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"Pfeiffer, Douglas"
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Effects of Interspecific Larval Competition on Developmental Parameters in Nutrient Sources Between Drosophila suzukii (Diptera: Drosophilidae) and Zaprionus indianus
by
Shrader, Meredith Edana
,
Pfeiffer, Douglas G.
,
Burrack, Hannah J.
in
adults
,
Analysis
,
Animals
2020
Two invasive drosophilids, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) and Zaprionus indianus (Gupta) (Diptera: Drosophilidae) are expanding their geographic distribution and cohabiting grape production in the Mid-Atlantic. The ecological and economic impact of these two species within vineyards is currently unknown. Zaprionus indianus was presumably not capable of ovipositing directly into grapes because they lack a serrated ovipositor and may use D. suzukii oviposition punctures for depositing their own eggs. Therefore, an interspecific larval competition assay was performed at varying larval densities using commercial medium and four commonly grown wine grapes in Virginia to investigate the impact Z. indianus larvae may have on the mortality and developmental parameters of D. suzukii larvae. Zaprionus indianus did not affect D. suzukii mortality or development parameters even at high interspecific densities when reared in commercial medium, but it did cause higher D. suzukii mortality within grapes. Mortality was also influenced by the variety of grape in which the larvae were reared, with smaller grapes having the highest D. suzukii mortality. Presence of Z. indianus also increased development time to pupariation and adult emergence for most interspecific competition levels compared with the intraspecific D. suzukii controls. Pupal volume was marginally affected at the highest interspecific larval densities. This laboratory study suggests that competition from Z. indianus and grape variety can limit D. suzukii numbers, and the implications on D. suzukii pest management be further verified in the field.
Journal Article
Drosophila suzukii (Diptera: Drosophilidae) Oviposition and Adult Emergence in Six Wine Grape Varieties Grown in Virginia
by
Shrader, Meredith Edana
,
Pfeiffer, Douglas G.
,
Burrack, Hannah J.
in
adulthood
,
Analysis
,
Bioassays
2019
Drosophila suzukii (Matsumura) is a pest of small fruits and grapes in the United States and in its home range of Japan. Physiological and morphological laboratory testing was performed on six commonly grown wine grape varieties inVirginia. Skin thickness, penetration force, and °Brix were analyzed to determine ovipositional preferences. Experiments were performed for three consecutive years from grapes collected at one Virginia vineyard. More eggs were laid in intact Viognier grapes than any other variety. Oviposition into intact grapes was not affected by skin thickness or °Brix; however, oviposition increased when penetration force decreased. An ovipositional choice test determined no varietal preferences. Survivorship from egg to adulthood using uninjured and injured grapes was also assessed to determine varietal suitability as D. suzukii hosts, with more flies emerging from injured grapes than uninjured. However, D. suzukii adults did emerge from intact grapes and at higher percentages than previously recorded in other wine grape studies. All varieties had eggs oviposited into them when injured. Determining the time at which each grape variety became susceptible to oviposition was determined using a D. suzukii bioassay spanning 12 wk using grapes from the green pea stage until ripe. Susceptibility to D. suzukii oviposition was based upon ripening period and penetration force. Early ripening varieties may be more susceptible to D. suzukii oviposition in the field with later maturing, harder fleshed-varieties which may escape D. suzukii oviposition.
Journal Article
Clinical imaging physics : current and emerging practice
by
Pfeiffer, Douglas E.
,
Samei, Ehsan
in
Diagnostic imaging
,
Diagnostic imaging-Methodology
,
Medical physics
2020
Clinical Medical Imaging Physics: Current and Emerging Practice is the first text of its kind--a comprehensive reference work covering all imaging modalities in use in clinical medicine today. Destined to become a classic in the field, this book provides state-of-practice descriptions for each imaging modality, followed by special sections on new and emerging applications, technologies, and practices.
Authored by luminaries in the field of medical physics, this resource is a sophisticated, one-volume handbook to a fast-advancing field that is becoming ever more central to contemporary clinical medicine.
* Summarizes the current state of clinical medical imaging physics in one volume, with a focus on emerging technologies and applications
* Provides comprehensive coverage of all key clinical imaging modalities, taking into account the new realities in healthcare practice
* Features a strong focus on clinical application of principles and technology, now and in the future
* Contains authoritative text compiled by world-renowned editors and contributors responsible for guiding the development of the field
Practicing radiologists and medical physicists will appreciate Clinical Medical Imaging Physics as a peerless everyday reference work. Additionally, graduate students and residents in medical physics and radiology will find this book essential as they study for their board exams.
