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Drosophila suzukii Matsumura (Diptera: Drosophilidae) has caused significant economic damage to berry and stone fruit production regions. Markers that are systemic in plants and easily transferred to target organisms are needed to track D. suzukii exploitation of host resources and trophic interactions. High and low concentrations of the trace element, rubidium (Rb), and the stable isotope, 15N, were tested to mark D. suzukii larvae feeding on fruits of enriched strawberry plants grown in containers under greenhouse conditions. Fly marker content and proportion of flies marked 1, 7, and 14 d after emergence from enriched fruits and fly dry mass were analyzed. Nearly 100% of the flies analyzed 14 d after emerging from 15N-enriched plants were marked, whereas only 30-75% and 0-3% were marked 14 d after emerging from high and low Rb concentration plants, respectively. Rapid Rb decay, strong 15N persistence, and the economics of using these markers in the field to elucidate D. suzukii pest ecology are discussed.

Environ. Entomol. 42(6): 1348Ð1355 (2013); DOI: http://dx.doi.org/10.1603/EN13148 ABSTRACT Drosophila suzukii (Matsumura), an invasive pest of small and stone fruits, has been recently detected in 39 states of the United States, Canada, Mexico, and Europe. This pest attacks ripening fruit, causing economic losses including increased management costs and crop rejection. Ongoing research aims to improve the efÞcacy of monitoring traps. Studies were conducted to evaluate how physical trap features affect captures ofD.suzukii. We evaluated Þve colors, two bait surface areas, and a top and side position for the sy entry point. Studies were conducted at 16 sites spanning seven states and provinces of North America and nine crop types. Apple cider vinegar was the standard bait in all trap types. In the overall analysis, yellow-colored traps caught signiÞcantly more sies than clear, white, and black traps; and red traps caught more than clear traps. Results by color may be insuenced by crop type. Overall, the trap with a greater bait surface area caught slightly more D. suzukii than the trap with smaller area (90 vs. 40 cm 2 ). Overall, the two traps with a side-mesh entry, with or without a protective rain tent, caught more D. suzukii than the trap with a top-mesh entry and tent.

Drosophila suzukii Matsumura (Diptera: Drosophilidae), a recent invasive pest of small and stone fruits, has been detected in more than half of the U.S. states, and in Canada, Mexico, and Europe. Upon discovery, several different trap designs were recommended for monitoring. This study compared the trap designs across seven states/provinces in North America and nine crop types. Between May and November 2011, we compared a clear cup with 10 side holes (clear); a commercial trap with two side holes (commercial); a Rubbermaid container with mesh lid and rain tent (Haviland), and with 10 side holes and no tent (modified Haviland); a red cup with 10 side holes (red); and a white container with mesh lid and rain tent (Van Steenwyk). Although fly catches among traps varied per site, overall, the Haviland trap caught the most D. suzukii, followed by the red, Van Steenwyk, and clear trap. The modified Haviland and commercial trap had low captures. Among five crop types in Oregon, a clear cup with mesh sid...

Root weevils in the genus Otiorhynchus are cited as one of the most important pests in the major nursery and small fruit production areas throughout the United States, western Canada, and northern Europe. A major problem in combating weevil attack is monitoring and timing of control measures. Because of the night-activity of the adult weevils growers do not observe the emerging weevils in a timely manner and oviposition often starts before effective control measures are taken. Several vine weevil electroantennogram-active plant volatiles were identified from a preferred host plant, Euonymus fortunei. Main compounds evoking antennal responses on the weevils' antennae were (Z)-2-pentenol, (E)-2-hexenol, (Z)-3-hexenol, methyl benzoate, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene, methyl eugenol, and (E, E)-alpha-farnesene. Several of these compounds were tested alone and in mixtures on attractiveness for the vine weevil Otiorhynchus sulcatus (F.) in field-grown strawberry in Oregon. O. sulcatus were attracted to (Z)-2-pentenol (approximately 3 x more than control) and a 1:1 ratio mixture of (Z)-2-pentenol and methyl eugenol (4.5 x more than control). This is the first report of field-active attractants for O. sulcatus which holds promise for the development of new monitoring strategies for growers in the near future.

