Native
Epiblema strenuana (Walker) (Tortricidae: Olethreutinae: Eucosmini)
Common name: ragweed borer moth
Synonyms: antaxia (Eucosma), exvagana (Grapholita), flavocellana (Steganoptycha), subversana (Grapholita)
FWL: 4.0-9.0 mm
Head and thorax gray to brown; forewing with ground color pale brown, but heavily dusted with dusty gray scales as to obscure much of the ground color; interfascial spot whitish to bronzy-gray, often barely distinguishable; ocellusocellus:
forewing pattern element - an ovoid region anterior to the tornus; adult head - a simple insect "eye" located dorsal to the compound eye 
prominent, white, with a black longitudinal dashdash:
a short, sharp, black line on the forewing 
; costal strigulaecostal strigulae:
small, usually pale, semirectangular marks along the costa 
weakly contrasting except towards apexapex:
the point furthest removed from the base or at the end of the costal area 
where they are often separated by patches of orange scales; males without costal fold; hindwing pale brown.
Male genitalia are characterized by long, finger-like sociisocii:
a pair of lightly sclerotized setose lobes
and valvaevalvae:
plural of "valva"
with a broad concavity on the ventralventral:
lower, to the bottom, on the under side
margin of the valve between the sacculussacculus:
the ventral margin of the male valva 
and cuculluscucullus:
the distal portion of the male valva
. Female genitalia are characterized by a rectangular and elongate sterigmasterigma:
the sclerotized region surrounding the female ostium bursae 
; ductus bursaeductus bursae:
a membranous tube connecting the ostium bursae to the corpus bursae
with a twist-like sclerotizedsclerotized:
hardened; usually in reference to larval structures or adult genitalia 
contortion near the juncture of the ductus seminalis; and two large blade-like signasigna:
plural of "signum"
.
The following account is summarized from MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..
Mature larvae are approximately 12-15 mm in length, width of head 1.0-1.2 mm. Head brown, occasionally with black pigmentation laterally; prothoracic shieldprothoracic shield:
a sclerotized plate on the dorsal surface of the prothorax 
brown; thoracic legs and anal shieldanal shield:
a sclerotized plate on the dorsal surface of the last abdominal segment (in larvae) 
brown; body pale; anal fork absent. SV groups on A1, 2, 7, 8, 9 usually 2:2:2:2:1.
A complete description of larval chaetotaxychaetotaxy:
the arrangement of setae (in reference to Lepidoptera larvae), often depicted on a "setal map"
is available in MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..
Several species of Epiblema are very similar to E. strenuana, especially E. minutana and E. luctuosissima. Dissection is usually necessary to separate them. Males of E. minutana tend to have shorter and sometimes more triangular sociisocii:
a pair of lightly sclerotized setose lobes whereas the females of E. minutana tend to have a shorter, less rectangular sterigmasterigma:
the sclerotized region surrounding the female ostium bursae compared to E. strenuana. Males of E. strenuana have a more constricted medialmedial:
to the middle, center, toward center line 
portion of the valvaevalvae:
plural of "valva" compared to E. luctuosissima. Females of E. strenuana have larger signasigna:
plural of "signum" in the corpus bursaecorpus bursae:
a dilated membranous sac at the anterior end of the bursa copulatrix
compared to E. luctuosissima.
The following account is summarized from McClay (1987)McClay (1987):
McClay, A. S. 1987. Observations on the biology and host specificity of Epiblema strenuana [Lepidoptera, Tortricidae], a potential biocontrol agent for Parthenium hysterophorus [Compositae]. Entomophaga. 32: 23-34..
Eggs are laid singly or in small groups and attached to the stems or leaves of the host plant. In Mexico, eggs hatch in approximately 4 days in early March. Newly hatched larvae will feed externally on most any part of the plant, but seems to especially prefer axillary buds and young foliage. Larvae then bore into a stem of the plant, forming a thing, elongate gall. The mature larvae will then cut a thin walled emergence hole in the upper portion of the gall and pupate. Adult eclose and leave the exuviae extruding from the exit hole in the gall. Typically, three generations occur per year in northern Mexico, with larvae active from March to November. Overwintering occurs in the larval stage with pupation occurring in the early spring. Two generations occur per year in the midwestern United States (Gilligan et al. 2008Gilligan et al. 2008:
Gilligan, T. M., Wright, D. J., Gibson, L. D. 2008. Olethreutine moths of the midwestern United States, an identification guide. Ohio Biological Survey, Columbus, Ohio. 334 pp.).
