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Xyleborine ambrosia beetles (Coleoptera: Scolytinae: Xyleborini) are among the most important and destructive pests in forests, tree nurseries and plantations worldwide. Their cryptic lifestyle, fungal mutualism, inbreeding and broad host range have predisposed them to become remarkably successful invaders and colonize novel habitats across the world. The black timber bark beetle, Xylosandrus germanus (Blandford), is native to East Asia, but now established in North America and Europe. It is an economically significant invasive pest in North American nurseries and orchards, and European forests. Managing and preventing the spread of exotic species such as X. germanus requires an understanding of invasion pathways and mechanisms associated with their source populations. In this study, we sequenced the mitochondrial gene COI and nuclear gene ArgK from six native and 24 non-native X. germanus populations to identify their origins. The genetic structure of X. germanus in non-native habitats is highly uniform and points to introductions from Honshu and/or Hokkaido, Japan. However, different haplotypes of the inferred Japanese source lineage, which dominate in North America and Europe today, together with temporal incidence of records of X. germanus indicate that these continents were invaded independently. While European populations were probably introduced only once prior to 1951, the genetic pattern of North American populations suggests that X. germanus was introduced several times.

Rapid ʻōhiʻa death (ROD) is caused by two recently described species of Ceratocystis, C. lukuohia and C. huliohia. These fungi are decimating ʻōhiʻa lehua (Metrosideros polymorpha), the keystone native tree species of Hawaiʻi. Viable Ceratocystis propagules can persist in ambrosia beetle frass (Coleoptera: Scolytinae), and movement of the frass may play a key role in the spread of the disease. In order to prevent the spread of ROD, we developed effective and practical surface (e.g., tools and shoes) decontamination methods to be used by researchers, managers, and the public alike. We first tested different household and laboratory disinfectants on the Ceratocystis fungi in culture, and then we applied the effective culture disinfectants to contaminated ambrosia beetle frass. Laboratory-grade ethanol (70, 80, and 95%), Clorox bleach (10%, 0.825% active ingredient [a.i.]), and isopropanol (70 and 91%), were all equally effective at decontaminating cultured C. lukuohia and C. huliohia. Although all concentrations of isopropanol (50, 70, and 90%) and ethanol (50, 70, and 90%) were effective disinfectants of Ceratocystis-contaminated frass, treatments of frass with up to 20% Clorox bleach (1.2% a.i.) were not completely adequate at killing the fungus. These data reveal that bleach is not a sufficient ROD disinfectant when frass is present, and isopropanol or ethanol are the more reliable options.

The Ambrosia Fusarium Clade (AFC) comprises at least 16 genealogically exclusive species-level lineages within clade 3 of the Fusarium solani species complex (FSSC). These fungi are either known or predicted to be farmed by Asian Euwallacea ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in the tribe Xyleborini as a source of nutrition. To date, only 4 of the 16 AFC lineages have been described formally. In the absence of Latin binomials, an ad hoc nomenclature was developed to distinguish the 16 species lineages as AF-1 to AF-16. Herein, Fusarium species AF-3, AF-5, and AF-7 were formally described as F. floridanum, F. tuaranense, and F. obliquiseptatum, respectively. Fusarium floridanum farmed by E. interjectus on box elder (Acer negundo) in Gainesville, Florida, was distinguished morphologically by the production of sporodochial conidia that were highly variable in size and shape together with greenish-pigmented chlamydospores. Fusarium tuaranense was isolated from a beetle-damaged Paŕa rubber tree (Hevea brasiliense) in North Borneo, Malaysia, and was diagnosed by production of the smallest sporodochial conidia of any species within the AFC. Lastly, F. obliquiseptatum was farmed by an unnamed ambrosia beetle designated Euwallacea sp. 3 (E. fornicatus species complex) on avocado (Persea americana) in Queensland, Australia. It uniquely produces some clavate sporodochial conidia with oblique septa. Maximum likelihood analysis of a multilocus data set resolved these three novel AFC taxa as phylogenetically distinct species based on genealogical concordance. Particularly where introduced into exotic environments, these exotic mutualists pose a serious threat to the avocado industry, native forests, and urban landscapes in diverse regions throughout the world.

Ten species of ambrosia beetles of the tribe Xyleborini,Amasabeesoni(Eggers, 1930),Amasaopalescens(Schedl, 1937),Amasacylindrotomica(Schedl, 1939),ArixyleborushirsutulusSchedl, 1969,Beaveriumlatus(Eggers, 1923),Cnestusprotensus(Eggers, 1930),Coptodryasquadricostata(Schedl, 1942),CryptoxyleborusconfususBrowne, 1950,Cryptoxyleboruspercuneolus(Schedl, 1951) andCyclorhipidionvigilans(Schedl, 1939), are recorded here for the first time in Thailand. Diagnostic characters, illustrations, distribution and biological data are provided for each species.Xylosandrusramulorum(Schedl, 1957),stat. res.is removed from synonymy withAmasacylindrotomicaand reinstated as a valid species.

