Population Dynamics of Spotted Wing Drosophila (Drosophila suzukii (Matsumura)) in Maine Wild Blueberry (Vaccinium angustifolium Aiton)

A long-term investigation of D. suzukii dynamics in wild blueberry fields from 2012–2018 demonstrates relative abundance is either still increasing or exhibiting periodicity seven years after the initial invasion. Relative abundance is determined by physiological date of first detection and air temperatures the previous winter. Date of first detection of flies does not determine date of fruit infestation. The level of fruit infestation is determined by year, fly pressure, and insecticide application frequency. Frequency of insecticide application is determined by production system. Non-crop wild fruit and predation influences fly pressure; increased wild fruit abundance results in increased fly pressure. Increased predation rate reduces fly pressure, but only at high abundance of flies, or when high levels of wild fruit are present along field edges. Male sex ratio might be declining over the seven years. Action thresholds were developed from samples of 92 fields from 2012–2017 that related cumulative adult male trap capture to the following week likelihood of fruit infestation. A two-parameter gamma density function describing this probability was used to develop a risk-based gradient action threshold system. The action thresholds were validated from 2016–2018 in 35 fields and were shown to work well in two of three years (2016 and 2017).

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Population Dynamics of Spotted Wing Drosophila (Drosophila suzukii Matsumara) in Maine Wild Blueberry (Vaccinium angustifolium Aiton)

10.20944/preprints201905.0034.v1 ◽

2019 ◽

Author(s):

Francis Drummond ◽

Elissa Ballamn ◽

Judith Collins

Keyword(s):

Relative Abundance ◽

Predation Rate ◽

Drosophila Suzukii ◽

Insecticide Application ◽

Wild Fruit ◽

Air Temperatures ◽

Action Threshold ◽

Gamma Density ◽

Action Thresholds ◽

Wild Blueberry

A long-term investigation of D. suzukii dynamics in wild blueberry fields from 2012 - 2018 demonstrates relative abundance is still increasing seven years after initial invasion. Relative abundance is determined by physiological date of first detection and air temperatures the previous winter. Date of first detection of flies does not determine date of fruit infestation. The level of fruit infestation is determined by year, fly pressure, and insecticide application frequency. Frequency of insecticide application is determined by production system. Non-crop wild fruit and predation influences fly pressure; increased wild fruit abundance results in increased fly pressure. Increased predation rate reduces fly pressure, but only at high abundance of flies, or when high levels of wild fruit are present along field edges. Male sex ratio might be declining over the seven years. Action thresholds were developed from samples of 92 fields from 2012 - 2017 that related cumulative adult male trap capture to the following week likelihood of fruit infestation. A two-parameter gamma density function describing this probability was used to develop a risk-based gradient action threshold system. The action thresholds were validated from 2016-2018 in 35 fields and were shown to work well in two of three years (2016 and 2017).

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Dispersal From Overwintering Sites, Action Thresholds for Blueberry Maggot Fly (Diptera: Tephritidae), and Factors That Can Influence Variation in Predicted Fruit Infestation Levels in Maine Wild Blueberry: Part I

Journal of Economic Entomology ◽

10.1093/jee/toz333 ◽

2019 ◽

Vol 113 (2) ◽

pp. 851-859 ◽

Cited By ~ 3

Author(s):

Francis A Drummond ◽

Judith A Collins

Keyword(s):

Field Studies ◽

Site Quality ◽

Physiological Status ◽

Rhagoletis Mendax ◽

Action Threshold ◽

Action Thresholds ◽

The University ◽

Blueberry Maggot Fly ◽

Wild Blueberry ◽

Overwintering Site

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.

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IMMEDIATE AND LONG-TERM EFFECTS OF INSECTICIDE APPLICATION ON PARASITOIDS IN JACK PINE STANDS IN QUEBEC

The Canadian Entomologist ◽

10.4039/ent104263-2 ◽

1972 ◽

Vol 104 (2) ◽

pp. 263-270 ◽

Cited By ~ 3

Author(s):

Peter W. Price

Keyword(s):

Relative Abundance ◽

Jack Pine ◽

Ground Vegetation ◽

Long Term Effects ◽

Aerial Application ◽

Insecticide Application ◽

Number Of Species ◽

Adult Parasitoid ◽

Pine Stands

AbstractParasitoid populations were sampled before, and for 4 years following, an aerial application of the insecticide phosphamidon to control a sawfly outbreak. Adult parasitoid mortality was high because of spraying, but a reservoir of parasitoids in host cocoons remained to repopulate the treated areas. In moister sites the number of species decreased and their relative abundance changed, but moderate numbers of parasitoids remained 4 years after spraying. In a dry site with little ground vegetation, none of the species present before spraying remained by the fourth year.

