Mass reproduction of Polygraphus proximus Blandford in fir forests of Siberia infected with root and stem pathogens: monitoring, patterns, biological control
I. N. Pavlov1,2, Yu. A. Litovka1,2, D. V. Golubev1,3, S. A. Astapenko4, P. V. Chromogin1, Yu. V. Usoltseva1, P. V. Makolova1,2, S. M. Petrenko1
1V. N. Sukachev Institute of Forest of SB RAS, Krasnoyarsk, Russia
2Reshetnev Siberian State University of Science and Technology
3Federal Forestry Agency “Russian center of forest health” Branch “Centre of forest health of Krasnoyarsk region”
4Federal Forestry Agency “Russian center of forest health” Branch “Centre of forest health of Krasnoyarsk region”, Krasnoyarsk, Russia
Keywords: усыхание, Abies sibirica, Polygraphus proximus, корневые патогены, Armillaria borealis, Heterobasidion annosum s. s, Neonectria fuckeliana, Beauveria bassiana, вирулентность, биоконтроль, биоинсектицид, forest decline, root pathogens, virulence, biocontrol, bioinsecticide
Abstract
Conifer decline ( Abies sibirica Ledeb. stands) as a result of complex biotic effects on the territory of the Krasnoyarsk region by 2018 reached an area of 541,4 thousand hectares; the potential area of further death of A. sibirica is up to 10 million hectares. The main reason is the phytopathogenic fungi Armillaria mellea s. l. and Heterobasidion annosum s. l. when combined with bark beetle Polygraphus proximus . Trees affected by root pathogens are centers of forest dieback, from which pathological outbreaks spread, including due to the effects of P. proximus and its phytopathogenic mycoassociates. Neonectria fuckeliana (C. Booth) Castl & Rossman is among the concomitant pathogens in the scale of the lesion, which causes a resin flow that is similar to the effects of P. proximus attack. The phytopathogenicity of pure cultures of the dominant root pathogens of Armillaria borealis Marxm. & Korhonen and Heterobasidion annosum (Fr.) Bref . , as well as the stem pathogen of N. fuckeliana , has been confirmed by a series of experiments in vitro . Promising natural agents for the regulation of P. proximus abundance are highly virulent aboriginal strains of Beauveria bassiana (Bals.-Criv.) Vuill., resulting in maximum insect death (up to 100 %) for 7-11 days and retaining activity in the temperature range of (16-24) ± 1 °C.
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