During the course of a targeted bark beetle survey of the Hawaiian Islands, insect sampling undertaken in native forest biotopes on Moloka‘i island revealed the presence of one native and three exo...

The aim of this study was to determine whether the morphometrics, which is the study of variation and change in structure of an organism both in shape and size, allows an adequate species identification of the tribe Xyleborini, mainly the genus Xyleborus. The species chosen for this analysis were Xyleborus ferrubineus, X. volvulus, X. affinis, X. scheldi, Xylosandrus morigerus (= Xyleborus morigerus) and Sampsonius dampfi. The dependent variables were the length of body, pronotum and elytra, width of pronotum and base of elytra, and the proportions of the body length per width of the base of elytra, length per width of pronotum and length per width of elytra. The average values of 10 specimens per species for each variable were included in a multivariate analysis for the construction of a phenogram. After comparing the results obtained with the works of Wood (1982) and Rabaglia (2006), the conclusion was that morphometrics is a very useful tool for separating species of the tribe Xyleborini, but in addition to other characters not covered in this work. El presente trabajo tuvo por objetivo determinar si la morfometría, que es el estudio de la variación y cambio de las estructuras de un organismo tanto en forma como en tamaño, permite una adecuada identificación de especies de la tribu Xyleborini, con énfasis en el género Xyleborus. Las especies escogidas para este análisis fueron Xyleborus ferrugineus, X. volvulus, X. affinis, X. scheldi, Xylosandrus morigerus (= Xyleborus morigerus) y Sampsonius dampfi. Las variables de estudio fueron la longitud del cuerpo, pronotum y los elytra; el ancho del pronotum y la base de los elytra; y las proporciones longitud del cuerpo por ancho de la base de los elytra, longitud por ancho del pronotum y longitud por ancho de los elytra. Los valores promedio de 10 especímenes por especie para cada variable fueron incluidos en un análisis multivariado para la construcción de un fenograma. Tras comparar los resultados obtenidos con lo expuesto previamente por Wood (1982) y Rabaglia (2006), se concluyó que la morfometría es una herramienta muy útil para separar especies de la tribu Xyleborini, pero en complemento con otros caracteres no contemplados en el presente trabajo.

A new genus of xyleborine ambrosia beetle, Melanesicus Beaver & Petrov gen. n., with type species Xyleborus partitus Browne (1974) is described from the Melanesian region. The following new combinations are proposed: M. caledoniae (Beaver & Liu, 2016) comb. n., M. deformatus (Browne, 1974) comb. n., M. granulosus (Schedl, 1975) comb. n., all from Xyleborus Eichhoff, 1864. Melanesicus tishechkini Petrov sp. n. is described from Vanuatu, and Melanesicus nukuruanus sp. n. Beaver from Fiji. The taxonomy, distribution and biology of the species included are briefly reviewed.

Xylosandrus compactus (Eichhoff) (Col.: Curculionidae, Scolytinae) is an ambrosia beetle species native to subtropical Eastern Asia, with great concern due to its high invasive ability. This species has invaded 54 countries worldwide, including 4 European countries (Italy, France, Greece, and Spain); it was detected in Mallorca (Balearic Islands, Spain) in October 2019. In the present work, X. compactus is recorded for the first time in the Iberian Peninsula (Girona province, NE Spain); specimens were collected in Banyoles (August 2020, attacking twigs of Laurus nobilis and Liquidambar styraciflua) and Platja d’Aro (October 2020, attacking twigs of L. nobilis). Up-to-date information is presented about its geographical distribution, host plants, biology, symptoms, associate damages, and the possible origin of this species in Europe.

