Summary
Decline of pear trees in the region of Čačak (Serbia) is becoming a significant problem and a limiting factor in the production of this fruit species. This phenomenon may be due to the ...damages caused by xilophagous insects, representatives of the family Scolytidae. Economically the most important species of this family is a pear blight beetle (Xyleborus dispar), which causes symptoms of decline and/or wilting of pear trees. Such damages have not been documented so far in the region of Čačak. The aim of this study was to determine the cause of sudden appearance of pear trees decline in an orchard in this region (locality of Miokovci). The orchard has 180 trees (Stark Delicious, Santa Maria and Williams) in the sixth year of vegetation. Inspections were carried out every 30 days (20 April - 21 August 2016). Visual inspection identified X. dispar activity on 165 trees (about 92% of the trees in the orchard). Holes were registered on the trees up to a height of 160 cm and in all primary branches. The average number of entry openings on a random sample of 20 trees was 27 for the height from the soil surface to the first branch (70 cm), while it was 61 for the height up to 160 cm. The recommended treatment is eradication of pests with mandatory incineration (burning) of the collected plant material by the end of February of the following growing season. This is the first report of X. dispar as pear pests in the vicinity of Čačak.
Potential Dutch elm disease vector beetle species were caught with pheromone bottle traps and handpicked in 2019: in total, seven species and 261 specimens were collected. The most common was
, but ...by percent, the incidence of
was highest in
, followed by
and
. We analysed the beetles
DNA using PacBio sequencing to determine vector beetles of
.
was found on six out of seven analysed beetle species:
, S
,
,
,
and
. The last two beetles were detected as vectors for
for the first time. Previous knowledge on the spread of beetles is discussed.
Düzce ili Esentepe, Çamlıpınar ve Hamamüstü köylerindeki fındık üretim alanlarındaki yazıcıböcek türleri (Col: Scolytidae) 2013 ve 2014 yılında yapılan bu çalışma ile tespit edilmiştir. Çalışma ...sonucunda, Xyleborus dispar Fabricius, Xyleborus saxeseni Ratzeburg, Xyleborus germanus Blanford ve Lymantor coryli Perris olmak üzere 4 tür saptanmıştır. Bu zararlılardan L. coryli’ ye sadece Çamlıpınar köyünde çok az oranda rastlanılmıştır. 2014 yılında Esentepe köyünde diğer türlere oranla X. dispar erginlerinin sayısı fazla iken Çamlıpınar ve Hamamüstü köylerinde Xyleborus saxeseni erginlerinin sayısı daha fazla bulunmuştur. Çamlıpınar köyündeki yazıcıböceklerin 2013 yılındaki ilk ergin çıkışları 13-18 Mart arasında belirlenmiştir. 2014 yılında X. dispar ve X. saxeseni’nin ilkbahardaki ilk ergin çıkışları Mart ayının ikinci haftasından itibaren (13-19 Mart) saptanmışken, X. germanus’un ilkbahardaki ilk ergin çıkışları Mart ayının son haftasında (21-27 Mart) olmuştur. X. dispar’ ın yaz dönemindeki çıkışı Temmuz ayının ilk haftasından itibaren başlamıştır. 2013 ve 2014 yılında bahçelerde yazıcıböcek zarar oranı tespit edilmiştir.
The entomopathogenic bacterium Bacillus thuringiensis is the most widely used biopesticide. In this study, to find and identify the more toxic B. thuringiensis strains against coleopteran pests, we ...isolated a B. thuringiensis strain (Xd3) from European shot-hole borer, Xyleborus dispar (Coleoptera: Scolytidae), a higly damaging pest of hazelnut. Based on various morphological, physiological, biochemical, and molecular characteristics, the bacterial isolate was identified as B. thuringiensis subsp. tenebrionis (morrisoni) serovar H8a8b. This isolate was compared with the reference strains by scanning electron microscopy, SDS-PAGE analysis, cry gene content, and insecticidal activity. Isolate Xd3 forms a flat-square inclusion containing a protein component of c. 70 kDa. PCR analysis showed that the Xd3 has a cry gene, cry3. Toxicity tests were performed against coleopteran species. One hundred percent mortality was observed against larvae of Agelastica alni (Coleoptera: Chrysomelidae). The others were 90% for Amphimallon solstitiale (Coleoptera: Scarabaeidae), and Melolontha melolontha (Coleoptera: Scarabaeidae). Our results indicate that B. thuringiensis subsp. tenebrionis (Xd3) may be valuable as biological control agent for coleopteran insects.