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Pupation Behavior and Predation on Drosophila suzukii (Diptera: Drosophilidae) Pupae in Maine Wild Blueberry Fields

Journal of Economic Entomology ◽

10.1093/jee/tox233 ◽

2017 ◽

Vol 110 (6) ◽

pp. 2308-2317 ◽

Cited By ~ 17

Author(s):

Elissa S Ballman ◽

Judith A Collins ◽

Francis A Drummond

Keyword(s):

Drosophila Suzukii ◽

Pupation Behavior ◽

Wild Blueberry

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Sampling Techniques and Setting Thresholds

Turfgrass Insects of the United States and Canada ◽

10.7591/cornell/9781501747953.003.0026 ◽

2020 ◽

pp. 381-398

Author(s):

Patricia J. Vittum

Keyword(s):

Sampling Techniques ◽

Insect Management ◽

Site Specific ◽

Tolerance Level ◽

Management Regime ◽

Action Threshold ◽

Insect Populations ◽

Action Thresholds ◽

Inspection Techniques ◽

Standard Techniques

This chapter looks at sampling techniques and setting thresholds. The cornerstone of any integrated insect management regime is accurately identifying pest insects (including assessing population density) and developing appropriate action thresholds. Various methods have evolved by which the populations of insects present in the turf environment may be determined relatively rapidly and efficiently. These methods have become standard techniques for reporting insect densities. The chapter differentiates between passive sampling techniques (use of traps) and active visual inspection techniques (actual quantification of insect populations). Thresholds in turf integrated pest management usually are more accurately considered tolerance levels, or action thresholds. The tolerance level, or action threshold, for turfgrass insects is site-specific and depends on many factors.

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Octabor (boron) as a Low Toxicity Control Tactic for the Spotted Wing Drosophila, Drosophila suzukii (Matsumura)

Journal of Agricultural Studies ◽

10.5296/jas.v6i3.13232 ◽

2018 ◽

Vol 5 (4) ◽

pp. 63

Author(s):

Troy Cloutier ◽

Francis Andrew Drummond ◽

Judith Collins

Keyword(s):

Field Study ◽

The United States ◽

Fruit Production ◽

Spotted Wing Drosophila ◽

Drosophila Suzukii ◽

Delayed Effect ◽

Control Fruit ◽

Small Fruit ◽

Sugar Addition ◽

Wild Blueberry

The recently introduced spotted wing drosophila is one of the most serious pests in small fruit production in the United States and Europe. Most control relies upon multiple applications of synthetic insecticides. In an effort to find less-toxic insecticides to consumers, farm workers, and wildlife, we conducted two laboratory trials and a semi-field trial in order to assess the potential for disodium octaborate tetrahydrateformulated and sold as Octabor®(U.S. Borax, Inc.) as a control for spotted wing drosophila in wild blueberry. We found that Octabor at 0.6 and 1.0% (w/v) applied to wild blueberry fruit resulted in higher mortality of flies than non-treated control fruit. Addition of sugar to Octabor enhanced mortality in one of the two trials, with an interaction between sugar addition and Octabor rate suggesting that the addition of sugar provided the greatest enhancement at the low rate. Our semi-field study showed that an apparent repellency effect of Octabor provided protection of fruit from infestation for up to 3 days. Also in the semi-field study, we observed a delayed effect on fly mortality. Increased fly mortality occurred over time, relative to the non-treated control fruit. The greatest fly mortality, relative to the non-treated control, resulted from flies being exposed to fruit treated 3 and 7 days prior to fly exposure, but not immediately after the treatment of Octabor. We speculate on why this type of delay in mortality might have occurred.

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Evaluation of Current Tarnished Plant Bug (Hemiptera: Miridae) Thresholds in Transgenic MON 88702 Cotton Expressing the Bt Cry51Aa2.834_16 Trait

Journal of Economic Entomology ◽

10.1093/jee/toaa075 ◽

2020 ◽

Vol 113 (4) ◽

pp. 1816-1822

Author(s):

J C Corbin ◽

T B Towles ◽

W D Crow ◽

A L Catchot ◽

D R Cook ◽

...

