David Bartels

United States Department of Agriculture | USDA · USDA APHIS Plant Protection and Quarantine

Predictive models, based upon epidemiological principles and fitted to surveillance data, play an increasingly important role in shaping regulatory and operational policies for emerging outbreaks. Data for parameterising these strategically important models are often scarce when rapid actions are required to change the course of an epidemic invadin...

In October 2015, a Mexican lime exhibiting citrus canker symptoms was found by the USDA APHIS PPQ in a residential property in Rancho Viejo, Cameron County, Texas. Real-time PCR analysis detected the presence of Xanthomonas citri subsp. citri; USDA APHIS PPQ in Beltsville, MD confirmed this diagnosis. A delimiting survey was initiated and suspect l...

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The spatial niche occupation of the Asian citrus psyllid, Diaphorina citri Kuwayama, 1908, was evaluated to determine its field colonization and food resource exploitation strategies in citrus groves. Mature grapefruit and sweet orange groves were surveyed as part of an area-wide program in 2009–2010 to determine D. citri population densities and b...

Huanglongbing (HLB), also known as citrus greening, is a destructive citrus disease associated with 3 α-proteobacteria species of Candidatus Liberibacter. The first report of HLB in the USA was from Florida in 2005 and Ca. L. asiaticus (Las) is the only species currently confirmed in the USA. In January 2012, a Valencia sweet orange tree in a comme...

Population genetic diversity of the oriental fruit fly, Bactrocera dorsalis (Hendel), on the Hawaiian islands of Oahu, Maui, Kauai, and Hawaii (the Big Island) was estimated using DNA sequences of the mitochondrial cytochrome c oxidase subunit I gene. In total, 932 flies representing 36 sampled sites across the four islands were sequenced for a 1,5...

Phytosanitary treatments are official pre-shipment or quarantine processes recognized internationally and used by National Plant Protection Organisations (NPPOs) to mitigate biosecurity risks associated with plants or plant-based products. Various chemical and physical treatments are used to ensure pests and other organisms (hitch-hikers) are preve...

Field capture of boll weevils, Anthonomus grandis Boheman, in pheromone traps adjacent to fields of cotton, Gossypium hirsutum L., and along fence lines and roads is an important tool used by Boll Weevil Eradication Programs to monitor abundance of the insect pest. For quality control, previously collected and frozen boll weevils are marked with fi...

Retinal sensitivity of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) was examined with an aim to improve trap efficacy for the beetle. Electroretinogram (ERG) recordings from dark-adapted compound eyes of male and female were measured at different wavelengths across the spectrum ranging from 300 to 700 nm. The spectral sensitivity curves...

Water strongly absorbs mid-infrared (1300-2500 nm) radiation, resulting in this region of the spectrum being sensitive to the water content within features. Little information is available on using an electronic digital camera filtered to this region of the spectrum to assess natural resources. The objectives of this study were to assemble an elect...

A 4-yr landscape-scale study was conducted to investigate spatial and temporal dynamics of overwintering Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) in the lower San Joaquin Valley, California. Spatial structures of H. coagulata distributions were characterized with Moran's I index, and spatial associations between H. coagulata and the su...

Glassy-winged sharpshooter (GWSS) was recently introduced into California and poses a serious threat to the grape industry because it is a very effective vector of the bacterium that causes Pierce's disease. We studied how GWSS was affected by a new technology called particle film, Surround™ WP, that protects plants from insect feeding, oviposition...

Field studies were done in 1995-1996 to assess the efficacy of three sweet corn hybrids that express the Bacillus thuringiensis (Bt) toxin, CrylAb, against two lepidopteran pests, Ostrinia nubilalis (Hubner) and Helicoverpa zea (Boddie). The Bt hybrids tested were developed by Novartis Seeds, using the event BT-11, which expresses Bt toxin in green...

Field experiments were conducted during 1997 to evaluate commercially available pheromone lures for Z-strain European corn borer, Ostrinia nubilalis (Hübner) at Rosemount and Le Sueur, Minnesota. Improved pheromone lures, available from Trece, Inc. and Hercon Environmental Co., were compared with a University of Minnesota pheromone lure (MN-lure) a...

Several pheromone trap designs have been reported as being effective for monitoring European corn borer, Ostrinia nubilalis (Hübner). Field experiments were conducted during 1995-1996 at Rosemount and Le Sueur, MN, to determine the most efficient pheromone trap design for monitoring Z-strain O. nubilalis males. Designs tested included several versi...

Commercial pheromone lures for monitoring European corn borer, Ostrinia nubilalis (Hübner), captured significantly fewer moths and indicated a delayed peak emergence compared with blacklight traps in Minnesota. Pheromone trap studies were therefore conducted during 1992-1994 at Rosemount and Le Sueur, MN, to determine the relative attractiveness of...

Alfalfa blotch leafminer, Agromyza frontella, has been a serious pest of alfalfa, Medicago sativa, in the northeastern U.S. and in eastern Ontario, Canada. Until recently, the western edge of the A. frontella distribution in the U.S. was limited to eastern Ohio. We document for the first time, the occurrence of A. frontella in Minnesota and Wiscons...

