Life history and description of immature stages of Neaspilota footei freidberg and mathis (diptera: Tephritidae) on aster occidentalis (Nuttall) torrey and a. Gray (Asteraceae) in southern california

16 Pages·2001·7.7 MB·

by  R D Goeden

PROC. ENTOMOL. SOC. WASH.
103(1), 2001, pp. 191-206
LIFE HISTORY AND DESCRIPTION OF IMMATURE STAGES OF
NEASPILOTA FOOTEI FREIDBERG AND MATHIS (DIPTERA:
TEPHRITIDAE) ON ASTER OCCIDENTALIS (NUTTALL) TORREY AND A.
GRAY (ASTERACEAE) IN SOUTHERN CALIFORNIA
Richard D. Goeden
Department of Entomology, University of California, Riverside, CA 92521, U.S.A. (e-
mail: [email protected])
—
Abstract. Neaspilota footei Freidberg and Mathis is a univoltine, monophagous or
nearly monophagous, fruit fly (Diptera: Tephritidae) developing in the flower heads of
Aster occidentalis (Nuttall) Torrey and A. Gray (Asteraceae) belonging to the subtribe
Asterinae of the tribe Astereae in southern California. It also has been reported from
Conyza (as Erigeron) canadensis (L.) (Cronquist) (and as E. pusillus) and Chrysothamnus
sp., but both of these host records need confirmation. The egg, first-, second- and third-
instar larvae and puparium are described and figured, and these immature stages are
compared with those of other Neaspilota. The anterior thoracic spiracles of the second
and third instars of A^. footei have three papillae. The second and third instars also have
an undetermined number of oral ridges with dentate posterior margins in a vertical series
lateral to the oral cavity. The appearance and placement of these oral ridges is a distin-
guishing generic larval character. The larvae feed mainly on the corollas of florets and
ovules as first instars; on corollas, ovules, and soft achenes as second instars; but as third
instars, they feed mainly on ovules and soft achenes. A single annual generation is pro-
duced on A. occidentalis in southern California. The life cycle is of the aggregative type
and overwintering mainly occurs as puparia attached to uneaten achenes and fragments
thereof in dead flower heads. Pteromalus sp. (Hymenoptera: Pteromalidae) was reared as
a solitary, larval-pupal endoparasitoid of A^. footei; Eurytoma sp. (Hymenoptera: Eury-
tomidae) and Mesopolobus sp., as probable, solitary, larval-pupal endoparasitoids.
Key Words: Insecta, Neaspilota, Aster, Asteraceae, nonfrugivorous Tephritidae, biology,
taxonomy of immature stages, allopatry, flower-head feeding, aggregative
life cycle, seed predation, parasitoids
Revision of the genus Neaspilota (Dip- aenigma Freidberg and Mathis (Goeden
tera: Tephritidae) by Freidberg and Mathis 2000b), N. appendiculata Freidberg and
(1986) facilitated identification of speci- Mathis (Goeden 2000c), A^. pubescens
mens reared from California Asteraceae Freidberg and Mathis (Goeden 2000d),
(Goeden 1989) and stimulated several and N. achilleae Johnson (Goeden 2001).
life-history studies, including those on N. This paper describes the immature stages
viridescens Quisenberry (Goeden and and life history of an eighth species from
Headrick 1992), N. wilsoni Blanc and California, A^. /oor^/ Freidberg and Math-
Foote (Goeden and Headrick 1999), N. is, and is the last paper in this series on
signifera (Coquillett) (Goeden 2000a), N. Neaspilota.
—
192 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
Materials and Methods period. A single pair of a virgin male and
female obtained from emergence cages also
The present study was based in large part
were held in a clear-plastic, petri dish pro-
on dissections of samples of flower heads
visioned with a flattened, water-moistened
of Aster occidentalis (Nuttall) Torrey and
pad of absorbant cotton spotted with honey
A. Gray (Asteraceae) mainly collected on
(Headrick and Goeden 1994) for observa-
the north shore of Big Bear Lake at 2,020-
m elevation, Serrano Meadows Picnic Area, tions of their courtship and copulation be-
havior.
