Notes on the biology, hosts, and immature stages of Tomoplagia cressoni Aczél in southern California (Diptera : tephritidae)

10 Pages·1991·4.6 MB·

by  R D Goeden

PROC. ENTOMOL. SOC. WASH.
93(3), 1991, pp. 549-558
NOTES ON THE BIOLOGY, HOSTS, AND IMMATURE STAGES OF
TOMOPLAGIA CRESSONI ACZEL IN SOUTHERN CALIFORNIA
(DIPTERA: TEPHRITIDAE)
Richard D. Goeden and David H. Headrick
Department ofEntomology, University ofCalifornia, Riverside, California 92521.
—
Abstract. Tomoplagia cressoni Aczel is oligophagous in flower heads ofPerezia mi-
cwcephala (deCandolle) Gray and Trixis californica Kellogg (Asteraceae) in southern
California. Both hosts are in the tribe Mutiseae. Third instar larvae and puparia, and two
new types of sensilla on them, are described for the first time. The larvae feed on the
floral tubes and ovules as first and second instars, respectively, but most growth occurs
in the third instar. The third instar feeds mainly on sap that collects in a cup-shaped
cavity it chews in the receptacle. Most seeds in infested heads were undamaged. Mating
behavior is described, which is unique among non-frugivorous Tephritidae for the more
posterior, upright position ofthe male and the back and forth, rhythmic movements of
his abdomen during initial phases of copulation. The unusual "butterfly stroke" wing
movements ofadults when walking also are described. This tephritid has a spring gen-
eration on Tr. californica, a. summer generation on P. microcephala, and facultatively, a
fallgeneration, again on Tr. californica, dependingontheincidence oflate-summer, desert
rainfall triggering a second flowering.
Eurytoma veronia Bugbee (Eurytomidae), Colotrechnus ignotus Burks (Pteromalidae),
and Pteromalus sp. (Pteromalidae) are reported as primary, solitary, hymenopterous par-
asitoids of To. cressoni.
Key Words: Insecta, Tomoplagia, Perezia, Trixis, life history, parasitoids, sensilla
Taxonomy
This paper concerns the rare, stenopha-
gous, previously little-known species, To- Aczel (1955) first described To. cressoni
moplagiacressoniAczel,whichdoesnotlend and partly illustrated the adultswith simple
itselfreadilyto fieldorlaboratorystudy. To. drawingsand a photograph ofawing. Foote
cressoni Aczel is the only representative of and Blanc (1963) also provideda wingpho-
its genus in California (Foote and Blanc tograph.
1963); one ofonly two species ofTomopla- Larvae and puparia excised from flower
gia known from North American north of headso^Perezia microcephala(deCandolle)
Mexico; andoneof43 known speciesin this Gray (Asteraceae) were examined with
genus, most ofwhich are restricted to trop- scanning electron microscopy (SEM) by
ical and subtropical America (Aczel 1955). DHH. Materials, methods, and nomencla-
Our admittedly incomplete findings on To. ture were as used by Headrick and Goeden
cressoni provide a base ofknowledge ofits (1990a) and Goeden and Headrick (1990).
biology, hosts, and immature stages. Means ± SEareusedthroughoutthispaper.
550 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
1—Firgu.go1s.e pTahdisr;d2i—nsmtaorutlharhvoao,ksT;om3o—plmaegdiiaacnreosrsaolnil.obAe.; 4Ha—bitthuosra;ci1c—sveennstirlallumt.raCn.svAenrtseerifoorldss.enBs.orAyntoerrgainosr;en1d—;
dorsal sensory organ; 2—anterior sensory lobe; 3—sensillum; 4—lateral sensory organ; 5—terminal sensory
organ; 6—lateral sensory lobe; 7—integumental petals. D. Abdominal segment, lateral view; 1—sensillum; 2—
spiracle scar.
