Abstract Euwallacea fornicatus (Eichhoff) is an important forest pest that has caused serious damage in America and Vietnam. In 2014, it attacked forests of Acer trialatum in the Yunnan province of ...China, creating concern in China’s Forestry Bureau. We used the CLIMEX model to predict and compare the potential distribution for E. fornicates in China under current (1981–2010) and projected climate conditions (2011–2040) using one scenario (RCP8.5) and one global climate model (GCM), CSIRO-Mk3-6-0. Under both current and future climate conditions, the model predicted E. fornicates to be mainly distributed in the south of China. Comparing distributions under both climate conditions showed that the area of potential distribution was projected to increase (mainly because of an increase in favourable habitat) and shift to the north. Our results help clarify the potential effect of climate change on the range of this forest pest and provide a reference and guide to facilitate its control in China.
The ambrosia beetle morphologically identified as Euwallacea fornicatus consists of several cryptic species that exhibit large differences in the DNA sequences of several nuclear and mitochondrial ...gene regions.
Based on these differences, we suggest that there are at least three different species each with distinct phylogeography.
Members of this cryptic species complex have invaded many areas outside their native range and cause substantial damage to both agriculture (avocado in particular) and other tree species.
Three of these cryptic species have invaded the USA: two species in California and a third species in both Florida and Hawaii.
Identification of their native range allows directed search for their natural enemies that may be used in biological control of these tree pests.
This study identifies fungi associated with Euwallacea fornicatus and determines whether these fungal species play the role of primary symbiont. E. fornicatus adults that emerged from the branches of ...infested trees in Okinawa main island, Japan, were collected and used to isolate fungi. Fusarium kuroshium and Penicillium citrinum were the most dominant fungal associates of females and males, respectively. F. kuroshium was much more frequently isolated from the head, including mycangia (fungus-carrying organs), of females than any other body parts. We inoculated healthy mango saplings with F. kuroshium or F. decemcellulare, both of which were symbionts of E. fornicatus females infesting mango trees. F. kuroshium decreased leaf stomatal conductance and rate of xylem sap-conduction area and increased length and area of xylem discoloration of the saplings, thereby weakening and killing some. These results suggest that F. kuroshium, a mycangial fungus of E. fornicatus, inhibits water flow in mango trees. This study is the first to report that F. kuroshium causes wilt disease in mango trees and that it is a primary fungal symbiont of E. fornicatus.
Ambrosia beetles of the
(Eichhoff, 1868) species complex are emerging tree pests, responsible for significant damage to orchards and ecosystems around the world. The species complex comprises seven ...described species, all of which are nearly identical. Given that the morphology-defined species boundaries have been ambiguous, historically, there has been much disagreement on species validity, which was compounded by the presumed loss of the type series of
. The species complex was recently reviewed using morphometrics to associate the type specimens to the clades delineated with molecular data under the assumption of the lost type series. We rediscovered a syntype of
, and reevaluated the species in the complex using morphometrics. We propose the following taxonomic changes to the species complex:
(=
(Schedl, 1951); =
(Schedl, 1942))
);
(Eggers, 1923) (=
.
(Schedl, 1951)
);
(Gomez and Hulcr, 2018) and
(Schedl, 1951)
. These taxonomic changes shift the species name associated with the widely used common names for two taxa, namely:
should be used for the "Polyphagous Shot Hole Borer", and
for the "Tea Shot Hole Borer clade a". A lectotype is designated for
in order to stabilize the use of the name.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The polyphagous shothole borer (
, PSHB), an ambrosia beetle, with its fungal symbiont,
, is responsible for Fusarium dieback (FD) in a wide range of woody hosts. In 2019, the first suspected case of
...was reported in macadamia in South Africa. The aims of this study were to confirm the
report and thereafter to assess the susceptibility of commercially planted macadamia cultivars to FD caused by
The identities of the beetle and associated fungal symbionts were confirmed by means of DNA sequence analysis of the 28S ribosomal large subunit gene for beetles and the internal transcribed spacer region for fungi. Isolates identified as
species were further characterized by phylogenetic analysis of the translation elongation factor 1α and the β-tubulin gene regions. Thereafter, Koch's postulates regarding
were fulfilled on a mature
tree planted at the experimental farm of the University of Pretoria. In order to determine susceptibility against FD, additional cultivar screening was conducted on nine commercially planted cultivars by means of pathogenicity trials using sterilized or inoculated toothpicks inserted into detached branches. Detached branch inoculations showed no significant lesion development six weeks post inoculation, except for cultivar 816. The restricted growth of
observed in macadamia tissues therefore suggests that macadamia may not be a suitable host for
and that the threat of FD in macadamia in the event of
infestation is less than for other
hosts. Future work on beetle attraction to macadamia is recommended for a more comprehensive understanding of the interaction between
and its fungal symbionts and macadamia.