Filbertworm, Cydia latiferreana (Walsingham) (Lepidoptera: Tortricidae), is a key insect pest associated with hazelnuts, Corylus avellana L. (Fagales: Betulaceae), in North America. This study investigated the feasibility of entomopathogenic nematodes as an alternative strategy for filbertworm control. Laboratory and field experiments were conducted between October 2007 and May 2008 in Benton County, OR, to evaluate the ability of the nematode Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae) to infect filbertworm larvae and pupae. The susceptibility of larvae with and without hibernacula as well as pupae to S. carpocapsae was tested in laboratory bioassays using nematode concentrations between 40 and 200 infective juveniles (IJs) per cm2. Percentage of nematode infection was not significantly affected by the presence of hibernacula (infection range, 90–92%) compared with larvae without hibernacula (80–95%), or by pupal stage (50–75%) compared with larvae (65–75%). In additional field trials, the effect of nematode rate, water application rate, and orchard floor cover on nematode efficacy was determined in October 2007 and May/June 2008. Sentinel filbertworm larvae in plots with either bare soil or debris (leaves, twigs, husks, and blank nuts) were treated with S. carpocapsae at rates ranging from 40 to 150 IJs per cm2 applied in 75 or 190 ml/m2 water. Average filbertworm mortality ranged from 2 to 11% and from 50 to 78% in October and May, respectively. Larval mortality increased with increasing nematode concentration, but was not significantly affected by water application rate or orchard floor cover. Our experiments suggest that S. carpocapsae can play a role in the control of filbertworm larvae overwintering on the orchard floor.

The ecology of fungal entomopathogens in the rhizosphere is an understudied area of insect pathology. The rhizosphere is the region of soil in which the release of root exudates influences the soil microbiota, and may provide a favorable environment for fungal entomopathogens. The objective of this review is to bring together the relatively scant data available to date on the subject of fungal entomopathogens colonizing the rhizosphere and to highlight the importance of these findings. Gaining a better understanding of the ecology of fungal entomopathogens in the rhizosphere will help in the development of successful microbial control strategies against root-feeding insect pests.

Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae) is one of the most damaging insect pests of corn. Studies were conducted to determine whether live larval counts obtained from corn whorls were predictive of the amount of larval tunneling that would result in the stalk of the plant 40 d later at the end of larval development. Whorls from plants treated with Dipel 10G (6,400 IU per whorl) and untreated controls, both infested with O. nubilalis neonates, were evaluated for the number of live larvae in 50 whorls 5, 7, 9, and 12 d after Bacillus thuringiensis (Berliner) (Bacillales: Bacillaceae) application. Forty days after larval infestation, 25 plants from each plot were split from tassel to base, and the length of larval tunneling was recorded. There was a strong relationship between numbers of live larvae in the plant whorl and the length of larval tunneling that resulted. While linear at each location, there was significant variation in the relationship among locations, indicating that comparisons could not be made between years or locations within a year. Blocks within a location on a given year did not vary significantly and reproducible results were obtained each year within a given location as well as on any of the whorl pulling dates evaluated. Because of its ease of use, predictability, and rapid return of results, we propose this technique as an additional method to shot-hole feeding and stalk splitting to evaluate the effectiveness of O. nubilalis management strategies.

The purpose of this study was to characterize the behavior of black vine weevil larvae, Otiorhynchus sulcatus (F.), in the presence of two possible control options: the synthetic pyrethroid bifenthrin and the entomopathogenic fungus Metarhizium anisopliae (Metch.) Sorokin. Five third-instar black vine weevil were placed in two-choice soil olfactometers that allowed larvae to infest one of two pots. Larvae were allowed to choose between M. anisopliae (1 × 106 spores/g dry media) and untreated media, bifenthrin (25 ppm) and untreated media, as well as M. anisopliae– and bifenthrin-treated media. For all comparisons, experiments were conducted without plants in the system to test for innate responses, as well as with plants to test host–plant influence. Larvae were significantly deterred by bifenthrin without plants present in the system. No significant effect on larval preference was observed when M. anisopliae was present in media for trials without plants. M. anisopliae–treated media was preferre...

Wholesale container-grown ornamentals are often maintained at the nursery for at least two growing seasons and are subject to infestation by black vine weevil (BVW), Otiorhynchus sulcatus F., for several months each year. Therefore, a potting media amendment aimed at controlling BVW needs to persist for an extended period of time. These studies were conducted to determine the persistence and ecology of Metarhizium anisopliae (MetchnikoV) Sorokin incorporated into peat and bark-based potting media with and without a crab meal amendment in container-grown Picea abies ‘Nidiformis.’ Rooted cuttings of P. abies were planted into potting media amended with M. anisopliae (1 g of formulated product/L; »6 log10 CFU/g dry potting media). The fungal population in bulk potting media was quantitatively determined using selective media at 14, 21, 28, 35, 49, 63, 77, 91, 105, 119, 143, 175, 203, 231, 258, 287 and 342 days. The fungal population in the rhizosphere was quantitatively determined at 203, 231, 258, 287, and 342 days. M. anisopliae colonized the rhizosphere of P. abies and the fungal population in the rhizosphere was signiWcantly greater than in the surrounding bulk media. M. anisopliae persisted in the peat and bark-based potting media at 6.22 and 5.74 log10 CFU/g dry potting media for 342 days, respectively. Bioassays using bark and peat-based potting media inoculated with M. anisopliae at 6 log 10 CFU/g dry potting media resulted in 93.5% and 97.5% infection of last instar BVW, respectively. P. abies roots inoculated with M. anisopliae infected 76% of 2nd–3rd instar BVW. Inoculation of roots with M. anisopliae represents a novel method for delivering entomopathogenic fungi and would greatly reduce application costs. Factors associated with fungal biology outside the host may be more important than virulence in a laboratory bioassay.

