Der Asiatische Laubholzbockkäfer Anoplophora glabripennis (Motschulsky, 1853) (Cerambycidae, Coleoptera) in Bayern

In 2004 in the village Neukirchen/Inn the introduction of the invasive longicorn beetle Anoplophora glabripennis to Bavaria was detected. A maple tree near to a truckage company dealing with granite stones from Asia showed less foliation. Two larvae were found in a branch and to confirm the supposition the larvae were sent to the Federal Forest Research Centre in Vienna for a DNA-analysis. After the unambiguous identification of A. glabripennis a safety zone was established around the centre of the infestation. Monitorings for damaged deciduous trees which were assumed to be host plants were carried out. The citizens of the affected area were informed about the invasive species and a general ordinance was published committing the inhabitants for assistance in eradication measures. 16 trees have been cut down, chaffed and burned during the season 2004: five maples, four willows, four white chestnuts, two birches and one poplar. In 2005 only one maple tree and one whitebeam followed but new egg deposition sites could be found in the middle of October. All trees stood within a radius of 500 metres of the centre of infestation. In 2004 infested branches were carried to Freising and kept under conditions of quarantine. From this wood 47 adults emerged in 2004 and one specimen emerged in 2005. The beetles lived about three to four weeks. The antennae length, the body length and the body width were measured. The situation in Neukirchen/Inn is still tense and the monitoring has to be continued.     

Gummosis and wilt of Acacia mearnsii in South Africa caused by Ceratocystis fimbriata

A dieback of Acacia mearnsii trees was observed in the Mkomasi river valley, Natal Province, South Africa. A fungus, tentatively identified as Ceratocystis fimbriata , was consistently isolated from affected twigs and branches. Reinoculation of the pathogen resulted in the development of typical wilt and dieback of A. mearnsii seedlings and saplings and in a dieback of Protea cynaroides plants. This is the first report of this disease in South Africa.     

First record of ambrosia beetle (Euplatypus parallelus) infestation on cashew from Goa, India

The occurrence of ambrosia beetle Euplatypus parallelus (Fabricius) (Coleoptera: Curculioninae: Platypodinae) infestation on cashew (Anacardium occidentale L.) is reported for the first time from Goa, India. Most of the infested trees were either previously attacked by cashew stem and root borer Plocaederus ferrugineus (Coleoptera: Cerambycidae) or were pruned trees. The visible symptoms of attack include appearance of numerous round bore holes on the tree trunk and branches, and extrusion of fibrous dust frass on the tree trunk and in loose piles at the base of the tree. Large numbers of larvae, pupae and adults were observed in the galleries of the affected trees. Adult beetles measure 4.0–4.3 mm in length and are brown in color, having long and slender bodies with yellow hairs. They have a characteristic feature of absence of pores on the pronotum. Male and female insects were identified based on the elytral declivity.     

Reassessment of rust fungi on weeping willows in the Americas and description of Melampsora ferrinii sp. nov.

Rust fungi in the genus Melampsora usually cause disease on hosts in the Salicaceae. Identification of Melampsora species is often complicated due to few differences in spore morphology and little publicly available comparative sequence data. Weeping willow trees (primarily Salix babylonica and its hybrids) have been reported to be infected by 11 Melampsora species; however, most of these records are based on morphological characterization. New collections of rust fungi on weeping willows from the central USA were analysed using a combination of morphology, ITS and LSU rDNA sequencing, and host data to determine that they represent an undescribed rust fungus, Melampsora ferrinii sp. nov. Additional studies of herbarium material revealed that M. ferrinii has occasionally been collected but identified as M. epitea. In addition to North America, M. ferrinii is also present in South America and has been infecting weeping willows there since at least the 1990s.     

