Cydalima Perspectalis Research Articles

Temperatures during the development season are increasingly favourable for polyvoltine pest species in Switzerland

With global warming, the mean temperature during the insect development season has been increasing in Switzerland over the last decades, and this trend is predicted to continue. As a result, the annual number of generations could increase for polyvoltine insect species. Some pest species, such as the box tree moth (Cydalima perspectalis), the grapevine moth (Lobesia botrana), the codling moth (Cydia pomonella), and the Comstock mealybug (Pseudococcus comstocki), are therefore likely to produce more generations in the future, leading to more damage to forests, vineyards and crops. These species all have a base development temperature (tb) of around 10 °C. In this study, we examined the extent to which changes in daily mean temperature (Tmean) averaged over the development season (April through September) could potentially increase the voltinism of these species in various regions of Switzerland. We analysed long-term daily Tmean data from the period 1980–2021 at 67 meteorological stations covering an elevation range from 203 to 2283 m a.s.l. We then used two climate scenarios (RCP2.6 and RCP8.5) to analyse daily Tmean during the period 2022–2099. We computed growing degree days (GDDs) above tb = 10 °C and looked at the trends across elevation. Our results show that daily Tmean averaged across the development season increased more than the daily Tmean averaged over the entire year over the last 40 years. There was an average increase of 60 GDDs per decade during this period, with larger increases occurring at lower elevations. Our results indicate that by the end of the 21st century there could be more GDDs on the Swiss Plateau than currently occur at lower elevations on the southern side of the Alps and that the number of GDDs currently occurring on the Swiss Plateau could be found at middle elevations (800–1400 m a.s.l.). Future temperature conditions can thus be expected to favour additional generations of pests annually at lower elevations and to allow them to complete a full single cycle per year at higher elevations.

Study on the possibility control of box tree moth, Cydalima perspectalis (Lepidoptera: Crambidae) using microbial, organic and low risk insecticides

Study on the possibility control of box tree moth, Cydalima perspectalis (Lepidoptera: Crambidae) using microbial, organic and low risk insecticides

Harmful entomofauna in forestry and green infrastructure

The national invention of the forests of the Republic of Srpska established over 100 species, with the entire volume of wood mass being dominated by deciduous trees (beech 45%, oak 8%, other deciduous trees 7%, tribal deciduous trees 3%). Beech has the largest share in state forests in the supplies (43%), followed by fir about 20%, and spruce by 16%. Of the harmful endomofauna of fir, one third are gradeogenic species, which can cause great economic and environmental damage. Harmful endomofauna of beech number 32 species, of which economically significant primary species are prone to mass occurrences and trophical relations related to the leaf (15.75% of species). Harmful endomofauna of oak species represent 40 most common species. Outbreaking primary species make up one quarter, feed predominantly on leaves and cause defoliation (50%). Harmful for seeds or acorns are 15% of pests, which can have a detrimental effect on the reproduction and regeneration of oak forests. The most common pests in spruce forests are species that occur frequently and can only occasionally cause minor damage (56.25%). The most economically important are bark beetles and wood borers, which tend to outbreak (12.5%) and cause dammage on a hudge area. Outbreaking species are also pest of seed and cones, which participate in the spruce pest complex with 14.58%. Pests in nurseries are important for reproduction in forestry and for providing nursery stock for the establishment of green infrastructure. Of the 54 harmful species, almost a quarter are non-native species (24.07%). Often, non-native pests are transferred from nurseries to public green spaces, green corridors, and entrepreneurs are ofteen serving as a pathway for introduction of non-native harmful species into forest ecosystems. Therefore, ornamental plants are rightly considered the most important pathways for introduction of invasive alien species in mannaged and protective forests. Non-native and invasive species that are introduced in the Republic of Srpska e.g. emerging pests are folowing: Aproceros leucopoda, Cameraria ohridella, Corythucha arcuata, Corythucha ciliata, Cydalima perspectalis, Eopineus strobi, Gillettella cooleyi, Leptoglossus occidentalis, Metcalfa pruinosa, Obolodiplosis robiniae, Phyllonorycter platani, Pseudaulacaspis pentagona, Stictocephala bisonia etc. Most of these species are pests in nurseries and ongreen infrastructure. Some native insect species appear as emerging pests due to their increase of population , as an answer to changing weather conditions. One example is the ash wasp Tomostethus nigritus (F.) (Hymenoptera: Tenthredinidae), which in the last ten years appear in local outbreaks in tree lines or other green areas at the territory of Southeastern Europe from the Balkan Peninsula to the Nordic countries. Increased populations of Zeuzera pyrina (Lepidoptera: Cossidae) were also applied in nurseries and on elements of green infrastructure. Due to the climate change, the species Ovalisia (Palmar) festiva migrated from the Mediterranean area, setting a dangerous pest in nurseries, while the linden bug Oxycarenus lavaterae is common on lindens, building large colonies but so far with no significant damage on trees. In order to prevent introduction and stop the spread of alien invasive species, there is need to ensure the maintenance of a high level of health protection status in agriculture, green infrastrucrure and forestry.

