|scientific name Greya subalba |
Dry prairie where Lomatium is present (Davis et al. 1992).
In Alberta, adults have been collected in late June to early July (Davis et al. 1992).
Davis et al. (1992) provide a description of the adults and immatures as follows: Females more yellow than males, and significantly smaller. Wingspan 11-13 mm in female, 13-16 mm in male. Forewing white in male to yellowish in female; hindwing grey. Thorax dorsally white to yellowish; ventrally white; legs white ventrally, grayish dorsally. Vertex and frons of the head white with ochreous area between antennae, especially in male; antennae 0.55-0.65 the length of the forewings, 31-33 segmented. Maxillary palpus white to pale ochreous with all three or four segments short, fourth segment longer than third if present. Abdomen pale brownish white to yellowish white dorsally, white ventrally.
Apex of female ovipositor compressed and acute; males with uncus superficially bilobed, base slightly constricted, valva broad to pollex. Larvae up to 1.1 mm long and 0.2 mm wide. Egg white, 0.5 mm long, 0.3 mm wide.
Females lay eggs in the seeds of the host plant. Larvae feed within the schizocarp until seeds start to dry out, upon which they cut an exit hole in the seed and fall to the ground to complete their development (Thompson 1986). The species is parasitized by a braconid wasp (Agathis thompsoni sp.), the only major source of mortality while the larvae are inside the the schizocarps (Thompson 1986). Predators of the moths include thomisid spiders (Davis et al. 1992).
Larval host plants are in family Umbelliferae: Lomatium ambiguum, L. dissectum, L. grayi, L. triternatum, L. macrocarpum (Brown et al. 1994). Adults do not feed (Davis et al. 1992). This is the only species of Greya that has ever been observed to simultaneously use different hosts at the same site (Thompson 1987).
Waterton Lakes area of Alberta, southwest through the Pacific Northwest states to southeastern Oregon (Pellmyr 2000).
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