Thirdinstarlarva.—Fourlarvaewereused edge (Fig. lB-1). The paired dorsal sensory
for SEM. The mature larva of To. cressoni organs are composed ofa single, spherical
has a distinct habitus (Fig. lA); it is more papilla(Fig. 1C-1). Ventradand slightly lat-
elongate and not barrel-shaped like other erad to the dorsal sensory organs are the
non-frugivorous, tephritid larvae thus far paired anterior sensory lobes (Fig. lC-2).
examined. The larva has deeply furrowed The relative position of these sensory or-
segmental lines, which circumscribed its gans is atypical among the tephritid larvae
body,andtransversefolds ventrallyoneach examined to date. Headrick and Goeden
segment (Fig. lA-1). The integument in life (1990a) noted thatplacementofthe sensory
is yellowish and shagreened; this texture is organs among non-frugivorous tephritid
caused by evenly distributed, smooth, larvaeisrelativelyconstant. Mostoften, the
domed-shaped verrucae, seen with SEM. dorsal sensory organ is dorsad to the ante-
Thegnathocephalon isroundedandbears rior sensory lobe along a dorso-ventral line
many rugose pads. The pads laterad to the that is parallel with the midline ofthe body
mouth lumen are serrated on their ventral (cf.,ParacanthagentHis, HeadrickandGoe-
VOLUME 93, NUMBER 3 551
den 1990a). However, in To. cressoni the ofsensilla is a small ecdysial scar which is
dorso-ventro axis of the anterior sensory the vestige ofthe lateral abdominal spiracle
lobes is directed slightly laterad ofthe mid- (Fig. 1D-2). Thetracheaeofthisspiraclecan
line, and the dorsal sensory organs lay me- be seen within the puparium after adult
diadtotheanteriorsensorylobesandslight- emergence (cf., Headrick and Goeden
ly closer to the mouth lumen. 1990a).
The anterior lobes appear to bear three The caudal segment has the typical four-
sensoryorgans; however, thepit sensoryor- dorsal, six-ventral arrangement of sensilla
gan is not visible on the specimen used for arounditsposteriormargin (Fig. 2A). These
Fig. IC. Apapillatesensillum islocateddor- sensilla are composed oftwo distinct mor-
sally on the anterior lobe (Fig. lC-3), and phological types. The first type is a basal
may represent an aberration, as this sen- crown ofsix points, from which projects a
sillum type and placement has not been ob- finger-like process. This type ofsensillum is
served on any other tephritid larvae ex- morphologicallydistinct fromothersensilla
amined to date (Headrick, unpublished reported in the Tephritidae thus far, and
data). Both thelateral sensoryorganandthe accordingly, we termed it a "stelex" sensil-
terminal sensory organ are typical in place- lum (Fig. 2B). There are dorsal and ventral
ment and form (Fig. lC-4, -5). pairs ofthese sensilla locatedjust laterad of
The lateral lobesare located dorso-lateral the dorso-ventral midline (Fig. 2A-1). The
to the mouth lumen and bear several sen- other more common type is a domed sen-
silla (Fig. lC-6). The mouth lumen is sur- sillum withacentral papilla(Fig. 2C). Three
rounded by integumental petals (Fig. lC-7) pairs ofdomed sensilla located laterally on
that are not as reduced as those ofTephritis the posterior margin complete a ring of 10
baccharis (Coquillett) (Goeden and Head- sensilla (Fig. 2A-2). A pair of previously
rick, submitted) nor as developed as those undescribed sensoryorgansliedorsadofthe
ofParacanthagentills Hering(Headrick and posterior spiracles on either side ofthe dor-
Goeden 1990a). The mouthhooks have one so-ventral midline(Fig. 2A-3). Thissensory
large, curved, bluntly tapered tooth distally organ is smooth, dome-shaped, and bears
(Fig. 1B-2), andbasallyasmaller, morestout two sensilla (Fig. 2D), a dorsal stelex sen-
tooth on the lateral edge (not shown in Fig. sillum and a ventro-lateral smaller dome
IB). The median oral lobe is laterally flat- with aclusteroffinger-like filaments, which
tened,andhasaroundedapexandasmooth we term a "medusoid" sensillum (Fig. 2E).
