The genus Scirtothrips in Australia (Insecta, Thysanoptera, Thripidae)
Author
Hoddle, Mark S.
Author
Mound, Laurence A.
text
Zootaxa
2003
268
1
40
journal article
10.5281/zenodo.157021
161551bf-ef8c-4d6a-abe5-38226f776208
11755326
157021
Scirtothrips pilbara
sp. nov.
[
Figs 17
,
45
]
Female macroptera
.
Colour
: Yellow, compound eyes with 4 ommatidia weakly to deeply shaded; tergites II – VIII brown medially, ocellar triangle and anterior half of mesonotum sometimes brown; antecostal ridges on tergites IIIVIII dark medially but paler laterally; sternal antecostal ridges on IIIVII dark; forewings uniformly weakly shaded; antennal segment 1 pale, II variable, III – IV pale with apex shaded, V VIII dark.
Structure
: Vertex closely striate, ocellar triangle with transverse lines; bases of ocellar setae pair III usually separated by at least the length of these setae, arising well anterior of tangent to anterior margins of posterior ocelli toward margins of ocellar triangle; three pairs of postocular setae at least as long as ocellar setae pair III; mouth cone long, extending to mesosternum. Pronotum with anastomosing transverse striae closely spaced; 68 anteromarginal setae, 1220 discal setae; 5 pairs of posteromarginal setae, S2 about twice the length of S1, S1 subequal to S3 and both longer than S4 and S5. Metanotal sculpture transversely reticulate anteriorly and longitudinally reticulate posteriorly; median setae close to margin. Forewing scale with 45 marginal setae; first vein setae 314+19+12+0 1+01; second vein 46 setae; proximal posteromarginal fringe cilia straight. Bases of median tergal setae on segments IIIV almost inline with tergal discal setae, separated by no more than 0.75 times the length of these setae; tergal microtrichial fields with 3 discal setae; VIII with a few discal microtrichia anteromedially, posteromarginal comb interrupted medially; tergite IX with microtrichia on posterior half. Sternites IIIVI with 3 pairs of posteromarginal setae; microtrichia reduced, scarcely extending mesad of S3.
Measurements of
holotype
female
. Body length 1300. Head, length 75; width 175; p.o.
S1 20
. Pronotum, length 125; width 190; posteromarginal setae
S1 13
,
S2 30
. Forewing length 750. Antennal segments III – VI, 52, 47, 35, 47.
Male
macroptera
. Similar in colour and sculpture to female, but smaller; abdominal segment IX without paired drepanae, anterior margin convex and extending into segment VIII; aedeagus without paired array of spines laterally, but with group of small spines at apex.
Holotype
female.
Western
Australia
,
20 km
west of Millstream, from
Acacia xiphophylla
[Leguminosae],
23.ix.1995
. (LAM 2810).
Paratypes
:
7 females
and
1 male
collected with
holotype
;
40 km
southwest of Yalgoo,
3 females
from
Acacia ramulosa
,
26.iv.1997
(LAM 3237);
Material excluded from
type
series
:
Western
Australia
,
50 km
south east of Wittenoom,
9 females
from?
Crotalaria
flowers,
24.ix.1995
(LAM 2823);
170 km
south of Carnarvon,
1 female
from
Acacia grasbyi
25.iv.1997
(LAM 3219);
75 km
southwest of Yalgoo,
1 female
collected from
Acacia
sp.
26.iv.1997
(LAM 3239);
100 km
west of Paraburdoo,
1 female
collected from
Acacia
sp.
23.iv.1997
(LAM 3207);
Queensland
,
15 km
west of Mt Glorious,
3 females
and
3 males
collected from
Acacia bipinnate
sp.,
19.iii.2002
(LAM 4127);
Australian Capital Territory
,
Casuarina Sands
,
1 female
collected from
Acacia mearnsii
,
6.xii.1994
(LAM 2606).
Comments.
The three
paratypes
from
Acacia ramulosa
have a clearly defined brown area medially on the tergites, whereas the females taken with the
holotype
have this area with weak and diffuse shading. The nonparatypic females listed above from
Crotalaria
flowers near Wittenoom are all considerably darker than the
type
series. They not only have the tergites extensively brown, but the forewing second vein bears 8 – 12 setae, and ocellar setae pair III arise further apart close to the anterior margins of the ocellar triangle. In contrast, the specimens from Mt Glorious, Queensland, are considerably smaller and clear yellow, with ocellar setae III separated by no more than the diameter of the first ocellus. Moreover the males in this sample have a paired array of slender spines laterally on the aedeagus. The pattern of variation amongst these specimens excluded from the
type
series of
S. pilbara
is such that it is not possible to conclude how many species might be involved. Even the single female taken from near Canberra cannot be distinguished with confidence from the Western Australian specimens. Presumably this speciesgroup, in which the mouth cone usually extends to the mesosternum, is associated with various species of
Acacia
.