Corresponding author: Andrew J. Johnson (
Academic editor: M. Alonso-Zarazaga
Johnson AJ, Li Y, Mandelshtam MYu, Park S, Lin C-S, Gao L, Hulcr J (2020) East Asian
Global forest health is threatened by a global redistribution of species introducing novel pathogens or vectors, coupled with stress from land management and climate change. Understanding the current biodiversity is a critical step in recording, reporting, and mitigating introductions of pests which affect the health of forest and agricultural systems. Bark and ambrosia beetles (
Identification of
The beetles are challenging to identify due to their small size and soft bodies. Museum specimens are often discoloured and imploded, require high magnification microscopes to clearly see the diagnostic characters, or require dissection of the proventriculus or aedeagus, for which most species do not have adequate references to enable identification.
East Asia has a long history of taxonomic work on
Developments in molecular tools give promise to enable accurate and rapid identification of difficult taxa, but rely on studies linking the identification of vouchered material, thorough descriptions, or sequence data with vouchered representatives (
Specimens were obtained from various collection methods, including hand collecting from plant material and traps by the authors.
Specimens were initially sorted and identified with a stereo microscope (Olympus SZX16). Photographs were taken with taken with a digital SLR (Canon rebel t3i) mounted on an Olympus UIS2 system (BX53 microscope) with 5× – 40× objectives, illuminated by diffused halogen lights. Photographs were stacked with Helicon Focus (Helicon Soft) using the pyramid stacking algorithm (method:C), and edited in Photoshop (version CC2015,
Material was studied in ethanol, partially dried for photography, and later side-mounted on card points using Gelva ethanol soluble PVA (no longer manufactured). Pieces of dissected specimens were stored in ethanol or used for attempted DNA extraction.
Specimen data are maintained with unique identifiers in the
Taxonomic work follows the most recent review and reclassification treating
The following acronyms are used for specimens.
Species are primarily described with a morphological species concept. To be considered a species, individuals have a distinct set of morphological characters based on a reasonable sample which the authors assume represents an evolutionary unit. Taxonomic changes are registered with ZooBank (
DNA sequence data were obtained when possible, to facilitate future molecular identification and corroborate species delimitation. The method used are as used by
Morphological terminology follows contemporary literature for bark and ambrosia beetles. Particularly, the funiculus includes the pedicel. Serrations are the asperities along the anterior margin of the pronotum. Converging aciculations refers to the texture appearing scratched, with irregular grooves and ridges, typically on the frons of some
The recorded host plants summarise the plant species from which the beetles were collected, primarily based on the material examined, with additional records from literature listed explicitly as uncertain. Similarly, the summarised distribution is based on examined material, listed as countries, with states or provinces listed specifically for the United States, Russia, and China. Relevant unconfirmed distribution records are explicitly cited as such.
An identification key is not provided at this time for the following reasons: all species in the region have not been thoroughly studied, especially the large diversity associated with coniferous trees, and the rate of species discovery is high and there are likely many more species yet to be reported, so keys may lead to misleading identifications. This study contributes towards a larger effort to make identification resources by providing thorough, complete descriptions and likely diagnostic characters with the intention to produce a key at a later date. Some types of species elsewhere are in poor condition and may correspond to aberrant individuals of the species included here but cannot be easily diagnosed. This approach is justified taxonomically, because it is important that names exist of the species in a timely manner. It is also justified economically, as several of the species here have been reported as pests, are related to pests, or are introduced elsewhere. Widely deposited type material, high resolution photographs and sequence data should ensure that conspecific specimens are identifiable in the future, enabling better descriptions of the distribution and biology of the species included, and enabling mitigation of potential pests.
