Type

Native

Taxonomy

Argyrotaenia franciscana (Walsingham) (Tortricidae: Tortricinae: Archipini)

Common names: orange tortrix, apple skinworm

Synonyms: citrana (Tortrix), kearfotti (Argyrotaenia)

Note: Argyrotaenia franciscana and A. citrana are considered separate species in much of the economic literature. Landry et al. (1999) concluded that they form a single species based on molecular data.

Subspecies: A. franciscana insulana (Anacapa Island, California)

Adult Recognition

FWLFWL:
forewing length; the distance from the base of the forewing to the apex, including fringe
: 6.0-10.0 mm

In California, A. franciscana has two common phenotypes that were previously separated into two species. One form (formerly A. citrana) has broad, orange to orange-brown forewings with a well-defined dark median fasciafascia:
a dark transverse band on the forewing
and outer spot on the costacosta:
the anterior margin of each wing
, and the hindwings are white to gray. The other form (typical A. franciscana) has narrow, gray to brownish-gray forewings with a dark, variably defined median fasciafascia:
a dark transverse band on the forewing
and an outer spot on the costacosta:
the anterior margin of each wing
, and the hindwings are primarily gray. Wing pattern and size can be quite variable although most individuals show remnants of a median fasciafascia:
a dark transverse band on the forewing
and outer costal spotcostal spot:
a patch of contrasting scales on the costa, usually a remnant of the postmedian or preterminal fascia
. Males lack a forewing costal foldforewing costal fold:
a flap or fold at the base of the forewing that contains specialized sex scales
.

Male genitalia are characterized by a moderate, parallel-sided, finger-like uncusuncus:
a sclerotized process which is fused to the posterodorsal margin of tergum IX
; reduced sociisocii:
a pair of lightly sclerotized setose lobes
; and large, subtriangular valvaevalva:
an appendage flanking the intromittent organ that is used to clasp the female during copulation
with a well-developed sacculussacculus:
the ventral margin of the male valva
. Female genitalia are characterized by a ductus bursaeductus bursae:
a membranous tube connecting the ostium bursae to the corpus bursae
with a sclerotizedsclerotized:
hardened; usually in reference to larval structures or adult genitalia
plate near the ostiumostium:
see ostium bursae
and a large, hook-shaped signumsignum:
a sclerotized projection or patch on the interior of the corpus bursae
in the corpus bursaecorpus bursae:
a dilated membranous sac at the anterior end of the bursa copulatrix
.

Larval Morphology

The following account is summarized from MacKay (1962a).

Mature larva 13-15 mm in length; width of head approximately 1.1-1.3 mm; head, prothoracic shieldprothoracic shield:
a sclerotized plate on the dorsal surface of the prothorax
light brown to brownish yellow, unmarked; legs brown; body color varies with host plant, but usually pale to dark green; anal shieldanal shield:
a sclerotized plate on the dorsal surface of the last abdominal segment (in larvae)
concolorous with body; anal fork well-developed; SV group on A1, 2, 7, 8, 9 numbering 3:3:3:2:2.

Detailed figures of larval chaetotaxychaetotaxy:
the arrangement of setae (in reference to Lepidoptera larvae), often depicted on a "setal map"
are available in MacKay (1962a).

Similar Species

Adults most closely resemble some forms of Epiphyas postvittana. Males of Argyrotaenia franciscana can be distinguished by the lack of a costal fold. The genitalia of both sexes are distinct. Choristoneura rosaceana males have been captured in A. franciscana pheremone traps; however, adults of these two species are unlikely to be confused.

Larval damage by Pandemis pyrusana may resemble that of A. franciscana and the larvae are similar in appearance. Argyrotaenia franciscana larvae are similar to those of many other Archipini that have a brown, unmarked head and prothoracic shieldprothoracic shield:
a sclerotized plate on the dorsal surface of the prothorax
.

Biology

The following account is summarized from Powell (1964b).