Effect of cultural practices on the development of arabica coffee berry disease,caused by <Emphasis Type="Italic">Colletotrichum kahawae</Emphasis>

In the high altitude regions of Africa, coffee berry disease (CBD), caused by Colletotrichum kahawae, is the main constraint for arabica coffee (Coffea arabica) production. However, certain agricultural practices can reduce losses caused by the disease and thereby promote optimum production. On small family farms in Cameroon, mixed cropping with fruit trees, intercropping with food crops and maintenance pruning of coffee trees are very widespread agricultural practices that can affect CBD epidemics. Consequently, an epidemiological study was conducted to assess how cultural practices affected the disease in an arabica coffee smallholding in Cameroon. The disease was monitored on a weekly basis over four successive years (2002–2005) on coffee trees in diverse cultural situations. Cultural practices likely to reduce losses due to CBD were identified. The infection rate was significantly lower on coffee trees grown intensively than on coffee trees grown in the traditional manner. Coffee trees located under the shade of fruit trees were significantly less attacked than those located in full sunlight. In addition, berries on the leafless parts of branches, near the main trunk of the coffee tree, were less infected than those on leafy sections. These results show that maintenance pruning, removal of mummified berries, and mixed cropping with shade plants are cultural practices which create environmental conditions that limit CBD development.     

Canker and wood rot pathogens present in young lemon orchards in south-west Arizona

Canker and wood rots are economically important preharvest diseases of lemons in south-western Arizona, where commercial lemon production is concentrated. However, the aetiology and epidemiology of canker and wood rots are not well understood. This study comprised a large survey of canker and wood rot incidence and severity in Arizona and the characterization of fungal species associated with the disease. A total of 5431 trees with ages ranging from 1 to 20 years old in 10 lemon orchards were surveyed from 2018 to 2020. Our survey results revealed that canker and wood rot occurred in all 10 lemon orchards studied. Canker and brown rots of twigs, branches, and trunks were the most prevalent symptoms of affected trees ranging from 1 to 20 years old. In contrast, canker and white rots of twigs and branches were observed mostly on 1- to 5-year-old trees. Disease incidence for both diseases was less than 2% on 1- and 2-year-old trees. Brown rot increased significantly in older trees, ranging from 62.9% to 100%. Fungi were isolated from canker and wood rot samples and identified based on morphological characters and DNA sequences. Fomitopsis meliae and Hypoxylon macrocarpum were the primary canker and wood rot pathogens isolated from the surveyed orchards, at frequencies of 89% and 11%, respectively. In pathogenicity tests, both fungi were capable of causing canker and wood rots on lemon cv. Lisbon branches and the necrotic length caused by F. meliae was twofold greater than that caused by H. macrocarpum.     

Yield loss caused by huanglongbing in different sweet orange cultivars in São Paulo,Brazil

Citrus huanglongbing (HLB) reduces an affected orchard’s economic life. This work aimed to characterize yield loss due to HLB for different sweet orange cultivars and determine the relationship between disease severity and yield. Disease severity and yield were assessed on 949 individual trees distributed in 11 different blocks from sweet orange cultivars Hamlin, Westin, Pera and Valencia. In each block, plants showing a range of HLB severity levels and asymptomatic plants were selected. Total yield (weight of harvested fruit), mean weight of asymptomatic and symptomatic fruit, relative yield (symptomatic tree yield/mean yield of asymptomatic trees from the same block) and relative number of fruits (fruit number from symptomatic tree/mean number of fruits from asymptomatic trees from the same block) were determined. The weight of symptomatic fruit was lower than the weight of asymptomatic fruit, but the weights of asymptomatic and symptomatic fruit were not correlated with disease severity, indicating that the effects of HLB were restricted to symptomatic branches. The relationship of the relative yield with HLB severity can be satisfactorily described by a negative exponential model. The rates of yield decrease as a function of disease severity were similar for all assessed cultivars. A relative yield (up to 19%) was observed even for trees where disease severity was 100%. The strong linear relationship between relative number of fruits per tree and the relative yield per tree suggested that the yield reduction was due primarily to early fruit drop or lack of fruit set on affected branches.     

Pollinia pollini (Costa, 1857) (Hemiptera,Asterolecaniidae) infesting olive trees: a first record in Tunisia

During January 2019, mealybugs were observed on branches of olive trees (Olea europaea, L.) for the first time at Nebeur and Charket Saboune (Governorate-Kef, Tunisia). Samples were collected and brought to the laboratory for identification. The mealybug species was identified based on its morphological characteristics as Pollinia pollini (Costa, 1857) (Hemiptera, Asterolecanidae). This is the first report of this species in Tunisia.     