Pest Status of the Brown Marmorated Stink Bug, Halyomorpha Halys in the USA
by
Shearer, Peter W.
,
Rodriguez-Saona, Cesar
,
Koplinka-Loehr, Carrie
in
Brown Marmorated Stink Bug
,
Halyomorpha Halys
,
Invasive Pest
2012
Since its initial discovery in Allentown, PA, USA, the brown marmorated stink bug (BMSB), Halyomorpha halys (Heteroptera: Pentatomidae) has now officially has been detected in 38 states and the District of Columbia in the USA. Isolated populations also exist in Switzerland and
Canada. This Asian species quickly became a major nuisance pest in the mid-Atlantic USA region due to its overwintering behavior of entering structures. BMSB has an extremely wide host range in both its native home and invaded countries where it feeds on numerous tree fruits, vegetables, field
crops, ornamental plants, and native vegetation. In 2010, populations exploded causing severe crop losses to apples, peaches, sweet corn, peppers, tomatoes and row crops such as field corn and soybeans in several mid-Atlantic states. Damaging populations were detected in vineyards, small fruit
and ornamentals. Researchers are collaborating to develop management solutions that will complement current integrated pest management programs. This article summarizes the current pest status and strategies being developed to manage BMSB in the USA.
Journal Article
Mitochondrial Dynamics and Motility Inside Living Vascular Endothelial Cells: Role of Bioenergetics
by
Kao, Chiu-Yen
,
Pfeiffer, Douglas R.
,
Alevriadou, B. Rita
in
Adenosine Triphosphate - physiology
,
Biochemistry
,
Bioenergetics
2012
The mitochondrial network is dynamic with conformations that vary between a tubular continuum and a fragmented state. The equilibrium between mitochondrial fusion/fission, as well as the organelle motility, determine network morphology and ultimately mitochondrial/cell function. Network morphology has been linked with the energy state in different cell types. In this study, we examined how bioenergetic factors affect mitochondrial dynamics/motility in cultured vascular endothelial cells (ECs). ECs were transduced with mitochondria-targeted green fluorescent protein (mito-GFP) and exposed to inhibitors of oxidative phosphorylation (OXPHOS) or ATP synthesis. Time-lapse fluorescence videos were acquired and a mathematical program that calculates size and speed of each mitochondrial object at each time frame was developed. Our data showed that inner mitochondrial membrane potential (ΔΨ
m
), ATP produced by glycolysis, and, to a lesser degree, ATP produced by mitochondria are critical for maintaining the mitochondrial network, and different metabolic stresses induce distinct morphological patterns (e.g., mitochondrial depolarization is necessary for “donut” formation). Mitochondrial movement, characterized by Brownian diffusion with occasional bursts in displacement magnitude, was inhibited under the same conditions that resulted in increased fission. Hence, imaging/mathematical analysis shed light on the relationship between bioenergetics and mitochondrial network morphology; the latter may determine EC survival under metabolic stress.
Journal Article
Brown Rice Vinegar as an Olfactory Field Attractant for Drosophila suzukii (Matsumura) and Zaprionus indianus Gupta (Diptera: Drosophilidae) in Cherimoya in Maui, Hawaii, with Implications for Attractant Specificity between Species and Estimation of Relative Abundance
2019
Drosophila suzukii (Matsumura) is an agricultural pest that has been observed co-infesting soft-skinned fruits with Zaprionus indianus Gupta. The characterization of olfactory preferences by species is a necessary step towards the development of species-specific attractants. Five olfactory attractants were used to survey the populations of two invasive drosophilids in cherimoya in Maui, Hawaii. The attractants used were apple cider vinegar (ACV), brown rice vinegar (BRV), red wine (RW), apple cider vinegar and red wine (ACV+RW; 60/40), and brown rice vinegar and red wine (BRV+RW; 60/40). For D. suzukii, BRV+RW resulted in more captures than BRV, ACV, and RW, while ACV+RW resulted in more captures than ACV. No differences were observed between BRV+RW and ACV+RW. BRV had greater specificity in attracting D. suzukii compared to ACV, ACV+RW, and RW. For Z. indianus, no significant differences were observed in either the mean captures or specificity for any attractant used. Collectively, these findings demonstrate that (1) BRV and BRV+RW are effective field attractants and (2) D. suzukii has unique olfactory preferences compared to non-target drosophilids, while (3) Z. indianus’ preferences do not appear to vary from non-target drosophilids, and (4) the accuracy of relative abundance is impacted by the specificity of the attractants.
