External microstructure of the ambrosia beetle Platypus koryoensis (Coleoptera: Curculionidae: Platypodinae)

Platypus koryoensis is a minute ambrosia beetle found in forests. It can cause significant economic damage to oak trees. Recently in Korea, it has been reported as a major pest of oak trees, because it causes sooty mold of oak by introducing the pathogenic fungus Raffaelea sp. In this paper, we demonstrate the fine structural aspects of the external body of the ambrosia beetle using field emission scanning electron microscopy, as a part of basic research into this pest so that strategies for its control might be developed. This beetle has a sensory system well developed to respond to both visual and chemical stimuli. Both sexes have a pair of faceted compound eyes and a pair of knobbed antennae, but simple eyes are absent. The mouthparts on its distinct snouts are effective devices for penetration and for boring holes. The mouthparts consist of the labrum, a pair of mandibles, a pair of maxillae and the labium. Both the maxillary and the labial palpi have the function of directing the food to the mouth and holding it while the mandibles chew the food. The distal ends of these palpi are flattened and have shovel‐like setae. The thorax has a particularly hard exoskeleton and hard elytra, including powerful muscles that operate both the wings and the legs. The legs are multi‐segmented and have a strong femur and tibia, including one pair of claws on the end of each tarsal segment. Characteristically, both male and female beetles have mycangial cavities for storing spores and other microorganisms, but only females have three pairs of large depressions on their dorsal thorax.     

The role of beetle and host volatiles in host colonization in the European oak bark beetle, Scolytus intricatus (Ratzeburg) (Col., Scolytidae)

Abstract:  To understand the role of chemical signals involved in Scolytus intricatus (Ratzeburg) (Col., Scolytidae) host colonization, the attractiveness of intact and beetle colonized host material was investigated in the field and in the laboratory. In the field, chemical signals operating at long range were investigated by means of sticky traps. In the laboratory, close-range chemical interactions were investigated with an arena olfactometer. Field experiments showed no differences in the attractiveness between infested and non-infested host material. On the contrary, laboratory experiments revealed higher attractiveness of infested host and beetle-produced frass in comparison with intact host and mechanically produced sawdust respectively. Laboratory data also disclosed the attractiveness of beetle extracts of both sexes. Our data show that: (1) host kairomones play an important role during host colonization, and that (2) S. intricatus does not use a sex-specific secondary attractant system. Differences between results of field and laboratory trials are discussed.     

Pine wilt disease in Yunnan,China: Evidence of non-local pine sawyer Monochamus alternatus (Coleoptera: Cerambycidae) populations revealed by mitochondrial DNA

Abstract Monochamus alternatus (Hope) specimens were collected from nine geographical populations in China, where the pinewood nematode Bursaphelenchus xylophilus (Steiner et Buhrer) was present. There were seven populations in southwestern China in Yunnan Province (Ruili, Wanding, Lianghe, Pu’er, Huaning, Stone Forest and Yongsheng), one in central China in Hubei Province (Wuhan), and one in eastern China in Zhejiang Province (Hangzhou). Twenty-two polymorphic sites were recognized and 18 haplotypes were established by analyzing a 565 bp gene fragment of mitochondrial cytochrome oxidase subunit II (CO II). Kimura two-parameter distances demonstrated that M. alternatus populations in Ruili, Wanding and Lianghe (in southwestern Yunnan) differed from the other four Yunnan populations but were similar to the Zhejiang population. No close relationship was found between the M. alternatus populations in Yunnan and Hubei. Phylogenetic reconstruction established a neighbor-joining (NJ) tree, which divided haplotypes of southwestern Yunnan and the rest of Yunnan into different clades with considerable bootstrapping values. Analysis of molecular variance and spatial analysis of molecular variance also suggested significant genetic differentiation between M. alternatus populations in southwestern Yunnan and the rest of Yunnan. Our research suggests that non-local populations of M. alternates, possibly from eastern China, have become established in southwestern Yunnan.     

Synthesis of tryptophol and O-acetyltryptophol from tryptophan by Ceratocystis fagacearum

Tryptophol (TOL) and O-acetyltryptophol (OAcTOL) were identified as tryptophan metabolites of C. fagacearum; OAcTOL was the only metabo     

不同波长黑光灯对椰子木蛾的诱集效果

为评估不同波长黑光灯对椰子木蛾的诱集效果,在海南省万宁市兴隆镇设置试验点,利用8种不同波长的黑光灯进行诱集试验。结果显示:椰子木蛾对365 nm和368 nm的波长敏感,诱虫总量显著多于其它波长的黑光灯;365 nm黑光灯诱捕椰子木蛾雄虫最多,368 nm黑光灯诱捕椰子木蛾雌虫最多,均显著大于其它黑光灯诱集到的雌雄虫数量。23∶00-2∶00为最适宜诱捕椰子木蛾时段。为利用黑光灯监测椰子木蛾提供了基础依据。     

