Field Perimeter Trapping to Manage Rhagoletis mendax (Diptera: Tephritidae) in Wild Blueberry

2020 ◽  
Vol 113 (5) ◽  
pp. 2380-2389
Author(s):  
Francis A Drummond ◽  
Judith A Collins

Abstract Rhagoletis mendax Curran (the blueberry maggot fly) is a major pest of wild blueberry. It is a direct pest of the fruit. Females lay eggs in fruit resulting in infestations of larvae unacceptable to most consumers. Three field perimeter interception tactics were tested for control of R. mendax in wild blueberry, Vaccinium angustifolium Aiton (Ericales: Ericaceae), between 2000 and 2010. We investigated field perimeter deployment of baited, insecticide-treated, green spheres (2000–2005), baited, yellow Trécé PHEROCON AM traps (2005 and 2006), and baited, Hopper Finder, sticky barrier tape (2008–2010). Only the Hopper Finder tape provided significant reduction in R. mendax adults and fruit infestation over the 3-yr field study. However, the reduction in fruit infestation compared with control plots was only 48.2 ± 7.3%, a level of reduction in damage that would be unsuitable for many commercial wild blueberry growers as a stand-alone tactic, but could be an important reduction as part of a multiple tactic IPM strategy. In addition, we constructed an agent-based computer simulation model to assess optimal trap placement between three patterns: 1) a single row of traps along field perimeter; 2) a double row of traps along the field perimeter at half the density of the single row; and 3) a grid of traps spread throughout the field but with the largest distance between traps. We found that the single row deployment pattern of traps was the best for reducing immigration of R. mendax adults into simulated fields.

2019 ◽  
Vol 113 (2) ◽  
pp. 720-730 ◽  
Author(s):  
Francis A Drummond ◽  
Judith A Collins

Abstract Between 1998 and 2017, we conducted studies in wild blueberry, Vaccinium angustifolium Aiton (Ericales: Ericaceae), to elucidate the temporal dynamics of the blueberry maggot fly, Rhagoletis mendax Curran, and its parasitoid, Biosteres melleus (Gahan). A predictive model for the emergence of R. mendax was validated at two sites over 3 yr. A second predictive model for the major parasitoid, B. melleus, of R. mendax was constructed and suggests that the delay in emergence of the parasitoid relative to its host provides a period or ‘biological window’ of 9 d where insecticide sprays can be applied to manage R. mendax with a limited impact on the parasitoid. A 20-yr study on the parasitoid/host dynamics showed parasitism rates ranging from 0.5 to 28.2%. It appears that R. mendax populations in Maine wild blueberry are characterized by stable equilibrium dynamics, significantly affected by stochastic processes. There was a weak, but significant relationship between B. melleus density and R. mendax intrinsic rates of growth. Our data suggest that R. mendax population dynamics in wild blueberry is characterized by an unstable equilibrium tipping point of 7.9 maggots per liter of blueberries or an average of 10 flies per trap.


1989 ◽  
Vol 37 (1) ◽  
pp. 232-233 ◽  
Author(s):  
Fulgentius N. Lugemwa ◽  
Wilber Lwande ◽  
Michael D. Bentley ◽  
Michael J. Mendel ◽  
A. Randall Alford

2019 ◽  
Vol 113 (2) ◽  
pp. 851-859 ◽  
Author(s):  
Francis A Drummond ◽  
Judith A Collins

Abstract Between 1996 and 2003 field studies were conducted in wild blueberry, Vaccinium angustifolium Aiton (Ericales: Ericaceae) to determine action thresholds for the blueberry maggot fly, Rhagoletis mendax Curran (Diptera: Tephritidae). Thresholds were based upon cumulative fly trap captures on baited Pherocon AM traps. The cumulative numbers of R. mendax flies captured over time was a significant predictor of infested fruit levels (maggots/liter blueberries). Fifty percent of the variance in fruit infestation is explained by fly captures. Based upon this relationship, the University of Maine Cooperative Extension has recommended action threshold of 10 cumulative fly captures/trap. However, this threshold is liberal in terms of risk as only 50% of the variance in fruit infestation is explained by fly captures. The dynamics of colonization rate and fly physiological status entering fruit-bearing fields might partially explain the variance in the action threshold. The majority of flies emerge from pruned fields or along forest scrub/shrub field edges, and it takes between 1 and 10 d (mean = 4.1 ± 0.9 d) for the populations to enter adjacent fruit-bearing fields. Flies dispersed from pruned fields at a decreasing rate the farther they dispersed. The rate of dispersal into fruit-bearing wild blueberry fields also depends upon the overwintering site quality. Sites with fruit exhibited both delayed colonization and lower colonization rates into fruit-bearing fields than adjacent pruned fields with no fruit. We also found that as the season progressed the proportion of flies capable of laying eggs varied greatly by location and year.


Arthroskopie ◽  
2021 ◽  
Author(s):  
Paul Borbas ◽  
Karl Wieser ◽  
Florian Grubhofer
Keyword(s):  

ZusammenfassungArthroskopische Rotatorenmanschettenrekonstruktionen wurden initial mit einer einreihigen („single row“) Technik beschrieben. Im Rahmen technischer Weiterentwicklungen der arthroskopischen Chirurgie wurden diverse Techniken zur zweireihigen („double row“), transossären und transossär-äquivalenten Sehnenfixation entwickelt, nicht zuletzt durch eine zunehmende Verbreitung knotenloser Anker. Die klinischen Ergebnisse zeigen keine relevanten Unterschiede zwischen den jeweiligen Techniken. Biomechanisch sind zweireihige Rekonstruktionen jedoch durch Vergrößerung der Kontaktfläche an der Insertionsstelle und der erreichten Stabilität überlegen, insbesondere mit medial geknoteten Fäden, welche in eine laterale Reihe als sog. Suture-Bridge abgespannt werden. Klassischerweise wurden Schraubanker aus Metall für eine arthroskopische Sehnenfixierung verwendet. Im Laufe der letzten Jahre wurde das Anker-Portfolio jedoch durch moderne bioresorbierbare und nichtresorbierbare (PEEK) Schraub- und Einschlaganker sowie auch um reine Fadenanker (All-suture) erweitert. Ein allgemeingültiger Goldstandard für die Ankerverwendung existiert bis dato nicht, wobei die meisten gängigen Anker – zumindest bei guter Knochenqualität – ausreichende Stabilität gewährleisten. Beim Nahtmaterial kam es ebenso zu relevanten Weiterentwicklungen, sodass dem Versagen der Nähte heutzutage weniger Bedeutung zukommt. Das Aufkommen von bandartigem Nahtmaterial (Tapes) konnte in diversen biomechanischen Studien seine Überlegenheit nachweisen, jedoch ist bei geknoteten Techniken mit Tapes aufgrund des womöglich negativen Einflusses durch größere Knoten Vorsicht geboten. Nicht zuletzt ist die mediale Stichposition möglichst nahe des Rotatorenkabels von großer Bedeutung, da der häufigste Versagensmechanismus einer Rotatorenmanschettenrekonstruktion mit modernem Naht- und Ankermaterial weiterhin ein Hindurchschneiden der Fäden durch das vorgeschädigte Sehnengewebe ist.


2021 ◽  
Vol 30 (7) ◽  
pp. e458
Author(s):  
Punn Kuhataparuks ◽  
Jia-Min Sheng ◽  
Khye Soon Andy Yew ◽  
Siaw Meng Chou ◽  
Soon Huat Tan ◽  
...  

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