San Bernardino Nat. Forest (N Section),
SW Plant names used in this paper follow
San Bernardino Co., during 1996 and
Hickman (1993) and Bremer (1994); te-
1997. One-liter samples of excised, imma-
phritid names and adult terminology follow
ture and mature flower heads containing
Foote et al. (1993). Terminology and tele-
eggs, larvae, and puparia were transported
graphic format used to describe the imma-
in cold-chests in an air-conditioned vehicle
ture stages follow Goeden (2000a, b, c, d,
to the laboratory and stored under refrig- 2001), Goeden et al. (1998), Goeden and
eration for subsequent dissection, photog-
Headrick (1992, 1999), Goeden and Teerink
raphy, description, and measurement. Three
(1997a, b, 1998, 1999a, b), Teerink and
eggs, six first-, 14 second-, and 15 third- Goeden (1999), and our earlier works cited
instar larvae and seven puparia dissected therein. Means ± SE are used throughout
fErtoOmHflfoowrershceaanndisngwereelecptrreosnervmeidcrionsc7o0p%y this paper. Voucher specimens of A^. footei
immature stages, adults, and parasitoids re-
(SEM). Additional prepuparia and puparia side in my research collections.
were placed in separate, glass shell vials
stoppered with absorbant cotton and held in Results and Discussion
humidity chambers at room temperature for
Taxonomy
adult and parasitoid emergence. Specimens
for SEM were hydrated to distilled water in Adult. Neaspilotafootei was described
a decreasing series of acidulated EtOH. by Freidberg and Mathis (1986, p. 49-52),
They were osmicated for 24 h, dehydrated who pictured the unpattemed wing, along
through an increasing series of acidulated with drawings (p. 50) of the lateral aspect
EtOH and two, 1-h immersions in hexa- of the head, male right foretarsus, epan-
methyldisilazane (HMDS), mounted on
drium, distiphallus, epandrium and cerci,
stubs, sputter-coated with a gold-palladium aculeus and its apex enlarged, and sper-
alloy, and studied and photographed with a matheca.
—
Philips XL-30 scanning electron micro- Immature stages. The egg, first-, sec-
scope in the Institute of Geophysics and ond- and third-instar larvae, and puparium
Planetary Physics, University ofCalifornia, are described below for the first time.
Riverside. Egg: Fifty-four eggs dissected from
Most adults reared from isolated prepu- field-collected flower heads were white,
paria and puparia were individually caged opaque, smooth, elongate-ellipsoidal, 0.62
in 850-ml clear-plastic, screened-top cages ± 0.004 (range, 0.56-0.68) mm long, 0.17
with a cotton wick and basal water reser- ± 0.002 (range, 0.16-0.20) mm wide,
voir and provisioned with a strip of paper smoothly rounded at tapered basal end (Fig.
toweling impregnated with yeast hydroly- lA); pedicel button-like, 0.02 mm long, cir-
zate and sucrose. These cages were usedfor cumscribed apically by semicircular or el-
studies of longevity and sexual maturation liptical aeropyles arranged singly or in two
in the insectary of the Department of En- compressed or separate rows parallel to the
tomology, University of California, River- long axis of the egg (Figs. IB, C).
side, at 25 ± 1°C, and 14/10 (L/D) photo- The egg of TV. footei is similar in shape
VOLUME NUMBER
103, 1 193
1992), but about 30% shorter and narrower
than those ofN. wilsoni (Goeden and Head-
rick 1999) and about 10% shorter than
those ofN. appendiculata (Goeden 2000c);
the latter two species have the largest adults
among southern California Neaspilota
(Freidberg and Mathis 1986). The aeropyles
of A^. appendiculata are arranged in one to
three rows around the apex of the pedicel
(Goeden 2000c), those ofA^. viridescens are
irregularly scattered around the apex (Goe-
den and Headrick 1992), and those of TV.
wilsoni fully cover the pedicel (Goeden and
Headrick 1999).