ventral edge (Fig. 1B-3). This sensillum superfically resembles the
The integument of the thoracic segment coniform sensillar complexes found on the
isroughenedwithrowsofflattened verrucae antennae ofthe nymph ofthe stonefly, Par-
anddottedwithlargerpapillatesensilla,each agnetinamedia(Walker)(Kapoor 1986),and
with a central pore (Fig. 1B-4). The anterior the styloconic sensillum on the antenna of
thoracic spiracles each bear three tubular the adult of Glossina austeni Newstead
spiracular openings (see puparium Fig. 3B). (Lewis 1970). However, the terminal fila-
The succeeding segments have both their ments of the T. cressoni sensillum appear
anterior and posterior edges marked with to be free from each other in life, and not
rows of bluntly pointed acanthae. The in- attachedas in the stonefly nymph and Glos-
tegument is shagreened with small, evenly sinaadult. Thus, wedonot includethissen-
distributed, dome-shaped verrucae. Later- sillum in the coniform sensillar group until
ally, each abdominal segment bears a ver- transmission electron microscopy studies
tical rowofthreedome-shaped sensilla, each canconfirm similarnervousinnervationand
withacentralpore(Fig. 1D-1). Alsooneach a porous substructure to each of the fila-
abdominal segment, andanteriortothe row ments; features which are fundamental to
552 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
VOLUME 93, NUMBER 3 553
of two to four branches, the longest mea- (1987a, 1988, 1989) called attention to the
suring 25.0 ju (Fig. 2F-2). often misleadingnatureofsweeprecords for
Puparium.—Fifteenpupariameasured3.8 adults offlower head-infesting Tephritidae.
mm
± 0.07 (range, 3.4-4.3) in length, and Goeden (1983, 1987b) reported rearing
mm
1.4 ± 0.03 (range, 1.2-1.7) in width. To. cressoni from samples of flower heads
Thepuparium issuperficallysmooth, blunt- of Trixus californica Kellogg (Asteraceae),
ly rounded at the ends, and somewhat dor- which it infested to a limited degree along
so-ventrally flattened (Fig. 3A). In life it is with Trupaneaconjuncta(Adams)(Diptera:
fuscous and quite distinct from the small, Tephritidae) and Tru. actinobola (Loew),
black, shiny puparia of its co-inhabitants, bothofwhichspeciesweremuchmorecom-
i.e. Trupanea spp. (see below). The anterior mon in these heads (Goeden and Ricker
RDG
endisdemarcatedbythefracturelineswhich 1989). Inaddition, reared To. cressoni
extend laterally on the first threeabdominal from samples of heads of P. microcephala
segments. The anterior spiracles lay just along with Tru. nigricornis and Tru. whee-
dorsad ofthe lateral midline and bear three leri Curran, again, with To. cressoni as the
tubular openings (Fig. 3B-1). Closer obser- leastcommon associate. These host records
vation revealed that the puparium surface from P. microcephala confirm rearing rec-
maintained the shagreened texture of the ords for both species of Trupanea (Was-
last larval stage. The posteriorendisunique bauer 1972), and confirm and clarify the
among tephritid puparia examined thus far rearing record for To. cressoni in Foote and
in that the sensilla were not collapsed. In Blanc (1963). This co-occurrence of To.
other puparia such surface features are in- cressoni with two different species of te-
distinguishable from the integument; how- phritids in each of these two host plants,
ever. To. cressoni puparia maintain erect withonlythedevelopmentalbiologyofTru.
sensilla (Fig. 3C). conjucta well known (Goeden 1987b), was
onereason wedid notattemptfurtherstudy
Distribution, Hosts, and
ofits early larval stages.
Study Sites Only three plant species, Tri. californica,
Aczel (1955) described To. cressoni from P. microcephala, and Hecastoleis shockleyi
specimens collected from three separate lo- Gray, comprise the Tribe Mutiseae in Cal-
cations in interior valleys ofsouthern Cal- ifornia (Munz and Keck 1959). This tribe
ifornia and from one location in central Ar- is foundchiefly in Mexicoand South Amer-
izona. Foote and Blanc (1963) added New ica. Thus, the two hosts now known for To.