This study was conducted at the University of Minnesota Rosemount Agricultural Experiment Station. Cabbage was transplanted bare-root on 28 Jun. Plots consisted of two 25 ft (7.6 m) rows on 40 inch (1.0 m) centers with plants spaced 13 inches (0.33 m) apart. Ten ft (3.0 m) borders and 10 ft (3.0 m) alleys separated plots. Treatments were arranged i...

This test was conducted on the University of Minnesota Southern Experiment Station at Waseca, MN. Sweet corn was planted 1 Jul. Plots consisted of 4 rows, 25 ft (7.6 m) long on 30 inch (0.8 m) centers with 2 untreated border rows and 6-ft (1.83 m) alleys separating plots. Treatments were arranged in a RCB design with 4 replications. A Hagie highboy...

This study was conducted at the University of Minnesota Rosemount Agricultural Experiment Station. Cabbage was transplanted 14 Jun. Plots consisted of two 25 ft (7.6 m) rows on 40 inch (1.0 m) centers with plants spaced 13 inches (0.33 m) apart. Ten ft (3.0 m) borders and 10 ft (3.0 m) alleys separated the plots. Treatments were arranged in a RCB d...

This test was conducted on the University of Minnesota Southern Experiment Station at Waseca, MN. Sweet corn was planted 14 Jun. Plots consisted of four rows, 25 ft (7.6 m) long on 30 inch (0.8 m) centers with two untreated border rows and 6 ft (1.83 m) alleys separating the plots. Treatments were arranged in a RCB design with four replications. A...

This test was conducted at the University of Minnesota Rosemount Agricultural Experiment Station, Rosemount, MN. ‘Jubilee’ sweet corn was planted 12 Jun in plots consisting of a single 30 ft row on 30 inch centers. Each plot was separated by one untreated border row on each side and 7 ft alleys at each end. Treatments were arranged in a RCB design...

Ground-applied treatments of two commercial Bacillus thuringiensis subsp. kurstaki formulations (MVP and Dipel ES) and tank-mixes with a pyrethroid (Ambush 2E) were evaluated for control of European corn borer, Ostrinia nubilalis (Hübner), larvae in sweet corn. Treatments were applied at average intervals of 3.4, 5, 7, and 10 days to determine fiel...

Aerial applications of Bacillus thuringiensis subsp. kurstaki and tank-mixes with synthetic insecticides were evaluated for control of Ostrinia nubilalis (Hübner) and Helicoverpa erpa zea (Boddie) in Minnesota sweet com during 1990-1992. In addition to natural infestations, sweet com was manually infested with first-instar O. nubilalis to investiga...

Field and laboratory studies were conducted using selected carbamate, organophosphate, and pyrethroid insecticides to quantify their toxicity to European corn borer, Ostrinia nllhilalis (Hübner), eggs and residual mortality to neonates. Field studies included most insecticides currently registered for Q. nubilalis on vegetable crops, as well as rec...

This test was conducted on the University of Minnesota Rosemount Agricultural Experiment Station. Sweet corn was planted 15 Jun in plots consisting of single rows, 30 ft long on 30 inch centers. Each plot was separated by 5 ft alleys and had no buffer rows. Hybrids were arranged in a randomized complete block design with four replications. Experime...

Two insecticide trials were conducted in a commercially grown field of pumpkins managed by Owatonna Canning Co., in Mower County, Minnesota. The field was planted 18 May. Plots in both trials consisted of single 25 ft (7.62 m) rows on 5 ft (1.52 m) centers. Plant spacing was 18 inches (0.46 m). Both trials were arranged in a randomized complete blo...

This test was conducted on the University of Minnesota, Rosemount Experiment Station, in snap beans planted 2 Jun. Plots consisted of three 30 ft (9.14 m) rows on 30 inch (0.76 m) centers. Two untreated border rows and 7 ft (2.13 m) alleys separated the plots. Treatments were arranged in a split-plot design with four replications. Insecticide treat...

This test was conducted on the University of Minnesota Southern Experiment Station at Waseca, MN. Sweet corn was planted 16 Jun in plots consisting of four rows, 25 ft (7.6 m) long on 30 inch (0.8 m) centers. Two untreated border rows and 6 ft (1.83 m) alleys separated the plots. Treatments were arranged in a randomized complete block design with f...

This study was conducted in a commercially grown field of pumpkin managed by Owatonna Canning Co., in Dodge County, Minnesota. The predominant cultivar in the field was ‘Buckskin’ but some ‘Dickinson’ was also present. The field was planted 18 May. Plots consisted of single 25 ft (7.62 m) rows on 5 ft (1.52 m) centers. Plant spacing was 18 inches (...

This study was conducted on the University of Minnesota Rosemount Agricultural Experiment Station. Cabbage was transplanted 23 Jun into plots consisting of two 25 ft (7.62 m) rows on 40 inch (1.02 m) centers. Plants were spaced 13 inches (0.33 m) apart. Ten ft (3.05 m) borders and 7 ft (2.13 m) alleys separated the plots. Treatments were arranged i...