Economic analysis of a biotechnical control method against the Box tree moth (Cydalima perspectalis) in Türkiye

Economic analysis of a biotechnical control method against the Box tree moth (Cydalima perspectalis) in Türkiye

First Report of Phytophthora occultans Causing Dieback of Buxus sempervirens in the Czech Republic.

In Nov 2011, and then recurrently since Sep 2020, an extensive decline has been recorded in boxwood (Buxus sempervirens), sometimes with several dozens of damaged individuals planted in private gardens and public areas and purchased in amateur markets in the Czech Republic. The leaves of the plants first showed orange-bronze discoloration, then dried and fell off, and the affected plants died. The roots, collars and stems of these plants had dark brown to black necrotic lesions. Phytophthora occultans Man in 't Veld & K. Rosend. was consistently isolated on selective medium PARPNH (Jung et al. 1996) directly from segments of symptomatic collar tissues and from rhododendron leaf pieces used to bait excised roots. On 20% V8 agar (V8A) and on carrot agar (CA), colonies had a stellate pattern. Radial growth at 25°C was 9.4 mm/day on V8A and 5.3 mm/day on CA. The cardinal growth temperatures were min. 7°C, optimum 25 to 27°C, and max. 32°C. The isolates were homothallic and produced on CA colorless globose oogonia ranging from 25.4 to 36.4 µm (n = 40) in diam. Oospores were slightly aplerotic and measured (n = 40) 22.5 to 31.9 µm in diam., with a 0.9 to 1.5 µm thick wall. The antheridia were predominantly paragynous and averaged 11.5 × 9.9 µm (height × width, n = 40). Noncaducous sporangia were obpyriform, ovoid, elongated to irregular and semipapillate, sometimes bipapillate and measured (n = 40) 31.4 to 73.4 × 17.8 to 32.1 µm, and the L:B ratio was 1.9 to 2.0. Chlamydospores and hyphal swellings were not observed. The morphological characteristics resembled those described for P. occultans (Man in't Veld et al. 2015). The isolates were deposited in the Czech Collection of Phytopathogenic Oomycetes (CCPO) under accession nos. 551.11, 1158.20, 1176.21, 1201.21, 1218.21, 1236.21 and 1261.22. For molecular identification, the internal transcribed spacer (ITS) region, cytochrome oxidase subunit 1 gene (COX1), and translation elongation factor-1α (EF) gene from all isolates were amplified and sequenced using the primer pairs ITS4/ITS5 (White et al. 1990), COXF-CIT/COXR-CIT (Man in't Veld et al. 2015), and ELONGF1/ELONGR1 (Kroon et al. 2004), respectively. The resulting sequences of representative isolates P1158.20 and P1176.21 were deposited in GenBank (accession nos. MW750576 and OP326036 for ITS, ON862131 and OP313505 for COX1 and MW762616 and ON862132 for EF). BLASTn searches of GenBank, using the partial ITS, COX1, and EF sequences, revealed 100, 100, and 99% sequence identity, respectively, to P. occultans ex-holotype culture CBS101557 accessions JX978155, JX978156 and KF650770 (Man in't Veld et al. 2015). Concatenated sequences of the three genes were used to conduct a phylogenetic analysis using the maximum likelihood method in MEGA 11 (Tamura et al. 2021). The isolates were identified as P. occultans based on morphology and a multigene phylogenetic analysis. Koch´s postulates were confirmed by a soil infestation test. Healthy 2-year-old B. sempervirens plants were inoculated (9 plants per isolate and control, isolates no. 1158.20, 1176.21, 1261.22) with three 5-mm-diam. V8A mycelial plugs by inserting into the substrate near the collar. Control plants were treated with sterile agar plugs. All plants were kept in a greenhouse at 25°C and exposed to 24 h of flooding up to collar once a week. All inoculated plants showed wilting, collar lesions and root rot occurred after 21 days, while control plants remained healthy. The pathogen was reisolated from infected plants and confirmed by molecular identification. P. occultans was found for the first time in 1998 on Buxus sempervirens in the Netherlands and later in Belgium, the United Kingdom, Germany and Romania (Man in´t Veld et al. 2015, Nechwatal et al. 2014), as well as in the USA (Reeser et al. 2015, Gitto et al. 2018). This is the first report of P. occultans in the Czech Republic. This pathogen likely poses another significant threat to boxwood cultivation in addition to the previously invaded Cydalima perspectalis and Calonectria pseudonaviculata.