Larvae have been reported as stem borers in annual ragweed (Ambrosia artimisiifolia), Santa Maria feverfew (Parthenium hysterophorus) and other Asteraceae. It has also been recorded feeding on Chenopodium (Amaranthaceae) and Polygonum (Polygonaceae).
| Host plant | Host plant family | Reference(s) |
| Ambrosia artemisiifolia | Asteraceae | Heinrich 1923bHeinrich 1923b: Heinrich, C. 1923b. Revision of the North American moths of the subfamily Eucosminae of the family Olethreutidae. Bulletin of the United States National Museum. 123: 1-298.; MacKay 1959MacKay 1959: MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338.; Kimball 1965Kimball 1965: Kimball, C. P. 1965. The Lepidoptera of Florida: an annotated checklist. In : Arthropods of Florida and neighboring land areas, vol. 1. Florida Department of Agriculture, Division of Plant Industry, Gainesville. 363 pp.; Stegmaier 1971Stegmaier 1971: Stegmaier, C.E. 1971. Lepidoptera, Diptera, and Hymenoptera associated with Ambrosia artemisiifolia (Compositae) in Florida. The Florida Entomologist. 54(3): 259. |
| Ambrosia chamissonis | Asteraceae | Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.; Powell & Opler 2006 |
| Ambrosia psilostachya | Asteraceae | Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA. |
| Ambrosia trifida | Asteraceae | Heinrich 1923bHeinrich 1923b: Heinrich, C. 1923b. Revision of the North American moths of the subfamily Eucosminae of the family Olethreutidae. Bulletin of the United States National Museum. 123: 1-298.; Kimball 1965Kimball 1965: Kimball, C. P. 1965. The Lepidoptera of Florida: an annotated checklist. In : Arthropods of Florida and neighboring land areas, vol. 1. Florida Department of Agriculture, Division of Plant Industry, Gainesville. 363 pp.; Wan & Ding 1993; Powell 2006Powell 2006: Powell, J. A. 2006. Database of Lepidoptera rearing lots, 1960-2005. University of California Berkeley, CA.; Gilligan et al. 2020aGilligan et al. 2020a: Gilligan, T. M., Wright, D. J., Brown, R. L., Augustinus, B. A., Schaffner, U. 2020a. Taxonomic issues related to biological control prospects for the ragweed borer, Epiblema strenuana (Lepidoptera: Tortricidae). Zootaxa. 4729(3): 347-358. |
| Ambrosia sp. | Asteraceae | Miller & Pogue 1984; Wan & Ding 1993 |
| Helianthus sp. | Asteraceae | Wan & Ding 1993 |
| Parthenium hysterophorus | Asteraceae | MacKay 1959MacKay 1959: MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338.; McFadyen 1976, 1985, 1992; Jayanth 1987Jayanth 1987: Jayanth, K. P. 1987. Investigations on the host-specificity of Epiblema strenuana (Walker) (Lepidoptera: Tortricidae), introduced for biological control trials against Parthenium hysterophorus in India. Journal of Biological Control. 1.2: 133-137.; McClay 1987McClay 1987: McClay, A. S. 1987. Observations on the biology and host specificity of Epiblema strenuana [Lepidoptera, Tortricidae], a potential biocontrol agent for Parthenium hysterophorus [Compositae]. Entomophaga. 32: 23-34.; McClay et al. 1995McClay et al. 1995: McClay, A. S., Palmer, W. A., Bennett, F. D., Pullen, K. R. 1995. Phytophagous arthropods associated with Parthenium hysterophorus (Asteraceae) in North America. Annual Review of Entomology. 24: 796-809.; Dhileepan et al. 1996; Dhileenpan & McFadyen 1997; Navie et al. 1998Navie et al. 1998: Navie, S.C., Priest, T.E., McFadyen, R.E., Adkins, S.W. 1998. Efficacy of the stem-galling moth Epiblema strenuana Walk. (Lepidoptera: Tortricidae) as a biological control agent for ragweed parthenium (Parthenium hysterophorus L.). Biological Control 13: 1-8.; Raman & Dhileepan 1999; Dhileepan 2001Dhileepan 2001: Dhileepan, K. 2001. Effectiveness of introduced biocontrol insects on the weed Parthenium hysterophorus (Asteraceae) in Australia. Bulletin of Entomological Research. 91: 167-176. |
