The Ants of Africa
SUBFAMILY FORMICINAE
Provisional Key to Genus Paratrechina and relatives
Contents - Formicinae - Paratrechina 2010 Introduction

Notes
Wheeler (1922: 942) listed Paratrechina vividula (Nylander, 1847: 900) as tropicopolitan and gave a single African finding as from Zare, at Niapu, collected by Lang & Chapin. This seems exceptional and, I surmise, was of Paratrechina weissi, but I included vividula below, showing a specimen from Egypt and a new finding from South Africa.

If LaPolla et al (2010) is accepted, the species P. kohli is regarded as Prenolepis kohli and the sole African representative of that genus. In the original description, Forel (1916) gave the mandibles as with 6 teeth and not as LaPolla et al state "can possess a small eighth tooth on the inner mandibular margin". LaPolla et al note "it has a number of morphological traits that suggest it belongs in Prenolepis. Among these characters are : (i) a mesothoracic constriction immediately behind the pronotum (although not as pronounced as in other species); (ii) mandibles with more than six teeth (up to eight in some specimens, although the eighth tooth is usually very small and found on the inner mandibular margin); (iii) striations across the mandibles as seen in most Prenolepis species; (iv) very long scapes that surpass the posterior margin of the head by more than half their length; (v) eyes convex, placed posterior to the midline of the head; and (vi) the propodeum with a very high domed shaped dorsal face. [The very long scapes feature can be applied to other African "Paratrechina"].

As on the genus page, I am convinced the original Paratrechina genus definition was unambiguous and the type species was wrongly designated by Wheeler (1911) as P. longicornis stemming from a failure to read the original Motschoulsky paper and to not realising Emery (1892) was not definitive in his synonymy of P. currrens and P. longicornis.


Further note: LaPolla & Fisher (2014) argue for the reversal of their earlier opinion on Paratrechina/Prenolepis kohli and go back to the genus placement as Emery (1925) had it, that is in the genus Paratrechina.

Reference: LaPolla, J.S., Fisher, B.L. (2014) Then there were five: a reexamination of the ant genus Paratrechina (Hymenoptera, Formicidae). ZooKeys, 422, 35–48. doi: 10.3897/zookeys.422.7779


New key to genera known from sub-Saharan Africa

This pays regard to LaPolla et al. but resists their acceptance of P. longicornis as the type for Paratrechina senso strictu.

A Maxillary palps with 5 or fewer segments; polymorphic
[this seems a very odd placement by LaPolla et al as the two species do not have the alitrunk erect hairs matching the Paraparatrechina criterion]; I retain the old separation for convenienc
Two African Paraparatrechina (former Pseudolasius) Parap. weissi and Parap. bufonus
-- Maxillary palps with 6 segments; monomorphic to slightly polymorphic B
B Mandibles always with 5 teeth; mesothorax not constricted immediately behind pronotum, scapes always lacking erect hairs C
-- Mandibles typically with 6-7 teeth D
C Propodeum without erect hairs; erect hairs on head scattered across surface; dorsal face of propodeum broad and gently rounded; femora and tibiae with large erect hairs [LaPolla et al have - Paratrechina - monotypic (?) P. longicornis. I have two species both with mandibles crossing when closed and scapes without erect hairs] Pseudoparatrechina
-- One pair of erect hairs on propodeum; erect hairs on the head form a pattern of 4 on the posterior margin and 6-7 rows from the posterior margin to the clypeal margin; dorsal face of propodeum typically short and angular; femora and tibiae without erect hairs Paraparatrechina
D Mesothorax constricted behind pronotum; eyes largely above midlength of head; mandibles with distinct striations across anterior surface Prenolepis kohli
-- Mesothorax not constricted immediately behind the pronotum; eyes set with about half their length each side of the mid-point of the head; mandibles without striations across anterior surface Paratrechina


Provisional key to "Paratrechina" workers from Africa with amendments in part following LaPolla et al (2010)

Paraparatrechina section in part derived from LaPolla, Cheng & Fisher (2010) http://www.mapress.com/zootaxa/2010/f/zt02387p027.pdf

For the present I have retained the use of Paratrechina on the species pages other than Paraparatrechina.

LaPolla et al (2010: 13) state that bourbonica and vaga are thought to be introduced species to the Afrotropical Region and that the species boundaries between the two are "poorly defined". They neither provided records of Afrotropical occurrence for these nor for vividula.