Mexico and Texas to its distribution and cressonisuggestapredictablepattern, which
mapped many collection records from rearings from flower heads ofH. shockleyi
coastal, interior valley, and Colorado Des- should confirm (that is, ifthis rare, mono-
ert locations in southern California. Most typic plant species reported from the envi-
ofthese California records were from bait- rons ofDeath Valley and the isolated, rug-
trapcollections, which oflerednocluetothe ged, eastern slope ofInyo Mountain [1] can
hostaffinitiesofTo. cressoni; however, Foote be located and [2] sampled when bearing
and Blanc(1963) also listed a U.S. National mature flower heads!).
Museum record for two males reared from The principal study site with Tri. califor-
Perezia microcephala as well as sweep rec- nica was among large, granite boulders in
ords from non-hostAcacia, Juglans, Solan- and above the main wash at the mouth of
NW
urn, and Solidago spp. Aczel (1955) report- Chino Canyon, 1 km ofPalm Springs,
ed To. cressoni from peach, Prunus persica Riverside Co., during 1983-1987. Tomo-
(L.) Batchelor, which Wasbauer (1972) plagiacressoniwasreared from flowerheads
properly termed "doubtful." Goeden collected at this location on 25-V-1983, 7-
554 PROCEEDINGS OFTHE ENTOMOLOGICALSOCIETY OF WASHINGTON
cluded: Yaqui Pass, NE San Diego Co.,
11-1-1984; Com Spring, E Riverside Co.,
12-1-1984; Desert Center, E Riverside Co.,
14-111-1984; Graham Pass, E Riverside Co.,
21-ill-1984, 12-111-1986. Theonlystudysite
with P. microcephala was a steep, west-fac-
ing,graniticscreeatthemouthofMillCreek
Canyon, San Bernardino National Forest
SW
(NorthernSection), San BernardinoCo.,
during June-August, 1989.
Biology
Egg.—The eggs of Tomoplagia cressoni
were not observed during this study, nor
were gravid females swept, reared from pu-
paria, or obtained after caging reared fe-
males (see below). Most larvae and puparia
were found singly in heads of P. micro-
cephala and Tri. californica; although, one
offourInfestedheadsexaminedofthelatter
host bore three puparia. This suggested that
eggs usually are laid singly in heads.
Nosignoftunnelingbyearly-instarlarvae
was found in floral tubes or bracts outside
ofthesinglelayerofachenesandfloretsthat
surrounded each mature larva and pupar-
ium(Fig. 4A,4B). Nooviposltionpunctures
werenotedintheouterphyllariesofInfested
heads. One to four, adjacent, floral tubes
and ovules (this term is used to distinguish
presumably unfertilized achenes in young
capltula before anthesls; Harris 1990,
Headrick and Goeden 1990c) from the en-
circling ring offlorets in each head showed
tunneling by an early stage larva. This sug-
gested that eggs were Inserted between or
within floral tubes ofimmature florets by a
femalefrom anexternalpositionattheapex
Fig. 3. PupariumofTomoplagiacressoni. A. Hab- ofa head after anthesis, and not by punc-
itus. B. Anteriorend; 1—anteriorthoracicspiracle. C. turing the phyllaries laterally with her ovi-
Posteriorend, ventro-lateral view.
positor to gain access to the interior of a
head,e.g. likeParacanthagentilis(Headrick
vi-1983, 21-vi-1983, 7-vii-1983, l-x-1983, and Goeden 1990b). Indeed, one sexually
15-xi-1983, 29-xi-1983, 13-111-1984, 11-lv- immature female of To. cressoni (deter-
1984, 24-1V-1984, and 8-V-1984. Addition- mined by later dissection) was noted in a
al locations at which flower heads of Tri. laboratory cage probing an open head with
californica were sampled on the dates In- herovipositorfrom suchan apical position,
dicated, and which yielded To. cressoni, in- though, ofcourse, no egg was recovered.