Potential of entomopathogens in biological control of the box-tree moth, Cydalima perspectalis (Lepidoptera: Crambidae)

The box-tree moth pyralid, Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae) is the most important insect pest of box trees. Although C. perspectalis is an invasive species, studies on the isolation, characterization and insecticidal activity of entomopathogens that cause disease in the natural populations of box tree moth are scarce. There are few studies on the entomopathogenic organisms that cause diseases in the natural populations of C. perspectalis. C. perspectalis populations can be controlled with entomopathogens such as Bacillus thuringiensis, baculoviruses, fungi and nematodes. Bacillus thuringiensis and baculoviruses are the most promisining pathogens against C. perspectalis. Investigations to find the most effective entomopathogen against C. perspectalis should be continued. This also supports the need to find its specific entomopathogens causing diseases in its natural populations. The present paper compares data on potential entomopathogens found in the literature by discussing the current situation of the damage, distribution of C. perspectalis and the effects of the entomopathogens isolated from or tested against this pest insect. Keywords: biological control, entomopathogens, box tree, Cydalima perspectalis

Ecophysiological responses of individually and group reared Cydalima perspectalis (Lepidoptera: Crambidae) to alkaloid-containing host plants.

The box tree moth, Cydalima perspectalis (Walker), is an invasive pest of Hyrcanian forests in Iran. In the current study, the effects of two boxwood species, Buxus hyrcana Pojark and B. microphylla Sieb. and Zucc. (Buxales: Buxaceae), were examined on ecophysiology of the pest. The demographic parameters were evaluated based on the age-stage, two-sex life table theory. The physiological characteristics of C. perspectalis were considered through fresh/dry weights and individually/group rearing methods. The results showed that C. perspectalis larvae were able to develop, survive and reproduce on both boxwood species. The developmental times were 41.62 and 41.46 days on B. hyrcana and B. microphylla, respectively. The total lifespan did not differ on boxwood species. However, the difference of fecundity on B. hyrcana (412.82 eggs/female) and B. microphylla (286.06 eggs/female) was significant. The intrinsic rate of increase (r) and finite rate of increase (λ) were significantly higher on B. hyrcana than B. microphylla. The nutritional indices showed that the consumption index (CI) on B. hyrcana were significantly lower than on B. microphylla based on fresh/dry weights in both rearing methods. Conversely, the efficiency of conversion of digested food (ECD) and the efficiency of conversion of ingested food (ECI) on B. hyrcana were significantly higher than on B. microphylla. Despite nonsignificant differences in leaf nutrient contents (except calcium), total protein, triglyceride, and alkaline phosphatase activity were inversely different in larvae compared to adult stage on boxwood species. These findings could help to comprehensively understand the performance of the pest on boxwood species.

The Complete Mitochondrial Genome of Box Tree Moth Cydalima perspectalis and Insights into Phylogenetics in Pyraloidea