We provide an overview of both traditional and innovative control tools for management of three Xylosandrus ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), invasive species with a history of damage in forests, nurseries, orchards and urban areas. Xylosandrus compactus, X. crassiusculus and X. germanus are native to Asia, and currently established in several countries around the globe. Adult females bore galleries into the plant xylem inoculating mutualistic ambrosia fungi that serve as food source for the developing progeny. Tunneling activity results in chewed wood extrusion from entry holes, sap outflow, foliage wilting followed by canopy dieback, and branch and trunk necrosis. Maintaining plant health by reducing physiological stress is the first recommendation for long-term control. Baited traps, ethanol-treated bolts, trap logs and trap trees of selected species can be used to monitor Xylosandrus species. Conventional pest control methods are mostly ineffective against Xylosandrus beetles because of the pests’ broad host range and rapid spread. Due to challenges with conventional control, more innovative control approaches are being tested, such as the optimization of the push–pull strategy based on specific attractant and repellent combinations, or the use of insecticide-treated netting. Biological control based on the release of entomopathogenic and mycoparasitic fungi, as well as the use of antagonistic bacteria, has yielded promising results. However, these technologies still require validation in real field conditions. Overall, we suggest that management efforts should primarily focus on reducing plant stress and potentially be combined with a multi-faceted approach for controlling Xylosandrus damage. This research was supported by the University of Catania (Project Emergent Pests and Pathogens and Relative Sustainable Strategies - 5A722192113; PhD fellowship to AG). P.H.W.B. was supported by the German Research Foundation (DFG Emmy Noether Grant BI 1956/1–1). Funding to MGW: USDA-NIFA, ARS and APHIS; ISDA Hatch; Hawaii Dept. of Agriculture. JH and YL were funded by the USDA APHIS and USDA Forest Service. HK was partially supported by Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research, KAKENHI, Nos. 18KK0180, 19H02994 and 20H03026). KH was partially supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes, Brazil; Finance code 001). Open access funding provided by Università degli Studi di Catania within the CRUI-CARE Agreement.

Simple Summary Xylosandrus germanus (Curculionidae: Scolytinae: Xyleborini) has been recorded attacking grapevines (cv Glera) in the Conegliano Valdobbiadene DOCG area (Vidor, Veneto, Northern Italy). Here, we documented the first case of this invasive species damaging Vitis vinifera in Italy, supplying the second record ever in Europe. The type of the attack is illustrated and the possible causes of the onset of the infestation are discussed. In addition, an updated checklist of world Scolytinae attacking Vitaceae is provided. A total of 34 scolytine species, in eight tribes and fifteen genera, are recorded. Abstract The invasive ambrosia beetle Xylosandrus germanus (Curculionidae: Scolytinae: Xyleborini) is recorded for the first time infesting wine grapes in Italy. The type of the attack is illustrated and the possible causes of the onset of the infestation are discussed. Furthermore, given the continuously increasing number of alien wood-borer beetles introduced worldwide, we provide and discuss the updated world checklist of Scolytinae attacking Vitaceae, and Vitis sp. in particular.

Exotic ambrosia beetles (Curculionidae: Scolytinae) in the tribe Xyleborini include destructive pests of trees growing in horticultural cropping systems. Three species are especially problematic: Xylosandrus compactus (Eichhoff), Xylosandrus crassiusculus (Motschulsky), and Xylosandrus germanus (Blandford). Due to similarities in their host tree interactions, this mini-review focuses on these three species with the goal of describing their host-selection behaviour, characterising associated semiochemicals, and assessing how these interactions relate to their management. All three of these Xylosandrus spp. attack a broad range of trees and shrubs. Physiologically stressed trees are preferentially attacked by X. crassiusculus and X. germanus, but the influence of stress on host selection by X. compactus is less clear. Ethanol is emitted from weakened trees in response to a variety of stressors, and it represents an important attractant for all three species. Other host-derived compounds tested are inconsistent or inactive. Verbenone inhibits attraction to ethanol, but the effect is inconsistent and does not prevent attacks. Integrating repellents and attractants into a push–pull management strategy has been ineffective for reducing attacks but could be optimised further. Overall, maintaining host vigour and minimising stress-induced ethanol are keys for managing these insects, particularly X. crassiusculus and X. germanus.

Due to the increasing interest and the importance of ambrosia beetles, particularly those in the tribe Xyleborini, we considered it necessary to update the distribution and host reports of the species in Mexico. In this paper we focus on new records of Xyleborini from states of Mexico. The information comes from the review of national and international entomological collections, as well as material collected in various states of Mexico. New state records are given for 22 species in seven genera. Three species are recorded from Mexico for the first time: Theoborus micarius (Wood), Xyleborus pubescens Zimmermann, and Xyleborus sparsipilosus Eggers; moreover, we include some new host plant records.

