Ambrosia beetle guild attacking a deciduous oak tree Quercus serrata in the Central Japan and species risk assessment in relation to potential invasiveness and aggresiveness based on niche analysis

For decades, secondary ambrosia beetle species have been increasingly observed to attack apparently healthy trees. Some of them cause mortality to living trees. In Japan, Platypus quercivorus that is widely distributed in Asia has caused mass mortality of trees belonging to the family Fagaceae by vectoring Raffaelea quercivora. Similar disease has been in epidemic in Korea by attacks of Platypus koryoensis. On the other hand, unexpected introduction of ambrosia beetles to non-indigenous area has been increasing because of globalization. Some has become major components of ambrosia beetle fauna in the non-indigenous area. The worst example among invasive ambrosia beetles is Xyleborus glabratus that causes laurel wilt in US by vectoring Raffaelea lauricola. The laurel wilt has caused enormous economic damage to avocado farmers in US. However, ecological backgrounds of these phenomena are still unclear. Therefore, ecological information on ambrosia beetles is needed from a view point of biodiversity conservation as well as economic importance. The purpose of this study was to determine ambrosia beetle guild, factors influencing the guild, and niche of each species attacking on an oak tree Quercus serrata. Risks of invasion and of vectoring tree-killing disease were evaluated for each species. The study was conducted in three locations of the University of Tokyo Forests in the Central Japan. Timing of cutting trees (= TC) was controlled by preparing bolts monthly from March to September in Chichibu. They were covered by metal mesh to protect from insect attacks and left on the forest floor in the three locations: Aichi (LOC-A), Chiba (LOC-B), and Chichibu (LOC-C) (= LOC). The LOC-A had Japanese oak wilt (JOW). However, the LOC-B and the LOC-C had no historical records of JOW. Timing of exposure (= TE) was controlled by removing the metal mesh so that wood oldness (= WO) at the timing of exposure after cutting tree was also experimentally controlled. Bait bolts were exposed to insect attacks for one month in a Normal experiment, while they were left until the end of September in a Conditioning experiment. Twenty eight regimes, each consisted of four bolts, were set in each of a Normal and a Conditioning experiment so that the total number of bolts on each location was 224. Ambrosia beetles were collected by dissecting the bolts after the exposure and identified into species. The number of entry holes was used as an indicator for abundance of each species. In the Normal experiment, twenty morphospecies of Scolytinae and six species of Platipodinae were collected. In the Conditioning experiment, six Scolytid and two Platypodid species disappeared, whereas one Scolytid species recruited so that fifteen species of Scolytinae and four species of Platypodinae were collected. In total, twenty one morphospecies of Scolytinae and six species of Platipodinae were collected. Species richness and abundance peaked on bolts prepared in April–May, on bolts exposed in July, and on 2–3-month-old bolts. Eliminating greatest influences of LOC on abundance, results of hierarchical partitioning showed that TC had a strong influence on both species richness and abundance. LOC-A (Aichi), in which Japanese oak wilt disease (JOW) incidence