Population dynamics of bark beetles, with special reference to Ips typographus: contributions of applied bark beetle studies to basic research in ecology and population biology (original) (raw)
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Non-target Bark Beetles in Ips duplicatus (Sahlberg) Pheromone Traps Baited with Host Volatiles
Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 2015
Response of several non-target bark beetles (Coleoptera: Curculionidae, Scolytinae) to different combinations of the northern spruce bark beetle's synthetic pheromone with the monoterpenes (-)-alpha-pinene and (+)-limonene has been studied in choice experiments in the field with flight barrier traps. The experiments were organized in four Norway spruce stands (40-50 years old) outside its natural area, in the northeast of Romania, where Ips duplicatus (Sahlberg) populations had reached an epidemical level. Each experiment had five treatments randomly replicated in six blocks within each experimental plot. Four non-target bark beetle species were captured together with Ips duplicatus: I. typographus (L.) (2611 beetles), Pityogenes chalcographus (L.) (184 beetles), Hylastes cunicularius Erichson (107 beetles) and Dryocoetes autographus (Ratzeburg) (24 beetles), representing 1.77%, 0.13%, 0.07% and 0.02% respectively of total captures. Beetles of I. typographus were attracted by synthetic pheromone blend of I. duplicatus and have intensified their response in the presence of (-)-alphapinene or a combination between (-)-alpha-pinene and (+)-limonene, but the other species have been captured in the traps accidentally. The positive response of I. typographus to the present formulation of I. duplicatus pheromone suggests the possibility to use the pheromone dispensers for both species in the same traps when mass-trapping is the main goal, but new studies should clarify the real effects of putting together pheromone dispensers of I. typographus or P. chalcographus with those of I. duplicatus.
Folia Forestalia Polonica, 2021
Pheromone traps are used for monitoring I. typographus populations in Norway spruce stands of the Tatra National Park (TPN) in Poland. The presented study is based on the set of pheromone traps of precisely known location (23) located in the whole area of the TPN and operated continuously in 2010–2019. The data on the captures of beetles were compared with two kinds of data concerning the mortality: the area covered by standing dead trees (airborne photographs) in the no-intervention zone, and the volume of trees infested by bark beetles processed in the active protection zone. No relationship was found between the mean numbers of beetles captured yearly in all pheromone traps in the whole TPN area and the volume of infested trees removed from the stands in the active protection zone. The captures in the two selected study areas were correlated with the area of spots with dead trees in the 500 m circle around the traps, however, this correlation is not statistically significant. The...
2011
The numbers of Ips typographus beetles captured in treated tripod trap logs (tripods) were compared to catches from Theysohn pheromone traps (TPTs). In 2010, at each of the three localities, five TPTs and five tripods baited with Pheagr IT pheromone evaporators were installed with 10 m spacing. Weekly inspections were made during the entire period of I. typographus flight activity (April 30 – October 1). The tripods were treated with insecticide Vaztak 10 SC on April 23, 2010 and then repeatedly every seven weeks along with the renewal of the pheromone evaporator. The study showed that the TPTs trapped approximately one-third more beetles than did the tripods. The TPT captures showed a dominance of females over males, while in tripods the sex ratio was balanced. The TPTs and tripods both trapped approximately the same numbers of males, but the females were distinctly more numerous in the TPTs. In both cases, more adults were captured during spring than in summer. K e y w o rd s : Ip...
Field response of spruce bark beetle,Ips typographus, to aggregation pheromone candidates
Journal of Chemical Ecology, 1987
Six compounds previously identified from hindguts of unmated male Ips typographus (L.) during host colonization: 2-methyl-3-buten-2-ol (MB), cis-verbenol (cV), trans-verbenol (tV), myrtenol (Mt), trans-myrtanol (tM), and 2-phenylethanol (PE), were tested for their attractivity in the field with a subtractive method. The amounts of MB and cV released from a pipe trap were similar to those given off from the commercial bait Ipslure as well as that from a Norway spruce tree, Picea abies (L.) Karst., under mass attack. The blend of the compounds became nonattractive when either MB or cV was subtracted, while subtraction of any of the other four compounds bad no effect. Addition of ipsdienol (Id) to the blend did not significantly increase the attraction. In a second comparative test, the addition of three compounds as a group (tV + Mt + PE) to MB + cV again had no effect on the attraction, but the addition of Id increased the catch somewhat. Addition of host logs to a bait releasing MB + cV at a rate lower than in previous experiments did not influence the attraction to pipe traps. Sticky traps containing natural pheromone sources (50 males in a log), which released 1-5 rag/day of MB as determined by aerations with deuterated MB as internal standard, were less attractive than a synthetic source releasing similar amounts of MB.
Migration in spruce bark beetles ( Ips typographis L.) and the efficiency of pheromone traps
Journal of Applied Entomology, 1997
Mark-release-recapture experiments with both newly emerged and flight experienced Ips typographus L. were performed in a pine forest near Prague. Three concentric trap circles around the release site with a radius of 5 m, 200 m and 500 m, and intertrap distances of 6 m, 16 m and. maximally, 40 m, were installed with the intention of collecting all dispersing bark beetles ready to respond to pheromone lures. The results show that even without wind and no potential host trees in the surroundings, only about one-third (35.4%) of the emerging beetles in an infested site can be eliminated locally with phermomone traps. At least 12.2% of the emerging beetles (25.7% of the recaptures), perform an adaptive migration flight, which brings them beyond the range of local pheromone traps. The estimated proportion of emigrants can rise over 50%, if most of the freshly emerged beetles that have never been recaptured are assumed to have left the experimental area. Electroantennograms recorded in the laboratory at different times after emergence indicate that the delayed response to aggregation pheromones in migrating bark beetles is not the result of a delayed maturation of the antennal receptor cells, but obviously governed by the central nervous system. The notion of precopulatory migration in 25–50% of the individuals in an I. typographus population can explain why pheromone traps can never eliminate all emerging beetles, and why so many bark beetles can be collected far away from any breeding sites.