Journal Article
AAPM Medical physics practice guideline 15.A: Peer review in clinical physics
by
Pfeiffer, Douglas E.
,
Halvorsen, Per H.
,
Lofton, Kate E.
in
AAPM Reports & Documents
,
Accreditation
,
Health physics
2023
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. While must is the term to be used in the guidelines, if an entity that adopts the guideline has shall as the preferred term, the AAPM considers that must and shall have the same meaning. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances.
Journal Article
Development of rearing methodology for the invasive Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae)
by
Nixon, Laura J.
,
Keena, Melody
,
Ludwick, Dalton
in
Adults
,
Ailanthus altissima
,
Biological control
2022
Lycorma delicatula , White (Hemiptera: Fulgoridae), spotted lanternfly, is a univoltine, phloem-feeding, polyphagous and invasive insect in the USA. Although a primary host for this species is Ailanthus altissima , tree of heaven, L. delicatula also feeds on a wide range of hosts important to the USA including cultivated grapevines. Due to the need for classical or augmentative biological control programs to reduce impacts of L. delicatula across invaded areas, we developed a laboratory-based rearing protocol for this invasive species. Here, we evaluated the use of A. altissima apical meristems, epicormic shoots, and fresh foliage cut from A. altissima as a food source for rearing newly hatched L. delicatula . On these sources of plant material <20% of L. delicatula developed into adults and no oviposition occurred. However, when young, potted A. altissima trees were used as a food source, >50% of L. delicatula nymphs developed to the adult stage under natural daylengths and temperatures ranging from 20–25°C. The addition of wild grapevine, Vitis riparia , did not increase survivorship or reduce development time. To elicit mating and oviposition, adults were provided with A. altissima logs as an oviposition substrate and maintained under shortened daylengths and reduced nighttime temperatures (12L:12D and 24°C:13°C). This resulted in 2.12 egg masses deposited per female, which was 4× more than when adults were maintained in standard rearing conditions (16L:8D and 25°C). Based on these experiments, we present a protocol for reliably rearing L. delicatula under laboratory and/or greenhouse conditions.
Journal Article
Dendrochronology reveals different effects among host tree species from feeding by Lycorma delicatula (White)
2023
The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), was first detected in the United States in Berks County, Pennsylvania, in 2014. Native to China, this phloem-feeding planthopper threatens agricultural, ornamental, nursery, and timber industries in its invaded range through quarantine restrictions on shipments, as well as impacts on plants themselves. The long-term impacts of L. delicatula feeding on tree species have not been well studied in North America. Using standard dendrochronological methods on cores taken from trees with differing levels of L. delicatula infestation and systemic insecticidal control, we quantified the impact of L. delicatula feeding on the annual growth of four tree species in Pennsylvania: Ailanthus altissima, Juglans nigra, Liriodendron tulipifera , and Acer rubrum . The results suggest that L. delicatula feeding is associated with the diminished growth of A. altissima , but no change was observed in any other tree species tested. The results also suggest that systemic insecticides mitigate the impact of L. delicatula feeding on A. altissima growth.
Journal Article
Evaluating a polyculture trap crop for organic management of Halyomorpha halys and native stink bugs in peppers
2017
Organic farming systems are significantly challenged by the invasive
Halyomorpha halys
(Stål) and native stink bug species that injure vegetable crops. This two-year study evaluated a polyculture trap crop composed of sunflower and sorghum for organic pepper production at 11 sites in 8 mid-Atlantic and Southeastern states. Stink bug densities in the trap crop and peppers were recorded weekly (mid-June through September), and stink bug fruit injury was compared for trap crop-protected and unprotected control peppers. The trap crop was highly attractive, harboring 5–50× more stink bugs per m
2
than the peppers and providing an 8-week attraction period coinciding with peak stink bug activity. Despite this attractiveness, the trap crop was not effective at diverting adult stink bugs away from the pepper crop during the early fruiting period at most sites. However, the average density of stink bug nymphs in pepper plots surrounded by trap crops was 4× lower than controls 5 weeks after planting for pooled sites. Trap crop-protected peppers also had significantly less injury compared to control peppers pooled across sites and years. However, the resulting reduction in pepper damage was insufficient to be economically viable. Overall, results provide evidence that a polyculture trap crop was most effective during the latter weeks of the pepper crop cycle. Future research should address spatial arrangement of the trap crop or integration of complimentary management tactics within the trap crop earlier in the growing season to target the initial colonizing adult stink bugs.
Journal Article