Exotic, but established
Grapholita delineana (Walker) (Tortricidae: Olethreutinae: Grapholitini)
Common names: Eurasian hemp borer
Synonyms: apicatana (Grapholita), mundana (Grapholitha), quadristriana (Laspeyresia), sinana (Grapholitha), terstrigana (Grapholitha), tetragrammana (Grapholitha)
FWL: 4.5-6.5 mm
Adults are dark brown with two pairs of white dorsaldorsal:
upper, to the top, on the back 
strigulae and multiple pairs of costal strigulaecostal strigulae:
small, usually pale, semirectangular marks along the costa 
on each forewing. Males lack a forewing costal foldforewing costal fold:
a flap or fold at the base of the forewing that contains specialized sex scales
. Hindwings are dark brown with a white fringe.
Male genitalia are characterized by the absence of an uncusuncus:
a sclerotized process which is fused to the posterodorsal margin of tergum IX
, valvaevalvae:
plural of "valva"
with a well-developed cuculluscucullus:
the distal portion of the male valva
, and an aedeagusaedeagus:
the male intromittent organ (penis); see "phallus" 
that narrows abruptly. Female genitalia are characterized by a short ductus bursaeductus bursae:
a membranous tube connecting the ostium bursae to the corpus bursae
and two horn-like signasigna:
plural of "signum"
in the corpus bursaecorpus bursae:
a dilated membranous sac at the anterior end of the bursa copulatrix
.
The following account is summarized from Komai (1999)Komai (1999):
Komai, F. 1999. A taxonomic review of the genus Grapholita and allied genera (Lepidoptera: Tortricidae) in the Palaearctic region. Entomologica Scandinavica Supplement 55. 226 pp..
Larvae are similar to those of other Grapholita. Head, prothoracic shieldprothoracic shield:
a sclerotized plate on the dorsal surface of the prothorax 
yellow, yellowish brown, or brown; body whitish yellow; anal fork absent.
Detailed figures of larval chaetotaxychaetotaxy:
the arrangement of setae (in reference to Lepidoptera larvae), often depicted on a "setal map"
are available in Komai (1999)Komai (1999):
Komai, F. 1999. A taxonomic review of the genus Grapholita and allied genera (Lepidoptera: Tortricidae) in the Palaearctic region. Entomologica Scandinavica Supplement 55. 226 pp..
Wing pattern is similar to other Grapholita, especially Grapholita tristrigana in eastern North America. The dorsaldorsal:
upper, to the top, on the back strigulae in G. delineana are usually narrow and distinctly separated, while those in G. tristrigana may be confluent. The two species can be separated by genitalia: in G. tristrigana the male aedeagusaedeagus:
the male intromittent organ (penis); see "phallus" tapers evenly and females lack a 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.
The following account is summarized from Miller (1982)Miller (1982):
Miller, W. E. 1982. Grapholita delineana (Walker), a Eurasian hemp moth, discovered in North America. Annals of the Entomological Society of America. 75: 184-186..
Grapholita delineana completes 2-3 generations per year. Adults are present in mid-May to August in North America.
Females lay eggs on the leaves and stems of the host plant. Larvae feed in the stems, on developing seeds, and also on flowers. Infested plants show a swelling in the stem and possibly and entrance hole with extruded frass. Pupation occurs in the soil.
Larvae can be pests on marijuana, hemp, and hops (Cannabaceae) and have also been recorded on knotweed (Polygonaceae).
| Host plant | Host plant family | Reference(s) |
| Cannabis sativa | Cannabaceae | MacKay 1959MacKay 1959: MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338.; Danilevsky & Kuznetzov 1968; Vassilaina-Alexopoulou & Mourikis 1976; Miller 1982Miller 1982: Miller, W. E. 1982. Grapholita delineana (Walker), a Eurasian hemp moth, discovered in North America. Annals of the Entomological Society of America. 75: 184-186.; Park 1983bPark 1983b: Park, K. T. 1983b. Microlepidoptera of Korea. Insecta Koreana. 3: 8-24. |
| Humulus japonicus | Cannabaceae | Danilevsky & Kuznetzov 1968; Kawabe 1982Kawabe 1982: Kawabe, A. 1982. Tortricidae and Cochylidae, pp. 62-151. In : Inoue, H., Sugi, S., Kuroko, H., Moriuti, S., Kawabe, A. (eds.), The Moths of Japan, Part 1: 62-258, Part 2: 158-183.; Park 1983bPark 1983b: Park, K. T. 1983b. Microlepidoptera of Korea. Insecta Koreana. 3: 8-24. |
| Humulus lupulus | Cannabaceae | Park 1983bPark 1983b: Park, K. T. 1983b. Microlepidoptera of Korea. Insecta Koreana. 3: 8-24. |
| Polygonum sp. | Polygonaceae | Fletcher 1932Fletcher 1932: Fletcher, T. B. 1932. Life histories of Indian insects, Microlepidoptera, second series. The Imperial Council of Agricultural Research, Sci. Monogr. 2. 58 pp. |
View full screen host table here
Grapholita delineana is a native of East Asia that has spread into Europe, Asia Minor, Transcausasia, and North America along with the commercial production of hemp. It was first recorded from North America in 1943 (Miller 1982Miller 1982:
Miller, W. E. 1982. Grapholita delineana (Walker), a Eurasian hemp moth, discovered in North America. Annals of the Entomological Society of America. 75: 184-186.) and it is currently distributed from New York west to Minnesota and south to Missouri.