The black vine weevil Otiorhynchus sulcatus (F.) is the primary insect pest of field and container-grown woody ornamentals in the Pacific Northwest (PNW). These studies were conducted to determine the natural occurrence of soil-borne entomopathogens in PNW nursery soils and determine their virulence to black vine weevil. Soil samples were collected July–September of 2002 from field-grown woody ornamental nursery stock in Oregon, Washington, and Idaho. Sample collection in each state took place in the major nursery production areas. A total of 280 samples was collected (Oregon, 170; Washington, 50; Idaho, 60). Entomopathogens were isolated using insect baiting (nematodes and fungi) as well as semiselective media (fungi). Bacillus thuringiensis Berliner was isolated through sodium acetate selection. Soil-borne entomopathogenic fungi occur widely throughout the major nursery production areas in the PNW. The entomopathogenic fungi Metarhizium anisopliae (Metchnikoff) Sorokin, Beauveria bassiana (Bals...

The entomopathogenic fungus Beauveria bassianainfects a wide range of insects and survives as a soil saprophyte and a plant endophyte. The objective of our study was to determine the role of rainfall in dispersing B. bassiana(Balsamo) Vuillemin to the surface of corn (Zea mays) from soil with different levels of crop residue. Laboratory studies which simulated field tillage systems, had levels of crop residue which covered 0.53 (control), 34, 59 and 84% of the soil surface. Simulated rainfall in a raindrop tower at an intensity of 73 mm/h caused a significant increase in the mean number of B. bassianacolony forming units (CFU) isolated from the surface of corn plants. Plants receiving rain had a mean (±S.E.M.) of 8.8 ± 2.8 CFU per plant; controls had a mean of 0.03 ± 0.01 CFU per plant. The mg of soil collected from the surface of plants also was significantly influenced by rainfall. Plants receiving rain had a mean of 15 .7 ± 1.7 mg of soil per plant while controls had a mean of 3.4 ± 0.4 mg of soil per plant. Linear regression revealed highly significant negative relationships between the mean mg of soil and the mean number of CFU per plant, over the four levels of crop residue. The amount of soil and number of CFU per plant decreased significantly with increasing levels of crop residue. In field studies with conservation- and no-till systems, results were similar to those recorded in the raindrop tower. The mean number of CFU and mg of soil per plant were both higher in conservation-till plots than in no-till plots, where surface residue averaged 45 and 95%, respectively. Rainfall plays an active role in the dispersal of B. bassianafrom the soil environment to the surface of whorl-stage corn. Increased levels of crop residue reduce the amount of soil and fungal transfer to the surface of young corn. © 2002 Elsevier Science B.V. All rights reserved.

In August 2008, the first detection of the spotted wing drosophila, Drosophila suzukii, to the North America mainland in California caused great concern, as the fly was found infesting a variety of commercial fruits. Subsequent detections followed in Oregon, Washington, Florida and British Columbia in 2009; in Utah, North Carolina, South Carolina, Michigan, and Louisiana in 2010; and in Virginia, Montana, Wisconsin, Pennsylvania, New Jersey, Maryland and Mexico in 2011. In Europe, it has been detected in Italy and Spain in 2009 and in France in 2010. Economic costs to the grower from D. suzukii include the increased cost of production (increased labor and materials for chemical inputs, monitoring and other management tools) and crop loss. An effective response to the invasion of D. suzukii requires proper taxonomic identification at the initial phase, understanding basic biology and phenology, developing management tools, transferring information and technology quickly to user groups, andevaluatingtheimpactoftheresearchandextensionprogramonaneconomic,social,andenvironmentallevel.AsD.suzukii continues to expand its range, steps mustbe initiated in each new region to educate and inform the public as well as formulate managementtactics suitable for the crops and growing conditions in each. c � 2011 Society of Chemical Industry