A survey for scolytine bark and ambrosia beetles undertaken on the entomologically understudied and ecologically devastated Hawaiian island of Lāna‘i, revealed the remarkable presence there of Xyleborus mauiensis Perkins, 1900, an endemic Hawaiian ambrosia beetle in the tribe Xyleborini not previously recorded from the island. Its presence on Lāna‘i ‘fills the gap’ in a distribution encompassing the now isolated islands of Molokai and Maui that together with Lanai composed the single historically large island of Maui Nui more than half a million years ago. We emphasize the reliance of X. mauiensis upon its only known host plant, the endemic Hawaiian Cheirodendron trigynum (Araliaceae), and highlight the conservation importance of ensuring the persistence of even a small number of native plants in environments otherwise dominated by exotic flora. We also report five additional new species records for introduced exotic bark and ambrosia beetles in the tribes Xyleborini and Trypophloeini new to Lāna‘i, discussing their significance to our understanding of the distribution of bark beetles in Hawai‘i. We provide a checklist of all Scolytinae recorded from Lāna‘i to date, together with their known host plants and photographs of the newly recorded beetles together with a map indicating where they were sampled.

Silva, Mauricio Pérez, Atkinson, Thomas H., Martínez, Armando Equihua, Cruz, Manuel Pérez De La (2020): Description of new species of Ambrosiodmus Hopkins and Dryocoetoides Hopkins (Curculionidae: Scolytinae: Xyleborini) from Mexico. Zootaxa 4869 (3): 444-450, DOI: https://doi.org/10.11646/zootaxa.4869.3.11

The Southeast Asian xyleborine ambrosia beetle fauna is reviewed for the first time. Thirty-four genera and 315 species are reviewed, illustrated, and keyed to genera and species. Sixty-three new species are described:Amasa cycloxystersp. nov.,Amasa galeodermasp. nov.,Amasa gibbosasp. nov.,Amasa linisp. nov.,Amasa tropidacronsp. nov.,Amasa youliisp. nov.,Ambrosiophilus caliginestrissp. nov.,Ambrosiophilus indicussp. nov.,Ambrosiophilus lannaensissp. nov.,Ambrosiophilus papilliferussp. nov.,Ambrosiophilus wantaneeaesp. nov.,Anisandrus achaetesp. nov.,Anisandrus aucosp. nov.,Anisandrus auratipilussp. nov.,Anisandrus congruenssp. nov.,Anisandrus cryphaloidessp. nov.,Anisandrus feroniasp. nov.,Anisandrus herasp. nov.,Anisandrus paragogussp. nov.,Anisandrus sinivalisp. nov.,Anisandrus venustussp. nov.,Anisandrus xuannusp. nov.,Arixyleborus crassiorsp. nov.,Arixyleborus phiaoacensissp. nov.,Arixyleborus setosussp. nov.,Arixyleborus silvanussp. nov.,Arixyleborus sittichayaisp. nov.,Arixyleborus titanussp. nov.,Coptodryas amydrasp. nov.,Coptodryas carinatasp. nov.,Coptodryas inornatasp. nov.,Cyclorhipidion amasoidessp. nov.,Cyclorhipidion amputatumsp. nov.,Cyclorhipidion denticaudasp. nov.,Cyclorhipidion muticumsp. nov.,Cyclorhipidion obesulumsp. nov.,Cyclorhipidion petrosumsp. nov.,Cyclorhipidion truncaudinumsp. nov.,Cyclorhipidion xeniolumsp. nov.,Euwallacea geminussp. nov.,Euwallacea neptissp. nov.,Euwallacea subalpinussp. nov.,Euwallacea testudinatussp. nov.,Heteroborips fastigatussp. nov.,Heteroborips indicussp. nov.,Microperus latesalebrinussp. nov.,Microperus minaxsp. nov.,Microperus