1 Mandibles always with 5 teeth; mesothorax not constricted immediately behind pronotum, scapes usually lacking erect hairs 2
-- Mandibles typically with 6-7 teeth; propodeum always without erect hairs (?)
11
2 Propodeum without erect hairs; erect hairs on head scattered across surface; dorsal face of propodeum broad and gently rounded; femora and tibiae with large erect hairs Pseudoparatrechina - 3
-- One pair of erect hairs on propodeum; erect hairs on the head form a pattern of 4 on the posterior margin and 6-7 rows from the posterior margin to the clypeal margin; dorsal face of propodeum typically short and angular; femora and tibiae without erect hairs
Paraparatrechina - 4
. Pseudoparatrechina .
3 {Paratrechina longicornis}TL 2.5-3.0 mm, CI 82, SI 235, very slender with elongated legs and antennae; alitrunk profile sinuous with the mesonotum shallowly concave and propodeum near flat to very weakly convex; pale smoky brown with paler appendages often with purple irridescence; erect hairs long and blunt Pantropical tramp - Pseudoparatrechina longicornis
--
Paratrechina hagemanniTL ca 2.5 mm; propodeum profile more convex; no erect hairs anywhere on the alitrunk; the eyes near circular rather than ovoid;  in full face view, the head has convex sides rather than the usual near parallel sides; raised metanotal spiracles, set behind the weakly convex mesonotum (shallowly concave in longicornis); the propodeal spiracle is set in the centre of the side, on longicornis it is set almost on the border of the declivity Congo Basin & Sudan - Pseudoparatrechina hagemanni
-- {Paratrechina zanjensis}TL 2.6-3.2 mm, CI 71-79, SI 198-220, readily separated by the presence of short erect hairs on the scapes; also a distinctly convex profile to the propodeum
Southern Africa tramp - Pseudoparatrechina zanjensis
. Paraparatrechina .
4 Alitrunk elongate in lateral view, pronotum gently rising towards mesonotum; SI > 150 5
-- Alitrunk compact in lateral view, pronotum steeply rising towards mesonotum, SI variable all <140 6
5 Paraparatrechina splendidaSL >0.72 mm; tibiae and protrochanter same dark brown as alitrunk, meso/metatrochanters may be lighter; mandibles and antennae typically same brown as head
TL 1.41-2.6 mm, HL 0.54-0.64, HW 0.48-0.50, CI 76-86, SL 0.73-0.83, SI 157-172
Gabon & Uganda - Paraparatrechina splendida
-- Paarparatrechina concinnataSL <0.72 mm; tibiae whitish to brownish-yellow, all trochanters white; mandibles and antennae yellowish-brown, contrasting with brown head; pubescence golden
TL 1.73-2.16 mm, HL 0.49-0.53, HW 0.38-0.43, CI 75-86, SL 0.63-0.69, SI 158-173
Cameroun, CAR, Gabon - Paraparatrechina concinnata
6 Yellow to yellowish-brown, gaster may be darker 7
-- Overall brown to dark brown 10
7 Paraparatrechina umbranatisGaster brown, contrasting with yellow head and alitrunk
TL 1.19-1.57 mm, HL 0.38-0.41, HW 0.34-0.36, CI 87-92, SL 0.38-0.43, SI 108-120
Angola, Gabon & Kenya - Paraparatrechina umbranatis
-- Overall yellow to yellowish-brown 8
8 {Paratrechina sp undet T1}TL 1.3 mm; shiny yellow-orange; head rectangular with near straight anterior margin; scapes slender and just surpassing the occiput
On this website since 1978, posted as Paratrechina minima on 18 January 2010
Nigeria - Paraparatrechina minima new species
. {Paraparatrechina gnoma}Listed specimens include mine from Nigeria
TL 1.20-1.44, HL 0.36-0.38, HW 0.32-0.34, CI 85-94, SL 0.34-0.38, SI 102-115
Ghana & Nigeria - Paraparatrechina gnoma
-- Larger HL & SL > 0.4 mm TL 9
9 Paraparatrechina oreiasHead and scapes with appressed pubescence; metanotum well defined with raised spiracles
TL 1.40-1.75, HL 0.45-0.46, HW 0.37-0.39, CI 80-87, SL 0.41-0.45, SI 105-120
Cameroun (Mt Cameroon only) - Paraparatrechina oreias
-- {Paratrechina subtilis}TL 1.5 mm; brown-yellow; submatt; scapes exceeding occiput by about 1/4 of their length; with coarse short pubescence giving a shaggy appearance; erect hairs long, yellow, thickish, 4 pairs on the alitrunk
.
. {Paratrechina subtilis}LaPolla & Cheng state TL 1.45-1.65 mm, HL 0.46-0.50, HW 0.37-0.42, CI 77-87, SL 0.43-0.48, SI 110-122 West Africa & Congo Basin - Paraparatrechina subtilis
10 {Paraparatrechina albipes}Brown, near black, dorsum of alitrunk and gaster lighter; tarsi, mandibles and petiole pale; matt; with distinct pruinose pubescence; scapes exceeding occiput by about 1/3 of their length; propodeum profile an acute angle with the dorsum much shorter than the declivity; my TL 1.56 mm, HL 0.47, HW 0.39, SL 0.54, PW 0.28
.
. {Paraparatrechina albipes}LaPolla & Cheng state white coloured pubescence covering body
TL 1.41-1.89 mm, HL 0.39-0.47, HW 0.35-0.42, CI 81-93, SL 0.48-0.53, SI 119-140
West Africa & Congo Basin - Paraparatrechina albipes
-- {Paratrechina brunnella}Antennae and mandibles yellowish-brown contrasting with rest; golden pubescence covering body
TL ca 1.2-1.6 mm, HL 0.37-0.41, HW 0.32-0.37, CI 81-94, SL 0.35-0.46, SI 102-124
Ghana, Cameroun, Gabon & Kenya - Paraparatrechina brunnella
. Mandibles typically with 6-7 teeth .