Nosema pyrausta is an obligate pathogen causing reduced fecundity and longevity of Ostrinia nubilalis. This study was conducted to determine the combined effects of N. pyrausta infection and temperature on O. nubilalis egg production and hatch. N. pyrausta-infected and noninfected O. nubilalis were maintained in two different temperature regimes. The first regime allowed females to oviposit under optimum conditions (27 degrees C, 65% RH, 16:8 (L:D)), while females in the second regime were held initially under the same humidity and light conditions, but a constant temperature of 16 degrees C for 1 week after which they were transferred to optimum ovipositional conditions. Studies were performed initially with O. nubilalis populations and later with individual mating pairs. In studies with O. nubilalis populations, the mean number of eggs laid per female under optimum conditions was 660, while N. pyrausta-infected females held initially at 16 degrees C laid 116 eggs per female. In studies with individual mating pairs, N. pyrausta infection reduced egg production per female 53 and 11% in the 16 and 27 degrees C temperature regimes, respectively, compared to noninfected females under optimum conditions. Exposure to 16 degrees C temperatures early in the ovipositional period had a more profound impact on reducing egg production in N. pyrausta-infected than noninfected O. nubilalis.

The influence of adjacent habitats, trap location, and trap height on capture numbers of predators and a parasitoid were monitored in Iowa cornfields using insect traps (Gempler's . AM No-Bait). Traps re fastened to a single wood lathe (122 by 3.8 by 1.3 cm) with wire ties at and 1 m above ground level. Traps at the 2 heights were placed in corn and their adjacent habitat. The adjacent habitat consisted of 1 of 3 types- herbaceous, wooded, and intermediate. Adjacent habitat did not significantly influence the number of Macrocentrus grandii Goidanich (Hymenoptera: Braconidae) captured but slid influence the capture of Coleomegilla maculata (De Geer) (Co-leoptera: Coccinellidae), Coccinella spetempunctata L. (Coleoptera: Coccinellidae), and Chrysoperla carnea Stephens( Neuroptera: Chrysopidae ) with increased captures from fields with the herbaceous and intermediate habitats. Distance that traps were placed in corn and trap height significantly influenced numbers of M. grandii and C. maculata captured. Significantly more M. grandii and C. maculata were captured from traps 11 m into corn than from traps 2.5 m into corn or in the adjacent habitat. Capture rates of M grandii also were significantly higher on traps 1 m above ground. Data from this research indicate that M. grandii is synchronized with its host Ostrinia nubilalis (Hubner), in central Iowa.

An epizootic is defined as an outbreak of disease with an unusually large number of cases. A central question in insect pathology is: what are the factors that cause an epizootic? The question is addressed through epizootiology, the study of animal disease dynamics on a population level. The major factors influencing an epizootic can be divided into four basic components: the pathogen population, the host population, transmission, and the environment. The question pertaining to the causes of an epizootic is of great interest to all aspects of insect pathology, and particularly to microbial control efforts. Microbial control can be defined as the use of entomopathogens (viruses, fungi, bacteria, protists, or nematodes) for pest suppression. This chapter presents a summary and analysis of epizootiological principles and concepts of microbial control. The goal is to promote expanded studies in epizootiology, and foster research and implementation toward improved microbial control programs.

Understanding habitat selection of fungal entomopathogens is critical to improve the efficacy, persistence and cost of these fungi as microbial insecticides. This study sought to determine the prevalence of Metarhizium and Beauveria spp. isolated from the rhizosphere of strawberry, blueberry, grape and Christmas tree crops in the Willamette Valley of Oregon. Entomopathogenic fungi were assigned to thirteen species based on molecular phylogenetic criteria. Four species of Metarhizium were isolated including Metarhizium brunneum, Metarhizium guizhouense, Metarhizium robertsii, and Metarhizium flavoviride var. pemphigi. Nine Beauveria species were isolated including, Beauveria brongniartii, an undescribed species referred to as Clade C and seven phylogenetic species of Beauveria bassiana. Strawberries and blueberries were significantly associated with M. brunneum and Christmas trees with M. guizhouense and M. robertsii. Grapes were significantly associated with B. bassiana phylogenetic species Bbas-16. All of the Metarhizium isolates screened were pathogenic to Otiorhynchus sulcatus larvae in laboratory bioassays but only M. brunneum and M. robertsii caused significant levels of infection. The study results suggest that certain species of Metarhizium and Beauveria are significantly associated with the strawberry, blueberry and Christmas tree rhizosphere and could potentially provide better control of O. sulcatus.

Over 2,500 species of insects and mites are destructive to nursery crops in the United States (Johnson and Lyon, 1991). Likewise, there is a large and diverse number of nursery plant species used in different landscape settings and geographic regions. Nursery and landscape plants represent a complex challenge for insect control products because of the large number of plant species, insect pests, growing conditions, potting media, and production techniques (Martin, 1997).