Effects of Volatile Emissions of Picea abies Fresh Debris on Ips duplicatus Response to Characteristic Synthetic Pheromone

Ips duplicatus is an important pest of Norway spruce (Picea abies) planted outside of its natural range. This species uses olfactory signals to identify the spruce trees favourable for colonisation. The knowledge of the beetlesâ€™ response to these stimuli is important for managing this pest. Therefore, the response of Ips duplicatus to a specific synthetic pheromone was investigated under some natural sources of volatile emissions characteristic of Norway spruce. The pheromone traps were installed in two types of forests: one with fresh and large Norway spruce stumps and piles of branches, releasing large amounts of host volatile substances (terpenes and alcohols) and one without such fresh material. The experiment was repeated in three pairs of sites located in plantations out of the natural range of Norway spruce. Finally it was found that Ips duplicatus beetles, regardless of sex, have been concentrated in areas where large amounts of fresh material were available, confirming that Ips duplicatus beetles are using both natural pheromones and specific host volatiles as olfactory stimuli in searching for breeding material.

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Disparity of Phoresy in Mesostigmatid Mites upon Their Specific Carrier Ips typographus (Coleoptera: Scolytinae)

Insects ◽

10.3390/insects11110771 ◽

2020 ◽

Vol 11 (11) ◽

pp. 771

Author(s):

Marius Paraschiv ◽

Gabriela Isaia

Keyword(s):

Picea Abies ◽

Norway Spruce ◽

Mite Species ◽

Ips Typographus ◽

The Body ◽

Immature Stages ◽

Body Parts ◽

Large Area ◽

Important Pest ◽

Symbiotic Fungi

Ips typographus Linnaeus, 1758, the most important pest of Norway spruce (Picea abies Linnaeus, 1753) from Eurasia has damaged, in the last decades, a large area of forest in Romania. Associations between beetles and their symbiotic fungi are well known compared to beetle-mite relationships. The objectives of the study are to determine: (i) the diversity of mites species associated with I. typographus in a local outbreak from Central Romania; (ii) the mite’s preferences concerning the body parts of their carriers; and (iii) how phoresy changes during seasonal flight activity of the host. A total of 7896 adult I. typographus were analyzed and six mite species (both adults and immature stages) were found: Dendrolaelaps quadrisetus Berlese,1920, Proctolaelaps fiseri Samsinak, 1960, Trichouropoda polytricha Vitzthum, 1923, Histiostoma piceae Scheucher, 1957, Uroobovella ipidis Vitzthum, 1923, and Uroobovella vinicolora Vitzthum, 1926. Most mites were observed under the carriers’ elytra (46.8%), while 26.7% and 25.8% were seen on the thorax and elytral declivities, respectively. Mite phoresy peaked in the spring corresponding to the dispersal flight of the carrier. A smaller peak in phoresy occurred in the summer during the second beetle generation.

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Comparing natural regeneration of Norway spruce Picea abies (L.) Karst. in the Kaszuby Lake District and in the other regions of northern Poland

Forest Research Papers ◽

10.1515/frp-2017-0034 ◽

2017 ◽

Vol 78 (4) ◽

pp. 303-314

Author(s):

Marcin Szydlarski ◽

Jerzy Modrzyński ◽

Mateusz Stopiński ◽

Michał Majewski ◽

Krzysztof Maras

Keyword(s):

Picea Abies ◽

Norway Spruce ◽

Natural Regeneration ◽

Rank Correlation ◽

Lake District ◽

The West ◽

Basal Diameter ◽

Diameter Increment ◽

Spearman’S Rank Correlation ◽

Natural Range

Abstract The paper investigates the biometric characteristics natural Norway spruce (Picea abies (L.) Karst.) regeneration in the Kaszuby Lake District, which is beyond the acknowledged Norway spruce range, with the natural regeneration in the Augustów Forest situated deep within the natural range, Warmia, at the edge of the natural range and in the West-Pomerania Lake District far beyond the natural range. For each region, four tree stands with similar light conditions on the forest floor were selected, including two cambisols and two brunic arenosols. All sites contained naturally regenerating spruces 16–17 years of age. The features of the forest stand and the biometric features of the saplings were determined for the selected stands on circular research plots. Altogether, the characteristicts of 400 saplings (100 in each region) were measured and analyzed using basic descriptive statistics. ANOVA with the Tukey’s multiple comparison test was performed to compare the features of forest stands and the natural regeneration of spruce in each region. The degree of interrelation between regeneration features was described by Pearson’s, ‘r’ factor or Spearman’s rank correlation coefficient. A discriminatory analysis was carried out to determine the set of regeneration features differentiating regions from each other. The features of regeneration that differed between regions the most were: height of regeneration, basal diameter, mean height increment, and mean basal diameter increment of the saplings. The parameters for Warmia and the West-Pomerania Lake District were similar. The Augustów Forest showed the lowest values for the regeneration parameters, while the Kaszuby Lake District produced the highest values. The regeneration in the Kaszuby Lake District was markedly different from all other regions as indicated by more dynamic growth. Additionally, this population shows a great distinctness, indicating adaptation to local environmental conditions, which may be proof for the insular presence hypothesis of spruce in this region. Due to their good quality, spontaneously developing natural regenerations in the Kaszuby Lake District should be supported by appropriate cutting and silvicultural measures.

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