The estimated phylogeny reveals some notable discoveries: Specimens from Thailand and China determined as
Preliminary phylogeny of
Eye deeply emarginated; antennal club flat with three sutures marked by setae; third tarsal segment emarginated; the hypomeron with bifurcating setae (rare exceptions); proventriculus with large flat apical plates, tight median suture, often with sutural teeth, and distinct apical teeth, moustache-like, in multiple transverse layers; aedeagus with paired tegminal apodemes (few exceptions) (
Malaysia • 1 ♀
China • 4 ♀♀, 4 ♂♂; Hainan; 儋州市宝岛新村试验场七队桑园 [Danzhou, Baodaoxincun, No.7 farm, Mulberry field];
Proventriculus of
Thailand • 1 ♂; Phatthalung, Srinagarindra District, Khao Banthat wildlife sanctuary; Jun. 2015; S. Steininger, and W. Sittichaya leg.; DNA: 28S:
This species can be diagnosed from similar
Aedeagus of
China (Yunnan, Hainan); Thailand; Malaysia.
Abundant in ethanol bottle trap samples in Yunnan. This species was listed as “spThailandScaly” in
Myanmar • 1 ♂
China • 1 ♀; Guangdong, Shenzhen, Yantian;
Mexico • 1 ♀; Tabasco, La Frontera;
Oman • 1 ♀; Mar. 2005; Randy Ploetz leg.; ex.
This species can be diagnosed by the combination of the transverse carina on the male frons, by the pronotal margin which projects slightly, by the scale-like setae on the pronotal disc, by the barely apparent striae, and by the long spatula-shaped setae on the protibia and the spur on the mesofemur of males. The spine on the mesofemur is known exclusively in this species among all
China (Guangdong, Yunnan); Myanmar; also recorded from Malta; Italy; Tunisia; UAE; Oman; India; Pakistan; Bangladesh; Mexico (all
Chinese: 刺足梢小蠹 [= spur-footed twig bark beetle]; English: Spurred bark beetle.
This species is associated with diseases of mango and die-off of edible fig. These new records confirm that it is widespread in Southern China; previously it was only known from an interception.
China • 1 ♀; Hainan, Qiongzhong, Wanling;
Thailand • 1 ♂; Phatthalung, Srinagarindra District, Khao Banthat wildlife sanctuary; Jun. 2015; S. Steininger, and W. Sittichaya leg.;
Vietnam • 1 ♀; Hải Châu District, Da Nang; 10 Dec. 1966; H. P. Schurtleff leg.; S.L.Wood Collection;
The combination of the size (1.60–1.90 mm), body proportions (1.75 × as long as wide), the transverse ridge on the male frons, scale-like setae on the pronotal disc, the very short pronotal disc, the smooth elytra with barely visible rows of strial punctures, and the presence of sparse interstrial bristles on only odd-numbered interstriae, and long spatula-shaped setae on the male protibiae distinguish this species from others in East Asia.
Similar to female except: Length 1.60–1.80 mm. Frons with straight transverse carina and sulcus above the level of eyes. Gular surface impressed and glabrous, surrounded by sparse hair-like setae. Pronotal profile triangular, almost constricted on antero-lateral edges. Pronotal declivity almost flat (not broadly rounded). Procoxae with large feather-like setae. Protibiae and protarsi with large spatula-shaped setae along inner margin. Last abdominal ventrite emarginated. Proventriculus same as female. Aedeagus not examined.
China (Hainan, Yunnan); Thailand; Vietnam.
Japan • 1 ♂
Japan • 1 ♀; Yamagata, Tendo; 06 May 1982; I Ueno leg.; Photographed by SP;
Russia • 1 ♀; Sakhalin Oblast, South Kuril urban district, Kunashir Island, Tret’yakovo; 29 Jul. 2008; Michail Yu. Mandelshtam leg.; ex.
South Korea • 1 ♂; Gangwon-do, Inje-gun, Inje-eub, Nambuk-ri;
This species is diagnosed from others in East Asia by the size (1.30–1.55 mm), by the proportions (2.20× as long as wide), by the male frons with a short transverse carina, by the antennal sutures (approximately horizontal), by the setae on the pronotal disc (entirely hair-like), and by the elytral striae devoid of ground vestiture.
