What is a genus-interpreting structural diversity among species of urothripine Phlaeothripinae (Thysanoptera)
Author
Mound, Laurence A.
Author
Lima, Élison Fabrício B.
Author
O’Donnell, Cheryle A.
text
Zootaxa
2023
2023-07-24
5319
1
91
102
http://dx.doi.org/10.11646/zootaxa.5319.1.6
journal article
57776
10.11646/zootaxa.5319.1.6
55424897-b73c-4e41-9aee-f5ad464d4275
1175-5326
8182213
F74A47A2-8711-45A5-856E-804C16B3C4C1
Stephanothrips
Trybom
Stephanothrips
Trybom, 1912: 42
.
Type
species
Stephanothrips buffai
Trybom.
Baenothrips
Crawford, 1948: 39
.
Type
species
Baenothrips guatemalensis
Crawford
,
syn.n.
Verrucothrips
Stannard, 1952: 128
.
Type
species
Amphibolothrips
(
Verrucothrips
)
caenosa
Stannard.
Ramachandraiella
Ananthakrishnan, 1964: 228
.
Type
species
Ramachandraiella minuta
Ananthakrishnan.
Transithrips
Bournier, 1963: 81
.
Type
species
Transithrips asper
Bournier.
Bournieria
Ananthakrishnan, 1966: 2
.
Type
species
Bournieria indica
Ananthakrishnan.
Four of the generic synonyms indicated above were discussed by
Mound (1972: 92)
, but the validity of
Baenothrips
has not been questioned since
Stannard (1952)
. The sole distinction between
Baenothrips
and
Stephanothrips
has been in the degree of separation between antennal segments III–V, being separate in the first genus but largely fused in the second.
Baenothrips guatemalensis
, the type species of that genus, is interpreted as having segments III–V distinct from each other (
Fig. 5
), although the separation between them is by no means clear. Among the various species placed in
Baenothrips
only
asper
and
cuneatus
have these segments clearly separate (
Fig. 8
). In the only known specimen of
guatemalensis
segments VII and VIII are fused with scarcely any trace of suture, and this is also true of
chiliensis
(
Fig. 7
). Very similar to these in structure and sculpture, the Australian species,
moundi
, has segment VIII clearly distinct (
Fig. 6
). A further problem is that in another Australian species,
B. caenosus
, antennal segments VII and VIII can be either fused or separate (
Mound 1972
). There is also a lack of clarity in distinctions between some described species. For example,
Bhatti (2002)
published a detailed morphological study of a
paratype
of
asper
, recognizing that specimens identified as
asper
from
India
do not represent that African species. The original illustration of
asper
by Bournier, as well as the illustrations of a
paratype
by Bhatti, indicate that, in this species from
Angola
, antennal segments III–V are clearly distinct from each other, much as in
cuneatus
(
Fig. 8
). In contrast, the antennae of Indian specimens labelled by Ananthakrishnan as
asper
(Ooty,
vii.1970
) have segments III–V broadly joined.
Our interpretation is that antennal segment fusion has been subject to several reversals among the various species, and that this character state cannot be employed to distinguish natural groups. As a result, the genus
Baenothrips
is here considered a synonym of
Stephanothrips
, and that genus will now include 47 species. These comprise 26 species from the Asian tropics, nine from
Australia
, three from Africa, and four from southern
USA
, plus four from South America where they are possibly introduced (see above Geographic considerations). In addition, because the only known males of
occidentalis
were taken in
Thailand
(
Okajima & Urushihara 1995b
), it is probable that this pantropical species is also Asian in origin. Since several of the nine species from
Australia
are known only from the northern subtropical parts of this continent, it is clear that the distribution of species in this genus is primarily in association with the southeast Asian tropics. The new synonymy of
Baenothrips
with
Stephanothrips
results in the 15 new combinations listed in
Table 1
.