occurred, showed the greatest species richness and the smallest value of Pielou’s evenness. Abundance of the most abundant (“the major”) species was more than twice that of the second major species, which was a likely cause of the smallest evenness in LOC-A. Trees killed by JOW may have increased the abundance of the major species. On the contrary, in LOC-C (Chichibu), Pielou’s evenness and alpha and gamma diversity and the Shannon index were greatest among the three locations although species richness was smallest. High similarity between guilds in LOC-A and LOC-B (Chiba) was probably caused by similarity in vegetation. The LOC had the greatest effect on determining guild structure. Effect of TE was greater than TC. The effect of WO was negligible. A hierarchical structure among the three factors was a likely cause of their relative importance determining guild structure. Niche center and niche breadth were estimated for the three niche contexts. Colonizing ability of ambrosia beetles for bolts that had been exploited by other species. Abundance was compared between the Normal and the Conditioning experiments before each species stated to attack in Normal experiment. If the number in a regime No. 1 was smaller than 3 and no galleries were found in a regime No.2 and 8, the species was included in the analysis. A paired t-test was employed to test if the difference was significant. Species that have been reported as an alien species tended to have broader niche. All Scolytid species collected in my study have a habit of haplodiploidy and sibling mating so that Scolytid have a higher risk of invasion than Platypodid. Platypodid species tended to attack fresh bolts compared to Scolytid so that Platypodid have higher risk to vector tree-killing disease than Scolytid. Among Platypodinae, Crossotarsus niponicus and Platypus calamus significantly increased in the Conditioning experiment so that they are good competitors and high risk species of invasion. However, they did not show strong preference to fresh bolts compared to other Platypodid species. Xylosandrus germanus and Xylosandrus crassiusculus, which attack living trees in non-indigenous area, also did not show a strong preference to fresh bolts so that there are no guarantees that C. niponicus and P. calamus are safe enough in non-indigenous area. Xylosandrus germanus and of X. crassiusculus supported that they became invasive alien species. Euwallacea validus significantly decreased in the Conditioning experiment compared to the Normal experiment so that this species seemed a poor competitor, whereas this species tended to attack fresh bolts. Xyleborus ganshoensis was considered as the highest potential to establish population in non-indigenous area because of its broad niche. Xyleborus ganshoensis was also likely to attack living trees since many individuals attacked fresh bolts but unlikely an invasive alien species. Platypus quercivorus, a vector of the Japanese oak wilt, showed the highest mean abundance on 0-month-old bolts. On the other hand, Xyleborus seiryorensis had the smallest value of WO niche center, indicating that this species could be aggressive enough to attack living trees. The method developed in this study would be applicable to similar risk assessment of ambrosia beetles on other host species and in other countries.報告番号: ; 学位授与年月日: 2012-05-14 ; 学位の種別: 課程博士 ; 学位の種類: 博士（農学） ; 学位記番号: 博農第3850号 ; 研究科・専攻: 農学生命科学研究科生圏システム学専