Effects of huanglongbing on fruit quality of sweet orange cultivars in Brazil

Citrus huanglongbing (HLB), associated with Candidatus Liberibacter asiaticus and Ca. L. americanus and transmitted by the Asian psyllid Diaphorina citri, is the most serious disease of citrus worldwide because of crop devastation and difficulty to control. Since 2004, approximately 3 million trees were eliminated in attempts to limit its spread in Brazil. Where HLB becomes endemic, the disease progression in the orchard and the increasing symptom severity throughout the tree canopy can be relatively fast, greatly reducing the economic life of affected orchards because of tree decline and yield reduction. Although the majority of the fruit from symptomatic branches drop before harvest, a significant amount of affected fruit remain attached, are available for harvest, and can affect juice quality. To quantify and compare the effects of HLB on fruit quality of the most important sweet orange cultivars grown in São Paulo State, 4–6 year-old sweet orange trees from 26 blocks (two of ‘Valencia Americana’, eight of ‘Hamlin’, four of ‘Westin’, seven of ‘Pera’, and five of ‘Valencia’) were selected prior to harvest. In each block, 14–21 HLB-symptomatic trees were chosen. In each tree, the quality of 20 fruit normal in appearance from asymptomatic branches and 20 symptomatic fruit from symptomatic branches were assessed. In general, compared to normal fruit, the symptomatic fruit were small, light, more acidic, and had lower juice percentage, Brix, total soluble solids per box, total soluble solids per fruit, and Brix/acidity ratio. These effects of fruit quality were less pronounced on early and mid season sweet orange cultivars than on late season cv. Valencia.     

Anoplophora glabripennis infestation (col.: cerambycidae) in Italy

In June 2007, the Asian longhorned beetle Anoplophora glabripennis (Motschulsky) was found at Corbetta, in Lombardy, 23 km west of Milan, Italy. The invasive exotic pest was observed in four host trees, one sycamore maple Acer pseudoplatanus L. and three silver birches Betula pendula Rothmahler. During summer 2007, 20 living and 107 dead A. glabripennis beetles were collected on or around the infested trees. The dissection of the infested material showed that 287 beetles emerged from the trees during previous years and 158 living larvae of varied ages were still developing in April, 2008. Fortunately, it appears that predation by birds on early stage larvae developing under the bark, played a major role in limiting the developing pest population. A. glabripennis is native to China and Korea where it is considered as a serious pest of many deciduous trees including maples, poplars, and willows. During the last decade, it was accidentally introduced into the USA, Canada, Austria, Germany and France in wood packaging material of goods imported from China. The current discovery in Italy is the first record of the Asian pest in this country.     

桑枝枯菌核病的发病规律研究

桑枝枯菌核病是近年来在江苏发现的一种新的桑树病害,该病主要危害春季一年生枝条上已萌发的桑芽及新梢,常造成桑芽枯萎和病芽上方的枝条干枯死亡。经鉴定,病原菌为子囊菌亚门,核盘菌属真菌[Sclerotina sclerotiorum(Libert)de Bary]。病原菌在桑芽或新梢的寄生部位能形成黑色菌核。菌核随采叶、伐条等田间操作而掉入土中越冬越夏,成为翌年的初侵染源。病害发生与桑树品种关系密切,育2号为易感病品种。桑园间作是造成病害交互感染的重要原因。     

Monilia Disease

Monilia is a well-known parasite of stone fruit trees. It normally attacks flowers, buds and fruits, producing the diseases known as “brown rot” and “mummified fruit”. In certain circumstances, however, Monilia can also attack older branches, producing chronic or acute symptoms. In the first case, the affected branches wilt after a certain time, while in the second, this wilting is extremely fast; these are the classical symptoms of dieback. The parasite penetrates through wounds in the branches and first damages the phloem. If it reaches the cambium and girdles it, the branch dies from the area of attack to the tip. If there is no, or only moderate damage to the cambium, the tree can recover, or the disease may become chronic. The speed of disease development depends, primarily, on environmental conditions.     