First instar: White, elongate-cylindrical,
bluntly rounded anteriorly and posteriorly
(Fig. 2A); body segments well-defined,
nearly free of minute acanthae; gnathoce-
phalon smooth, lacking oral ridges, with
pair of prominent integumental petals dor-
sad of mouthhooks (Figs. 2B-1, C-5); dor-
sal sensory organ a well-defined, dome-
shaped papilla (Figs. 2B-2, C-1, D-1); an-
Acc.V SpotMagn Det WD terior sensory lobe (Figs. 2B-3, C-2, D-2)
10.0kV3.0 2578X SE 26.1 bears terminal sensory organ (Figs. 2C-3,
D-3); lateral sensory organ (Fig. 2D-4), su-
pralateral sensory organ (Fig. 2D-5), and
pit sensory organ (Fig. 2D-6); stomal sense
organ ventrolaterad ofanterior sensory lobe
(Figs. 2B-4, C-4, D-7), integumental petal
(Figs. 2B-1, C-5, D-8) fused laterally with
stomal sense organ (Figs. 2B-4, C-4, D-7);
mouthhook bidentate (Figs. 2B-5, C-6);
median oral lobe laterally flattened (Figs.
2B-6, C-7), posterolateral pair of verruci-
form sensilla on gnathocephalon (Figs. 2B-
7, C-8); meso- and metathoracic and ab-
dominal lateral spiracular complexes not
Fig. 1. Egg oi Neaspilotafootei: (A) habitus, an-
teriorend to left; (B) pedicel showing pattern ofaero- seen; caudal segment with two stelex sen-
pyles; (C) pedicel ofa differentegg with itsaeropyles. silla, dorso- and ventrolaterad of posterior
spiracular plate (Fig. 2E-1), neither stelex
sensillum basally ringed with minute acan-
to those of N. viridescens (Goeden and thae; posterior spiracular plate bears two
mm
Headrick 1992), N. wilsoni (Goeden and ovoid rimae, ca. 0.004 in length (Fig.
Headrick 1999), and N. appendiculata 2E-2), and four interspiracular processes,
(Goeden 2000c). The egg of N. footei is each with two to four branches, longest
about 10% longer on average than the eggs measuring ca. 0.01 mm (Fig. 2E-3); inter-
of N. viridescens (Goeden and Headrick mediate sensory complex with one stelex
194 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
—Fig. 2. First instar of"Ne—aspilotafootci: (A) habitus,—anterior to left; (B) gnathoc—ephalon, frontolateral vie—w,
1 integumen—tal petal, 2 dorsal se—nsory organ, 3 anterior sensor—y lobe, 4 stomal sense o—rgan, 5
mouthhook, 6 —median oral lobe, 7 verr—uciform sensillum; (C) 1— dorsal sensory organ,—2 anterior
se—nsory lobe, 3 termina—l sensory organ, 4 stomal sen—se organ, 5 integumental—petal, 6 mouthhook,
7 — median oral lobe, 8 ve—rruciform sensillum; (D) 1 — dorsal sensory organ, 2 a—nterior sensory lobe,
3 —terminal sensory organ, 4— lateral sensory organ, 5 supralateral sens—ory organ, 6 pit sensory orga—n,
7 sto—mal sensory organ, 8 integumental petal; (E) caudal segment,—1 posterior spiracula—r plate, 2
rima, 3 interspiracular process; (F) intermediate sensory complex, 1 stelex sensillum, 2 medusoid
sensillum.
VOLUME NUMBER
103. 1 195
sensillum (Fig. 2F-1) and one medusoid aenigma (Goeden 2000b), where the up-
sensillum with short papillae (Fig. 2F-2). right acanthus is solitary and rounded api-
The first instar is similar in general hab- cally; and in A^. appendiculata (Goeden
itus (Fig. 2A) to that of A^. viridescens 2000c), where the three basal acanthae are
(Goeden and Headrick 1992), N. wilsoni present, but poorly developed.