This test was conducted in a 2-year-old alfalfa stand located at the University of Minnesota Agricultural Experiment Station at Rosemount. Plots measuring 32 × 45 ft were replicated 4 times in a randomized complete block design. A single treatment was applied 21 Jul to exploit unusually late AW and high PLH infestations in the same trial. Applicati...

This test was conducted on the University of Minnesota Southern Experiment Station at Waseca in corn planted 4 Jun. Plots consisted of four 30 ft (9.14 m) rows on 30 inch (0.76 m) centers. Two untreated border rows and 6 ft (1.83 m) alleys separated the plots. Treatments were arranged in a randomized complete block design with four replications. A...

This test was conducted in a 1-year-old alfalfa stand located at the University of Minnesota Agricultural Experiment Station at Rosemount. Plots measuring 20 × 40 ft were replicated 4 times in a RCBD. A single treatment was applied 29 May using a tractor-drawn FMC sprayer with 25-ft boom, delivering 20 gpa at 40 psi. All treatments were applied bet...

This test was conducted on the University of Minnesota, Rosemount Experiment Station in corn planted 1 Jun. Plots consisted of single rows on 30" centers, 30 ft in length, and separated by untreated border rows and 4 ft alleys between replicates. Treatments were arranged in a randomized complete block design with 4 replications. All plots were infe...

This study was conducted on the University of Minnesota Rosemount Agricultural Experiment Station in cabbage seeded 9 May and transplanted 14 Jun. Plots consisted of two 25 ft (7.62 m) rows on 40 inch (1.02 m) centers. Plant spacing was set for 13 inches (0.33 m). Ten ft (3.05 m) borders and 7 ft (2.13 m) alleys separated the plots. Treatments were...

This test was conducted on the University of Minnesota, Rosemount Experiment Station, in snapbeans planted 8 Jul. Plots consisted of three 30 ft (9.14 m) rows on 30 inch (0.76 m) centers. Two untreated border rows and 7 ft (2.13 m) alleys separated the plots. Treatments were arranged in a randomized complete block design with 4 replications. Treatm...

This test was conducted on the University of Minnesota Southern Experiment Station at Waseca in corn planted 29 May. Four-row plots, 9.1 m (30 ft) long with 1.2 m (4 ft) alleys, and separated by two rows of corn, were arranged in a randomized complete block design. A Hagie highboy sprayer with two flat fan (8003VS) nozzles/row, delivering 53.6 1/ha...

This study was carried out at the University of Minnesota, Agricultural Experiment Station, at Rosemount in cabbage transplanted 11 Jun. Treatments were replicated 4 times and arranged in a randomized complete block design. Each replicate consisted of 2 rows on 91.4 cm (36 inch) centers, measuring 9.14 m (30 ft) in length. All plots were separated...

This test was conducted on the University of Minnesota Agricultural Experiment Station at Rosemount in cabbage transplanted on 14 Jun. Plots were two rows on 36" centers, 40 ft long, and separated by 7 ft alleys on the sides and 10 ft alleys at the ends. They were arranged in a randomized complete block design with 4 replications. A Spirit sprayer...

This test was conducted on the University of Minnesota Agricultural Experiment Station at Rosemount in corn planted 13 Jun. Two-row plots, 30 ft long with 4 ft alleys, and separated by one skip-row, were arranged in a randomized complete block design. A backpack COa sprayer with two hollow-cone (TX-10) nozzles/row, delivering 25 gal/acre at 33 psi,...

This test was conducted in a 3-yr-old alfalfa stand located on the University of Minnesota Agricultural Experiment Station at Rosemount. Plots measuring 25 × 40 ft were replicated 4 times in a randomized complete block design. Treatments were applied 6 Jul with a tractor-drawn 25-ft boom sprayer delivering 19 gal/acre at 40 psi. Treatments were app...

This test was conducted on the University of Minnesota Agricultural Experiment Station at Rosemount in corn planted 10 Jul. One-row plots, 25 ft long with 3-ft alleys, and separated by one skip-row, were arranged in a randomized complete block design. A backpack CO2 sprayer with two hollow-cone (TX-10) nozzles/row, delivering 25 gal/acre at 33 psi,...

This experiment was conducted at the Rosemount Agricultural Experiment Station, Rosemount, Minn. 'Green Giant Code 40' sweet corn was planted on 7 Jun. Plots consisted of a single 30-ft row on 36-inch centers and were arranged in a randomized complete block design with 4 replications. Plots were infested with first instar ECB larvae on 24 Jun to si...

This test was conducted on the University of Minnesota Agricultural Experiment Station at Rosemount in corn planted 14 Jun. Two-row plots, 30 ft long, and separated by one skip-row and 4 ft borders at the end of each plot, were arranged in a randomized complete block design. A backpack CO2 sprayer with one flat-fan (LF-3) nozzle/row, delivering 27...

This test was conducted on the University of Minnesota Agricultural Experiment Station at Rosemount in corn planted 18 Jun. Two-row plots were 25 ft long with one untreated border row between each plot and 4 ft borders at the end of each plot. Treatments were replicated 4 times in a randomized complete block design. A backpack CO2 sprayer with one...