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


 * 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


 * 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


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

7
return to couplet #5
 * Scape with lateral fringe of erect setae; occurs in coastal and southern California . . . . . Monomorium ergatogyna


 * 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 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

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

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

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


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