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Gallery construction and oviposition of the bark beetle Ips typographus (Coleoptera : Scolytidae) at different breeding densities

Abstract. 1. The bole of a Norway spruce, Picea abies(L.) Karst., was cut in 25 cm sections and infested in the laboratory with 2 or 8 females/dm2 of Ips typographus (L.) and an equal number of males. 2. One log of each beetle density was dissected every second day, beginning 2 days after female introduction. 3. The oviposition rate was highest at the beginning of the breeding period for both dens

Behavior of male and female spruce bark beetles, Ips typographus, on the bark of host trees during mass attack

The behavior of 118 spruce bark beetles, Ips typographus, was observed on trees under colonization. Most individuals were followed from when they landed until they entered or left the tree. Both males and females spent most time inspecting crevices and searching for a place to start boring or for a hole to enter. These behaviors accounted for 87 and 70% of all behavioral acts recorded for males an

Causes and effects of individual quality in bark beetles

A summary of the present knowledge of variation in individual quality within a bark beetle population is given, with emphasis on the spruce bark beetle Ips typogrophus, A major causal factor is density, mediated by competition during larval development. Density negatively influences individual quality measured as weight, fat content and pheromone production. Together with decreasing mean values at

Mass attack of trees by Ips typographus induced by sex‐specific pheromone : a model of attack dynamics

A model of attack dynamics on a single tree under mass attack by the spruce bark beetle Ips typographus is developed from earlier studies of pheromone production and response of the flying population to the pheromone signal. The model is explored for different numbers and sex‐ratios of pioneer beetles and responding beetles. Both numbers of pioneers and responders were important for the dynamics,

Modelling bark beetle flight : a review

In studying the attraction of spruce bark beetles Ips typographus to a pheromone trap, we have proposed a simple diffusion model with drift as a description of the flight of the bark beetles. The model predictions were compared with the results of a release‐recapture experiment, and here we recapitulate the main results from the fitting of models to the data. Several modifications of the basic mod

Effects of pheromone trap type, position and colour on the catch of the pine sawfly Neodiprion sertifer (Geoff.) (Hym., Diprionidae)

Two novel easy‐to‐make pheromone traps, a cross‐barrier sticky trap and an open horizontal sticky trap, are described. Both types caught about the same number of male pine sawflies, Neodiprion sertifer, when baited with the synthetic pheromone (2S, 3S, 7S)‐3,7‐dimethylpentadec‐2‐yl acetate. The catch on unbaited cross‐barrier traps was about 17% compared with baited traps, whereas unbaited horizon

Survival of parent and brood adult bark beetles, Ips typographus, in relation to size, lipid content and re‐emergence or emergence day

ABSTRACT. This study investigated a possible trade‐off between bark beetle reproductive effort and future survival. Parent adult Ips typographus (L.) (Coleoptera: Scolytidae) were collected when they re‐emerged from a laboratory culture after completing their first brood and held at constant temperatures of 4 or 25oC. As a comparison, emerging brood adults were collected and held at 25oC. The long

Electrochemical Characterization and Bioelectrocatalytic H2O2 Sensing of Non-Symbiotic Hexa-Coordinated Sugar Beet Hemoglobins

The biological role of non-symbiotic plant hemoglobins (Hbs) is not well understood. It may involve sensing and signaling of reactive nitrogen and oxygen species–a property that can be used in electrochemical sensing. Here, we electrochemically studied two novel non-symbiotic Beta vulgaris Hbs: BvHb1.2 and BvHb2 expressed in E. coli. At pH 7, we observed close potentials of their Fe2+/3+ hemes, −3

Bioarchaeological field analysis of human remains from the mass graves at Phaleron, Greece

In 2016, archaeological excavations undertaken by the Ephorate of Antiquities of West Attica, Piraeus and Islands 3.8 km south-west of Athens, Greece, revealed mass burials of 79 skeletons in three rows. The burials are dated to the 7th century BC. The anthropological field documentation was undertaken by The Swedish Institute of Athens, and followed established bioarchaeological protocols regardi

Differences in morphology and sexual size dimorphism between the Dutch elm disease vectors Scolytus laevis and Scolytus scolytus (Col., Scolytidae)

The external differences between the well‐documented S. scolytus and the little studied S. laevis are clarified with the help of SEM micrographs of the frons and abdomen of both sexes of the two species. The convex frons of both male and female S. scolytus is densely covered with short hairs. S. laevis males have a flat frons with long hairs in a pair of bundles, whereas the females have a convex

A model for the temperature and density dependent reemergence of the bark beetle Ips typographus

A model is presented that describes the reemergence of parent spruce bark beetles, Ips typographus, based on breeding density and temperature conditions. Laboratory data obtained at one constant temperature provide the distribution of reemergence time and different combinations of threshold temperatures and degreedays (°D) at mean reemergence. Of these combinations, 167.71 °D above 7.5 °C gave the

Intraspecific competition affecting parents and offspring in the bark beetle Ips typographus.

Parents re-emerged sooner at higher densities but the total proportion that re-emerged was independent of density. Over 20 offspring per female were produced at the lowest density (0.5/100 cm2) but only 0.6 per female at the highest density (31/100 cm2). Offspring from the lowest density were about 50% heavier than those from the highest density and also the fat content increased with decreasing d

Dispersal of reemerged spruce bark beetles, Ips typographus (Coleoptera, Scolytidae) : a mark‐recapture experiment

An experiment to investigate the dispersal and supposed reattack by parent spruce bark beetles, Ips typographus (L.), was performed. More than 20,000 parent beetles were marked with fluorescent powder and immediately released from platforms when they reemerged from trees attacked during the spring swarming. Thirty‐eight marked and over 8000 unmarked beetles were trapped on sticky traps covering 21

Sick leave before and after arthroscopic partial meniscectomy due to traumatic meniscal tear

Summary Objective There is limited knowledge on sick leave associated with arthroscopic partial meniscectomy (APM) due to traumatic meniscal tear and its potential gender differences. Thus, our aim was to determine gender-specific sick leave before and after APM. Method In Skåne region, Sweden, we identified patients, aged 18–59 years diagnosed with traumatic meniscal tear without ligament injury,

Multi-disciplinary lidar applications

Lidar is a powerful technique normally associated with atmospheric monitoring. However, lidar techniques, also of the laser-induced fluorescence and laser-induced breakdown spectroscopy varieties, provide many new possibilities in unconventional fields including cultural heritage and ecological applications.

A 15-year follow-up of former self-harming inpatients in child & adolescent psychiatry - a qualitative study

Purpose: Self-harm is common among adolescents, and is even more frequent among psychiatric populations. The aim of this study was to increase knowledge and understanding of different aspects of life for adults who, when adolescents, had engaged in severe self-harm during inpatient stays.Material and methods: Individual semi-structured interviews were held with seven former inpatients with a histo