sagmatussp. nov.,Streptocranus petilussp. nov.,Truncaudum bullatumsp. nov.,Xyleborinus cuneatussp. nov.,Xyleborinus disgregussp. nov.,Xyleborinus echinopterussp. nov.,Xyleborinus ephialtodessp. nov.,Xyleborinus huifenyinaesp. nov.,Xyleborinus jianghuansunisp. nov.,Xyleborinus thaiphamisp. nov.,Xyleborinus tritussp. nov.,Xyleborus opacussp. nov.,Xyleborus sunisaesp. nov.,Xyleborus yunnanensissp. nov.,Xylosandrus bellinsulanussp. nov.,Xylosandrus spinifersp. nov.. Thirteen new combinations are given:Ambrosiophilus consimilis(Eggers)comb. nov.,Anisandrus carinensis(Eggers)comb. nov.,Anisandrus cristatus(Hagedorn)comb. nov.,Anisandrus klapperichi(Schedl)comb. nov.,Anisandrus percristatus(Eggers)comb. nov.,Arixyleborus resecans(Eggers)comb. nov.,Cyclorhipidion armiger(Schedl)comb. nov.,Debus quadrispinus(Motschulsky)comb. nov.,Heteroborips tristis(Eggers)comb. nov.,Leptoxyleborus machili(Niisima)comb. nov.,Microperus cruralis(Schedl)comb. nov.,Planiculus shiva(Maiti & Saha)comb. nov.,Xylosandrus formosae(Wood)comb. nov.Twenty-four new synonyms are proposed:Ambrosiophilus osumiensis(Murayama, 1934) (=Xyleborus nodulosusEggers, 1941syn. nov.);Ambrosiophilus subnepotulus(Eggers, 1930) (=Xyleborus cristatuloidesSchedl, 1971syn. nov.);Ambrosiophilus sulcatus(Eggers, 1930) (=Xyleborus sinensisEggers, 1941syn. nov.; =Xyleborus sulcatulusEggers, 1939syn. nov.);Anisandrus hirtus(Hagedorn, 1904) (=Xyleborus hirtipesSchedl, 1969syn. nov.);Cnestus protensus(Eggers, 1930) (=Cnestus rostratusSchedl, 1977syn. nov.);Cyclorhipidion bodoanum(Reitter, 1913) (=Xyleborus misatoensisNobuchi, 1981syn. nov.);Cyclorhipidion distinguendum(Eggers, 1930) (=Xyleborus fukiensisEggers, 1941syn. nov.; =Xyleborus ganshoensisMurayama, 1952syn. nov.);Cyclorhipidion inarmatum(Eggers, 1923) (=Xyleborus vagansSchedl, 1977syn. nov.);Debus quadrispinus(Motschulsky, 1863) (=Xyleborus fallaxEichhoff, 1878syn. nov.);Euwallacea gravelyi(Wichmann, 1914) (=Xyleborus barbatomorphusSchedl, 1951syn. nov.);Euwallacea perbrevis(Schedl, 1951) (=Xyleborus molestulusWood, 1975syn. nov.;Euwallacea semirudis(Blandford, 1896) (=Xyleborus neohybridusSchedl, 1942syn. nov.);Euwallacea sibsagaricus(Eggers, 1930) (=Xyleborus tonkinensisSchedl, 1934syn. nov.);Euwallacea velatus(Sampson, 1913) (=Xyleborus rudisEggers, 1930syn. nov.);Microperus kadoyamaensis(Murayama, 1934) (=Xyleborus pubipennisSchedl, 1974syn. nov.; =Xyleborus denseseriatusEggers, 1941syn. nov.);Stictodex dimidiatus(Eggers, 1927) (=Xyleborus dorsosulcatusBeeson, 1930syn. nov.);Webbia trigintispinataSampson, 1922 (=Webbia mucronatusEggers, 1927syn. nov.);Xyleborinus artestriatus(Eichhoff, 1878) (=Xyelborus angustior[sic] Eggers, 1925syn. nov.; =Xyleborus undatusSchedl, 1974syn. nov.);Xyleborinus exiguus(Walker, 1859) (=Xyleborus diversusSchedl, 1954syn. nov.);Xyleborus muticusBlandford, 1894 (=Xyleborus conditusSchedl, 1971syn. nov.; =Xyleborus lignographusSchedl, 1953syn. nov.). Seven species are removed from synonymy and reinstated as valid species:Anisandrus cristatus(Hagedorn, 1908),Cyclorhipidion tenuigraphum(Schedl, 1953),Diuncus ciliatoformis(Schedl, 1953),Euwallacea gravelyi(Wichmann, 1914),Euwallacea semirudis(Blandford, 1896),Microperus fulvulus(Schedl, 1942),Xyleborinus subspinosus(Eggers, 1930).