中部日本においてコナラに寄生するアンブロシアキクイムシのギルド構造およびニッチ解析による侵入生物と攻撃性のリスクアセスメント

For decades, secondary ambrosia beetle species have been increasingly observed to attack apparently healthy trees. Some of them cause mortality to living trees. In Japan, Platypus quercivorus that is widely distributed in Asia has caused mass mortality of trees belonging to the family Fagaceae by vectoring Raffaelea quercivora. Similar disease has been in epidemic in Korea by attacks of Platypus koryoensis. On the other hand, unexpected introduction of ambrosia beetles to non-indigenous area has been increasing because of globalization. Some has become major components of ambrosia beetle fauna in the non-indigenous area. The worst example among invasive ambrosia beetles is Xyleborus glabratus that causes laurel wilt in US by vectoring Raffaelea lauricola. The laurel wilt has caused enormous economic damage to avocado farmers in US. However, ecological backgrounds of these phenomena are still unclear. Therefore, ecological information on ambrosia beetles is needed from a view point of biodiversity conservation as well as economic importance. The purpose of this study was to determine ambrosia beetle guild, factors influencing the guild, and niche of each species attacking on an oak tree Quercus serrata. Risks of invasion and of vectoring tree-killing disease were evaluated for each species. The study was conducted in three locations of the University of Tokyo Forests in the Central Japan. Timing of cutting trees (= TC) was controlled by preparing bolts monthly from March to September in Chichibu. They were covered by metal mesh to protect from insect attacks and left on the forest floor in the three locations: Aichi (LOC-A), Chiba (LOC-B), and Chichibu (LOC-C) (= LOC). The LOC-A had Japanese oak wilt (JOW). However, the LOC-B and the LOC-C had no historical records of JOW. Timing of exposure (= TE) was controlled by removing the metal mesh so that wood oldness (= WO) at the timing of exposure after cutting tree was also experimentally controlled. Bait bolts were exposed to insect attacks for one month in a Normal experiment, while they were left until the end of September in a Conditioning experiment. Twenty eight regimes, each consisted of four bolts, were set in each of a Normal and a Conditioning experiment so that the total number of bolts on each location was 224. Ambrosia beetles were collected by dissecting the bolts after the exposure and identified into species. The number of entry holes was used as an indicator for abundance of each species. In the Normal experiment, twenty morphospecies of Scolytinae and six species of Platipodinae were collected. In the Conditioning experiment, six Scolytid and two Platypodid species disappeared, whereas one Scolytid species recruited so that fifteen species of Scolytinae and four species of Platypodinae were collected. In total, twenty one morphospecies of Scolytinae and six species of Platipodinae were collected. Species richness and abundance peaked on bolts prepared in April–May, on bolts exposed in July, and on 2–3-month-old bolts. Eliminating greatest influences of LOC on abundance, results of hierarchical partitioning showed that TC had a strong influence on both species richness and abundance. LOC-A (Aichi), in which Japanese oak wilt disease (JOW) incidence occurred, showed the greatest species richness and the smallest value of Pielou’s evenness. Abundance of the most abundant (“the major”) species was more than twice that of the second major species, which was a likely cause of the smallest evenness in LOC-A. Trees killed by JOW may have increased the abundance of the major species. On the contrary, in LOC-C (Chichibu), Pielou’s evenness and alpha and gamma diversity and the Shannon index were greatest among the three locations although species richness was smallest. High similarity between guilds in LOC-A and LOC-B (Chiba) was probably caused by similarity in vegetation. The LOC had the greatest effect on determining guild structure. Effect of TE was greater than TC. The effect of WO was negligible. A hierarchical structure among the three factors was a likely cause of their relative importance determining guild structure. Niche center and niche breadth were estimated for the three niche contexts. Colonizing ability of ambrosia beetles for bolts that had been exploited by other species. Abundance was compared between the Normal and the Conditioning experiments before each species stated to attack in Normal experiment. If the number in a regime No. 1 was smaller than 3 and no galleries were found in a regime No.2 and 8, the species was included in the analysis. A paired t-test was employed to test if the difference was significant. Species that have been reported as an alien species tended to have broader niche. All Scolytid species collected in my study have a habit of haplodiploidy and sibling mating so that Scolytid have a higher risk of invasion than Platypodid. Platypodid species tended to attack fresh bolts compared to Scolytid so that Platypodid have higher risk to vector tree-killing disease than Scolytid. Among Platypodinae, Crossotarsus niponicus and Platypus calamus significantly increased in the Conditioning experiment so that they are good competitors and high risk species of invasion. However, they did not show strong preference to fresh bolts compared to other Platypodid species. Xylosandrus germanus and Xylosandrus crassiusculus, which attack living trees in non-indigenous area, also did not show a strong preference to fresh bolts so that there are no guarantees that C. niponicus and P. calamus are safe enough in non-indigenous area. Xylosandrus germanus and of X. crassiusculus supported that they became invasive alien species. Euwallacea validus significantly decreased in the Conditioning experiment compared to the Normal experiment so that this species seemed a poor competitor, whereas this species tended to attack fresh bolts. Xyleborus ganshoensis was considered as the highest potential to establish population in non-indigenous area because of its broad niche. Xyleborus ganshoensis was also likely to attack living trees since many individuals attacked fresh bolts but unlikely an invasive alien species. Platypus quercivorus, a vector of the Japanese oak wilt, showed the highest mean abundance on 0-month-old bolts. On the other hand, Xyleborus seiryorensis had the smallest value of WO niche center, indicating that this species could be aggressive enough to attack living trees. The method developed in this study would be applicable to similar risk assessment of ambrosia beetles on other host species and in other countries.University of Tokyo (東京大学

A new Oriental genus of bostrichid beetle (Coleoptera: Bostrichidae: Xyloperthini), a new synonym and a lectotype designation for <i>Octodesmus episternalis</i> (Lesne, 1901)

