Трансмиссия фитопатогенных грибов сосновыми лубоедами

In the conditions of the North-West of the Russian Federation, studies have been conducted to clarify the composition of mycobiota carried by pine bast beetles at different stages of their life cycle, and to analyze possible associative relationships between phytopathogenic fungi and pine bast beetles. In north Karelia and the Leningrad region, in the summer and early autumn of 2024, beetles and larvae of Tomicus piniperda and T. minor were collected using sterile tweezers at different stages of the life cycle: the parental generation from the passages, young beetles during additional nutrition in pine shoots. Each beetle was immediately placed individually in sterile test tubes and then placed in Petri dishes on a nutrient medium in the laboratory. The medium consisted of microbiological agar-agar, carrot extract, water, and sucrose. The material was collected in northern Karelia and the Leningrad Region. Pure cultures were isolated from the mycobiota of these beetles, and species were identified. It was found that almost all pine beetles (96%), during supplementary feeding, transmit the widespread phytopathogenic fungus Sydowia polyspora, which causes pine scleromorphosis. This fungus was present on beetles collected from tunnels in only 20% of cases. In a similar experiment conducted by other authors in Spain, the occurrence of S. polyspora was two times lower. Ophiostoma spp. were found with varying frequencies on both parent and juvenile beetles in all sampling variants (30% and 22% of cases, respectively). The average frequency of occurrence is 26%, which is consistent with data from other authors. It is concluded that there is an associative relationship between Sydowia polyspora and pine beetles. The transfer of Ophiostoma spp. is largely random.