Review of the Nearctic species of Leiophron and Peristenus (Hymenoptera Braconidae: Euphorinae) parasitizing Lygus (Hemiptera: Miridae: Mirini:)
Author
Goulet, Henri
Author
Mason, Peter G.
text
Zootaxa
2006
2006-09-28
1323
1
1
118
https://biotaxa.org/Zootaxa/article/view/zootaxa.1323.1.1
journal article
10.11646/zootaxa.1323.1.1
11755334
5071178
071E8D92-514B-4E2B-9F3F-E085CACA976A
Peristenus gillespiei
n. sp.
(Table 16)
Type material.
Type locality:
Canada
,
British Columbia
,
West Harrison Road.
Holotype
, female (
CNCI
), labelled: [White] “
Canada
, BC West Harrison road
49º16'26"N
121º52'41"W
20.VI.2001
, emg.
19.V.2002
D. Gillespie
, clover”; [White] “Ex
Lygus shulli Knight Code
: WHR20VI01Ls19V02”; [Red] “
HOLOTYPE
Peristenus gillespiei CNC No.
23479”. Condition of
holotype
: excellent.
Allotype
male from
Canada
, BC, Silver &
Skagit Rd.
,
22.VI.2000
49º14'N
121º23'W
to
49º08'N
121º16'W
, 450–600 ms.
Paratypes
: all specimens reared from the following localities in
Canada
, BC:
West Harrison
road;
20–25 km
SE Chilliwack Lake
road;
Hemlock Valley
ski hill;
Mount Cheam
;
30 km
S Skagit Valley
road
.
Origin of species name.
This species is named in honour of David Gillespie who worked for many years on
Lygus
endoparasitoids. He reared several species, which benefited markedly our species concept along the Pacific coast of
Canada
. Moreover, Dave was instrumental in actively supporting our sampling efforts, which led to the discovery of new species of
Peristenus
and
Leiophron
in western
British Columbia
.
Diagnosis.
Clypeus black or dark brown, frons not densely punctate (especially between lateral ocellus and inner eye margin), forewing vein r generally developed, and a univoltine life cycle associated with first generation of
Lygus
nymphs.
Description.
FEMALE. Colour. Head and mesosoma black; metasoma black. Legs generally straw coloured, metacoxa brown to black; basal 0.3–0.5 of metatibia usually straw coloured or occasionally light reddish brown, and apical 0.5–0.7 of metatibia, and metatarsomere 1 clearly darker than base of metatibia, but metatarsomeres 2–5 less dark than metatarsomere 1. Palpi, tegula and mandible (except apex) straw coloured. Scape to flagellomere 2 straw coloured, thereafter brown to dark brown. Stigma dark brown but straw coloured in basal third.
Structure. Flagellum with 18–20 flagellomeres (respectively 12%, 53% and 35% of
17 specimens
) and flagellomeres enlarged in apical 0.5. Few of the preapical flagellomeres subquadrate (none 35%, one 50%, two 9% and three 6%). Length of gena behind eye 0.80–1.00 times as long as length of eye. Height of eye 1.36–1.46 times as long as minimum distance between inner eye margins (as in
Fig. 18
). Maximum width of head behind eyes subequal (0.92–0.96) to maximum head width at eye level. Occipital carina developed in dorsal third. Metasomal tergum 1 with lateral edges clearly convergent (posterior margin 2.2–2.5 times as wide as narrowest width near base) and elongate (medial length of tergum 1.5–1.8 times maximum width at posterior end). Radial cell length 0.83–1.06 as long as stigma width (as in
Figs. 58–63
). Forewing vein r of forewing in most specimens clearly developed (95% based on
100 specimens
) and short (as in
Figs. 60, 61
) and basal cell of forewing (except extreme base) pubescent (as in
Fig. 54
).
