Ceromasia auricaudata Townsend, 1908

O’Hara, James E., 2005, A review of the tachinid parasitoids (Diptera: Tachinidae) of Nearctic Choristoneura species (Lepidoptera: Tortricidae), with keys to adults and puparia, Zootaxa 938, pp. 1-46 : 19-20

Ceromasia auricaudata Townsend, 1908 , Fig. 39

Host records ex. Choristoneura fumiferana : † Dowden et al. 1948, as Masicera rutila ex. Archips fumiferana (eastern North America); Blais 1960 (QC); Huber et al. 1996, as Ceromasia aurifrons (NB) and C. auricaudata († America north of Mexico).

Host records ex. Choristoneura fumiferana , Choristoneura occidentalis and/or Choristoneura pinus : † Ross 1952, as Ceromasia aurifrons and C. auricaudata ex. spruce and/or jack pine budworm ( Canada); † Arnaud 1978, as Ceromasia aurifrons ( Canada) and C. auricaudata (BC, OR, CO, ON, QC) ex. C. fumiferana .

Host records ex. Choristoneura occidentalis: McKnight 1974 (CO); Harris & Dawson 1979 (BC); Schmid 1981 (NM); Torgersen et al., 1984 (WA, OR, ID, MT); † Harris & Dawson 1985 (BC); † Torgersen 1985 (WA, OR, ID, MT).

Host records probably ex. Choristoneura occidentalis: Tothill 1913 , as Masicera rutila ex. Tortrix fumiferana (BC); Wilkes 1946, ex. Archips fumiferana (BC); Coppel 1947, ex. Archips fumiferana (BC); Dowden et al. 1948, ex. Archips fumiferana (western North America); †Wilkes 1949, ex. Archips fumiferana (BC); Wilkes et al. 1949, ex. C. fumiferana (BC); Coppel 1953, ex. C. fumiferana (BC); Carolin & Coulter 1959, ex. C. fumiferana (OR); † Coppel 1960, ex. C. fumiferana (BC); † Zwolfer 1961, ex. C. fumiferana (BC); † Graham & Jones 1962, ex. C. fumiferana (BC); † McGugan & Coppel 1962, ex. C. fumiferana (BC); † Clausen 1978, ex. C. fumiferana (BC).

Host records ex. Choristoneura occidentalis and/or Choristoneura retiniana: Schaupp et al. 1991 (OR).

Ceromasia aurifrons and C. auricaudata were considered to be distinct species until recently, with the former having an eastern distribution and the latter a western distribution (e.g., Sabrosky & Arnaud 1965). O’Hara and Wood (2004) synonymized C. aurifrons with C. auricaudata and gave the known distribution of this species as transcontinental in Canada and ranging southward to California, New Mexico, Kansas, and Massachusetts. Adults are typically 7–9mm long, rather robust, and mostly gray with a mottled abdomen. The head and tip of the abdomen are usually golden, though less so in eastern specimens. The egg, three larval instars, and puparium of C. auricaudata were described and illustrated by Coppel and Maw (1954a). Ceromasia auricaudata was included in a key to the puparia of dipterous parasitoids of Choristoneura species by Ross (1952, as separate species C. aurifrons and C. auricaudata ) and in a key to the adults of dipterous parasitoids of Choristoneura occidentalis (as C. fumiferana ) in British Columbia by Coppel (1960).

Ceromasia auricaudata belongs to the Goniini and produces microtype eggs that are ingested by the host. Further information on general goniine biology is given below under Cyzenis incrassata . Ceromasia auricaudata attacks late instar larvae of Choristoneura species and the mature maggot emerges from the host pupa and pupariates in the soil ( Dowden et al. 1948; Coppel & Maw 1954a; Carolin & Coulter 1959). In a study of C. occidentalis parasitism in British Columbia by Harris and Dawson (1979), emergence from sixth instar hosts as well as from host pupae was reported. Adult flies emerge from their puparia in about 9–11 days ( Coppel & Maw 1954a).

Adults of the second generation of C. auricaudata overwinter in alternate hosts including pupae of the fall webworm, Hyphantria cunea (Drury) ( Coppel 1947) . The few other known hosts of C. auricaudata include two tortricids, a species each of Geometridae and Noctuidae , and three species of Pieridae and Pyralidae that served as hosts under laboratory conditions ( Arnaud 1978, including records from “ C. aurifrons ”).

The rate of parasitism of C. auricaudata in conifer­feeding Choristoneura is negligible in the East but significant in the West, with parasitism of up to 13% reported by Wilkes et al. (1949) and up to 16% reported by Harris & Dawson (1979) in British Columbia, and up to 13% reported by Schaupp et al. (1991) in Oregon. Wilkes et al. (1949) ranked C. auricaudata as the fourth most important parasitoid, and second most important dipterous parasitoid, of C. occidentalis (as C. fumiferana ) in British Columbia.

Efforts were made during the 1940s and 1950s to establish several western species of budworm parasitoids in eastern Canada to help control outbreaks of Choristoneura fumiferana . Among these was C. auricaudata , which was reared in huge numbers in Belleville, Ontario, from budworms collected mostly from the Lillooet area of British Columbia ( Wilkes 1946; Coppel 1947). About 21,000 C. auricaudata were released in eastern Canada between 1944 and 1953, with an additional 2363 specimens released in Maine and 6317 specimens released in New York during this period ( McGugan & Coppel 1962; Clausen 1978). There is no evidence that any western C. auricaudata became established in the East. Blais (1960) recorded a single C. auricaudata from Québec, but that specimen could well have represented parasitism from the endemic population of the species. The only other published report of C. auricaudata parasitizing Choristoneura fumiferana in the East is that of Huber et al. (1996, as C. aurifrons ) based on a rearing record from New Brunswick.

Figures

FIGURES 37 – 42. Habitus images. 37. Actia diffidens. 38. Actia interrupta. 39. Ceromasia auricaudata. 40. Compsilura concinnata. 41. Cyzenis incrassata. 42. Eumea caesar.