The double-spined spruce bark beetle, Ips duplicatus, has become an infamous secondary pest of Norway spruce, causing extensive ecological and economic destruction in many Central European countries. ...Antennae are the primary olfactory organs that play a fundamental role in insect-host chemical communication; therefore, understanding morphology is crucial before conducting electrophysiological investigations. Here, we present our analysis of sensilla types on the antennal surface of I. duplicatus for the first time, using high-resolution-scanning electron microscopy. We studied the external morphological characteristics of antennae and the types, numbers, and distribution of the antennal sensilla in males and females. Our results revealed the presence of five different types of morphologically distinct sensilla: sensilla chaetica, sensilla basiconica, sensilla trichodea, sensilla coeloconica, and Böhm's sensilla. We observed two subtypes of sensilla chaetica (SChI and SChII), four subtypes of sensilla basiconica (SBI, SBII, SBIII, and SBIV), three subtypes of sensilla trichodea (STrII, STrIII, and STrIV) and two subtypes of sensilla coeloconica (SCoI and SCoII), respectively in I. duplicatus males and females. Minor differences in length and numbers between the sexes for some sensilla types were found. Distribution maps for different sensillar types were constructed, and specific areas for the respective sensilla were found. Possible functions of observed sensilla types are discussed. The present study provides a basis for future electrophysiological studies to understand how I. duplicatus detects ecologically important olfactory cues. RESEARCH HIGHLIGHTS: • The first report of morphology and distribution pattern of the antennal sensilla in Ips duplicatus is discussed. • A total of 6 main types and 11 antennal sensilla subtypes were observed in male and female Ips duplicatus. • Minor sex-specific differences were seen in the length and numbers in several sensilla types.
In 2013–2014, a set of 30 pheromone traps baited with synthetic lures attracting
(Duplodor – 15 traps) and
(Cembrodor – 15 traps) was installed in 6 altitudinal transects (1000–1400 m a.s.l., every ...100 m of elevation) in the eastern, central and western part of the Tatra National Park (TPN) in Poland and operated during the entire growing season. The main aim of the survey was to check if and to what vertical extent these two species of bark beetles, not yet recorded, are presently distributed in TPN. Collected insects, including non-target Scolytinae and Cerambycidae, were determined. Overall 1896 Scolytid bark beetles belonging to 13 species, all occurring in the whole elevation range, were collected.
(28 specimens in total) was collected in the whole elevation profile, similarly as
(718 specimens in total). Among Cerambycidae (282 individuals) belonging to 19 species,
and
, found on all elevations, were the most abundant; 8 species were collected on the highest locality.
was found for the first time in the Tatra. Results indicate the upward spreading of the studied insects as a possible effect of climate change and the resulting environmental conditions favourable for those organisms.
Development of the double‐spined spruce bark beetle Ips duplicatus (Sahlberg, 1836) was investigated using the sandwich method under long‐day conditions (LD 18 : 6 h) at 10 constant temperatures: 7, ...10, 12, 15, 20, 25, 30, 33, 35 and 39 °C. The method proved unsuitable at lower temperatures (7–12 °C), where high mortality occurred.
At higher temperatures, development from egg to eclosion of adults shortened from 39.0 days at 15 °C to 10.3 days at 30 °C. Temperatures over 33 °C were lethal to all eggs, larvae and pupae. The developmental rate increased linearly at temperatures between 15 and 25 °C.
Stage‐specific parameters, such as upper and lower developmental thresholds and optimum temperature for development, were determined by linear and nonlinear (Logan‐Lactin) models. Lower developmental thresholds obtained from nonlinear regression were calculated to be 9 °C (eggs), 6.1 °C (larvae), 6.9 °C (pupae) and 6.3 °C (development from eggs to pupae). Upper developmental thresholds for all stages oscillated around 39 °C and optimal temperatures oscillated around 30 °C.
The rapid development of I. duplicatus at 15 and 30 °C 10 and 4 days faster than Ips typographus (L.), respectively may explain its recent outbreak dynamics and low effectivity of preventive control measures
The double‐spined spruce engraver Ips duplicatus is not present in Belgium and France. In summer 2003, several adult Ips duplicatus beetles were caught near quays in Herstal (Liege) during a survey. ...Large volumes of spruce logs, from Russia and the Baltic countries, had been imported to the immediate locality where the beetles had been caught. Thus, it is most likely that the capture specimens were introduced with these consignments.
Bark beetles are the most important forest pests in the Northern Hemisphere. The range of Ips duplicatus, an invasive bark beetle in central Europe, has been steadily expanding, and it is now ...responsible for a high proportion of the spruce wood infested by bark beetles. Apart from searching for and eliminating infested trees, there is no effective control method. The aim of this study was to determine whether trap trees with a pheromone evaporator can be used to capture I. duplicatus. Felled trap trees with branches and with pheromone lures (ID Ecolure®) were infested by I. duplicatus, at a median density of 1 nuptial chambers per 0.1 m2 (median); similar trees without lures and lying at a distance of 1, 5, or 10 m from the lure trees were rarely infested by I. duplicatus. The entire surface of the lure trees could capture <400 beetles per tree. The results indicate that lure trap trees (felled and with branches attached) could only be used in a limited number of situations; one such situation would involve forests that suffered wind damage and contained very high numbers of I. duplicatus.
