| Abstract: | An investigation was started in 1952 into the biology and foreststatus of Bupalus piniarius L., a potential menace to largeareas of pine plantations reaching vulnerable stages in GreatBritain. In 1953 an epidemic was observed at Cannock Chase,the first to be recorded in Great Britain, and in the winterof 1953–4 extensive sampling revealed a number of otherpine forests with abnormally high pupal populations, notablyCulbin Forest in Morayshire. The paper gives a detailed account with two maps and severaltables of the measures taken Ifin 1954 to combat the outbreakat Cannock and to anticipate it at Culbin. It discusses thedecision to spray DDT from the air; the delineation of treatmentareas; laboratory tests on toxicity; spray droplet size andcrown penetration; methods used to select starting date. Itdescribes the spraying operations themselves, the effects ofweather, the provision of markers and the subsequent check.The results are given under mortality counts and shoot assessments.Annual pupal Counts up to 1957–8 are given in detail intwo long tables. The operation at Cannock is regarded as reasonablysuccessful but was possibly not really needed at Culbin. Bothprovided valuable experience for future control work. |