Ambrosia beetles from the genus Xyleborus are important vectors of fungal pathogens in forest and agricultural systems, yet the influence of temperature on their morphological development has been poorly studied. Because host colonization and ambrosial fungi cultivation is mostly restricted to females, it is possible to speculate on strong sexual dimorphism expression in secondary sexual characters and ecological segregation between sexes. Here, we determined the effect of different growing temperatures (17, 23, 26 and 29 °C) on mandible ontogeny of larvae and adult individuals of X. affinis, and sexual dimorphism in adults, in shape and size variation using geometric morphometrics. Mandible shape change showed significant differences in magnitude and direction through larval ontogeny among temperature treatments. Sexual shape and size dimorphism were found in adult mandibles, and the degree of sexual dimorphism was dependent on growth temperature, with a significant effect of the interaction between temperature and sex on mandible shape and size variation. Higher morphological differences were observed at the base of mandibles among temperature treatments in adults and a gradual narrowing trend with temperature increments. These findings could have consequences on feeding performance and fungus cultivation inside colonies, potentially influencing their ability to establish populations in new geographical areas.

Symbiosis can facilitate the development of specialized organs in the host body to maintain relationships with beneficial microorganisms. To understand the developmental and genetic mechanisms by which such organs develop, it is critical to first investigate the morphology and developmental timing of these structures during the onset of host development. We utilized micro-computed tomography (μCT) to describe the morphology and development of mycangia, a specialized organ, in the Asian ambrosia beetle species Euwallacea validus which maintains a mutualistic relationship with the Ascomycete fungus, Fusarium oligoseptatum. We scanned animals in larval, pupal and adult life stages and identified that mycangia develop during the late pupal stage. Here we reconcile preliminary evidence and provide additional morphological data for a second paired set of structures, including the superior, medial mycangia and an inferior, lateral pair of pouch-like structures, in both late-stage pupae and adult female beetles. Furthermore, we report the possible development of rudimentary, or partially developed pairs of medial mycangia in adult male beetles which has never been reported for any male Xyleborini. Our results illustrate the validity of μCT in observing soft tissues and the complex nature of mycangia morphology and development.

Xylosandrus crassiusculus (Motchulsky) is a native Asian ambrosia beetle that has been accidentally introduced to many countries of the world, presumably through the international movement of nursery, timber, and wood products. The species is known in various tropical African countries but only as far south as Tanzania on the African continent. In this study, we report X. crassiusculus and its fungal symbiont for the first time from South Africa. The species was identified using both morphological characters and COI sequence data. Xylosandrus crassiusculus were obtained from three different provinces of South Africa and represent two distinct haplotypes. The fungal symbiont, Ambrosiella roeperi, was isolated and identified using DNA sequencing and morphological characterization.

Invasive ambrosia beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini) have recently become established in several regions of the US where they vector fungal pathogens responsible for vascular wilt diseases in avocado (Persea americana), woody ornamentals, and native forest trees. These include the redbay ambrosia beetle (Xyleborus glabratus) that vectors the fungus responsible for laurel wilt, and a group of cryptic species morphologically similar to tea shot-hole borer (Euwallacea fornicatus) that vectors the pathogen of Fusarium dieback. Ecologically, these wood-boring beetles function as primary colonizers, capable of attacking healthy unstressed trees. Thus, they are attracted to the volatile terpenoids emitted from host wood (i.e., kairomones used by females for host location). Since essential oils consist of concentrated plant terpenoids, they have provided an ideal substrate for development of lures for these pests. This chapter (a) summarizes the succession of essential oil lures used for redbay ambrosia beetle over the last decade, (b) outlines development of the current lure which is highly enriched in (−)-α-copaene, (c) presents chemical analysis of the α-copaene lure, and (d) describes its recent applications for detection of Euwallacea pests in Florida avocado groves.

A new genus, Eggersanthus Sittichaya & Smith gen. nov is described from a single species, Webbia sublaevis Eggers, 1927. The taxonomic characters of Eggersanthus and the morphologically similar genus Arixyleborus are analyzed and compared, and the status of the Webbia genus group is discussed.

Coptoborus ochromactonus Smith and Cognato is a recently described xyleborine ambrosia beetle pest associated with balsa, Ochroma pyramidale (Cav. Ex Lam.) Urb., in Ecuador. This pest has caused significant loss of cultivated balsa in Ecuador, but little is known of its biology and ecology. Based on examination of multiple gallery systems, this study describes the gallery pattern and life cycle of C. ochromactonus and confirms the generic identity of the symbiotic fungus. Females initiated attack, excavating a gallery perpendicular to the bole. The primary tunnel branched into a secondary tunnel at a mean 3.13 mm. This first secondary tunnel was excavated in a horizontal plane between the phloem and xylem for a mean 18.0 mm. Along its length, two tertiary tunnels were constructed on each side, measuring a mean 26.0 and 20.0 mm, respectively. Conidiophores and conidia of an unidentified Fusarium sp. grew on the tunnel walls and were fed upon by the beetle and her progeny. Coptoborus ochromactonus exhibits sexual dimorphism. The female is 2.6 mm long and possesses a round pronotum, whereas the male is 2.2 mm long and has a quadrate pronotum. The developmental stages last a mean 6, 14, 6, 4 and 30 d for egg, larva, pupa, teneral adult, and adult, respectively, when reared at 25°C. Three larval instars were present, with mean head capsule widths of 0.23, 0.31, and 0.42 mm, respectively. In general, the life cycle of C. ochromactonus is similar to those described for other xyleborine ambrosia beetle species.

We present the first record for Spain of the black twig borer, Xylosandrus compactus, an ambrosia beetle of Asian origin, collected from an infested carob tree located in Calvià (Majorca, Balearic Islands, Spain). X. compactus is included in the EPPO Alert List, and it has been recently reported causing damages in a Mediterranean maquis ecosystem in Italy and Southern France. Here, we discuss about the first steps of management of this Invasive Alien species (IAS), the eradication plan and the hypothesis of the path of introduction in this Western Mediterranean island.