11 {Prenolepis kohli}Mesothorax constricted behind pronotum; eyes largely above midlength of head; mandibles with distinct striations across anterior surface
TL 3.6-4.0 mm, CI 82, SI 154; mandibles matt and very densely striated, clypeus carinate and strongly vaulted, large eyes in posterior third of face, scape surpassing occipitum by about one-third its own length; red brown, legs and antennae reddish-yellow; overall matt and densely reticulate-punctate all over; erect hairs large and pointed but generally scarce
Central African Republic & Zare - Prenolepis kohli
-- Mesothorax not constricted immediately behind the pronotum; eyes set with about half their length each side of the mid-point of the head; mandibles without striations across anterior surface Paratrechina - 12
. Paratrechina (the Lapolla et al. Nylanderia) .
*
Paratrechina waelbroecki worker ?Queen and male only adequately described (see species page)
Possible worker shown, TL ca 5 mm
waelbroecki
12 Propodeum in profile raised and rounded (gibbous); with the dorsum and declivity about equal in length
13
-- Propodeum in profile angular or shallowly curved; with the dorsum always much shorter than the declivity
19
13 Base colour yellow or yellowish brown
14
-- Base colour darker brown to near black
15
14 Paratrechina luteafraTL ca 2.2-2.5 mm, head relatively short; legs and scapes the same colour as the body, and much brighter golden-yellow; erect hairs relatively stout and dark
Gabon & Cameroon luteafra
-- {Paratrechina incallida}TL ca 2.2 mm; scape surpasses occiput by more than half its length; colour red-brown, shiny; head ovoid with near straight occiput; erect hairs thin and pale
.
. Paratrechina incallida So Thom, Gabon & Ivory Coast - incallida
15 Paratrechina brevisetulaalitrunk with very short pilosity
Gabon & Cameroun brevisetula
--
Alitrunk with longer pilosity 16
16 TL > 2.5 mm 17
-- TL < 2.5 mm 18
17 Paratrechina silvulaTL 2.8-3.3; head, alitrunk and gaster a solid dark reddish-brown; scape length between 0.95–1.04 mm Kenya - silvula
--
Paratrechina impolitaTL 2.6-3.0 mm; dark brown with rugulose head and alitrunk
Angola north to Ghana impolita
18 {Paratrechina lepida}{Paratrechina lepida}TL ca 2.0 mm; antennal scape surpassing occiput by some 1/3 of its length; head smooth & shiny; black with a brown tint; bristly Cameroun & Congo Basin - lepida
-- {Paratrechina mendica}TL ca 2.0 mm; antennal scape surpassing occiput by about 1/5 of its length; head finely striato-reticulate; lateral pronotum rugulose; gaster distinctly striate; pitch black, appendages brown, palps & tarsi whitish; propodeum profile angular .
. Paratrechina mendica
Fernando Po I., Cameroun & Congo Basin - mendica
--
{Paratrechina grisoni}TL generally > 2.0 mm; metanotum with raised transverse welt; propodeum very humped, with small tooth at base of declivity; dark brown, shiny West Africa & Congo Basin, east to Kenya - grisoni
. Propodeum profile shallowly convex or angular, dorsum much shorter than declivity
.
19 {short description of image}TL 2.5-3.0 mm; clypeus quite strongly scalloped; eye oval longer than wide; propodeum with dorsum shorter than declivity; whole body with obtuse, quite coarse erect dark brown hairs; abundant pubescence; dark brown to blackish; mandibles reddish brown, legs and antennae dark brown pantropical tramp (Congo Basin; Pemba Is., Tanzania) - bourbonica
-- TL < 2.5 mm 20
.
Medium sized TL < 2.5 mm .
20 Paratrechina vividulaTL 2.0-2.5 mm; HL > HW; with only sparse pubescence on gaster and coarse erect hairs; overall brown, dark on head and gaster
Less than 10 erect hairs on the scape; eyes without visible micropilosity
South Africa & Egypt (pan-global tramp, in northern European hot-houses) - vividula
-- More than 10 erect hairs on each scape
21
21 Base colour brown to dark brown 22
-- Base colour yellow brown or paler
23
22 Paratrechina umbellaBase colour brown to dark brown; TL 2.2 mm; propodeum a fairly smooth curve, head with convex sides East Africa, Congo, Ghana & Nigeria - umbella
-- Paratrechina nsp CongoTL ca 1.85 mm, HL 0.46, HW 0.31, SL 0.46, PW 0.27; CI 72, SI 138; head with near parallel sides
Congo - new species
23 Eyes set close to margins of head in fullface view
24
-- Eyes distinctly distant from margins of head in fullface view 25
24 {Paratrexchina umbella}TL 1.8-2.0 mm; mesocoxae and metacoxae lighter than procoxae
Ivory Coast & Nigeria - scintilla
-- {short description of image}TL ca 2.5 mm; HW = HL = SL; head in full face view with convex sides and eyes almost interrupting the margins; darker at least red-brown, alitrunk lighter
Note P. boltoni is a junior synonym
West Africa - nimba
25 Paratrechina weissiTL 2.2 mm; matt, head a little shiny; colour generally yellow brown; propodeum with short dorsum and much longer near vertical declivity, transition weakly angular; erect pilosity long, fine and yellow Congo Basin - weissi
-- {short description of image}Major worker TL ca 3.7 (distended gaster) HW 0.78 HL 0.88 EL 0.21 SL 0.87 PW 0.60 CI 94 SI 115; minor worker TL 2.2-2.6 mm; HL > HW; with noticeable pubescence of gaster and fine erect hairs; somewhat darker yellow-brown; eyes with visible micropilosity