To resolve and reconstruct phylogenetic relationships within Pyraloidea based on molecular data, the mitochondrial genome (mitogenome) was widely applied to understand phylogenetic relations at different taxonomic levels. In this research, a complete mitogenome of Cydalima perspectalis was recorded, and the phylogenetic position of C. perspectalis was inferred based on the sequence in combination with other available sequence data. According to the research, the circular mitochondrial genome is 15,180 bp in length. It contains 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), 13 typical protein-coding genes (PCGs), and a non-coding control region. The arrangement of a gene of the C. perspectalis mitogenome is not the same as the putative ancestral arthropod mitogenome. All of the PCGs are initiated by ATN codons, except for the cytochrome c oxidase subunit 1 (cox1) gene, which is undertaken by CGA. Five genes have incomplete stop codons that contain only 'T'. All tRNA genes display a typical clover-leaf structure of mitochondrial tRNA, except for trnS1 (AGN). The control region contained an 'ATAGG(A)'-like motif followed by a poly-T stretch. Based on the mitochondrial data, phylogenetic analysis within Pyraloidea was carried out using Bayesian inference (BI) and maximum likelihood (ML) analyses. Phylogenetic analysis showed that C. perspectalis is more closely related to Pygospila tyres within Spilomelinae than those of Crambidae and Pyraloidea.

Dynamics of Forest Ecosystem Components at the Black Sea Coast of the Caucasus after the Destruction of Boxwood Forests Caused by the Invasion of Cydalima perspectalis Walker (Lepidoptera, Crambidae)

Dynamics of Forest Ecosystem Components at the Black Sea Coast of the Caucasus after the Destruction of Boxwood Forests Caused by the Invasion of Cydalima perspectalis Walker (Lepidoptera, Crambidae)

Invasion of the box tree moth Cydalima perspectalis (Walker, 1859) in the Balearic Islands (Western Mediterranean, Spain): a matter of islands

Invasion of the box tree moth Cydalima perspectalis (Walker, 1859) in the Balearic Islands (Western Mediterranean, Spain): a matter of islands

First discovery of the natural egg parasitoid of Cydalima perspectalis (Walker, 1859) in Turkey with molecular methods (Lepidoptera: Crambidae

The genus Trichogramma Westwood, 1833 are important biological control agents of especially Lepidoptera pests in all around the world. These tiny wasps can’t be reliably identified owing to their small size and lack of definable morphological characters. ITS2 (Internal transcribed spacer 2) sequence-based identification has been performed successfully for years for parasitoids of the genus Trichogramma. The use of indigenous Trichogramma species against pests is very important for the success of biological control. Therefore, accurate and precise species identification of Trichogramma plays a key role in biological control programs. In the study, egg parasitoids were obtainedfrom parasitized egg masses of Cydalima perspectalis (Walker, 1859) collected in Hatay province of Turkeyin May 2021. Trichogramma wasps were collected and only one species was determined by using both ribosomaland mitochondrial sequences. According to ribosomal and mitochondrial sequence results, all of the collectedsamples were determined to be Trichogramma evanescens Westwood, 1833. This is the first report of T. evanescensas egg parasitoid of C. perspectalis in the worldwide.

Ecological aspects of manifestations of the inva-sive species Cydalima Perspectalis (Walker, 1859) in urbanized ecosystems

Every year, the scale of the territories occupied by the invasive pest – the box tree moth (Cydalima perspectalis (Walker, 1859)) is growing rapidly. In 2005, this species was distributed in 16 countries of the European Union. Evidence of the presence of C. perspectalis on the territory of Ukraine was absent until 2013, the box tree moth was first detected in 2014. The box tree moth is a polyvoltine species that forms 2–3 generations per year, in the southern regions up to 4 generations, with obligatory diapauses of 6–8 weeks. The caterpillar feeds on boxwood leaves, and in their absence – bark. The pest hibernates in the stage of a pupa or caterpillar in a cocoon fixed in a thick web between boxwood leaves. During the years of research in 2019–2022, it was established that the invasive population of C. Perspectalis in the urban ecosystem of Bila Tserkva developed very rapidly, after isolated cases of detection of the invasive species Суdalima perspectalis in 2019 and 2020, there is complete local eating of boxwood in urban areas of Bila Tserkva in 2022, which indicates the aggressiveness of this insect species, its speed of reproduction and fecundity, and the possibility of development in several generations in the conditions of the Kyiv region. As a result of entomological monitoring of the manifestation of C. perspectalis (Walker, 1859), it was established that the ecological – phytochological zones of Bila Tserkva, Kyiv region, which change synchronously in space parallel to the gradient of plant groups, significantly influence the formation of the population of the invasive species. The specific microclimatic conditions of the urbogenic environment and its ecological features lead to certain changes in the dynamics of the spread of the invasive species C. perspectalis. The conducted studies of the manifestation of the pest on the fodder crop Buxus sempervirens L. in the conditions of the urban ecosystems of Bila Tserkva testify to the differences in the degree of distribution in various ecological and phytocenotic zones, which is a reflection of the influence of a complex of unfavorable factors of the urban environment. Key words: Buxus sempervirens L., Cydalima per-spectalis (Walker, 1859), ecological and phytocenotic zones of the city.

