Monomorium emarginatum

Head of Monomorium emarginatum queen

Profile of Monomorium emarginatum queen

Metanotum projecting to level of propodeum and scutellum; petiole and postpetiole emarginate; occurs along coastal regions from New Jersey to Florida . . . . . Monomorium viridum

Head of Monomorium viridum queen

Profile of Monomorium viridum queen

7

return to couplet #5

Scape with lateral fringe of erect setae; occurs in coastal and southern California . . . . . Monomorium ergatogyna

Head of Monomorium ergatogyna queen

Profile of Monomorium ergatogyna queen

Scape lacking lateral fringe of erect setae . . . . . 8

8

return to couplet #7

Basal face of propodeum 2X length of declivity; known only from type locality (Nayarit, Mexico) . . . . . Monomorium marjoriae

Basal face of propodeum never 2X length of declivity . . . . . 9

9

return to couplet #8

Head sculpturing greatly reduced, rugae only on lateral margin of clypeus; occurs in northern Florida . . . . . Monomorium trageri

Head of Monomorium trageri queen

Profile of Monomorium trageri queen

Head with rugae in addition to those on lateral margin of clypeus . . . . . 10

10

return to couplet #9

Gyne winged (sclerites near wing base not fused); postpetiole emarginate; common in central U. S. . . . . . Monomorium minimum

Head of Monomorium minimum queen

Profile of Monomorium minimum queen

Gyne wingless (sclerites fused); postpetiole not emarginate; occurs throughout central Mexico, Arizona, New Mexico, and parts of Texas . . . . . Monomorium cyaneum

Head of Monomorium cyaneum queen

Profile of Monomorium cyaneum queen

11

return to couplet #1

Metanotum reaching level of propodeum and scutellum; postpetiole emarginate . . . . . 12

Metanotum not reaching level of propodeum and scutellum; postpetiole not emarginate; known only from type locality (Livingston Co., Michigan) . . . . . Monomorium talbotae

Head of Monomorium talbotae queen

Profile of Monomorium talbotae queen

12

return to couplet #11

Mesonotum with notal furrow; petiole not emarginate; masticatory margin of mandible with 3 teeth; known only from type locality (Washington, D.C.) . . . . . Monomorium pergandei

Head of Monomorium pergandei queen

Profile of Monomorium pergandei queen

Mesonotum lacking notal furrow; petiole emarginate; masticatory margin of mandible with 2 teeth; known only from type locality (Estado de Mexico, Mexico) . . . . . Monomorium inquilinum