Smith, Sarah M., Beaver, Roger A., Cognato, Anthony I. (2020): Taxonomic Changes For Indo-Malayan Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini). The Coleopterists Bulletin 74 (1): 37-40, DOI: 10.1649/0010-065X-74.1.37

A new species, Cnestusquadrispinosus, is described from Thailand, Brunei Darussalam, and East Malaysia (Sabah). It is compared to three related species of Cnestus which lack a mycangial tuft of hairs on the pronotum, and have an impressed elytral declivity.

Bark and ambrosia beetles (Curculionidae, Scolytinae) display a conspicuous diversity of unusual genetic and ecological attributes and behaviors. Reconstructing the evolution of Scolytinae, particularly the large and ecologically significant tribe Cryphalini (pygmy borers), has long been problematic. These challenges have not adequately been addressed using morphological characters, and previous research has used only DNA sequence data from small numbers of genes. Through a combination of anchored hybrid enrichment, low-coverage draft genomes, and transcriptomes, we addressed these challenges by amassing a large molecular phylogenetic dataset for bark and ambrosia beetles. The resulting DNA sequence data from 251 protein coding genes (114,276 bp of nucleotide sequence data) support inference of the first robust phylogeny of Scolytinae, with a special focus on the species rich tribe Cryphalini and its close relatives. Key strategies, including inbreeding mating systems and fungus farming, evolved repeatedly across Scolytinae. We confirm 12 of 16 hypothesized origins of fungus farming, 6 of 8 origins of inbreeding polygyny and at least 11 independent origins of a super-generalist host range. These three innovations are statistically correlated, but their appearance within lineages was not necessarily simultaneous. Additionally, the evolution of extreme host plant generalism often preceded, rather than succeeded, fungus farming. Of the high-diversity tribes of Scolytinae, only Xyleborini is monophyletic, Corthylini is paraphyletic and Cryphalini is highly polyphyletic. Cryphalini sensu stricto is part of a clade containing the genera Hypothenemus, Cryphalus and Trypophloeus, and the tribe Xyloterini. Stegomerus and Cryptocarenus (Cryphalini) are part of a clade otherwise containing all Corthylini. Several other genera, including Ernoporus and Scolytogenes (Cryphalini), make up a distantly related clade. Several of the genera of Cryphalini are also intermixed. For example, Cryphalus and Hypocryphalus are intermingled, as well as Ernoporicus, Ptilopodius and Scolytogenes. Our data are consistent with widespread polyphyly and paraphyly across Scolytinae and within Cryphalini, and provides new insights into the evolution of inbreeding mating systems and fungus farming in the species rich and ecologically significant weevil subfamily Scolytinae.

Bark and ambrosia beetles (Scolytinae) are the most successful group of invasive wood borers worldwide, and the most invasive among them are species in the tribe Xyleborini. This haplodiploid, highly inbred, fungus-farming group is represented by 30 non-native species in North America, of which at least five are serious pests. The few identification resources for Xyleborini that exist are becoming outdated due to new species arrivals and nomenclatural changes. Here we present a new comprehensive key to Xyleborini currently known from the continental United States. Compared to the previous key, the following species have been added to the North American fauna:Ambrosiodmusminor(Stebbing),Ambrosiophilusnodulosus(Eggers),AnisandrusmaicheKurentsov,Coptoboruspseudotenuis(Schedl),Cyclorhipidionfukiense(Eggers),DryocoetoidesreticulatusAtkinson,Dryoxylononoharaense(Murayama),Euwallaceainterjectus(Blandford),Xyleborinusandrewesi(Blandford),Xyleborinusartestriatus(Eichhoff),Xyleborinusoctiesdentatus(Murayama),XyleborusbispinatusEichhoff,XyleborusseriatusBlandford,XyleborusspinulosusBlandford, andXylosandrusamputatus(Blandford).