Mapping dead understoreyBuxus hyrcana Pojarkusing Sentinel-2 and Sentinel-1 data

AbstractThe Hyrcanian Forests comprise a continuous 800-km belt of mostly deciduous broadleaf forests and are considered as Iran’s most important vegetation region in terms of density, canopy cover and species diversity. One of the few evergreen species of the Hyrcanian Forests is the box tree (Buxus), which is seriously threatened by box blight disease and box tree moth outbreaks. Therefore, information on the spatial distribution of intact and infested box trees is essential for recovery monitoring, control treatment and management. To address this critical knowledge gap, we integrated a genetic algorithm (GA) with a support vector machine (SVM) ensemble classification based on the combination of leaf-off optical Sentinel-2 and radar Sentinel-1 data to map the spatial distribution of box tree mortality. We additionally considered the overstorey species composition to account for a potential impact of overstory stand composition on the spectral signature of understorey defoliation. We consequently defined target classes based on the combination of dominant overstorey trees (using two measures including the relative frequency and the diameter at breast height) and two defoliation levels of box trees (including dead and healthy box trees). Our classification workflow applied a GA to simultaneously derive optimal vegetation indices (VIs) and tuning parameters of the SVM. Then the distribution of box tree defoliation was mapped by an SVM ensemble with bagging using GA-optimized VIs and radar data. The GA results revealed that normalized difference vegetation index, red edge normalized difference vegetation index and green normalized difference vegetation index were appropriate for box tree defoliation mapping. An additional comparison of GA-SVM (using GA-optimized VIs and tuning parameters) with a simple SVM (using all VIs and user-based tuning parameters) showed that our suggested workflow performs notably better than the simple SVM (overall accuracy of 0.79 vs 0.74). Incorporating Sentinel-1 data to GA-SVM, marginally improved the performance of the model (overall accuracy: 0.80). The SVM ensemble model using Sentinel-2 and -1 data yielded high accuracies and low uncertainties in mapping of box tree defoliation. The results showed that infested box trees were mostly located at low elevations, low slope and facing north. We conclude that mortality of evergreen understorey tree species can be mapped with good accuracies using freely available satellite data if a suitable work-flow is applied.

The current state of forest ecosystems in the Khosta Yew-Boxwood Grove

In this study, we aimed to assess the current state of forest ecosystems on the Black Sea coast of the Caucasus after the mass mortality of boxwoods. Soil and geobotanical studies were carried out in the Khosta Yew-Boxwood Grove, a convenient proving ground for assessment of the consequences of Cydalima perspectalis expansion. Hierarchical cluster analysis (nearest-neighbour and Euclidean distance methods), One-way ANOVA, and correlation analysis (Euclidean distance matrices for standardised data) were applied to process the soil and vegetation data. An increase in the illumination of the lower forest tiers due to the Buxus colchica destruction resulted in an intensive growth of vegetation cover and the formation of a soddy horizon in soils. These processes contributed to the accumulation of organic matter and high biological activity of the soils. The number of Buxus colchica seedlings was negatively correlated with the vegetation coverage and the number of grass and shrub species, as well as with some biological parameters of the soils. The most intensive seed regeneration of Buxus colchica was observed in forest plots with high crown density in the upper tier, undeveloped vegetation cover, and soddy soil horizon.

Surveys on the Pyraloidea and Geometridae (Lepidoptera) Fauna of Mount Ararat and its surroundings

The present study is carried out between 2017-2019, to determine Pyraloidea and Geometridae fauna of Mount Ararat and its surroundings. The studies are conducted at night with light traps and insect nets during the day. Samples are firstly identified by using their external morphological characteristics and genital structures of taxa are examined when necessary. As a result of the researches, 135 species from Pyraloidea superfamily and 70 species from Geometridae family are determined. Among these taxa, 65 species of Pyraloidea and 41 species of Geometridae are newly discovered in Lepidoptera fauna of Iğdır province. The number of pyraloid species in Iğdır province increased to 217 and the number of geometrid species increased to 118. Information on the new location records and distributions of Ancylodes pallens Ragonot, 1887, Aphyletes nigrisparsella (Ragonot, 1887), Calamotropha paludella (Hübner, [1824]), Cydalima perspectalis (Walker, 1859), Ephestia kuehniella Zeller, 1879, Gymnancyla nomiella (Ragonot, 1887) G. hornigii (Lederer, 1852), Myrlaea mimicralis (Amsel, 1950) and Tephris verruculella (Ragonot, 1887), whose distribution areas are limited in Turkey, are presented.