(Goeden and Headrick 1999), N. signifera Second instar: White, elongate-cylindri-
(Goeden 2000a), N. aenigma (Goeden cal, rounded anteriorly, truncated postero-
2000b), and N. appendiculata (Goeden dorsally (Fig. 3A), body segments well-de-
2000c). However, unlike A^. viridescens, but fined, anterior third of meso- and metatho-
like A^. wilsoni, N. aenigma, and A^. appen- rax and abdominal segments A-1 through
diculata, the dorsal sensory organ of the A-6 circumscribed anteriorly by minute
first instar ofA^.footei is well defined (Figs. acanthae also present on abdominal pleura;
2B-2, C-1, D-1), as is the anterior sensory dorsal sensory organ not well-defined, flat-
lobe (Figs. 2B-3, C-2, D-2) and integumen- tened (Figs. 3B-1, C-1, D-1); anterior sen-
tal petal (Figs. 2B-1, C-5, D-8). Also, the sory lobe (Figs. 3C-2, D-2) with terminal
pit sensory organ (Fig. 2D-6), not seen in sensory organ (Figs. 3C-3, D-3), lateral
A^. viridescens (Goeden and Headrick 1992) sensory organ (Fig. 3D-4), supralateral sen-
and hidden in specimens viewed ofA^. sig- sory organ (Fig. 3D-5), and pit sensory or-
nifera (Goeden 2000a), is present in A^. gan (Fig. 3D-6); stomal sense organ (Figs.
footei (Fig. 2D-6), as it is in A^. wilsoni 3C-4, D-7) ventrolaterad of anterior senso-
(Goeden and Headrick 1999), N. aenigma ry lobe; mouthhook bidentate (Figs. 3B-2,
(Goeden 2000b), and N. appendiculata C-5, D-8); median oral lobe laterally com-
(Goeden 2000c). A fused integumental pet- pressed (Fig. 3C-6); four papilliform, inte-
al and stomal sense organ also was reported gumental petals in each of two separate
in first instars of A^. wilsoni (Goeden and rows dorsad of each mouthhook (Figs. 3C-
Headrick 1999), N. signifera (Goeden 7, D-9); at least eight oral ridges, dentate
2000a), N. aenigma (Goeden 2000b), and along posterior margins, in vertical series
N. appendiculata (Goeden 2000c), as well laterad of oral cavity (Figs. 3B-3, C-8, D-
as Trupanea vicina (Wulp) (Goeden and 10); prothorax, circumscribed anteriorly by
Teerink 1999b), but these structures were at least two rows of posteriorly-directed,
separated in A^. viridescens (Goeden and minute acanthae (Figs. 3B-4, C-9, D-11);
Headrick 1992). anterior thoracic spiracle with three, doli-
Two stelex sensilla dorso- and ventrola- form papillae (Fig. 3E); lateral spiracular
terad of each posterior spiracular plate in complexes not seen; caudal segment with
the first instar of N. footei, N. aenigma two stelex sensilla dorsolaterad and ventro-
(Goeden 2000b), and N. appendiculata laterad of posterior spiracular plate; poste-
(Goeden 2000c) agreed with the four such rior spiracular plate bears three ovoid rimae
mm
sensilla reported to ring the caudal segment (Fig. 3F-1), ca. 0.011 long, and four
ofN. wilsoni (Goeden and Headrick 1999), interspiracular processes (Fig. 3F-2), each
but not the 10 sensilla reported to ring the with two to four, simple branches with one
caudal segment of A^. viridescens (Goeden or two, apical teeth, longest branch mea-
and Headrick 1992). The last number is suring 0.009 mm; intermediate sensory
probably erroneous, as discussed by Goe- complex with a stelex sensillum (Fig. 3F-
den (2000b). Lastly, A^. footei lacks the mi- 3) and a medusoid sensillum (Fig. 3F-4).
nute acanthae reported to ring basally the The habitus of the second instar of N.