| Xanthium strumarium | Asteraceae | MacKay 1959MacKay 1959: MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338.; Gilligan et al. 2020aGilligan et al. 2020a: Gilligan, T. M., Wright, D. J., Brown, R. L., Augustinus, B. A., Schaffner, U. 2020a. Taxonomic issues related to biological control prospects for the ragweed borer, Epiblema strenuana (Lepidoptera: Tortricidae). Zootaxa. 4729(3): 347-358. |
| Xanthium sp. | Asteraceae | Miller & Pogue 1984; Miller 1987aMiller 1987a: Miller, W. E. 1987a. Guide to the Olethreutine moths of midland North America (Tortricidae). USDA Forest Service Agriculture Handbook 660: 1-104.; Powell & Opler 2009 |
| Chenopodium sp. | Chenopodiaceae | Miller & Pogue 1984; Miller 1987aMiller 1987a: Miller, W. E. 1987a. Guide to the Olethreutine moths of midland North America (Tortricidae). USDA Forest Service Agriculture Handbook 660: 1-104. |
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Epiblema strenuana is broadly distributed across North America, from Minnesota west to Colorado and New Mexico and east to Florida and Maryland. It is also known from southern California and northern Mexico. MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338. reported it from the US Virgin Islands, but these records require verification. Its range appears to overlap with several of its known host plants, but some of these records may be confused in the literature with the formerly synonymized species Epiblema minutana (Gilligan et al. 2020aGilligan et al. 2020a:
Gilligan, T. M., Wright, D. J., Brown, R. L., Augustinus, B. A., Schaffner, U. 2020a. Taxonomic issues related to biological control prospects for the ragweed borer, Epiblema strenuana (Lepidoptera: Tortricidae). Zootaxa. 4729(3): 347-358.).
Epiblema strenuana has been released as a biological control agent in Australia (McClay 1987McClay 1987:
McClay, A. S. 1987. Observations on the biology and host specificity of Epiblema strenuana [Lepidoptera, Tortricidae], a potential biocontrol agent for Parthenium hysterophorus [Compositae]. Entomophaga. 32: 23-34.; Gerber et al. 2011Gerber et al. 2011:
Gerber, E., Schaffner, U., Gassmann, A., Hinz, H. L., Seier, M., Muuml;ller-Schauml;rer, H. 2011. Prospects for biological control of Ambrosia artemisiifolia in Europe: learning from the past. Weed Research. 51: 559-573.) and China (Wan et al. 1995Wan et al. 1995:
Wan, F.‐H., Wang, R., Ding, J. 1995. Biological control of Ambrosia artemisiifolia with introduced insect agents, Zygogramma suturalis and Epiblema strenuana , in China. In : Scott, R.R. (ed.), Eighth International Symposium on Biological Control of Weeds, Canterbury, New Zealand. CSIRO, Melbourne, pp. 193-200.; Ma et al. 2008Ma et al. 2008:
Ma, J., Guo, J., Wan, F. H., Hu, X. N. 2008. Biological control of Ambrosia artemisiifolia and A . trifida . In : Wan, F.H. (ed.), Biological Invasions: Biological control theory and practice. Science Press, Beijing, pp. 157-185.), but rejected as a proposed biological control agent in India (Jayanth 1987Jayanth 1987:
Jayanth, K. P. 1987. Investigations on the host-specificity of Epiblema strenuana (Walker) (Lepidoptera: Tortricidae), introduced for biological control trials against Parthenium hysterophorus in India. Journal of Biological Control. 1.2: 133-137.) and South Africa (McConnachie 2015McConnachie 2015:
McConnachie, A. J. 2015. Host range tests cast doubt on the suitability of Epiblema strenuana as a biological control agent for Parthenium hysterophorus in Africa. BioControl. 60: 715-723.).
