Cold hardiness in the pre-imaginal stages of the great web-spinning pine-sawflyAcantholyda posticalis
| Autor: | Külli Hiiesaar, Ingrid H. Williams, Katrin Jõgar, Kaljo Voolma, Angela Ploomi |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
biology Ecology Scots pine Forestry 04 agricultural and veterinary sciences biology.organism_classification 010603 evolutionary biology 01 natural sciences Moss Pupa Sawfly Insect Science 040103 agronomy & agriculture Pamphiliidae Litter 0401 agriculture forestry and fisheries Hardiness (plants) Agronomy and Crop Science Overwintering |
| Zdroj: | Agricultural and Forest Entomology. 18:432-436 |
| ISSN: | 1461-9555 |
| DOI: | 10.1111/afe.12172 |
| Popis: | The great web-spinning pine-sawfly Acantholyda posticalis Mats. (Hymenoptera: Pamphiliidae) is one of the major defoliating insects of pine forests. Mass outbreaks of this species have occurred in Scots pine (Pinus sylvestris L.) stands in Central Europe and in the southern parts of Eastern Europe and Siberia. Recently, the outbreak range has shifted northward and new outbreaks have been recorded in Estonia and Finland. The dynamics of the supercooling capability of pre-imaginal stages of A. posticalis (eonymphs, pronymphs, pupae) collected from the soil in a pine forest on the Island of Saaremaa, Estonia, were determined. The supercooling points (SCP) of overwintering eonymphs and pronymphs changed during the winter, although there were no significant differences between the mean SCPs of either larval stage on any measuring date. The mean SCPs decreased from October (−8 to −10 °C) to January and March (−15 to −17 °C) and increased once again in May (−9 to −11 °C). The average SCP of pupae was considerably higher (−5.3 °C). Overwintering larvae in the soil are potentially covered by an insulating layer of forest litter, moss and snow, thus avoiding direct exposure to low temperatures. Cold-hardiness in both overwintering larval stages of A. posticalis is sufficient for successful survival during winter in the northern Baltic region. At present, outbreaks of A. posticalis in higher latitudes are concentrated in milder maritime regions near the coast of the Baltic Sea, although these may expand in the future as a result of climate warming, with the sawfly possibly becoming a serious pest of pine forests of northern Europe. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|