Eumea caesar ( Aldrich, 1916 )

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 : 22-24

Eumea caesar ( Aldrich, 1916) , Fig. 42

Host records ex. Choristoneura conflictana: Prentice 1955 (SK, MB); † Arnaud 1978, as Aplomya caesar (SK, MB); † Huber et al. 1996 ( America north of Mexico).

Host records ex. Choristoneura fractivittana : † Wishart 1945, as Aplomya caesar ex. Archips “practivittana” (North America); † Arnaud 1978, as Aplomya caesar (North America); † Huber et al. 1996 ( America north of Mexico).

Host records ex. Choristoneura fumiferana: Wilkes & Anderson 1947, as Zenillia caesar ex. Archips fumiferana (ON, QC); Daviault 1950, as Aplomyia caesar (QC); Dowden et al. 1951, as Aplomya caesar ex. Archips fumiferana (NY); Jaynes & Drooz 1952, as Aplomya caesar (NY, ME); Raizenne 1952, as Epimasicera caesar (ON); Dowden et al. 1953, as Aplomya caesar (ME); Miller 1955, as Aplomya caesar (NB); McGugan & Blais 1959 (ON); Blais 1960 (QC); MacDonald & Webb 1963, as Aplomya caesar (NB); † Miller 1963 (NB); Blais 1965 (QC); † Tilles & Woodley 1984, as Aplomya caesar (ME); Hébert et al. 1989 (QC); Huber et al. 1996 (NB).

Host records ex. Choristoneura fumiferana and/or Choristoneura occidentalis: Tothill 1913 , as Exorista nigripalpis ex. Tortrix fumiferana (BC, QC); Brown 1941, as Zenillia caesar ex. Cacoecia fumiferana ( Canada) ; Sellers 1943, as Aplomya caesar ex. Archips fumiferana (North America); † Wishart 1945, as Aplomya caesar ex. Archips fumiferana (North America); Dowden et al. 1948, as Aplomya caesar ex. Archips fumiferana (North America); † Zwolfer 1961, ex. C. fumiferana (North America); † Arnaud 1978, as Aplomya caesar ex. C. fumiferana (BC, OR, ON, QC, NB, NF, NY, ME).

Host records ex. Choristoneura fumiferana , Choristoneura occidentalis and/or Choristoneura pinus : † Ross 1952, as Aplomya caesar ex. spruce and/or jack pine budworm ( Canada).

Host records ex. Choristoneura occidentalis: McKnight 1974 , as Aplomya caesar (CO); Harris & Dawson 1979, as Aplomya caesar (BC).

Host records probably ex. Choristoneura occidentalis: Wilkes et al. 1949, as Aplomya caesar ex. C. fumiferana (BC); Coppel 1953, as Zenillia caesar ex. C. fumiferana (BC); Carolin & Coulter 1959, as Aplomya caesar ex. C. fumiferana (OR); † Coppel 1960, ex. C. fumiferana (BC).

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

Host records ex. Choristoneura parallela: Sellers 1943 , as Aplomya caesar ex. Archips parallela (North America); † Wishart 1945, as Aplomya caesar ex. Archips parallela (North America); † Arnaud 1978, as Aplomya caesar (North America); † Huber et al. 1996 ( America north of Mexico).

Host records ex. Choristoneura pinus: Drooz & Benjamin 1956, as Aplomya caesar (Michigan) ; Kulman & Hodson 1961, as Aplomya caesar (Minnesota) ; Dixon & Benjamin 1963, as Aplomya caesar (Wisconsin) ; Allen et al. 1969, as Aplomya caesar (Michigan) ; † Arnaud 1978, as Aplomya caesar (Minnesota, Wisconsin, Michigan); Nealis 1991 (ON); † Huber et al. 1996 ( America north of Mexico).

Host records ex. Choristoneura rosaceana : † Wishart 1945, as Aplomya caesar ex. Archips rosaceana (North America); Raizenne 1952, as Epimasicera caesar ex. Archips rosaceana (ON); † Arnaud 1978, as Aplomya caesar (ON); † Huber et al. 1996 ( America north of Mexico).

Eumea caesar is a common tachinid found throughout temperate and boreal Canada, and south to California and Texas in the West and Virginia in the East ( O’Hara & Wood 2004). Adults are generally 7–8mm long and mostly black with a black­and­gray banded abdomen. It was included in a key to the puparia of dipterous parasitoids of Choristoneura species by Ross (1952, as Aplomya caesar ) and in a key to the adults of dipterous parasitoids of C. occidentalis (as C. fumiferana ) in British Columbia by Coppel (1960). Wishart (1945) described and illustrated the immature stages of E. caesar (as Aplomya caesar ) and provided a detailed account of larval development in the European corn borer ( Ostrinia nubilalis (Hübner)) . Tilles and Woodley (1984) included E. caesar (as Aplomya caesar ) among the five tachinids treated in their manual of spruce budworm parasitoids in Maine.

Eumea caesar belongs to the Goniini , and like other members of that tribe produces microtype eggs that are laid on foliage and ingested by the host (see Cyzenis incrassata above for further information on goniine biology). It parasitizes fifth or sixth instar budworms, and the fully developed maggot emerges from the sixth instar or pupa and pupariates away from the host ( Dowden et al. 1951; Carolin & Coulter 1959; Allen et al. 1969; Hébert et al. 1989). Eumea caesar has more than one generation per year and occasionally two maggots emerge from a single Choristoneura host ( Dowden et al. 1951). Dowden et al. (1951) reported that E. caesar overwinters in an alternate host, whereas Tilles and Woodley (1984) stated that it overwinters as a pupa in the soil.

Eumea caesar is recorded from a number of Tortricidae and six other families of Microlepidopera ( Arnaud 1978, as Aplomya caesar ). Parasitism of Choristoneura species in western North America is reportedly low ( Carolin & Coulter 1959; McKnight 1974; Harris & Dawson 1979; Schaupp et al. 1991) and E. caesar (as Aplomya caesar ) was not included by Wilkes et al. (1949) in the top 15 hymenopterous and dipterous parasitoids of C. occidentalis (as C. fumiferana ) in British Columbia. Parasitism of budworms in the East is also usually low but there are several reports of rates in excess of 25% ( Dowden et al. 1948; Jaynes & Drooz 1952; Blais 1965). Parasitism of C. pinus was reported as low by Drooz and Benjamin (1956) in Michigan, by Dixon and Benjamin (1963) in Wisconsin, and by Nealis (1991) in Ontario, but as high as 13% in a study by Allen et al. (1969) in Michigan.

Figures

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