BACKGROUND: In order to find and identify more toxic insecticidal Bacillus thuringiensis Berliner (Bt) strains, a survey was carried out of B. thuringiensis isolate pests belonging to Coleoptera, ...Lepidoptera and Diptera and from soils in hazelnut fields. Of 16 isolates having Bacillus cereus-B. thuringiensis morphology, eight were classified as B. thuringiensis because of the production of parasporal δ-endotoxin crystals.RESULTS: In this study, eight isolates of B. thuringiensis from hazelnut pests (isolates Bn1, Mm2, Mnd and Xd3) and from hazelnut soils (isolates 6, 27, 40 and 46) have been characterised in detail. These isolates were compared with reference strains by electron microscopy, SDS-PAGE analysis, cry gene content, serological test and insecticidal activity.CONCLUSION: Results indicate that Bn1 and MnD are B. thuringiensis subsp. kurstaki, and Mm2 and Xd3 are B. thuringiensis subsp. tenebrionis. In addition, isolate 6 is B. thuringiensis subsp. israelensis, isolates 27 and 46 are B. thuringiensis subsp. kumamotoensis and isolate 40 is B. thuringiensis subsp. indiana. The four B. thuringiensis isolates from hazelnut pests may be valuable as biological control agents against coleopteran and lepidopteran insects.
In this study, we have isolated and identified 5 bacterial isolates from European shot-hole borer,
Xyleborus dispar
(Coleoptera: Scolytidae), an important pest of hazelnut. After various ...morphological, physiological, biochemical and molecular characteristics were determined in detail, bacterial isolates were identified as
Pseudomonas fluorescens
(Xd1),
Bacillus megaterium
(Xd2),
Bacillus thuringiensis
(Xd3),
Pseudomonas rhizosphaerae
(Xd4) and
Pantoea cedenensis
(Xd5). Especially, the
B. thuringiensis
strain was identified in more detail as
Bacillus thuringiensis
subsp.
tenebrionis
(H8ab). The insecticidal activities were determined against the larvae of
Agelastica alni
L. (Col.: Chrysomelidae),
Amphimallon solstitiale
L. (Col.: Scarabaeidae),
Leptinotarsa decemlineata
(Say) (Col.: Chrysomelidae), and
Melolontha melolontha
L. (Col.: Scarabaeidae) larvae at 1.8×10
9
CFU/ml dose, within five days. The highest insecticidal activities are 100, 100, 80 and 100% for
Bacillus thuringiensis
subsp.
tenebrionis
(Xd3) on
A. alni, A. solstitiale, L. decemlineata
, and
M. melolontha
larvae, respectively. Our results indicate that especially
B. thuringiensis
subsp.
tenebrionis
(Xd3) may be valuable as a microbial control agent for coleopteran pests, respectively.
Erhebungen zum Flugverlauf des Ungleichen Holzbohrers (Xyleborus dispar) und des Schwarzen Nutzholzborkenkäfers (Xyleborus germanus) sind in den Jahren 1996–2002 auf dem Lehr- und Versuchsbetrieb für ...Obstbau Karlsruhe-Augustenberg durchgeführt worden. Im Mittelpunkt der Untersuchungen standen die Überwachung des Käferfluges und die Populationsschwankungen der Holzbohrerarten.Aufgrund einer falschen Bestimmung stimmt ein Teil der in der Veröffentlichung Rauleder H (2003) Beobachtungen zum Flugverlauf des Kleinen und des Ungleichen Holzbohrers (Xyleborus saxeseni und X. dispar), Gesunde Pflanzen 3:53–61 gemachten Angaben nicht und wird in diesem Artikel korrigiert.Der Käferflug des Ungleichen Holzbohrers beginnt im Frühjahr, wenn die maximalen Tagestemperaturen von 18°C erreicht bzw. überschritten werden. Dies ist i. d. R. Ende März oder in der ersten Aprilwoche der Fall. Der Flug dauert etwa bis Anfang Juli.Bei den von uns fälschlicherweise als Männchen des Ungleichen Holzbohrers bestimmten Käfer handelte es sich tatsächlich um den Schwarzen Nutzholzborkenkäfer (Bestimmung: Bayerische Landesanstalt für Wald- und Forstwirtschaft). Der Käferflug des Schwarzen Nutzholzborkenkäfers beginnt etwas später, Mitte bis üblicherweise Ende April.Der Anteil des Ungleichen Holzbohrers in den Alkoholfallen schwankte zwischen 9,1 und 53,3% und lag im Durchschnitt bei 27,4%. Der Anteil des Schwarzen Nutzholzborkenkäfers lag zwischen 3,3 bzw. 9,5%, im Durchschnitt bei 5,1%.
The ambrosia beetle Gnathotrichus materiarius, which originally came from North America, was discovered in southern Finland in 1996. In 1997, using Norwegian drainpipe traps baited with pheromones of ...Gnathotrichus retusus and G. sulcatus, we collected beetles in the region where the first specimen had been caught in order to determine whether this potential pest species had become established in the area. Samples from a total of 16 traps included 79 species of beetles and 719 individuals, but no specimens of G. materiarius. The most abundant species in the samples were the ambrosia beetles Xyleborus dispar and Trypodendron lineatum. Several predators and other associates of bark beetles were also captured. The majority of the beetles caught were saproxylic species.
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