Crocidosema plebejana

Status

NATIVE

PORT INTERCEPT | DOMESTIC SURVEY

Taxonomy

Crocidosema plebejana Zeller (Tortricidae: Olethreutinae: Eucosmini)

Common names: cotton tipworm

Synonyms: altheana (Penthina), bostrychodes (Crocidosema), charmera (Eucosma), excitana (Grapholitha), insulana (Crocidosema), iris (Crocidosema), lavaterana (Paedisca), obscura (Steganoptycha), peregrinana (Grapholitha), plebeiana (Crocidosema) ptiladelpha (Crocidosema), synneurota (Crocidosema), tornocycla (Eucosma)

Note: Crocidosema plebejana may represent a global species complex of several closely related species identifiable only subtle differences in the genitalia and/or DNA, but for the purposes of this site, we treat this entire putative complex as a single species. 

Adult Recognition

FWL: 5.0–8.0 mm

Males are dark brown to black with a conspicuous white ocellus and dorsal patch. Females are pale brown to tan with a dark basal patch that does not extend to the costa. Males lack a forewing costal fold.

Male genitalia are characterized by valvae with an enlarged, subtriangular cucullus. Female genitalia are characterized by a pair of lobes or "flaps" projecting from sternum VII and two signa in the corpus bursae.

Larval Morphology

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 larva approximately 8–10 mm in length; width of head 0.7–0.9 mm; head yellowish brown to dark brown with darker lateral pigmentation; prothoracic shield dark yellowish brown; body varies in color from whitish to yellowish brown to dark reddish brown; anal fork present with 4–6 teeth; SV group on A1, 2, 7, 8, 9 typically 3:3:2:2:2.

Detailed figures of larval chaetotaxy are available in MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist, Supplement 10: 1-338..

Similar Species

In the Nearctic, Crocidosema plebejana may appear similar to other Eucosmini, including other species of Crocidosema or Epinotia. A genitalic dissection can be used to confirm identity. The bean shoot moth, C. aporema, can be separated from C. plebejana by a parallel-sided cucullus in the male and a pair of shallow, rounded pockets on sternum VII in the female.

Larvae feeding on cotton can cause damage similar to that caused by the pink bollworm, Pectinophora gossypiella (Gelechiidae). Pink bollworm larvae can be separated from C. plebejana larvae by their pink coloration.

Distribution

Crocidosema plebejana is a cosmopolitan species that is distributed across southern Europe, northern Africa, Asia, Australia, North America, Central America, and South America. In the United States, it is found primarily in the Southeast, Texas, New Mexico, and California.

Biology

The following account is summarized from Bishop and Blood (1978)Bishop and Blood (1978):
Bishop, A. L., Blood, P. R. B. 1978. Temporal distribution, biology and life history of the cotton tipworm, Crocidosema plebiana [sic] Zeller, on cotton in the south-eastern Queensland region. Australian Journal of Zoology. 26: 147-152. and Bradley et al. (1979)Bradley et al. (1979):
Bradley, J. D., Tremewan, W. G., Smith, A. 1979. British Tortricoid Moths, Tortricidae: Olethreutinae. The Ray Society, London. 336 pp..

Crocidosema plebejana is not known to diapause although only 1–2 generations occur per year in southern England. In temperate regions, continuous generations occur, and adults are present year-round.

Larvae are reported as a pest of cotton (Gossypium sp.) in Australia, but this species has not reached pest status in the cotton-growing regions of North America. In areas where cotton is a preferred host, other malvaceous plants are utilized during times of the year when cotton is unsuitable or unavailable. The life history information provided here is applicable to cotton as the larval host.

Females lay eggs singly on the upper and lower surfaces of leaves in or close to the terminals and lateral buds. Early instars feed on leaves under loose silk webbing. Later instars move to the terminals and tunnel into stems; they may also feed on leaf petioles and young bolls. Pupation occurs in terminal regions in webbed or tied leaves.

Although members of the Malvaceae are preferred hosts, larvae have also been recorded feeding on plants in the Amaranthaceae, Anacardiaceae, Fabaceae, Myrtaceae, Poaceae, Rosaceae, Salicaceae, and Turneraceae.

Plant Associations

View full screen host table here

Links

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