Argyrotaenia franciscana is bivoltine or multivoltine, depending on location. In warmer inland areas of California, larvae aestivate during the summer and only two generations are completed. In cooler coastal areas there may be up to 5 continuous overlapping generations with adults present year-round.

Eggs are laid on smooth surfaces of leaves, fruits, and twigs in masses that contain approximately 200 individual eggs. Early instar larvae skeletonize leaves under a silk shelter; later instars roll, fold, or web leaves together or to fruits. Larvae complete 5-7 instars in a period of 20-30 days. Larvae or pupae overwinter in dead leaves, in mummified fruits, under buds, or on weedy herbaceous plants in the same vicinity as the host. Pupation occurs in the final larval shelter. Larvae can cause economic damage by directly feeding on developing fruit in citrus, apple, and grape. Larvae may also feed on stems, causing fruit to drop.

Argyrotaenia franciscana has been described as one of the most polyphagous tortricid species in North America. Its host list includes plants in more than 40 families, many of which are important crops.

Host plant table (embedded)

View full screen host table here

Distribution

Argyrotaenia franciscana is found along the west coast of North America, from Baja California north to British Columbia.

Photo Credits

Figs. 7-9: University of California Statewide IPM Program (UC IPM Web Site)

Links

Additional photos and a distribution map of this species in North America are available at Moth Photographers Group. 

Host plant	Host plant family	Reference(s)
Schinus molle	Anacardiaceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Ilex opaca	Aquifoliaceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Hedera helix	Araliaceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Achillea millefolium	Asteraceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Artemisia californica	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Artemisia douglasiana	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Baccharis pilularis	Asteraceae	De Benedictis et al. 1990De Benedictis et al. 1990: De Benedictis, J. A., Wagner, D. L., Whitfield, J. B. 1990. Larval hosts of Microlepidoptera of the San Bruno Mountains, California. Atala. 16: 14-35.; Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp., 2006
Baccharis sp.	Asteraceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Cirsium occidentale	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Coreopsis gigantea	Asteraceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Coreopsis sp.	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Corethrogyne sp.	Asteraceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.; Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Encelia californica	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Erigeron glaucus	Asteraceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Eriophyllum staechadifolium	Asteraceae	De Benedictis et al. 1990De Benedictis et al. 1990: De Benedictis, J. A., Wagner, D. L., Whitfield, J. B. 1990. Larval hosts of Microlepidoptera of the San Bruno Mountains, California. Atala. 16: 14-35.; Powell 1965Powell 1965: Powell, J. A. 1965. Supplementary notes on North American and Mexican species of Decodes and Argyrotaenia, with descriptions of new species (Lepidoptera: Tortricidae). Proceedings of the Biological Society of Washington. 78: 65-80.; Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Gnaphalium sp.	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Grindelia camporum	Asteraceae	Powell 1964bPowell 1964b: Powell, J. A. 1964b. Biological and taxonomic studies on tortricine moths, with reference to the species in California. University of California Publications in Entomology. Vol. 32. 317 pp.
Grindelia hirsutula	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Grindelia sp.	Asteraceae	De Benedictis et al. 1990De Benedictis et al. 1990: De Benedictis, J. A., Wagner, D. L., Whitfield, J. B. 1990. Larval hosts of Microlepidoptera of the San Bruno Mountains, California. Atala. 16: 14-35.; Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Isocoma veneta	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Lessingia sp.	Asteraceae	Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.
Pericallis hybrida	Asteraceae	LACM IndexLACM Index: LACM Index. Records from the card file at the Los Angeles County Museum of Natural History, Los Angeles, California; transcribed by Gaeden Robinson (BMNH).

Male	Male
Male	Female
Male genitalia	Female genitalia
Resting adults. © UC Statewide IPM Program, Agriculture and Natural Resources, University of California.	Larva. © UC Statewide IPM Program, Agriculture and Natural Resources, University of California.
Larva. © UC Statewide IPM Program, Agriculture and Natural Resources, University of California.	Larva (dorsal)