Fig. 1. Side view of a worker of
Myrmelachista sp. (from Serna, 1999).
Fig. 2. Head of a worker of Myrmelachista
sp. (from Serna, 1999).
Key to Myrmelachista1,2
1.
Antennal scapes with erect or
suberect hairs ………………………... 2
Antennal scapes without such
hairs …………………….…………... 11
2(1). Hairs on scapes conspicuously
long and confined to their anterior
surfaces ………………………..……. 3
Hairs on scape shorter, more
generally distributed …………………. 5
3(2). Petiolar border distinctly excised;
head red, clouded with brown only on
the occiput; length 2.3 mm; St. Vincent
…………...……….…… ambigua Forel
Petiolar border entire or feebly
sinuate; head largely black or dark
brown ……………………………..…. 4
4(3). Length 1.75-2.3 mm; second
funicular joint broader than long; Virgin
Islands, Puerto Rico, Santo Domingo
1
Modified from Wheeler ()
NOTE: This key is only for subgenus
Myrmedachista does not include Hincksidris
(which Snelling syn. with Myrmedachista).
2
………………..… ramulorum Wheeler
Length 2.3-2.6 mm; larger and
more stout; second funicular joint longer
than broad; Mona Island and Puerto Rico
…………..…….. var. fortior Wheeler
5(2). Antennal clubs not infuscated
……………………………………..… 6
Antennal clubs more or less
infuscated …..………………………... 8
6(5). Mesosoma and gaster black ..... 7
Thorax and gaster castaneous.
Length 1.5-2.5 mm. Cuba …………
…………………….. rogeri Ern. Andre
7(6). Head largely red; petiolar border
deeply excised. Length 1.75-2.5 mm.
Cuba ……………. var. rubriceps Mann
Only the anterior border of head
red; petiolar border feebly excised. Cuba
…...…..………….. var. manni Wheeler
8(5). Sides of head rather convex; base
of propodeum longer than the declivity.
Length 2.3 - 2.5 mm. Costa Rica
……………….... costaricensis Wheeler
Sides of head straight; base and
declivity of propodeum subequal ….… 9
9(8). Larger forms (2-2.5 mm.); head,
thorax and antennal clubs black; México
…………………….. skiarrae Wheeler
Smaller forms (1.5-1.75 mm.)
head and thorax not black; antennal
clubs fuscous ……………………….. 10
10(9). Head small, head, thorax and
petiole piceous brown; México .……..…
……………………. var. picea Wheeler
Head larger; head, thorax and
petiole yellowish red. México ………….
…………………….. var. lacta Wheeler
11(1). Fore tarsi enlarged; petiolar scale
oval; color reddish yellow, with dark
brown gaster and pale yellow antennae
and tibiae. Length 2 mm. Cuba ……
………………………..….
kroatzi
Roger
Fore tarsi not enlarged; petiolar
scale not oval ……………………..… 12
12(11). Head red ……………………. 13
1
Head castaneous or black
…………….………………………… 14
13(12). Petiolar scale broader than high,
with convex sides, broadest in the
middle; erect hairs absent on thorax;
gaster brown; length 2 mm; Costa Rica
………………….… plebecula Menozzi
Much smaller (1.2 mm.); petiolar
scale narrow, with nearly straight sides,
broadest above; erect hairs present on
thorax; gaster black; Brasil ……..……
……………………
brevicornis
Wheeler
14(12). Pronotum yellow or reddish
yellow, contrasting with remainder of
thorax. Length 1.5 - 1.75 mm; Mexico
…..…………………… amicta Wheeler
Pronotum
piceous,
black,
castaneous or brownish red, concolorous
with remainder of mesosoma; length 1.32 mm; British Guiana. …………
……….……..…… guyanensis Wheeler
Discussion.
Distribution.
Map 1. Myrmelachista amicta.
Habitat.
Biology.
Myrmelachista costaricesis
Wheeler
Figs. ; Map
Myrmelachista amicta Wheeler
Figs. ; Map
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
Discussion.
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
2
Map 1. Linepithema humile.
Discussion. Hincksidris
Distribution. Panamá,
Chiriqui.
Map 2. Linepithema humile.
Distribution.
Volcán
de
Map 3. Myrmelachista longinoda.
Habitat.
Biology.
Myrmelachista mexicana Wheeler
Figs. ; Map
Map 2. Myrmelachista costaricesis.
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
Habitat.
Biology.
Discussion. Hincksidris.
Myrmelachista longinoda Forel
Figs. ; Map
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
3
Map 3. Linepithema humile.
Discussion.
Distribution.
Map 5. Myrmelachista plebecula.
Map 4. Linepithema humile.
Distribution.
Mirador.
México,
Veracruz:
Habitat.
Biology.
Myrmelachista ramulorum
Wheeler
and var. fortior
Figs. ; Map
Map 4. Myrmelachista mexicana.
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
Habitat.
Biology.
Discussion.
Myrmelachista plebecula Menozzi
Figs. ; Map
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
4
Map 5. Linepithema humile.
Discussion.
Distribution.
Map 7. Myrmelachista skwarrae.
Map 6. Linepithema humile.
Distribution.
Habitat.
Biology.
Myrmelachista zeledoni Emery
Figs. ; Map
Map 6. Myrmelachista ramulorum.
Habitat.
Biology.
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
Discussion. Hincksidris.
Myrmelachista skwarrae Wheeler
and var. picea, lacta
Figs. ; Map
Fig. 306. Side view of the
mesosoma, petiole and first gastral
tergum of a worker of L. humile.
5
Map 7. Linepithema humile.
Fig. 12. Head of a female of M. longinoda
(from Forel, 1899).
Map 8. Linepithema humile.
Distribution.
Fig. 13. Side view of a female of M.
longinoda (from Forel, 1899).
Map 8. xx xx.
Habitat.
Biology.
Fig. 14. Head of a female of M. nodigera
flavicornis.
Fig. 15. Head of a worker of M. nodigera
flavicornis.
Fig. 11. Antenna of a worker of M. nigella.
Literature cited
6
Wheeler, W. 19__.
7