lateral stelex sensilla on the caudal segment footei (Fig. 3A) is more like that ofA^. wil-
in N. wilsoni (Goeden and Headrick 1999), soni (Goeden and Headrick 1999), N. sig-
where the upright acanthae among them nifera (Goeden 2000a), A^. aenigma (Goe-
number one to three and are pointed; in A^. den 2000b), N. appendiculata (Goeden
196 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
—Fig. 3. Second instar of—Neaspilotafootei:—(A) habitus, ant—erior to left; (B) gnathocephalon, lateral view, 1
dorsal senso—ry organ, 2 mouthhook,—3 oral ridge, 4 minute—acanthae; (C) gnathocephalon—, fronto-
lateral view, I —dorsal sensory —organ, 2 anterior sens—ory lobe, 3 terminal s—ensory organ, 4— stomal
sense organ, 5 mouthhook, 6 median oral l—obe, 7 integumental petal—, 8 oral ridge, 9 minu—te
acanthae, (D) lateral view—of gnathocephalon, 1 —dorsal sensory organ, 2 ant—erior sensory lobe, 3 —
terminal sensory organ,—4 lateral senso—ry organ, 5 suprlateral s—ensory organ, 6 —pit sensory organ, 7
stomal sense organ, 8 mouthhook, 9 integumental—petal, 10— oral ridge, 11 minute—acanthae; (E)
anteriorthoracic spiracle; (F) posterior—spiracularplate, 1 rima, 2 interspiracularprocess, 3 intermediate
sensory complex, stelex sensillum, 4 medusoid sensillum.
VOLUME NUMBER
103, 1 197
2000c), N. pubescens (Goeden 2000d), and brown to black, tapering and truncated an-
N. achilleae (Goeden 2001) than the "bar- teriorly; posterior spiracular plate on caudal
rel-shaped" (doliform) second instar of N. segment flattened and upturned dorsally ca.
vihdescens (Goeden and Headrick 1992). 60° (Fig. 4A), minute acanthae circum-
The dorsal sensory organ ofA^.footei is not scribe anterior fifth of mesothorax, anterior
well-defined in the second instar (Figs. 3B- fourth of metathorax and first abdominal
1, C-1, D-1), like A^. viridescens (Goeden segment (Al), and all of remaining abdom-
and Headrick 1992), A^. wilsoni (Goeden inal segments, except for pleura of segment
and Headrick 1999), A^. aenigma (Goeden A2, posterior half of A7, and most of A8,
2000b), and N. achilleae (Goeden 2001), dorsa of abdominal segments A7 and A8
but unlike A^. signifera (Goeden 2000a), A^. also covered with minute acanthae; gnath-
appendiculata (Goeden 2000c), and N. pu- ocephalon conical (Fig. 4B); dorsal sensory
bescens (Goeden 2000d), in which this or- organ defined by a crescentric fold (Figs.
gan is well-defined. The integumental pet- 4C-1, D-1) attached dorsally (Figs. 4C-1,
als of the second instars of all eight species D-1) and punctured peripherally by pores
studied to date are papilliform, but are only (Fig. 4D-2); anterior sensory lobe (Figs.
four in number above each mouthhook in 4B-1, C-2, D-3) bears terminal sensory or-
N. achilleae (Goeden 2001), like A^. signi- gan (Fig. 4D-4), lateral sensory organ (Fig.
fera (Goeden 2000a), but are six in number 4D-5), supralateral sensory organ (Fig. 4D-
in A^. viridescens (Goeden and Headrick 6), and pit sensory organ (Fig. 4D-7); 10
1992) and A^. pubescens (Goeden 2000d), papilliform (including two small, central)or
seven in A^. appendiculata (Goeden 2000c) spatulate, integumental petals in two rows
and N. wilsoni (Goeden and Headrick above each mouthhook (Figs. 4C-3, E-1);
1999), and eight in N. aenigma (Goeden at least seven oral ridges (Fig. 4C-4),
2000b) and N. footei (Figs. 3C-7, D-9). toothed ventrally and lateral to oral cavity;
