Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

Eight native (European) species of aphids (Hemiptera: Sternorrhyncha: Aphidomorpha) are associated with fir trees (Abies alba) in Poland. Two of them belong to the clade of oviparous aphids (Aphidina ovipara) and the family Adelgidae [Adelges (Dreyfusia) piceae, A. (Aphrastasia) pectinatae)], others to the viviparous aphid (Aphidina vivipara) clade of 4 families [(Aphididae: Elatobium abietinum, Lachnidae: Cinara (Cinara) confinis, C. (C.) pectinatae), Mindaridae: Mindarus abietinus, Pemphigidae: Prociphilus (Prociphilus) bumeliae, P. (P.) fraxini]. Under natural conditions (undisturbed by more than normative ecological factors), these taxa form a fir-associated consortium with a defined composition (max. 8 species), and their populations are stable, with a relatively constant abundance and its seasonal dynamics. Such a state does not threaten the host; on the contrary, it is desirable in a properly functioning ecosystem, while also being economically beneficial, as e.g. honeydew of the Cinara aphid is an excellent food for bees (honeydew coniferous honeys). The situation may be disrupted when abiotic (especially climatic) or biotic conditions change, e.g. appearance of a non-native species. In Poland, two such species with an invasive and alien (IAS) status have been detected – Adelges (Dreyfusia) nordmannianae and Cinara (Cinara) curvipes. The aim of the study was to determine the current status of the aphid fauna associated with fir trees, in the area of its reintroduction in the Karkonosze National Park. The material was collected using standard qualitative methods and ‘sticky bands’ set for 5 study periods were used to determine the dynamics of abundance. The investigations were carried out in 2021 and 2022; qualitative at 22 study sites and quantitative at 10 of them. Observations were also made outside the designated plots where possible. A total of 9 aphid species were found in the study area: 7 native (except for P. (P.) bumeliae), 2 IAS and a hybrid form between A. (D.) piceae and A. (D.) nordmannianae. The composition of the consortia (taking into account the “hybrid”) in the plots studied ranged from 3 to 5 taxa (with constant elements represented by Cinara pectinatae and Mindarus abietinus), indicating a character as yet unstable, tending towards a climax. The quantitative studies more or less reflected the life cycles of the aphids in general; with the fact that no reduction in the abundance of aphids from the genus Cinara was observed during the summer period, suggesting their slight migration to the roots, which could be related to the unfavourable conditions there for them. Based on the results of the study, the use of sticky bands may also be recommended to reduce the abundance of conifer woolly adelgids, especially Adelges nordmannianae, but only in the late winter to early spring period.