VOLUME 93, NUMBER 3 555
Larva.—In flower heads of Tri. califor- remained undamaged in 13 heads that con-
nica, the first instar of To. cressoni upon tained one mature larva or puparium each
hatching tunnels into a floral tube, which ofTo. cressoni. Uninfested heads contained
causes the basally attached ovule to abort. an average of 1 1 ±0.1 (range, 9-13, n =
The larva next transfers to and mines one 77) achenes. To. cressoni directly and in-
or two more floral tubes. Then, and prob- directly destroyed less than half of the
ably as a second instar, it mines one to four achenes in heads it infested. Flower heads
adjacent ovules. The larva next proceeds to ofP. microcephalawhich containedonepu-
score the receptacle. The third instar exca- parium each ofTo. cressoniand either Tru.
vates a cuplike depression in the receptacle nigricornis or Tru. wheeleri yielded adults
surface without observable tissue prolifer- ofboth species.
ation (no gall formation). It feeds by im- Schwitzgebel and Wilbur(1943) reported
bibing sap transported to the receptacle via that To. obliqua(Say)wasrearedfrom seeds
thevasculartissueswhichsuffusethisnurse- of ironweed, Vernonia interior Small, in
tissue for the developing florets (Romstock Kansas. F, larvae reportedly fed on the
1987). Theimbibitionofsap, whichcollects ovules; Fj larvae, on "seeds," presumably
in the feeding cavity, while concurrently meaningachenes, anddestroyedall seeds in
scraping ever deeper with the mount hooks ahead. In ironweed, To. obliquaco-infested
into the receptacle, represents the main heads with Neaspilota alba Loew, in which
modeoffeedingforthirdinstarsofTo. cres- the former tephritid also was the subordi-
soni (Fig. 4A). This feeding behavior was nate or much less common associate.
recently described as facultative and den- Pupa.—When feeding was completed in
sity-dependent among P. gentilis larvae in headsofP. microcephala, thelarvareversed
Cirsiumthistlecapitula(HeadrickandGoe- itself 180°and pupariated with its posterior
den 1990c), and has been found to be com- end cupped and lightly glued, probably by
mon, indeed obligatory (or at least consis- dried sap, within its feeding cavity in the
tent), even among solitary larvae of other receptacle (Fig. 4B). Empty puparia in ex-
native, flower head-infesting Tephritidae, cised, dry, open heads of Tri. californica
e.g. Neaspilota, Tephritis, and Urophora, that had been held for adult emergence in
currentlyunderstudyinsouthernCalifornia sleeve cages, on the other hand, had been
(Goeden, unpublished data). Three or four lifted off" the receptacles and were lightly
achenesremained intactwithin headsofTri. glued among pappus hairs.
californica infested by single To. cressoni(n Adults.—Adults(Fig. 4C)pushedupward
= 3). and outward through the pappus in exiting
Larval feedingin heads ofP. microcepha- the flower heads, as described and illustrat-
lawas similarto the above. First instars fed ed for P. gentilis by Headrick and Goeden
on two to four florets each, causing basally (1990b). A total of only 13 males and 11
attachedovulestoabort. Larvaenextmined females emerged from 11 of 33 weekly or
the growing ovules, then tapped into the biweekly samples of flower heads of Tri.
receptacle and became primarily sap feed- californicacollectedbetween May 1983 and
ers, at least as third instars. The larvae al- May 1984 at Chino Canyon. A total of27
waysfedattheperipheriesofthereceptacles males and 29 females was recovered from
in heads of P. microcephala. Larvae were three biweekly samples of heads ofP. mi-
located between the inner phyllaries and crocephalain 1989. Thesedataindicatedan
several, contiguous, undamageddeveloping equal sex ratio for To. cressoni.