Keyword(s):

Southern United States ◽

Lygus Lineolaris ◽

Tarnished Plant Bug ◽

Current Action ◽

Action Threshold ◽

Important Pest ◽

Current Threshold ◽

Action Thresholds ◽

Insecticide Sprays ◽

Recommended Action

Abstract The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton in many areas of the southern United States. An experiment was conducted at two locations in Mississippi during 2016 and 2017 to evaluate action thresholds for tarnished plant bug on a novel Bacillus thuringiensis cotton that expresses the Cry51Aa2.834_16 toxin. Treatments included the current action threshold, a 2× threshold, and treatments where insecticides were only applied during the early season (preflower) or only during late season (during flowering) based on the current action thresholds. These were compared to an untreated control and a weekly insecticide use regime that received weekly insecticide sprays. All treatments were imposed on both Bt Cry1Aa2.834_16 cotton and a nontraited cotton. The Bt Cry1Aa2.834_16 trait reduced the number of tarnished plant bugs and injury, and improved yields compared to nontraited cotton. For all spray treatments except the weekly insecticide use regime, yields were greater for the Bt Cry51Aa2.834_16 cotton than the nontraited cotton. In terms of thresholds, Bt Cry1Aa2.834_16 cotton sprayed based on current action thresholds resulted in similar yields to the weekly insecticide use regime of both cotton types. In contrast, the 2× threshold resulted in lower yields than the current threshold for both cotton types. Though thresholds intermediate to the currently recommended action threshold and the 2× threshold were not tested, these data suggest that currently recommended action thresholds appear appropriate for Bt Cry51Aa2.834_16 cotton. These results suggest that this trait will be an important component of current IPM programs in cotton where tarnished plant bug is an important pest.

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Spotted-Wing Drosophila (Diptera: Drosophilidae) Adult Movement, Activity, and Oviposition Behavior in Maine Wild Blueberry (Vaccinium angustifolium; Ericales: Ericaceae)

Journal of Economic Entomology ◽

10.1093/jee/toz059 ◽

2019 ◽

Vol 112 (4) ◽

pp. 1623-1633 ◽

Cited By ~ 7

Author(s):

Francis A Drummond ◽

Elissa Ballman ◽

Judith A Collins

Keyword(s):

Oviposition Behavior ◽

Field Studies ◽

Crop Canopy ◽

Drosophila Suzukii ◽

Dispersal Pattern ◽

Long Distance ◽

Vaccinium Angustifolium ◽

Fluorescent Marker ◽

Fluorescent Markers ◽

Wild Blueberry

Abstract Over a period of 5 yr (2012–2016), we conducted laboratory and field studies on activity, movement, and response to trap placement of adult Drosophila suzukii (Matsumura) in wild blueberry, Vaccinium angustifolium Aiton, fields in Maine. When measuring temporal patterns in fruit infestation, we found that D. suzukii females are most active in the morning and that they are 10 times more likely to lay eggs in blueberries at the top of the plant canopy compared with berries located in the lower part of the bush. Flies were found to be more abundant in fruit-bearing (crop) fields compared with pruned (vegetative) fields based on trap capture of adults. They are also most abundant along edges of fields compared with interiors. Trap efficiency is significantly better in traps 1.2 m above the ground and above the crop canopy of this low-growing crop plant than within the crop canopy. Three experiments involving the marking of laboratory-reared flies with fluorescent marker, their release, and capture with traps along a grid in fields suggest that: 1) fluorescent markers do not affect the distance moved of marked flies, 2) dispersal rates are not different between sexes, 3) there is little difference in the dispersal pattern through pruned fields and fruit-bearing fields, and 4) flies disperse at a low rate of 0.1–30 m per day, with an average of 5 m per day, but that long-distance dispersal over 1–2 km is feasible based on statistical model extrapolation.

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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

Insects ◽

10.3390/insects10030080 ◽

2019 ◽

Vol 10 (3) ◽

pp. 80 ◽

Cited By ~ 2

Author(s):

Brittany Willbrand ◽

Douglas Pfeiffer

Keyword(s):

Relative Abundance ◽

Red Wine ◽

Brown Rice ◽

Effective Field ◽

Drosophila Suzukii ◽

Zaprionus Indianus ◽

Apple Cider ◽

Olfactory Preferences ◽

Species Specific ◽

Rice Vinegar

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.

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