The role of <Emphasis Type="Italic">Euwallacea</Emphasis> nr. <Emphasis Type="Italic">fornicatus</Emphasis> (Coleoptera: Scolytinae) in the wilt syndrome of avocado trees in Israel

The polyphagous shot hole borer (PSHB), Euwallacea nr. fornicatus (Coleoptera; Scolytinae) has become a serious threat to the avocado industry and several shade tree species in Israel. Branch wilting and tree mortality is the outcome of PSHB galleries. Understanding the relationship between avocado trees and the PSHB is required for considering management strategies. In Israel, 52 tree species from 26 botanical families were attacked by the PSHB, but only 12 species were suitable for beetle reproduction. All examined avocado cultivars were attacked, but ‘Hass’ most severely. Large and medium diameter avocado branches were more resistant to PSHB, compared to thin branches. Effectively, gallery density increased as branch diameter decreased. Concomitantly, in large and medium diameter branches, extensive sugar exudation occurred and beetle attack rarely progressed to the formation of natal galleries, whereas minimal sugar exudation was observed in thin branches. This was more evident in those that were weakened by repeated attacks followed by successful beetle colonization. PSHB prefers and successfully colonized branches that had been previously attacked by its conspecifics, and reproduction was much higher in these branches, as opposed to initial attacks. Lesion frequencies increased from late spring (April) until late summer (September). Avocado branches at the early stages of beetle colonization may be identified by sugar exudation at the base of the thin branches. The main approach for reducing damage caused by the PSHB is sanitation, achieved by the removal of colonized branches and intact infested pruned slash.     

A serious canker disease caused by Immersiporthe knoxdaviesiana gen. et sp. nov. (Cryphonectriaceae) on native Rapanea melanophloeos in South Africa

Recent disease surveys in the Western Cape province of South Africa have revealed a previously unknown and serious stem canker disease on native Rapanea melanophloeos (Myrsinaceae, Ericales) trees. Cankers commonly result in the death of branches or entire stems. Fruiting structures typical of fungi in the Cryphonectriaceae were observed on the surfaces of cankers. In this study, the fungus was identified and its pathogenicity to R. melanophloeos was tested. Multigene phylogenetic analyses based on DNA sequences of the partial LSU gene, ITS region of the nuclear ribosomal DNA gene and two regions of the β‐tubulin (BT) gene, showed that the fungus represents a formerly undescribed genus and species in the Cryphonectriaceae. The fungus was also morphologically distinct from other genera in this family. Inoculation trials showed that the fungus described here as Immersiporthe knoxdaviesiana gen. et sp. nov. is an aggressive pathogen of R. melanophloeos trees.     

北京市区泡桐丛枝病发生特点研究

对北京市区泡桐丛枝病调查结果表明，２ａ以上树龄的泡桐树平均病株率为１９．２３％，病情指数达１０．２７，病害随树龄增大而加重。小片纯林受害最重，行道树次之，散植株最轻。周围高建筑物和稠密的植被可有效地阻止病害通过介体传播。在城市特殊生态环境中，种苗带毒是病害发生和发展的关键因子。在植株休眠期，病树丛枝的筛管中类菌原体（ＭＬＯ）浓度降低，但仍有一定数量的ＭＬＯ存活     

A grower-friendly method to transfer predacious mites to commercial orchards

The establishment of predacious mites in commercial orchards may be accelerated by the transfer of pruned wood in winter and summer from donor orchards to release orchards. Following winter pruning, 3-year-old and older wood is collected and transported as soon as possible in bundles to a release orchard for distribution. If the release orchard is composed of dwarf trees, then one or two bundles of 5 kg each are placed vertically at the base of the trunk of every tree in the block (0.5 to 1 ha); if the trees are of standard size, then four or five bundles used. Following summer pruning, annual shoots and suckers are distributed immediately in a release orchard composed of dwarf trees by placing 12–15 branches on the foliage of fruit-bearing branches; if the release orchard is composed of standard trees, then 50 branches are used. The pruned wood should have 20–25 leaves and not less than one predator per leaf. The release orchard should have a light infestation (two or three mites per leaf) of pest tetranychids. These phytophagous mites would serve as food and help establish the predators. The release orchard grower should develop a pest management program based on the same groups of pesticides used in the donor orchard. http://www.phytoparasitica.org posting Aug. 31, 2005.     