In plant pest diagnosis, Sanger sequencing of marker genes (DNA-barcoding) is the most applied and appropriate method for the identification of insects. Standard PM7/129 of the European and ...Mediterranean Plant Protection Organization (EPPO) includes a number of primers and PCR protocols for diagnosing insect pests. LCO1490 and HCO2198 primers recommended herein were shown to be excellent tools for amplifying a fragment of the
COI
gene from a vast range of arthropods. The
COI
barcoding region is available for thousands of arthropod taxa in public databases and ready-to-use for evolutionary studies. However, we found that LCO1490 and HCO2198 primers are not working for bark beetles of genus
Ips
. The attempt to amplify this gene fragment from an individual organism using the barcoding primers led to DNA amplification of associated wasps and nematodes, which were apparently vectored by the beetle. Thus, new primers for
Ips
that bind specifically to another (non-barcoding) region of the
COI
gene were developed in the past years. These primers were successfully applied in phylogenetic analyses of this genus, resulting in the adverse effect that
COI
-based
Ips
phylogenies cannot be expanded to higher systematic categories without sequencing the outgroups (as they are not available in databases yet). Here we provide new primers for
Ips
that differ significantly from DNA sequences of
Ips
-associated wasps and nematodes and bind to a
COI
fragment that largely overlaps with the barcoding region proposed in the EPPO standard. Furthermore, using these primers we developed a quick PCR-based test for detecting
Ips duplicatus
, a quarantine pest currently emerging in many European countries.
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 beetles' 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 arc using both natural pheromoncs and specific host volatiles as olfactory stimuli in searching for breeding material.
Ips duplicatus (Sahlberg, 1836), Xylosandrus germanus (Blandford, 1894) and Neoclytus acuminatus (Fabricius, 1775) are invasive species reported in Romania, but their current distribution is poorly ...known. The research aim was to provide new information on this issue. A survey was conducted over the period 2015–2017 in 82 locations, using flight-interception traps and bottle traps, baited with different attractants. Data obtained in our other unpublished studies were also taken into account. A total of 35,136 I. duplicatus beetles were collected in 30 survey locations. The highest captures were in the log yards of some factories processing logs of Norway spruce (Picea abies (L.) H. Karst.). Considering all known records so far, most of these are in the eastern part of Romania, where an outbreak took place during the years 2005–2014, mainly in spruce stands growing outside their natural range. During the survey, 4259 specimens of X. germanus were collected in 35 locations, but in our other studies the species was found in 13 additional places. It was collected at altitudes of 18–1200 m, and the largest catches were from beech stands, growing at 450–950 m. N. acuminatus was found in only six locations, in the western and southern parts of the country, at low altitudes, in tree stands composed of Fraxinus excelsior L., Quercus spp. and other broadleaf species, as well as in broadleaf log yards. The results suggest that I. duplicatus is established in most parts of the Norway spruce’s range, X. germanus is still spreading in the country, with some areas having quite high populations, while N. acuminatus is present only in the warmest regions of the country.
After the successful conclusion of the Joint Meeting of IUFRO’s 7.03.05 & 7.03.10 working parties and given the exciting and novel studies that have been presented in the framework of this meeting, ...we decided to present some of these studies in the current Special Issue of Forests. To make this issue more appealing and interesting to everyone in the field of Forest Protection, studies that cover a wide range of topics were selected, ranging from ecology and phylogeography to forest management and protection. More importantly, as these studies refer to pests and pathogens from different parts of the world, it is expected that the knowledge gained can be further used in the protection of natural environment worldwide.
The microsporidium Larssoniella duplicati (Weiser, Holuša, Žižka, 2006) is a specific pathogen of the bark beetle Ips duplicatus (C.R. Sahlberg, 1836), which is a serious pest of Norway spruce (Picea ...abies (L.) H. Karst) in Europe. From 2011 to 2016, infection levels of L. duplicati and other pathogens in I. duplicatus populations were assessed along a gradient, ranging from areas in the north, where the beetle is native, to areas in the south, where the beetle has only recently invaded. The 21 study sites ranged in altitude from 229 to 1009 m a.s.l. We found that pathogen infection levels in I. duplicatus populations decreased from the native areas in the north to the new areas of beetle expansion in the south. We also found that pathogen level increased with altitude. The L. duplicati infection levels were not associated with the infection levels of other beetle natural enemies. The infection level decreased with the length of time of beetle establishment in an area. The infection level increased with the number of beetles trapped and dissected at a site.
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