North Africa, Egypt & Sudan - jaegerskioeldi
-- Paratrechina zelotypaTL ca 2.7 mm, HL 0.71, HW 0.61, SL 0.60; head in full face view with a more evenly ovoid shape.
On natalensis the type specimen is a bizarre colour seemingly due to a veneer of contaminant; the size is almost identical
Tanzania & Zimbabwe - zelotypa
southern Africa - natalensis
-- Paratrechina usambaricaTL 2.3-2.8, HW 0.55-0.64,  HL 0.67-0.74, SL 0.73-0.80, PW 0.41-0.47; CI 82-87, SI 123-133; occiput distinctly medianly incurved, sides of head strongly curved; golden-yellow with contrasting dark erect hairs
Tanzania - usambarica

Undetermined species

Paratrechina species (indet.) (1)

Described as widespread, 794 workers from 12 sites, in Ghana semi-deciduous forest leaf litter by Belshaw & Bolton (1994b); probably Paratrechina grisoni/lepida listed by LaPolla, Hawkes & Fisher (2011)


Paratrechina species (indet.) (2)

Forty-eight workers found in secondary forest leaf litter at five sites, plus under cocoa at Bunso, in the Ghana semi-deciduous forest, by Belshaw & Bolton (1994b); probably Paraparatrechina grisoni/lepida listed by LaPolla, Hawkes & Fisher (2011); also from Mangkrang was Paraparatrechina gnoma


Paratrechina species (indet.) (3)

Many (148) workers found in leaf litter under cocoa at Effiduase, Asiakwa and Nankasi, and under forest at Bobiri, Ghana, by Belshaw & Bolton (1994b); probably Paraparatrechina albipes listed by LaPolla, Cheng & Fisher (2010)


Paratrechina species (indet.) (4)

A single worker was found in cocoa leaf litter at Asiakwa, Ghana, by Belshaw & Bolton (1994b); probably Paratrechina grisoni/lepida listed by LaPolla, Hawkes & Fisher (2011).


Paratrechina species 4

Found in Ghana, in dead wood on the ground and on herbs under cocoa at the Mampong Cemetery farm, and nesting in the dead wood (Room, 1971). Ten workers were collected from the ground at CRIG by Bigger (1981a). Paraparatrechina albipes listed by LaPolla, Cheng & Fisher (2010)


Paratrechina species

Listed from Ghana cocoa at Kade by Majer (1975).


Paratrechina species 56

From Ghana on cocoa mistletoe (Room, 1975). Possibly Paratrechina incallida listed by LaPolla, Hawkes & Fisher (2011)


Paratrechina species from Campo Forest

From Cameroun, Campo Forest trees (Campo forest survey, 1991). Nests under bark and in epiphyte axils (Dejean & colleagues). None examined by LaPolla, Hawkes & Fisher (2011).

Contents Subfamily Formicinae
2007, 2009, 2010, 2011, 2013, 2014, 2015 - Brian Taylor CBiol FSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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