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MameSlra configurara Walker, 51
Mericia ampelus (W1k.) was found in a very small percentage of bertha armyworm
larvae collected during outbreaks, but has not been collected between outbreaks
(Table 8). This species attaches its eggs to the leaves of plants and the larvae hatch 1-2
minutes after oviposition. It appears to be bivoltine in Canada, but only the second
generation parasitizes bertha armyworm. Larval survival is low, suggesting that Mamestra
configurala is not a preferred host (Wylie 1977b).
Pathogens have not been a major cause of mortality in the bertha armyworm. Wylie
& Bucher (1977) identified fungus pathogens of the genus Entomophthora and a
nuclear polyhedrosis virus as the main larval diseases in 1972. In addition, a protozoan
parasite, possibly of the genus Nosema, was recovered from a few larvae.
The cabbage moth, Mameslra brassicae (L.), is similar to M. configurala in its life
history and phenology. M. brassicae feeds on a wide range of plants and is a major pest
of cabbage in northern Eurasia. In western Europe (Switzerland, Austria, Germany)
and in the warmer climatic zones of the Soviet Union (Kiev, Kharkov, Voronetz, and
Krasnodar regions), it is bivoltine (CIBC Annual Project Statements 1974-80,
Dzhuran 1979, Agarkov 1974, Stenin 1974, Drozda & Garnaga 1978, Tsybul'ko 1973).
In cooler parts of the Soviet Union (Moscow, Gorky, Leningrad, Volgoda (Perm),
Tomsk, Altai, Irkutsk, and Sakhalin regions), it is univoltine (Hori 1935, Kopvillem
1960, Shchetinin 1974, Prokov'cva 1976, Kostylyova 1979). The univoltine populations
lie north and the bivoltine populations lie south of the annual isotherm for 2 200" days
over lOoC (Fig. 1).
The parasitoid complex of M. brassicae consists of 47 species, of which 20 occur in
the USSR (Razumov 1972, Kopvillem 1962). However, only 23 species are reported in
the CIBC Annual Project Statements and recent literature from the Soviet Union
(Table 9). Only two species, ErneSlia consobrina (Mg.) and Exelastes cinclipes (Retz.),
are abundant in both areas.
Ernestia consobrina occupies a similar position in the guild of parasitoids to that
occupied by Mericia ampeills in North America. E. consobrina larviposits on the food
plant of the host. Parasitism is most successful in third·instar larvae and M. brassicae is the
major host (Kopvillem 1960, 1962, CIBC Annual Project Statement 1974); E. consobrina
is the most important parasitoid of Mameslra brassicae in most of the Soviet Union
(KopviJIem 1962), but not in western Europe (CIBC Annual Project Statements
1974-80). It docs not occur in Primorskiy (far east) (Slabospitskii 1980). In the areas of
the Soviet Union where both host and parasitoid are bivoltine, it appears to have
problems in synchronization with its host. In the Kicv region, Dzhuran (1979) reports a
large decrcase in parasitism from the first to the second host generation while Drozda
& Garnaga (1978) note an increase in the second generation. In univoltine areas, E.
consobrina appears to be a more effective parasitoid than in bivoltine areas. High
levels of parasitism are reported from the Leningnld, Moscow. and Volgoda (Perm)
regions (Kopvillem 1960), the Gorky region (Razumov 1972), and the Irkutsk region of
western Siberia (Shchetinin 1974).
Exelastes cinclipes occupies a similar position in the guild of parasitoids to that
occupied by B. f/al'cscens in North America. E. cinclipes is bivoltine in western
Europe, where it parasitizes larvac of the second generation (CIBC Annual Project
Statement 1974). In the Moscow region. it is univoltine (Kopvillem 1960). This ichneumon
mainly parasitizes third·instar larvae and appears to be well synchronized with its
host (Kopvillem 1960). E. cinclipes is a common parasitoid in both western Europe and
the Soviet Union. In westcrn Europc and areas of the Soviet Union with bivoltine hosts,
it is more important than E. cOllsobrina (Tsybul'ko 1973. Agarkov 1974, CIBC Annual
Project Statements 1974-78). but in cooler parts of the Soviet Union it is less abundant
(Kopvillem 1962. Razumov 1972. Shchctinin 1974).
Microplilis mediator (Hal.). like B. flal't'scens in North America. attacks host larvae
in the early instars but unlikc it. M. mediator is multivoltine (CIBC Annual Project