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Pest Status
Background
Releases and Recoveries
Evaluation of Control Attempts
Recommendations
Chapter 12
Forficula auricularia L. , European
Earwig (Dermaptera: Forficulidae)
R.F. MORRIS
This report is an update on the European earwig, Forficula auricularia L., and its
parasitoid, Bigonichela selipennis (Fallen), in Newfoundland as last reported by
Morris (1971). This pest continued to spread throughout Newfoundland, and is now
found in the following communities: St. John's, Wedgewood Park, Mt. Pearl, Kilbride,
Petty Harbour, Logy Bay, Topsail, Long Pond, Torbay, Renews, Bay Roberts,
Clarkes Beach, Grand Bank, Fortune, Grand Falls, Stephenville.
The European earwig was first discovered in Newfoundland at St. John's in 1948. The
parasitoid, Bigonichela selipennis, was introduced from British Columbia to Newfoundland
in 1951, 1952, and 1953. It was successfully established but parasitism was
extremely low during the period 1955-59 (Morris 1971). Because of a slow build-up,
supposedly hardier strains of the parasitoid were obtained by the Research Institute at
Belleville from Sweden and Switzerland and released at St. John's in 1959, 1961, and
1963.
The use of traps and attractants to complement earwig control with parasitoids were
investigated and reported on by Morris (1965).
No additional releases of Bigollichela selipennis have been made since those recorded
by Morris (1971). Studies on its establishment and population increase were continued
during the period from 1969 to 1978. Results are shown in Table 5.
The introduced parasitoid, Bigonichela selipellllis, has successfully established itself
with a maximum parasitism of 16.4% in 1973. Although the initial parasitism was low,
4.4% in 1969, a steady increase was observed until 1973. There has been a considerable
reduction in earwig populations in the study area since 1972, making it impossible to
collect as large samples (4000 earwigs) as were used in the earlier years, and this
reduction is no doubt due to the high levels of parasitism during the 1972-76 period.
There has been a continuing spread of earwigs from the original site in St. John's with
populations now established 420 km and 775 km from St. John's. Studies should be
initiated to determine if the parasitoid has been introduced with its host to Grand
Bank, Fortune, Grand Falls, and Stephenville. If it has not been introduced naturally,
steps should be taken to artificially introduce Bigonichela selipellnis to these areas.
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