A review of the tachinid parasitoids (Diptera: Tachinidae) of Nearctic Choristoneura species (Lepidoptera: Tortricidae), with keys to adults and puparia
Author
O’Hara, James E.
text
Zootaxa
2005
938
1
46
journal article
10.5281/zenodo.171153
33181367-eefc-4e3a-90f2-ca6390420139
11755326
171153
Phryxe pecosensis
(
Townsend, 1926
)
,
Fig. 49
Host records ex.
Choristoneura conflictana
:
Prentice 1955
(SK, MB);
Schaffner 1959
, ex.
Archips conflictana
(northeastern
United States
); †
Arnaud 1978
(SK, MB, ME); †
Huber
et al.
1996
(
America
north of
Mexico
).
Host records ex.
Choristoneura fumiferana
:
Johannsen 1913
, as
Exorista vulgaris
ex.
Tortrix fumiferana
(ME);
Tothill 1913
, as
Exorista vulgaris
ex.
Tortrix fumiferana
(QC); †
Winn & Beaulieu 1915
, as
Exorista vulgaris
ex.
Tortrix fumiferana
(QC);
Wilkes & Anderson 1947
, ex.
Archips fumiferana
(ON, QC);
Daviault 1950
(QC);
Dowden
et al.
1951
, ex.
Archips fumiferana
(NY);
Jaynes & Drooz 1952
(NY, ME);
Raizenne 1952
(ON);
Dowden
et al.
1953
(ME);
Miller 1955
(NB);
McGugan & Blais 1959
(ON);
Schaffner 1959
, as
Phryxe vulgaris
(northeastern
United States
);
Blais 1960
(QC);
MacDonald & Webb 1963
(NB); †
Miller 1963
(NB);
Blais 1965
(QC); †
Arnaud 1978
, as
Phryxe vulgaris
(MA, QC, ME); †
Tilles & Woodley 1984
(ME);
Hébert
et al.
1989
(QC);
Huber
et al.
1996
(NB); †
Huber
et al.
1996
, as
Phryxe vulgaris
(
America
north of
Mexico
);
Cappuccino
et al.
1999
(QC).
Host records ex.
Choristoneura fumiferana
and/or
Choristoneura occidentalis
:
Brown 1941
, as
Zenillia vulgaris
ex.
Cacoecia fumiferana
(
Canada
)
;
Sellers 1943
, ex.
Archips fumiferana
(North
America
);
Dowden
et al.
1948
, ex.
Archips fumiferana
(North
America
); †
Zwolfer 1961
, ex.
C. fumiferana
(North
America
); †
Arnaud 1978
, ex.
C. fumiferana
(BC, OR, ON, QC, NB, NF, ME, NY).
Host records ex.
Choristoneura fumiferana
,
Choristoneura occidentalis
and/or
Choristoneura pinus
:
†
Ross 1952
, ex. spruce and/or jack pine budworm (
Canada
).
Host records ex.
Choristoneura occidentalis
:
McKnight 1974
(CO);
Harris & Dawson 1979
(BC).
Host records probably ex.
Choristoneura occidentalis
:
Wilkes
et al.
1949, ex.
C. fumiferana
(BC);
Carolin & Coulter 1959
, ex.
C. fumiferana
(OR); †
Coppel 1960
, ex.
C. fumiferana
(BC).
Host records ex.
Choristoneura pinus
:
Benjamin & Drooz 1954
(MI);
Drooz & Benjamin 1956
(MI);
Kulman & Hodson 1961
(MN);
Dixon & Benjamin 1963
(WI);
Allen
et al.
1969
(MI); †
Arnaud 1978
(MN, WI, MI); †
Huber
et al.
1996
(
America
north of
Mexico
).
Host records ex.
Choristoneura rosaceana
:
Raizenne 1952
, ex.
Archips rosaceana
(ON); †
Arnaud 1978
(ON); †
Huber
et al.
1996
(
America
north of
Mexico
).