新疆部分地区苹果、核桃和杨树腐烂病的病原鉴定

 树木腐烂病在新疆主林果种植区均有不同程度的发生,近年呈加重趋势。本研究在调查了新疆阿克苏、和田、伊犁、喀什和库尔勒等地区苹果树、核桃树和杨树3种林果腐烂病田间发病情况的基础上,重点对14个样本点的样品进行病原物的分离与鉴定。结果表明,各样本点3种林果均有不同程度的腐烂病发生,分离鉴定结果为引起苹果树腐烂病病原菌主要为Valsa mali var. mali(分离频率为64.5%),其次是V. mali var. pyri(25.8%)、V. malicola(3.2%)和V. nivea(6.5%);引起核桃树和杨树腐烂病病原菌为V. sordida(分离频率为83.3%和96%)和V. nivea(分离频率为16.7%和4%)。离体枝条及苹果果实上的致病性测定结果表明,3种林果上分离得到的病原菌均能感染原寄主。引起新疆部分地区苹果树腐烂病的主要病原菌是Valsa mali var. mali,核桃树和杨树腐烂病的主要病原菌是V. sordida。同时,基于实际生产中存在感病枯死杨树枝干作为苹果园、核桃园树体支撑木的现象,推测3种林果腐烂病菌间可能存在交叉感染的潜在风险。     

Evaluation of resistance to Phytophthora cinnamomi in seed-grown trees and clonal lines of Eucalyptus marginata inoculated in lateral branches and roots

Seed-grown trees and six clonal lines of 3·5–4·5-year-old Eucalyptus marginata (jarrah) growing in a rehabilitated bauxite mine site in the jarrah forest were underbark-inoculated on lateral branches (1995) or simultaneously on lateral branches and lateral roots (1996) with isolates of Phytophthora cinnamomi in late autumn. Individual seedlings from which the clonal lines were derived had previously been assessed as either resistant (RR) or susceptible (SS) to P. cinnamomi . At harvest, the acropetal lesion and colonization lengths were measured. Overall, the length of colonization in roots and branches was more consistent as a measure of resistance than lesion length, because colonization length recorded the recovery of P. cinnamomi from macroscopically symptomless tissue ahead of the lesion which, on some occasions, was up to 6 cm. In both trials, one RR clonal line was able to contain the P. cinnamomi isolates consistently, as determined by small lesion and colonization lengths in branches and roots. In contrast, the remaining two RR clonal lines used in both trials were no different from the SS line in their ability to contain lesions or colonization. These latter two RR lines may therefore not be suitable for use in rehabilitation of P. cinnamomi -infested areas. Differences in lesion and colonization lengths among P. cinnamomi isolates occurred only in the 1995 trial. Colonization and lesion lengths in branches were up to eight times greater in 1996 than in 1995, but the relative rankings of clonal lines were consistent between trials. Although colonization was always greater in branches than roots, the relative rankings of the lines were similar between branch and root inoculations. Branch inoculations are a valid option for testing the resistance and susceptibility of young jarrah trees to P. cinnamomi .     

Occurrence of Erwinia amylovora on pear in Albania

Pear trees were observed in the province of Durres (AL) with typical symptoms of fireblight on the shoots, fruit and branches. Bacteriological analysis of samples of diseased material confirmed the presence of Erwinia amylovora. The isolates were identified on the basis of phenotypical and pathogenic characteristics. The total protein electrophoretic profiles of the Albanian isolates were indistinguishable from those of the strain found in the Po valley (IT).     

西藏林芝杏树朝鲜毛球蚧生物学特性及防控对策

朝鲜毛球蚧已成为我国西藏林芝地区果树主要害虫之一,威胁到当地果树正常生长和产量。当前对其在西藏地区果树上的形态特征、生物学特性以及发生规律的报道很少。本研究通过野外定期取样调查对杏树朝鲜毛球蚧的形态特性、生活史和发生动态进行了研究,并对其防控措施进行简述。结果表明,林芝地区朝鲜毛球蚧1年发生1代,以2龄若虫固着在被害枝条上越冬,翌年4月出蛰,成虫4月中下旬发生,当年若虫孵化期在6月中-7月下旬,主要以固定若虫和雌成虫为害。雌虫产卵期可持续8~12d,卵量平均为985粒/雌。虫体膨大期(4月上旬)和若虫孵化游走盛期(6月上旬)是林芝地区杏树朝鲜毛球蚧防治的适宜期。可用40%氧化乐果或石硫合剂原液涂抹法进行防治。