Survey of Natural Enemies of the Invasive Boxwood Moth Cydalima perspectalis in Southwestern Mediterranean Europe and Biocontrol Potential of a Native Beauveria bassiana (Bals.-Criv.) Vuill. Strain.

Simple SummaryCydalima perspectalis (Lepidoptera: Crambidae), a species native to East Asia that feeds exclusively on Buxus spp., was first detected in Southwestern Germany and the Netherlands in 2007. Today, it is present in many countries in Europe. Since its detection, numerous researchers have studied the biology and the present or potential number of generations of C. perspectalis in European countries. However, less research has been devoted to detecting possible native biotic factors of mortality (predators, parasitoids, entomopathogenic microorganisms or nematodes) capable of reducing the pest populations. In this work, indigenous natural enemies in the boxwood of the southwest Mediterranean region were collected and identified. One of them, a native Beauveria bassiana strain from infected C. perspectalis larvae, showed potential for controlling this invasive crambid.Cydalima perspectalis (Lepidoptera: Crambidae), a species native to East Asia, has been especially devastating in the Mediterranean region and Catalonia, northeast Spain, where Buxus sempervirens is an essential component of the natural forest. As an invasive species, the lack of biotic mortality factors in the arrival region has been one of the main factors allowing its expansion. Therefore, this study aimed to collect and identify possible indigenous natural enemies adapting to the new species in the boxwood of the southwest Mediterranean region. Later, the efficacy of some of the collected species for controlling C. perspectalis larvae was tested in laboratory conditions. The larval collection was carried out in successive years in the boxwood of the region. Several collected larvae were infected with an entomopathogen, Beauveria bassiana, or parasitized by Compsilura concinnata, both common in native Lepidoptera caterpillars. The B. bassiana strain was found to be highly virulent against the developed larvae of C. perspectalis, which suggests that B. bassiana may be an effective treatment in parks and gardens when the first overwintering larvae are detected. The biology of the parasitoid identified is not very well known in Europe, which suggests the necessity of studying its biology and alternative hosts in the region in order to improve its population.

Türkiye'nin Tehdit Altındaki Doğal Şimşirlerinin (Buxus sempervirens L. ve Buxus balearica Lam.) Mevcut Durumu ve Kalan Son Lokasyonlar

We investigated the current status and the last locations of Turkey’s native Buxus species under threats especially with boxwood moth (Cydalima perspectalis) in detail throught the country for the first time. Within the scope of the studies, detailed field and survey studies were carried out to determine the latest status of existing boxwood existence in regions and provinces. The study was carried out in 26 (the existence of boxwood is definitely 23 provinces, 3 provinces are thought to be boxwood) provinces. According to the results obtained from field studies conducted in 23 provinces, 59 districts and 195 locations for which boxwood presence information was obtained, it was determined that boxwood remained in 29 locations in 15 provinces and 23 districts. With these results, it was determined that Turkey's boxwood presence has decreased by 85%, and only 15% of the presence of boxwood remains. Due to the continuing effect of the boxwood moth, it is under serious threat in the remaining locations. The last remaining locations of Turkey’s native Buxus species under threats were determined and described in this first pionering research study on this matter. We suggest urgent studies for the protection of boxwood genetic reseources in Turkey.