achenes oriented with their long axes par- Dissectionsofnewlyemergedfemalesde-
allel to these flowerhead parts(Fig. 4A). An termined that they are sexually immature
average of 6 ± 0.7 (range, 0-10) achenes (n = 3),andthatneithersexcontainedmuch
556 PROCEEDINGS OFTHE ENTOMOLOGICALSOCIETY OF WASHINGTON
Fig. 4. Life stages ofTo. cressoni. A. Third instar larva in flowerhead ofP. microcephala. B. Puparium in
flowerhead off. microcephala. C. Adult female on leafofTn. californica. Bars = 1 mm.
fat body tissue. Newly emerged adults of/*. Oct 1989. Courtship by these flies had not
gentilis (Headrick and Goeden 1990b) and been observed; however, this behavior had
all species of Trupanea studied in southern been seen earlier with one each, 28-30 and
California to date (Cavender and Goeden 58-60 days-old virginal males in separate
1982, Goeden 1987b, 1988, and unpub- pairings. These courting males had laterally
lisheddata)are sexually immature and con- ballooned abdominal pleura, and both ac-
tain little fat bodytissue, unlikesome newly tively pursued the same-aged females with
emerged gall-formers, e.g. Eutreta diana which they were caged. Alternatively, these
(Osten Sacken) (Goeden 1990). Further- males stood still, faced, and fanned their
more, although eight females lived an av- wings synchronously towards the females,
erage of 1 18 ± 11.3 (range, 67 to 152) days, but, again, no mating resulted. The bal-
and 11 males, 78 ± 9.6 (range, 31 to 126) looned abdominal pleura of To. cressoni
daysinindividualplasticcagessuppliedwith males appeared as photographed with Tru.
honey and water, as described by Goeden hisetosa (Cavenderand Goeden 1982). Bal-
and Headrick (1990), they remained sexu- looned males abdominal pleura have now
ally immature. been reported from several genera of non-
Only one of 13, 2-day-long pairings of frugivorous as well as frugivorous Tephrit-
these virginal flies between the ages of2 to idae,andarethoughttobeinvolvedinpher-
109 days resulted in mating. Plastic petri omone dissemination (Jenkins 1990,
dishes were used as arenas for mating tests Headrick and Goeden 1990b).
(afterJenkins 1990), which we modified for The copulatory position of To. cressoni
longer use by including a pad ofabsorbent diflers from postures described for other
cotton saturated with distilled water and mating, nonfrugivoroustephritids. Theovi-
spotted with drops ofhoney. A 94-day-old positoris held straightbackward, notcurved
male and a 105-day-old female (both vir- upward during copulation, which requires
gins)were firstobservedincopulaafterdusk that the male ride more posteriorly and up-
under artificial light at 18:24 h PST on 30 right, i.e. nearly perpendicular to the sub-
VOLUME 93, NUMBER 3 557
strate. Also, during the eariy stages of the he was caged. The onrushing females and
single, but protracted mating observed, the male came close to the other flies, but al-
female extended herovipositorto nearly its ways avoided touching by stoppingor turn-
full length, then retracted it, moving it in ing.
and out in a rhythmic manner whilejoined Seasonal history.—Tomoplagia cressoni
to the male. Accordingly, the abdomen of has at least two, sometimes three, annual
the male moved forward and backward generations in southern California: one on
through an arc of 30 to 40°. This pumping Tri. californica in the low-elevation Colo-
activity gradually ceased as mating contin- rado Desert each spring, another produced
ued. The foretarsi ofthe male grasped the on its alternate host, P. microcephala, in
middle ofthe abdomen ofthe female dor- interior valley foothills in the summer, and
solaterally, his midtarsi grasped the base of undercertain conditions, a third generation
her oviscape, and his hind tarsi rested on produced on Tri. californica in the fall. The
the substrate. The wings ofboth sexes were long-lived adults may migrate to bridge the
held motionless and parallel to the sub- time intervals and distances separating
strate.Thefemale'swingswerepartedabout flowering populations of these two hosts.