This species is very similar to
Russia (Southern Kuriles: Kunashir and Shikotan Isles in Sakhalin Oblast); Japan; South Korea, North Korea (Ju, 1964, unconfirmed), China (North-East, Krivolutskaya, 1996, unconfirmed).
Chinese: 北桑梢小蠹 [Northern mulberry twig bark beetle]; English: Northern mulberry bark beetle; Korean: 뽕나무애나무좀; Russian: крифал шелковичный.
Frequently misspelled as “
The original description (
We did not see any specimens representing this species in China (see remarks for
China • 1 ♀
China • 1; Guangdong, Shenzhen, Yantian;
China, Guangdong, Shenzhen, Dapeng dam (
The name is an adjective derived from a combination of
China (Guangdong).
Using the key of
China • 1 ♀
China • 7; Fujian, Quanzhou, Yongchun, Diyiyan;
Taiwan • 7; Nantou County, Sun Moon Lake; 22 Apr. 2013; Ching-Shan Lin leg.; DNA: 28S:
United States • 1 ♂; Florida, Escambia County, Pensacola, Ellyson industrial park;
China, Hong Kong, Kadoorie Centre (
This species is very similar to
This species is also very similar to
The name is derived from the Latin
China (Hainan, Fujian, Guangdong, Yunnan, Hong Kong); Taiwan; United States (Florida).
Chinese: 华南梢小蠹 [South China twig beetle].
This species is weakly attracted to ethanol-quercivorol traps. It was observed making cave-like galleries in material 2–5 cm diameter.
This species was referred to as
Using the key of
Japan • 1 ♀
China • 1 ♀; Fujian, Longyan, Songmao Ridge, Liancheng;
South Korea • 1 ♀; Chungcheongbuk-do, Cheongju-si, Oksan-myeon, Guksa-ri; 02 Jul. 2008; Sangwook Park leg.;
This species can be identified by the combination of the size (1.10–1.30 mm), the proportions (2.15× as long as wide) and the scale-like interstrial ground vestiture which is fused to the elytra.
China (Fujian, Guangdong, Jiangxi); Japan; South Korea.
Collected from branches 4–10 cm diameter.
This species is phylogenetically similar to
The aedeagus is somewhat unusual among
China • 1 ♂
Thailand • 1 ♂
China • 1 ♂; Guizhou, Weining, Maanshan;
Thailand • 1; Chang Mai, Nanthaburi District, Omkoi Wildlife Sanctuary; 28 Jun. 2013; Bateman leg.; DNA: 28S:
This species can be easily distinguished from all other Chinese species by the combination of the strong aciculations on frons, by the male frons without transverse ridge or sulcus, by the long hair-like ground vestiture (only slightly widened at the base) and by the proventriculus with single row of sutural teeth.
China (Guizhou, Sichuan, Shaanxi, Yunnan); Thailand.
Chinese: 华山松梢小蠹 [Huashan pine twig bark beetle] (
We examined the holotype and paratypes of
It appears that a holotype for
India • 1 ♀
Uganda • 1 ♀
China • 1 ♀; Fujian, Quanzhou, Nan’an, Pushan village;
Guadeloupe • 1 ♂; Basse Terre, Point a Lezard; 20 May 2012; R. Turnbow leg.;
Taiwan • 1; Kaohsiung, Liouguei; Tom Harrington, and Caroline Wuerst leg.; Lindgren trap with ethanol; DNA: 28S:
United States • 1; Florida, Homestead; 29 Jun. 2015; Thomas H. Atkinson leg.; ex.
Vietnam • 1 ♀; TamDao; Michelle Jusino, and James Skelton leg.; quercivorol and ethanol trap; DNA: 28S:
This species is distinguished from other similar
See notes for diagnosing the very similar
China (Fujian, Guangdong, Hunan, Yunnan); Taiwan; Thailand; Malaysia; Indonesia; India; Nepal; United States (Florida, Hawaii); Mexico; Puerto Rico; Cuba; Kenya, Uganda; American Samoa, Australia.
