Diurnal flight response of the walnut twig beetle, Pityophthorus juglandis Blackman (Coleoptera: Scolytidae), to pheromone-baited traps in two northern California walnut habitats

2012 ◽  
Vol 88 (2) ◽  
pp. 231-247 ◽  
Author(s):  
Steven J. Seybold ◽  
Jennifer A. King ◽  
Daren R. Harris ◽  
Lori J. Nelson ◽  
Shakeeb M. Hamud ◽  
...  
Author(s):  
Giovanni Bosio ◽  
Crystal Cooke-McEwen

The walnut twig beetle, Pityophthorus juglandis Blackman (Coleoptera Curculionidae Scolytinae), and thousand cankers disease are documented in the Piemonte region of Northern Italy for the first time.  Northern California is found to be the likely origin of the Piemonte walnut twig beetles based on the comparison of CO1 haplotypes. Multiple species of parasitoids have been reared from black walnut wood infested with the invasive walnut twig beetle.  These rearings constitute the first record of the genus Neocalosoter Girault and Dodd (Hymenoptera Pteromalidae Cerocephalinae) in Europe and are likely due to accidental introduction along with the host beetle. Two specimens of Theocolax spp. are described as morphological anomalies with geographical origins unknown.   


2020 ◽  
Vol 113 (6) ◽  
pp. 2772-2784 ◽  
Author(s):  
Jackson P Audley ◽  
Paul L Dallara ◽  
Lori J Nelson ◽  
Shakeeb M Hamud ◽  
Richard M Bostock ◽  
...  

Abstract The walnut twig beetle, Pityophthorus juglandis Blackman, and its associated fungal pathogen that causes thousand cankers disease, currently threaten the viability of walnut trees across much of North America. During a 2011 assessment of seasonal flight patterns of P. juglandis with yellow sticky traps baited with the male-produced aggregation pheromone component, 3-methyl-2-buten-1-ol, dramatically reduced catches were recorded when Tree Tanglefoot adhesive was used to coat the traps. In summer 2011, two trap adhesives were tested for potential repellency against P. juglandis in a field trapping bioassay. SuperQ extracts of volatiles from the most repellent adhesive were analyzed by gas chromatography–mass spectrometry, and limonene and α-pinene were identified as predominant components. In field-based, trapping experiments both enantiomers of limonene at a release rate of ~700 mg/d conferred 91–99% reduction in trap catches of P. juglandis to pheromone-baited traps. (+)- and (‒)-α-Pinene reduced trap catch by 40 and 53%, respectively, at the highest release rate tested. While a combination of R-(+)-limonene and (+)-α-pinene resulted in a 97% reduction in the number of P. juglandis caught, the combination did not consistently result in greater flight trap catch reduction than individual limonene enantiomers. The repellent effect of limonene may be valuable in the development of a semiochemical-based tool for management of P. juglandis and thousand cankers disease.


Author(s):  
Matteo Marchioro ◽  
Massimo Faccoli

AbstractThe Walnut Twig Beetle (WTB), Pityophthorus juglandis Blackman, is a small bark beetle native to Mexico and Southwestern USA recorded for the first time in Europe (NE Italy) in 2013. WTB attacks walnut (Juglans spp.) and wingnut trees (Pterocarya spp.) and is the vector of Geosmithia morbida Kolarík et al., a pathogen causing the thousand cankers disease (TCD). WTB and TCD represent a serious threat for walnut orchards in Europe. Spatiotemporal data of the WTB-TCD infestations recorded from an 8-year-long (2013–2020) monitoring conducted in 106 walnut orchards of NE Italy were used to develop a model in order to analyze: (i) the effective dispersal capacity of WTB, (ii) the factors affecting dispersal and (iii) the colonization risk of healthy walnut orchards. We registered a mean annual dispersal of 9.4 km, with peaks of about 40 km. Pest dispersal is affected by distance of suitable hosts from the nearest infested site, number of walnut orchards in the surroundings (both infested and healthy), orchard size and walnut species in the orchard. Using the model, it was also possible to calculate the colonization risk of a specific walnut orchard according to its characteristics showing, for instance, that a medium-size (5,000 trees) black walnut orchard located at 25 km from the nearest infested orchard has an infestation risk of about 50% of probability.


2019 ◽  
Vol 20 (3) ◽  
pp. 133-139 ◽  
Author(s):  
Melanie Moore ◽  
Jennifer Juzwik ◽  
Fredric Miller ◽  
Leah Roberts ◽  
Matthew D. Ginzel

Thousand cankers disease is caused by the coalescence of numerous Geosmithia morbida cankers on branches and stems of Juglans species, leading to branch dieback and eventual tree death. The fungus sporulates in galleries of the walnut twig beetle (Pityophthorus juglandis), allowing for acquisition of pathogen propagules and its subsequent transmission to other branches or trees following adult emergence. Recently, G. morbida has been isolated from Xylosandrus crassiusculus and Xyleborinus saxesenii collected in Ohio and Stenomimus pallidus collected in Indiana. These beetles are known to colonize diseased Juglans nigra in these states. In this study, an operational trap survey for ambrosia beetles, bark beetles, and other weevils was conducted in four eastern states, and captured beetles were assayed to detect G. morbida using both culture and PCR-based methods. A new primer pair (GmF3/GmR13), based on the β-tubulin region, was designed for G. morbida DNA detection. The pathogen was detected on 18 insect species using molecular methods, and live cultures were isolated from two species. This is the first report of the pathogen in Illinois and Minnesota.


2006 ◽  
Vol 41 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Christopher J. Fettig ◽  
Christopher P. Dabney

Bark beetles (Coleoptera: Scolytidae) are commonly recognized as the most important mortality agent in western coniferous forests. In this study, we describe the abundance of bark beetle predators collected in multiple-funnel traps baited with exo-brevicomin, frontalin and myrcene in northern California during 2003 and 2004. A total of 32,903 Temnochila chlorodia (Mannerheim), 79 Enoclerus lecontei (Wolcott), and 12 E. sphegeus (F.) were collected. The seasonal abundance of E. lecontei and E. sphegeus was not analyzed because too few individuals were collected. In general, T. chlorodia was most abundant in late spring, but a second smaller peak in activity was observed in late summmer. Overall, the ratio of males to females was 0.82. A significant temporal effect was observed in regard to sex ratios with more males collected during later sample periods. Temnochila chlorodia flight activity patterns were similar between years, but activity was generally delayed several weeks in 2003.


Forests ◽  
2014 ◽  
Vol 5 (6) ◽  
pp. 1185-1193 ◽  
Author(s):  
Gregory Wiggins ◽  
Jerome Grant ◽  
Paris Lambdin ◽  
Paul Merten ◽  
Katheryne Nix ◽  
...  

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