植物挥发物对柑橘木虱趋避机制的研究进展

柑橘木虱Diaphorina citri为半翅目Hemiptera木虱科Psyllidae,主要危害芸香科植物,是柑橘黄龙病（Citrus Huanglongbing, HLB）的主要昆虫传播媒介。HLB在柑橘产业中破坏性极大,柑橘木虱的及时防控可有效降低HLB传播风险。目前,柑橘木虱对化学药剂已产生一定的抗药性,而柑橘木虱在植物挥发物作用下的行为反应可为其绿色防控提供一定的参考。本文就往年研究中不同植物挥发物对柑橘木虱的引诱、驱避作用以及柑橘植株、HLB、柑橘木虱三者间通过植株挥发物产生的互作进行论述,旨在为柑橘木虱的科学高效绿色防控提供参考。     

甘薯兼抗薯瘟病和蔓割病种质筛选鉴定

用甘薯瘟2个致病型菌株对557份甘薯品种(系)分菌系做盆苗和田间接种鉴定,并用蔓割病菌接种鉴定.结果表明,筛选出兼抗薯瘟病2个菌系的品种(系)31份,兼抗甘薯瘟和蔓割病的品种(系)有16份,其中泉薯860、泉薯854、金山93、榕选416、金山908、广薯88-70和泉薯853等7份与我省主栽抗病品种湘薯75-55(CK)相比,具有类似的双抗性能力,而其抗瘟能力更强.福薯87、林泗2号、金山57和湛93-16等4份对照品种只抗单个病害或兼抗单个菌系.     

Geographical variation in the spatial synchrony of a forest-defoliating insect: isolation of environmental and spatial drivers

Despite the pervasiveness of spatial synchrony of population fluctuations in virtually every taxon, it remains difficult to disentangle its underlying mechanisms, such as environmental perturbations and dispersal. We used multiple regression of distance matrices (MRMs) to statistically partition the importance of several factors potentially synchronizing the dynamics of the gypsy moth, an invasive species in North America, exhibiting outbreaks that are partially synchronized over long distances (approx. 900 km). The factors considered in the MRM were synchrony in weather conditions, spatial proximity and forest-type similarity. We found that the most likely driver of outbreak synchrony is synchronous precipitation. Proximity played no apparent role in influencing outbreak synchrony after accounting for precipitation, suggesting dispersal does not drive outbreak synchrony. Because a previous modelling study indicated weather might indirectly synchronize outbreaks through synchronization of oak masting and generalist predators that feed upon acorns, we also examined the influence of weather and proximity on synchrony of acorn production. As we found for outbreak synchrony, synchrony in oak masting increased with synchrony in precipitation, though it also increased with proximity. We conclude that precipitation could synchronize gypsy moth populations directly, as in a Moran effect, or indirectly, through effects on oak masting, generalist predators or diseases.     

Using the nematophagous fungus Esteya vermicola to control the disastrous pine wilt disease

The present study evaluated the protective effects of the nematophagous fungus Esteya vermicola on the large pine trees of Mt. Wora, Jinju, South Korea for six years. When pine trees were treated with E. vermicola 110 days before artificial normal pinewood nematode (PWN) infection, 30–50% of the trees survived for six years. When pine trees were treated with E. vermicola one week after artificial normal PWN infection, 40% of the trees were saved. In contrast, all of the control trees were killed by pine wilt disease in the first year. Although it has been more than six years since the beginning of this experiment, the existence of E. vermicola inside the treated pine trees was successfully detected using a PCR method with two pairs of specific primers for E. vermicola. These results suggest that E. vermicola possesses great potential as a biocontrol agent to combat the disastrous pine wilt disease. This is the first report of using nematophagous fungi to control pine wilt disease in the field for a duration of over five years.     

Changes in Microfungal Communities in Roots of Quercus robur Stumps and their Possible Effect on Colonization by Armillaria

Sixteen fungal communities were sampled by isolating from 0.5–1 cm diameter roots of living trees and stumps of common oak (Quercus robur). The density of fungi was 1.5–2 times greater in roots from stumps than from living trees. The diversity of fungi was similar in living tree roots and stumps. Some of the fungal species with increased densities in stump roots (e.g. Aspergillus kanagawaensis, Chrysosporium pannorum, Cylindrocarpon destructans, C. didymum, Hormiactis candida, Monodictys lepraria, Mycelium radicis atrovirens, Penicillium daleae, P. janczewskii, and Trichocladium opacum) usually stimulated the growth of rhizomorphs of either Armillaria ostoyae or A. gallica in oak‐wood segments in vitro. Eight of 27 isolates that were studied stimulated the rhizomorph growth in both Armillaria spp. It is presumed that the increase in density of `stimulants' may predispose oak stumps to infection by A. ostoyae and A. gallica.     

Cloning and characterization of the platypus mitochondrial genome

The vertebrate mitochondrial genome is highly conserved in size and gene content. Among the chordates there appears to be one basic gene arrangement, but rearrangements in the mitochondrial gene order of the avian lineages have indicated that the mitochondrial genome may be more variable than once thought. Different gene orders in marsupials and eutherian mammals leave the ancestral mammalian order in some doubt. We have investigated the mitochondrial gene order in the platypus (Ornithorhynchus anatinus), a representative of the third major group of mammals, to determine which mitochondrial gene arrangement is ancestral in mammals. We have found that the platypus mtDNA conforms to the basic chordate gene arrangement, common to fish, amphibians, and eutherian mammals, indicating that this arrangement was the original mammalian arrangement, and that the unusual rearrangements observed in the avians and marsupials are probably lineage-specific. Correspondence to: N.J. Gemmell