Chinese: 芒果梢小蠹 [Mango twig bark beetle]; English: Mango bark beetle.
The holotype of
Japan • 1
China • 1 ♂ ; Fujian, Quanzhou, Yongchun, Diyiyan;
Japan • 1; Okinawa, Kunigami District, Yona Experimental Forest;
China (Fujian), Indonesia (Java), Japan (Ryukyu Islands)
The original spelling of the name, as “
China • 1 ♀
China • 1 ♀; Hebei, “Peking” [Beijing], “Pataling” [Badaling]; 11 Jul. 1972; Fusheng Huang leg.; ex.
South Korea • 1 ♂; “경남 함양 마천 백무동” [Gyeongsangnam-do, Hamyang-gun, Macheon-myeon, Baekmudong valley]; 07 Nov. 1982; “추 호 렬” [Choo Ho Yul leg.]; “기주: 뽕나무” [ex.
Taiwan • 1 ♂; Taichung, Taichung, Caohu;
CHINA, Hebei, Chengde, Shuangqiao,
This species can be distinguished from other
China (Hebei, Shandong, Shanghai); Taiwan; South Korea.
The name is an adjective derived from a combination of the stem of the Latin noun
Chinese: 南桑梢小蠹; English: Southern mulberry bark beetle; Korean: 남방뽕나무애나무좀.
This species has widely been misidentified and misspelled as “
Under the name
This species has been widely described as a pest of
Using the key by
China • 1 ♀
China • 1 ♂; Fujian, Quanzhou, Yongchun, Diyiyan;
China, Fujian, Quanzhou, Yongchun, Diyiyan; (
This species is distinguished from other similar
This species is externally very similar to
China (Fujian, Guangdong)
The name is derived from a combination of the Ancient Greek
Chinese: 伪芒果梢小蠹 ; English: False mango bark beetle.
The morphological differences are sexual characters, likely to be a reproductive barrier between the two species. In a location near the type locality (Nan’an), a sample reared from one log was of a mixture of
None of the examined types of synonyms of
Based on the key for Chinese
Russia • 1 ♂
China • 1 ♀; 辽宁清源N5 [Liaoning, Qingyuan N5]; 01 May 1987; 宋友文 [Youwen Song leg.]; 核桃楸 [
Russia • 2 ♀♀; “228. Майх. Оп. Л.” [Primorskiy Kray, Shkotovskiy District, Maikhe educational and experimental forest]; “усох ветки
This species can be distinguished from others in East Asia by the size (usually 1.70–2.0 mm), by the weakly aciculate frons without apparent sexual dimorphism, by the antennae with nearly straight sutures, by the pronotal disc occupying one third of the pronotal length, with entirely hair like setae, and by the interstrial ground vestiture of the female at the apex of the declivity, which is dense and elongate forming a brush.
Russia (Primorskiy Kray); North Korea (
Russian: Ореховый крифал; Chinese: 胡桃楸梢小蠹
The size range has been described as 1.50–1.90 (original description,
Russia • 1
Russia • 1 ♀; Primorskiy Kray, Laso Nature Reserve, Sukhoy River post; 15 Aug. 1990; M. Yu. Mandelshtam leg.; under bark of
Length 1.45–1.70 mm. Similar to female, except elytra slightly stouter than in female. Aedeagus not studied. Proventriculus not studied.
Russia (Primorskiy Kray); China (Shaanxi (
Russian: Калиновый крифал; Chinese: 荚蒾梢小蠹.
Despite discovering that this species had been incorrectly reported from northern China, we expect it to be present. We were unable to corroborate records from Shaanxi, or records collected on
Roger Beaver and one additional reviewer provided comments on the manuscript, and the SE Miguel Alonso-Zarazaga provided nomenclatural assistance. Wei Lin, Shengchang Lai, and Ling Zhang collected some of the specimens used. Collections from Hong Kong were supported by Benoit Guénard and Billy
Summary of sequences used for the phylogeny of
molecular data