A new genus and species of bostrichid beetle, Octomeristes gen. nov. and Octomeristes pusillus gen. et sp. nov., in the tribe Xyloperthini is described from litchi (Litchi chinensis Sonn.) wood in Thailand. The genus is compared to Octodesmus Lesne, 1901, the only other xyloperthine genus with eight-segmented antennae, and to the xyloperthine genera, Xylion Lesne, 1901, Xylionulus Lesne, 1901 and Xylobosca Lesne, 1901. A new combination, Octomeristes minutissimus (Lesne, 1932) comb. nov., is transferred from Octodesmus Lesne, 1901. A lectotype is designated for Octodesmus episternalis Lesne, 1901, the type species of Octodesmus. Octodesmus kamoli Chûjô, 1964 is designated a new synonym of Paraxylion bifer (Lesne, 1932). A key is provided to the species of Octodesmus and Octomeristes gen. nov.</p

Scolytus transcaspicus Eggers 1922

Scolytus transcaspicus Eggers, 1922 Distribution in Iran. Iran (no locality given) (Petrov 2013). General distribution. Kazakhstan, Russia (Daghestan, Astrakhan), Turkmenistan. Taxonomy. The species has been treated as a synonym of Scolytus schevyrewi Semenov, 1902 (Michalski 1973), but is considered a distinct species by Petrov (2013). Biology. The species breeds in species of Ulmus (Ulmaceae) (Petrov 2013).Published as part of Beaver, Roger A., Ghahari, Hassan & Sanguansub, Sunisa, 2016, An annotated checklist of Platypodinae and Scolytinae (Coleoptera: Curculionidae) from Iran, pp. 401-441 in Zootaxa 4098 (3) on page 422, DOI: 10.11646/zootaxa.4098.3.1, http://zenodo.org/record/25889

A review of the genus Carchesiopygus Schedl (Coleoptera: Curculionidae: Platypodinae), with keys to species

Beaver, Roger A., Sanguansub, Sunisa (2015): A review of the genus Carchesiopygus Schedl (Coleoptera: Curculionidae: Platypodinae), with keys to species. Zootaxa 3931 (1): 401-412, DOI: 10.11646/zootaxa.3931.3.

Hypoborus ficus Erichson 1836

Hypoborus ficus (Erichson, 1836) Distribution in Iran. Fars, Khorasan, Tehran (Modarres Awal 1997), Guilan (Modarres Awal 1997; Amini et al. 2013), Iran (no locality cited) (Mifsud & Kní&zcaron;ek 2009; Kní&zcaron;ek 2011). General distribution. Southern Europe, Azores, North Africa, East to Tajikistan. Biology. Recorded in Iran from Ficus carica and Ficus sp. (Moraceae) (Modarres Awal 1997; Amini et al. 2013). Kadyrov (1989) gives a brief account of the biology of the species in Tajikistan, and indicates that it is a serious pest of figs in that country. The species attacks weakened trees, and can cause death of branches and trees if present in high numbers (Ak&scedil;it et al. 2007). Infestations occur throughout the entire year. Ak&scedil;it et al. (2007) note that the parasitic mite, Pyemotes johnmoseri (Khaustov), was abundant in the gallery systems in Turkey attacking primarily the larvae. Mendel (1986) notes abundant attacks by an apparently host-specific braconid parasite, Ecphylus caudatus Ruschka. However, the potential of these species to act as biological control agents is uncertain.Published as part of Beaver, Roger A., Ghahari, Hassan & Sanguansub, Sunisa, 2016, An annotated checklist of Platypodinae and Scolytinae (Coleoptera: Curculionidae) from Iran, pp. 401-441 in Zootaxa 4098 (3) on page 411, DOI: 10.11646/zootaxa.4098.3.1, http://zenodo.org/record/25889