Compared to five papillae on the anterior stomal sense organ (Figs. 4C-5, D-8) ven-
spiracle of the second instar of in A^. pu- trolaterad of anterior sensory lobe; mouth-
bescens (Goeden 2000b) and eight in N. ap- hook (Figs. 4B-2, C-6, E-2) tridentate; me-
pendiculata (Goeden 2000c), N.footei only dian oral lobe reduced, laterally flattened,
has three papillae (Fig. 3E), like the three (Fig. 4E-3); gnathocephalon bears at least
or four papillae reported in second instars three verruciform sensilla posteriorad of
of N. viridescens (Goeden and Headrick each anterior sensory lobe and oral ridges
1992), N. wilsoni (Goeden and Headrick (Figs. 4B-3, C-7); prothorax circumscribed
1999), A^. signifera (Goeden 2000a), A^. by minute acanthae (Fig. 4B-4); verruci-
aenigma (Goeden 2000b), and N. achilleae form sensilla circumscribe prothorax pos-
(Goeden 2001). Finally, the interspiracular teriorad ofminute acanthae (Fig. 4B-5); an-
processes ofN.footei (Fig. 3F-2) each bear terior thoracic spiracle on posterior margin
two to four branches, like those of A^. sig- of prothorax bears three doliform papillae
nifera (Goeden 2000a), but not one to four (Fig. 4F); mesothoracic and metathoracic
branches like N. aenigma (Goeden 2000b) lateral spiracular complexes with five and
and N. pubescens (Goeden 2001), nor five four verruciform sensilla, respectively, each
to nine branches like N. viridescens (Goe- complex alligned vertically, mesothoracic
den and Headrick 1992), two to six branch- spiracle greatly reduced (not shown) and
es like N. wilsoni (Goeden and Headrick metathoracic spiracle not found; lateral spi-
1999), nor four branches like N. appendi- racular complex of abdominal segment A-
culata (Goeden 2000c) and N. achilleae 1 with a spiracle (Fig. 5A-1) and four ver-
(Goeden 2001). ruciform sensilla, one dorsoposteriorad of,
Third instar: Pale yellow, elongate-ellip- one posteriorad of, and two ventroposter-
soidal, with posterior spiracular plate dark iorad of the spiracle, the upper and first
198 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
—Fig. 4. Third instarofNea—spilotafootei: (A—) habitus, anteriorto left; (B—) gnathocephalon, fron—tolateralview,
1 anteriorsensory lobe, 2 mouthhook, 3 ver—ruciform sensillum, 4 min—uteacanthae, 5 verrucifo—rm
sensilla; (C) gnathocep—halon, frontolat—eral view, 1 dorsal se—nsory organ, 2 —anterior sensory lobe, 3
integumental petal, 4 —oral ridge, 5 stomal sen—se organ, 6 mouth—hook, 7 verruciform sen—sillum; (D)
anterior sensory l—obe, 1 dorsal sensory org—an, 2 peripheral pore, 3 an—teriorsensory lobe, 4 —terminal
sensory organ, 5 lateral senso—ry organ, 6 supralateral—sensory organ, 7— pit sensory organ, 8 stomal
sense organ; (E) oral cavity, 1 integumental petal, 2 mouthhook, 3 median oral lobe; (F) anterior
thoracic spiracle.
VOLUME NUMBER
103, 1 199
—
Fig. 5. —Third instar of Neaspilotafootei, continued: (—A) first abdominal, lateral spira—cular complex, 1
spiracle, 2 —verruciform sensilla; (B) cau—dal segment, 1 posterior spiracu—lar plate, 2 dorsolateral stelex
sensillum, 3 lateral stelex sensillum, 4 ventrolateral stelex sensillum, 5 intermediate sens—orycomple—x;
(C) lateral stelex sensillum; (D) ventrolateral stelex sensillu—m. (E) posterior spirac—ular plate, 1 rima, 2
interspiracular process, (F) intermediate sensory complex, I stelex sensillum, 2 medusoid sensillum.