45°from her midline, and the male's wings, How and if, the third potential host plant,
about30°fromhismidline. Themouthparts H. shockleyi, fits into this scheme has yet
of both sexes pumped rapidly (five to six to be determined. During and following the
pumps/sec.) during mating. This mating exceptionally wet winter of 1982-83, Tri.
lasted at least 3.5 h and was discontinued californica floweringand To. cressoniemer-
within 5 h after the lights had been turned gence were extended well into the summer
off. (July) at Chino Canyon. A second flush of
Otherbehaviorsthatdistinguish To. cres- flowerheads and a second generation ofTo.
soni adults involved resting and walking. cressoniwere produced at Chino Canyon in
Theusualrestingposturesofboth sexeswere October and November, 1983, in response
with their wings held outward about 80° to late-summer rainfall. However, with no
from their bodies, or sometimes at lesser fall rainfall, only one crop offlower heads
angles. The costal margin is curled for- and the spring generation offlies were pro-
ward, i.e. supination (HeadrickandGoeden duced at Chino Canyon in 1984. Appar-
1990b). Astheadultswalked forwards, they ently, To. cressoniusuallyinfeststheearliest
synchronously brought their wings upward andlatestflowerheads, buthaslittlesuccess
and forward, then downwards and back- competing with Tru. actinobola and Tru.
ward, the long axes of both wings moving conjuncta for the bulk of the flower heads
together in ellipses. This wing movement produced by Tri. californica (Goeden 1987,
appears much like the butterfly stroke of Goeden and Ricker 1989).
human swimmers. This movement is dis- Mortality factors.—Some ofthe parasit-
tinct from the agonistic wing thrusts de- oids and predators of Tru. conjuncta re-
scribed for females of Aciurina mexicana ported by Goeden (1987) probably also at-
byJenkins (1990)and others. Two- and 10- tack To. cressoni as well as Tru. actinobola
day-old, virgin females of To. cressoni re- in flowerheads ofTri. californica. One male
peatedly signaled their nonreceptiveness to and one female Eurytoma veronia Bugbee
same-agedmales,inarenas, byrapidlyrush- (Hymenoptera: Eurytomidae) were reared
ingtowards them with theirwingsextended as primary, solitary, larval-pupal endopar-
forwards, costal surfaces downward and asitoids of To. cressoni, and at least Tru.
ventral surfacesanteriorad. One 10-day-old wheeleri, in heads ofP. microcephala. Sim-
male displayed similar agonistic behavior ilarly, one female each of Colotrechmis ig-
towards the same-aged female with which notus Burks (Hymenoptera: Pteromalidae)
558 PROCEEDINGS OFTHE ENTOMOLOGICAL SOCIETY OF WASHINGTON
was reared as a solitary parasitoid from a California(Diptera: Tephritidae). Pan-PacificEn-
puparium of To. cressoni and a larva ofei- tomologist 66: 24-32.
ther Tru. nigricornis or wheeled in heads of Goeden, R. D. and D. Headrick. 1990. Notesonthe
P. micwcephala. Finally, a female Pter- biology and immature stages of Stenopa affinis
Quisenberry (Diptera: Tephritidae). Proceedings
omalus sp. (Hymenoptera: Pteromalidae) ofthe Entomological Society ofWashington 92:
was reared as a primary solitary parasitoid 641-648.
of To. cressoni. These parasitoids were Goeden, R. D. and D. W. Ricker. 1989. Phytopha-
reared from isolated parasitized hosts in a gous insect faunas of the desert shrubs, Bebbia
junceaand Trixiscalifornica. insouthern Califor-
humidity chamber (76% R.H.).
nia.AnnalsoftheEntomologicalSocietyofAmer-
ica 82: 315-331.
Acknowledgment Harris, P. 1990. Feeding strategy, coexistence and
Our thanks to D. W. Ricker and J. A. Diemlpfaocstseo,fEi.nsSe.c,tsedi.n.sPprootcteeeddkinngaspwoefetdhecaVpIiItulIan.teIrn-
Teerinkfortechnicalassistance. Thanksalso national Symposium on Biological Control of
to F. L. Blanc, A. J. Norrbom, G. J. Steck, Weeds, Rome, Italy, 1988. (In press.)
and J. A. Teerink for their reviews ofearly Headrick, D. and R. D.Goeden. 1990a. Description
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