Sculpture. Punctures on vertex
5–10 µm
in diameter, on frons and mesoscutum about
10–15 µm
in diameter (a little larger than diameter of ommatidia). Punctures
20–25 µm
apart on vertex (especially between lateral ocellus and inner eye margin),
5–15 µm
apart on frons to
5–10 µm
apart near antennal socket, and
20–25 µm
apart on mesoscutum. Punctures on mesopleuron generally dense occasionally scattered. Clypeus generally smooth, rarely punctate all over. Metasomal tergum 1 with about 10–12 longitudinal ridges, these often anastomosing on disc and forming a puncturelike sculpture.
MALE. Colour. As in female.
Structure. Flagellum with 21–23 flagellomeres and flagellomeres narrow in apical 0.5. Height of eye 1.00–1.14 times as long as minimum distance between inner eye margins. Otherwise structure and sculpture as in female.
Taxonomic notes.
Among the species of the
P. pallipes
complex with a black or dark brown clypeus,
P. gillespiei
is nearest
P. broadbenti
. Almost no structural differences were found between the two species. However, adults of the two species differ in their life cycle and their almost allopatric range (narrowly sympatric in the Cascade Mountains). A summary of measurement differences between
P. gillespiei
and
P. broadbenti
is given in Table 16.
Adults of
P. gillespiei
differ from those of
P. howardi
in the development of the forewing vein r, the common presence of males, and the univoltine life cycle. A summary of measurement differences between
P.gillespiei
and
P. howardi
is given in Table 16.
Adults of
P. gillespiei
could easily be confused with those of
P. braunae
a darkly coloured species. They are easily distinguished from those of
P. braunae
by the colour of the clypeus and metatibia, by the puncture density on the vertex especially between the lateral ocellus and the inner eye margin, by the the ratio of eye height to minimal distance between eye inner margins, and the ratio of length of flagellum to maximum width of head between outer eye margins.
Host and biological notes.
Adults of this species have been reared from various species of
Lygus
. Adults occur from early May to late June, with peak abundance probably in early June but late July at higher elevations (e.g., subalpine meadows). This is a univoltine species. Females of this species parasitize nymphs of only the first nymphal generation of
Lygus
.
Material examined and range.
53 (
13♂
,
40♀
) adults were studied.
Of
these, 20 were reared from
Miridae
and 33 were field collected.
The
species is known from the
Cascades
and
Coastal
ranges to the lowlands from
British Columbia
to
California
.
CANADA
. BC:
Boston Bar
,
15 km
N,
49º58'39"N
121º52'41"W
(
6♀
)
;
Mount Cheam
(
1♀
)
;
vic.
Chilliwack
,
49º07'32''N
122º06'10''W
(
3♀
)
;
Chilliwack Lake Rd.
,
49º06'N
121º36'W
,
800 m
(
3♂
,
4♀
)
;
Chilliwack Lake Rd.
,
20–25 km
SE (
2♀
)
;
Delta
,
49º04.996'N
123º00.949'W
(
1♀
)
;
Gagnon Rd.
,
10 km
W Terrace
(
5♀
)
;
Harrison Bay
(
3♀
)
;
Hemlock
ski hill,
49º22.846'N
121º56.111'W
,
700 m
(
4♂
,
5♀
)
;
vic.
Hope
,
49º22'47''N
121º31'22''W
(
1♂
)
;
Kleana Cr.
,
21 km
E Terrace
(
1♂
)
;
Silver
and
Skagit Rd.
, between
49º14'N
121º23'W
and
49º08'N
121º16'W
,
450–600 m
(
2♂
,
1♀
)
;
Skagit Valley Rd.
,
30 km
S,
49º08'43''N
121º17'36''W
(
1♂
)
;
Terrace
,
29 km
SW (
1♀
)
;
Terrace
,
51 km
SW (
1♀
)
;
West Harrison Rd.
,
49º16'26''N
121º52'41''W
(
7 ♀
)
.
USA
. CA:
Monterey Co.
,
Big Creek Station
,
1450 m
(
1♂
)
.