Fusarium oligoseptatum sp. nov. was isolated from the invasive Asian ambrosia beetle Euwallacea validis (Coleoptera, Scolytinae, Xyleborini) and from the galleries that females had constructed in dying Ailanthus altissima (tree-of-heaven) symptomatic for Verticillium wilt in south-central Pennsylvania, USA. This ambrosia fungus was cultivated by Euwallacea validis as the primary source of nutrition together with a second symbiont, Raffaelea subfusca . Female beetles transport their fungal symbionts within and from their natal galleries in paired pre-oral mycangia. Fusarium oligoseptatum was distinguished phenotypically from the 11 other known members of the Ambrosia Fusarium Clade (AFC) by uniquely producing mostly 1-2 septate clavate sporodochial conidia that were swollen apically. Phylogenetic analysis of multilocus DNA sequence data resolved F. oligoseptatum as a genealogically exclusive species-level lineage but evolutionary relationships with other members of the AFC were unresolved. Published studies have shown that F. oligoseptatum can be identified via phylogenetic analysis of multilocus DNA sequence data or a PCR multiplex assay employing species-specific oligonucleotide primers. In addition, to provide nomenclatural stability, an epitype was prepared from an authentic strain of F. ambrosium that was originally isolated from a gallery constructed in Chinese tea (Camellia sinensis ) by E. fornicatus in India, together with its lectotypification based on a published illustration.

Species within the Euwallacea fornicatus (Eichhoff) species complex are one of the few ambrosia beetles that infest healthy plants and are a potential phytosanitary threat as it causes considerable damage to many tree species in its native and introduced distribution. We updated the list to 412 plant species in 75 families that are known hosts for the E. fornicatus species complex, including 27 new host records, 20 of which are reproductive hosts, in the families Annonaceae, Apocynaceae, Araliaceae, Caricaceae, Euphorbiaceae, Fabaceae, Lauraceae, Magnoliaceae, Malvaceae, Meliaceae, Moraceae, Myristicaceae, Rubiaceae, Salicaceae, Sapindaceae, and Sapotaceae.

The complete mitogenome of Ips calligraphus was sequenced, the length was 19,144 bp which consists of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a major non-coding AT-rich region (GenBank accession no. MW589547). All of 13 protein-coding genes (PCGs) started with ATN. 12 PCGs used the typical stop codon ‘TAA,’ while ATP8 terminated with stop codon ‘TAG.’ Phylogenetic analyses were performed using mitochondrial PCGs for the I. calligraphus and other 18 species within the Scolytinae. The I. calligraphus was clustered together with the other two Ips species in tribe Ipini which were closely related to Xyleborini and Dryocoetini.

The species of Scolytinae subfamily have a worldwide distribution, and are found mainly in the Neo-tropic regions. They usually dominate the communities of wood borer insects. The aim of the present study was to determine the diversity among Scolytinae species associated with balsa, teak, rubber and gamhar plantations located in the humid tropical zone of the Ecuadorian littoral. In each plantation seven flight interception traps containing an ethanol / gel mixture were installed, with a collection frequency of 15 days for three months in the dry period. A total of 1437 specimens were collected, represented by Xyleborini, Cryphalini, Corthylini and Ipini tribes. In the four plantations, 18 species of Scolitids were collected, of which 16 were recorded in the balsa plantation, while in the other plantations 10 to 12 species were found. The most abundant Scolitids were Hypothenemus spp., Corthylus spp., Xyleborus affinis, Xyleborinus bicornatulus and Premnobium cavipennis. The Shannon-Wiener diversity index was higher in the balsa culture (H’= 2.37) and lower in Teak (H’= 1.57). The Jaccard similarity index was higher among the teak and rubber plantations (Cj = 0.9090) while the balsa plantation obtained less similarity with respect to the other three plantations. The greatest diversity of Scolitids was recorded in the balsa plantation, which is a native species, unlike the other forest species, which are exotic, indicating that the diversity would be influenced by the host tree and the location where they are found. The species of Scolytinae subfamily have a worldwide distribution, and are found mainly in the Neo-tropic regions. They usually dominate the communities of wood borer insects. The aim of the present study was to determine the diversity among Scolytinae species associated with balsa, teak, rubber and gamhar plantations located in the humid tropical zone of the Ecuadorian littoral. In each plantation seven flight interception traps containing an ethanol / gel mixture were installed, with a collection frequency of 15 days for three months in the dry period. A total of 1437 specimens were collected, represented by Xyleborini, Cryphalini, Corthylini and Ipini tribes. In the four plantations, 18 species of Scolitids were collected, of which 16 were recorded in the balsa plantation, while in the other plantations 10 to 12 species were found. The most abundant Scolitids were Hypothenemus spp., Corthylus spp., Xyleborus affinis, Xyleborinus bicornatulus and Premnobium cavipennis. The Shannon-Wiener diversity index was higher in the balsa culture (H’= 2.37) and lower in Teak (H’= 1.57). The Jaccard similarity index was higher among the teak and rubber plantations (Cj = 0.9090) while the balsa plantation obtained less similarity with respect to the other three plantations. The greatest diversity of Scolitids was recorded in the balsa plantation, which is a native species, unlike the other forest species, which are exotic, indicating that the diversity would be influenced by the host tree and the location where they are found.