The fast invasion of Europe by the box tree moth: an additional example coupling multiple introduction events, bridgehead effects and admixture events

Identifying the invasion routes of non-native species is crucial to understanding invasions and customizing management strategies. The box tree moth, Cydalima perspectalis, is native to Asia and was recently accidentally introduced into Europe as a result of the ornamental plant trade. Over the last 15 years, it has spread across the continent and has reached the Caucasus and Iran. It is threatening Buxus trees in both urban areas and forests. To investigate the species’ invasion routes, native and invasive box tree moth populations were sampled, and moth’s genetic diversity and structure were compared using microsatellite markers. Our approximate Bayesian computation analyses strongly suggest that invasion pathways were complex. Primary introductions originating from eastern China probably occurred independently twice in Germany and once in the Netherlands. There were also possibly bridgehead effects, where at least three invasive populations may have served as sources for other invasive populations within Europe, with indication of admixture between the two primary invasive populations. The bridgehead populations were likely those in the countries that play a major role in the ornamental plant trade in Europe, notably Germany, the Netherlands, and Italy. All these invasion processes likely facilitated its fast expansion across Europe and illustrate the role played by the ornamental plant trade not only in the moth’s introduction from China but also in the species’ spread across Europe, leading to an invasion with a complex pattern.

Eco-friendly control method against invasive pest box tree moth, (Cydalima perspectalis (Walker) (Lepidoptera: Crambidae))

BackgroundBuxus sempervirens (Boxwood) is a type of plant that has economic and cultural significance, danger of extinction due to various factors. Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae), an invasive species, has an important role as a boxwood pest. The inadequacy of the pheromone trap methods recommended to control the pest or the negative effects of chemical insecticides on the environment have led to seeking alternative approaches in this regard. In this study, it was conducted to determine whether entomopathogens can be applied in pest control, the insecticidal effects of Bacillus thuringiensis subsp. kenyae (FDP-8), Bacillus cereus (FD-63), Brevibacillus brevis (FD-1) and Vibrio hollisae (FD-70) bacterial strains at the concentration of 1 × 108 CFU/ml and Beauveria bassiana (Bals.-Criv.) Vuill. (Cordycipitaceae) (ET 10) fungal isolate at the concentrations of 1 × 106, 1 × 107 and 1 × 108 conidia/ml were tested under controlled conditions.ResultsAs compared the results of the bacterial strains and fungal tested, it was determined that the best results were obtained from in the fungal isolate at the concentration of 1 × 108 conidia/ml. After 192 and 216 h. of observation, the 1 × 108 CFU/ml of bacterial strains: B. cereus FD-63, B. brevis FD-1 and V. hollisae FD-70; also, 1 × 108 conidia/ml concentration of ET 10 fungal isolate of B. bassiana control C. perspectalis caused mortality rate of 100% under laboratory conditions.ConclusionFuture studies of these microorganisms against this pest in the field, may be an important alternative method to control this pest.

Susceptibility of Cydalima perspectalis (Lepidoptera: Crambidae) larvae to some reduced-risk insecticides in laboratory bioassays

Box tree moth (BTM) Cydalima perspectalis (Walker, 1859) is the most harmful pest of different boxwood species in Europe and Asia including Caspian boxwood Buxus hyrcana in the Hyrcanian forests of Iran. Accessible and effective eco-friendly insecticides are required for the pest control. Thus, susceptibility of 2<sup>nd</sup> and 4<sup>th</sup> instar larvae of BTM to commercial formulation of Bacillus thuringiensis (Bt), two plant extract formulations, Bio1<sup>®</sup> and Matrine<sup>®</sup>, and three insect growth regulator (IGR) insecticides, chlorfluazuron, chromafenozide and diflubenzuron were investigated in laboratory bioassay. Except for diflubenzuron, significant mortality of both instar larvae was observed. At the endpoint of the experiments (96 h), 75.2–90% of second and 80–85% of fourth instar larvae had already died, as a result of feeding on leaves treated with the highest concentration of the insecticides. Furthermore, based on Probit analysis, Matrine<sup>®</sup> exhibited the highest efficiency (lethal concentration LC<sub>50</sub> = 2.87 μL·L<sup>–1</sup>) on 2<sup>nd</sup> instar larvae and followed by Bio1<sup>®</sup> (8.07 μL·L<sup>–1</sup>), chlorfluazuron (173.3 μL·L<sup>–1</sup>) and Bt (326.3 mg·L<sup>–1</sup>). The LC<sub>50</sub> of Matrine<sup>®</sup> and Bt for 4<sup>th</sup> instar larvae were 1.75 μL·L<sup>–1</sup> and 335.8 mg·L<sup>–1</sup>, respectively. Our study revealed that Matrine<sup>®</sup> and chromafenozide could be alternatively used against BTM in situations where there is a permission and need to use insecticides.