ventroposterior sensilla aligned ventrally 5B-3, C), and ventrolaterad (Figs. 5B-4, D)
(Fig. 5A-2), as are the other two posteriorad of posterior spiracular plate, each sensillum
of the first pair (Fig. 5A-2); a stelex sensil- surrounded basally by four or five, minute
lum dorsolaterad (Fig. 5B-2), laterad (Figs. acanthae (Figs. 5C, D), smaller than other
200 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON
minute acanthae (Figs. 5C, D); each pos- gumental petals in the third instars ofall six
terior spiracular plate (Fig. 5E) bears three congeners examined to date, all of which
mm
ovoid rimae, ca. 0.014 in length (Fig. are arranged in a double row above each
5E-1), and four, simple or forked interspi- mouthhook and papilliform or spatulate
mm
racularprocesses, each 0.014 long (Fig. (Goeden and Headrick 1992, 1999; Goeden
5E-2); intermediate sensory complex (Fig. 2000a, b, c, d, 2001). The integumental pet-
5F) with a stelex sensillum (Fig. 5F-1), sur- als differ in numbers among species and
rounded basally by reduced minute acan- generally increase in number between the
thae (Fig. 5F-1), and a medusoid sensillum last two instars. The stomal sense organ of
(Fig. 5F-2). the third instar ofN.footei was obscuredby
The habitus ofthe third instar ofA^.footei debris in my specimens, and could thus not
is like that reported forN. viridescens (Goe- be compared readily with other congeners
den and Headrick 1992), N. wilsoni (Goe- (Figs. 4C-5, D-8), but it appears at least as
den and Headrick 1999), A^. signifera (Goe- complex as the stomal sense organ of the
den 2000a), N. aenigma (Goeden 2000b), second instar (Fig. 3D-4).
A^. appendiculata (Goeden 2000c), N. pu- The third instars of all seven species of
bescens (Goeden 2000d), and A^. achilleae Neaspilota examined to date have oral ridg-
(Goeden 2001). The pattern of the minute es with dentate ventral margins character-
acanthae that circumscribe the body seg- istically arranged in vertical series ventro-
ments is unique for A^. footei (see descrip- laterad of the dorsal sensory organ and lat-
tion above), but closest to N. achilleae erad of the oral cavity (Goeden and Head-
(Goeden 2001) in that the acanthae increase rick 1992, 1999; Goeden 2000a, b, c, d,
their coverage posteriorly from the anterior 2001; Fig. 4C-4). Though unfortunately
fifths of the thoracic segments to include partly hidden and not fully counted in A^.
nearly all of the abdominal segments, ex- footei (i.e., at least seven. Fig. 4C-4) and A^.
cept A7 and A8 in the former species; achilleae (Goeden 2001), the oral ridges
whereas, inA^. signifera (Goeden 2000a),A^. number eight in A^. pubescens (Goeden
appendiculata (Goeden 2000c) and A^. pu- 2000d), seven or eight in the third instar of
bescens (Goeden 2000d), the anterior part A^. aenigma (Goeden 2000b), seven in A^.
of each body segment is circumscribed, in appendiculata (Goeden 2000c), but six in
N. aenigma the anteriors, pleura, and pos- the second and third instars of the other
teriors of each segment are circumscribed three congeners examined to date (Goeden
(Goeden 2000b); in A^. wilsoni, all interseg- and Headrick 1992, 1999; Goeden 2000a).
mental areas and all abdominal segments The appearance and arrangement of these
except the pleura are circumscribed (Goe- oral ridges appears to be a generic charac-
den and Headrick 1999); and in N. virides- ter; however, Goeden (2000c, d) confirmed
cens, the intersegmental areas are free of that the oral ridges vary in number among
acanthae (Goeden and Headrick 1992). third instars of some Neaspilota species.
Like A^. viridescens (Goeden and Headrick Also, the most ventral, eighth oral ridge of
1992), A^. wilsoni (Goeden and Headrick A^. pubescens is not ventrally toothed (Goe-
1999), A^. pubescens (Goeden 2000d), and den 2000d). The third instars of Trupanea
A^. achilleae (Goeden 2001), but unlike A^. imperfecta (Coquillett), T.jonesi Curran, T.
signifera (Goeden 2000a), N. aenigma nigricornis (Coquillett), T. pseudovicina
(Goeden 2000b), and N. appendiculata (Hering), T. signata Foote, and T. wheeleri
(Goeden 2000c), the dorsal sensory organ Curran also bear serrated oral ridges (Goe-
is not well-defined and flattened, and not den and Teerink 1997b, 1998, 1999a; Goe-
dome-shaped, in the third instar ofN.footei den et al. 1998; Knio et al. 1996; Teerink
(Figs. 4C-1, D-1). and Goeden 1999), but these oral ridges ap-
Additional similarities involved the inte- pear to be fewer in number, and are not ar-