On the Weather Factors which Cause Outbreaks of Foliophagous Insects (on the Example of Black-veined White Aporia crataegi (L.) (Lepidoptera, Pieridae) in the Urals

On the example of the outbreak foci of black-veined white, that sprung up in the Urals in 2020, is shown how outbreak foci of the pest begin to develop. Besides in the article for the fi rst time the method of quantitative assessment of average span time during which occur formation of the outbreak foci of black-veined white and pine looper Bupalus piniarius (L.) is described. It is shown that outbreak foci of the both species come into being during interval of time no more than 1 hour. Average data of the black-veined white and pine looper outbreak foci formation in the south of Sverdlovsk region are 13 and 14 June accordingly.