Abstract The polyphagous shot hole borer (PSHB) beetle, Euwallacea fornicatus (Eichhoff) (Coleoptera: Curculionidae, Scolytinae), and its phytopathogenic fungal symbiont ( Fusarium euwallaceae ...Freeman et al.) threaten commercial and urban tree species worldwide. This pest–fungus complex has been newly discovered in the commercial deciduous fruit industry (Western Cape, South Africa), where its effect is still unknown. This study explored the impact of PSHB infestation on fruit quality and plant water‐use efficiency (WUE) – as indicated by carbon and nitrogen stable isotope ratios – of commercially cultivated Packham's Triumph pear trees within the first year of invasion, as well as changes in phenotypic plasticity (trait expression range). The impact of PSHB infestation is currently most evident in fruit quality traits, with a clear distinction between the control and most densely attacked tree categories. Fruit and leaf traits showed high variation and a significant change in phenotypic plasticity. Increased PSHB attack density was associated with smaller, duller‐toned, sweeter fruit at the time of harvest and data tended towards reduced plant WUE. Producers can expect significant variation in fruit quality and plant WUE even in hosts without branch dieback, visible plant stress or extensive beetle breeding, especially in orchards where infestations persist beyond the first year. These findings necessitate additional research to describe the long‐term impact, examine the threat to other deciduous fruit crops and cultivars and assess the need for adapted management or harvesting methods.
The polyphagous shot hole borer (PSHB), an ambrosia beetle (Coleoptera: Curculeonidae: Scolytinae) native to Asia, together with its fungal symbiont
Fusarium euwallaceae,
has emerged as an important ...invasive pest killing avocado and other trees in Israel and the United States. The PSHB is one of three cryptic species in the
Euwallacea fornicatus
species complex, the taxonomy of which remains to be resolved. The surge in the global spread of invasive forest pests such as the PSHB has led to the development of programmes utilising sentinel tree plantings to record new host-pest interactions. During routine surveys of tree health in botanical gardens of South Africa undertaken as part of a sentinel project, an ambrosia beetle/fungal associate was detected damaging
Platanus
x
acerifolia
(London Plane) in the KwaZulu-Natal National Botanical Gardens, Pietermaritzburg. Identification of the beetle by sequencing part of the mitochondrial cytochrome oxidase
c
subunit 1 (COI) gene confirmed its identity as PSHB, and specifically one of the invasive haplotypes of the beetle. The associated fungus
F. euwallaceae
was identified based on phylogenetic analysis of elongation factor (
EF 1-α
) sequences. Koch’s postulates have confirmed the pathogenicity of fungal isolates to
P.
x
acerifolia
. This is the first report of PSHB and its fungal symbiont causing Fusarium dieback in South Africa. This report also represents the first verified case of a damaging invasive forest pest detected in a sentinel planting project, highlighting the importance of such studies. Given the potential impact these species present to urban trees, native biodiversity and agriculture, both the PSHB and its fungal symbiont should be included in invasive species regulations in South Africa.