Phryxe pecosensis
ranges from Alaska to Newfoundland, and south to California and New
Mexico
in the West and Virginia in the East. It is a dark coloured species about 4.0–7.5mm long. The adult and puparium resemble those of the related
Madremyia saundersii
, and the puparia of the two species (
Figs. 24–25
) are not always easily distinguished.
Phryxe pecosensis
was included in a key to the puparia of dipterous parasitoids of
Choristoneura
species by
Ross (1952)
and in a key to the adults of dipterous parasitoids of
C. occidentalis
(as
C. fumiferana
) in British
Columbia
by
Coppel (1960)
. The egg, larval instars and puparium were described by
Maw and Coppel (1953)
.
Phryxe vulgaris
(Fallén)
is a widely distributed Holarctic species that is very similar in appearance to
P. pecosensis
. This similarity has resulted in frequent misidentifications of
P. pecosensis
as
P. vulgaris
in the literature.
Sellers (1943)
provided useful characters by which to separate the species, but the differences between the species are so subtle that misidentifications continue to occur.
Sellers (1943)
considered host records of
P. v u l g a r i s
from
C. fumiferana
(as
Archips fumiferana
) to be based on misidentifications of
P. pecosensis
, and I agree with his assessment.
Phryxe pecosensis
is an eryciine tachinid that develops mature eggs within the female reproductive system. In a study of the biology of this species,
Maw and Coppel (1953)
found that eggs are deposited directly on the host. The first instar usually emerges soon after egg deposition, exiting through the ventral surface of the egg and burrowing into the host.
Maw and Coppel (1953)
observed a maximum deposition of
32 eggs
in the laboratory but found many more eggs in the reproductive systems of dissected females, so females probably deposit close to
100 eggs
under natural conditions. Females have a preoviposition period of about 10 days and adults live up to about 50 days (
Maw & Coppel 1953
).
Phryxe pecosensis
attacks late instar larvae of
Choristoneura
species and emerges from the sixth instar or pupa (
Dowden
et al.
1948
;
Carolin & Coulter 1959
;
Allen
et al.
1969
;
McKnight 1974
). The fully mature maggot leaves the host to pupariate elsewhere (
Sellers 1943
;
Maw & Coppel 1953
). Adults are active from May to October, there are two or more generations per year, and the parasitoid overwinters as a larva in an alternate host (
Schaffner & Griswold 1934
;
Schaffner 1959
).
Phryxe pecosensis
is a commonly recorded parasitoid of
Choristoneura
species that is generally responsible for low levels of parasitism but occasionally has been found at higher levels. Parasitism of
C. pinus
was reported as low (less than 3% parasitism of late larvae) in Michigan by
Benjamin and Drooz (1954)
and
Allen
et al.
(1969)
and in Wisconsin by
Dixon and Benjamin (1963)
. In Quebec,
Daviault (1950)
reported spruce budworm parasitism as high as 7.4% in larvae and 1% in pupae, whereas
Blais (1960)
reported relative parasitism as high as 15%. In New York,
Dowden
et al.
(1951)
reported parasitism of spruce budworm larvae as high as 18% and of pupae as high as 6%.
Jaynes and Drooz (1952)
found up to 24% parasitism of mature larvae of spruce budworm in New York and up to 12% parasitism of budworm larvae in Maine.
Tilles and Woodley (1984)
included
P. pecosensis
as one of five tachinids in their manual of spruce budworm parasitoids in Maine. Parasitism in the West has been reported as low. Wilkes
et al.
(1949) ranked
P. pecosensis
fifteen among the 15 dominant dipterous and hymenopterous parasitoids of
C. occidentalis
(as
C. fumiferana
) in British
Columbia
.
The hosts from which
P. pecosensis
has been reported are many and varied: a species of
Tenthredinidae (Hymenoptera)
, a species each in
Danaidae
,
Hesperiidae
,
Pieridae
, and
Saturniidae
, two species of
Pyralidae
, several species in each of
Geometridae
and
Noctuidae
, and about ten species of
Tortricidae (
Arnaud 1978
)
.