Xyleborinus saxesenii Ratzeburg 1837

Xyleborinus saxesenii (Ratzeburg, 1837) Distribution in Iran. Generally distributed (Modarres Awal 1997 as Xyleborus saxeseni), Iran (no locality cited) (Mifsud & Kní&zcaron;ek 2009; Kní&zcaron;ek 2011). General distribution. Throughout the Palaearctic region. Introduced into North and South America, Australia and South Africa. Biology. It attacks a wide range of trees in many different families, including both conifers and angiosperms (Wood & Bright 1992). Recorded in Iran from Alnus sp., Corylus avellana (Betulaceae), Castanea sativa, Fagus orientalis (Fagaceae), Juglans regia (Juglandaceae), Fraxinus excelsior (Oleaceae), Malus pumila, Mespilus germanica, Prunus sp., Pyrus communis (Rosaceae), Populus sp., Salix sp. (Salicaceae), Acer sp. (Sapindaceae), Tilia begonifolia (Tiliaceae), Ulmus spp. (Ulmaceae) (Modarres Awal 1997). The biology of the species has been studied by Fischer (1954), Egger (1973), Hosking (1973), Peer and Taborsky (2007), Biedermann (2010), Biedermann & Taborsky (2011) and others. The larvae enlarge the gallery system as they develop, and frequently feed on fungus-infested wood rather than the ambrosia fungus alone (Wood 1982; Biedermann et al. 2009). The species is strongly attracted to ethanol (e.g. Markalas & Kalapanida 1997; Saruhan & Akyol 2012). It is a pest of hazelnut in the Mediterranean area (Saruhan & Akyol 2012), and of stressed trees in fruit orchards and forest plantations. Damage to timber is also caused by the galleries and associated staining of the wood (Chararas 1962). Comments. Nikolskayana mirabilis Bou&ccaron;ek, 1965 (Hymenoptera: Pteromalidae) was recorded by Abd-Rabou et al. (2005) and Ghahari & Huang (2012) as a parasitoid of X. saxesenii on Prunus sp. in Iran.Published as part of Beaver, Roger A., Ghahari, Hassan & Sanguansub, Sunisa, 2016, An annotated checklist of Platypodinae and Scolytinae (Coleoptera: Curculionidae) from Iran, pp. 401-441 in Zootaxa 4098 (3) on pages 422-423, DOI: 10.11646/zootaxa.4098.3.1, http://zenodo.org/record/25889

A new species of Lobesia Guenée, 1845 from Thailand (Lepidoptera: Tortricidae: Oletheutinae)

Charoensub, Thipmanee, Pinkaew, Nantasak, Sanguansub, Sunisa (2018): A new species of Lobesia Guenée, 1845 from Thailand (Lepidoptera: Tortricidae: Oletheutinae). Zootaxa 4434 (2): 381-384, DOI: https://doi.org/10.11646/zootaxa.4434.2.1

Scolytus amygdali Guerin-Meneville 1847

Scolytus amygdali Guérin-Méneville, 1847 Distribution in Iran. Alborz, Tehran (Magowski et al. 2007), Mazandaran (Samin et al. 2011), East Azarbaijan, Isfahan, Kermanshah, central provinces (Modarres Awal 1997). General distribution. Central and southern Europe, North Africa, Middle East, Pakistan. Biology. This species breeds in trees of the family Rosaceae (e.g. Amygdalus, Mespilus, Prunus). It has been recorded from Prunus amygdalus, P. armeniaca, Persica vulgaris (Rosaceae), and Ailanthus altissima (Simaroubaceae) in Iran (Modarres Awal 1997). Its biology has been described by Russo (1931) and Zeiri et al. (2011, 2015). It is a pest of rosaceous fruit trees in Israel (Mendel et al. 1997). Comments. Cerocephala cornigera Westwood, 1832 (Hymenoptera: Pteromalidae) is a parasitoid of S. amygdali in Iran (Abd-Rabou et al. 2005).Published as part of Beaver, Roger A., Ghahari, Hassan & Sanguansub, Sunisa, 2016, An annotated checklist of Platypodinae and Scolytinae (Coleoptera: Curculionidae) from Iran, pp. 401-441 in Zootaxa 4098 (3) on pages 417-418, DOI: 10.11646/zootaxa.4098.3.1, http://zenodo.org/record/25889