The tea shot-hole borer, Euwallacea fornicatus Eichhoff, is an ambrosia beetle endemic to Asia and a pest of commercial tea, Camellia sinensis (L.) Kuntze. Recently, a complex of species ...morphologically similar to E. fornicatus has been recognized, which includes new pests established in Israel and the USA, both in California and Florida. Collectively termed E. nr. fornicatus, these cryptic species carry symbiotic Fusarium spp. fungi, some of which cause dieback disease in susceptible hosts, which include avocado, Persea americana Miller. Due to the threat to this economically important crop, research was initiated to evaluate efficacy of kairomone-based lures for detection of the beetle in Florida (termed the Florida tea shot hole borer, FL-TSHB). A series of field tests were conducted in 2016 in commercial avocado groves known to have FL-TSHB at various population levels. All tests evaluated lures containing quercivorol (p-menth-2-en-1-ol) and α-copaene, presented separately and in combination; and one test evaluated effect of trap type on beetle captures. In addition, electroantennography (EAG) was used to quantify female olfactory responses to lure emissions. This study identified (-)-α-copaene as a new attractant for FL-TSHB, equivalent in efficacy to quercivorol (the standard lure for Euwallacea detection in the USA); however, the combination of lures captured significantly more FL-TSHB than either lure alone. This combination resulted in synergistic attraction at two field sites and additive attraction at a third site. Sticky panel traps captured more FL-TSHB than comparably-baited Lindgren funnel traps. Females engaged in host-seeking flight from 11:00 to 16:00 hr (EST), with peak numbers observed between 12:00 and 13:00 hr. EAG analyses confirmed olfactory chemoreception of both kairomones, with a higher response elicited with the combination of volatiles. Results indicate that detection of pest E. nr. fornicatus in Florida can be improved by using a two-component lure consisting of p-menth-2-en-1-ol and (-)-α-copaene.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Species belonging to the Euwallacea fornicatus Eichhoff (Coleoptera: Scolytinae) species complex have invaded the continental U.S. since at least 2003. Three species of this complex are known to have ...established, two in California (E. fornicatus; and Euwallacea kuroshio), and a third in Florida (Euwallacea perbrevis). Their native ranges are spread across southern and southeast Asia. In Taiwan, all three species occur in sympatry. They attack healthy trees of widely varied species and cause severe damage and death to the trees. The attractant quercivorol is commonly used to promote their detection by passive trapping. Recent studies in Florida have shown that trapping of E. perbrevis can be further improved by adding a synergist, α-copaene, alongside the quercivorol lure. Thus, we were interested in testing the effectiveness of α-copaene for trapping the other invasive members of the complex in California and in an area of Taiwan where all three species co-occur. We found that α-copaene marginally enhanced the trapping of E. perbrevis in Taiwan, but had no effect on the trapping of E. fornicatus or E. kuroshio in either California or Taiwan. We conclude that any enhancing effect of α-copaene is specific to E. perbrevis. This highlights the economic importance of accurate species identification in developing and implementing an efficient, and yet cost-effective, monitoring program for the management of E. fornicatus and E. kuroshio in California and elsewhere.
Studies addressing the economic impacts of invasive alien species are biased towards ex-post assessments of the costs and benefits of control options, but ex-ante assessments are also required to ...deal with potentially damaging invaders. The polyphagous shot hole borer Euwallacea fornicatus (Coleoptera: Curculionidae) is a recent and potentially damaging introduction to South Africa. We assessed the potential impact of this beetle by working across economic and biological disciplines and developing a simulation model that included dynamic mutualistic relations between the beetle and its symbiotic fungus. We modeled the potential growth in beetle populations and their effect on the net present cost of damage to natural forests, urban trees, commercial forestry, and the avocado industry over 10 yr. We modeled high, baseline, and low scenarios using discount rates of 8, 6, and 4%, and a plausible range of costs and mortality rates. Models predicted steady growth in the beetle and fungus populations, leading to average declines in tree populations of between 3.5 and 15.5% over 10 yr. The predicted net present cost was 18.45 billion international dollars (Int. $), or about 0.66% of the country's GDP for our baseline scenario ($2.7 billion to $164 billion for low and high scenarios). Most of the costs are for the removal of urban trees that die as a result of the beetle and its fungal symbiont, as has been found in other regions. We conclude that an ex-ante economic assessment system dynamics model can be useful for informing national strategies on invasive alien species management.
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