scholarly journals Screening of Predatory Mites as Potential Control Agents of Pest Mites in Landscape Plant Nurseries of the Pacific Northwest

2000 ◽  
Vol 18 (4) ◽  
pp. 218-223
Author(s):  
P.D. Pratt ◽  
B.A. Croft
Keyword(s):  
Biological Control ◽  
Life History ◽  
Pacific Northwest ◽  
Spider Mite ◽  
Life History Traits ◽  
Predatory Mites ◽  
Spider Mites ◽  
Landscape Plant ◽  
Landscape Plants ◽  
The Pacific

Abstract To select a biological control agent for suppression of spider mites on landscape plants in western regions of the Pacific Northwest, we compared life history traits of Galendromus occidentalis Nesbitt, Neoseiulus californicus (McGregor) and Neoseiulus fallacis (Garman). We also evaluated abilities of these predatory mites to suppress spider mites in 4 landscape plant species under field conditions. Comparing life history traits from the literature, intrinsic rate of increase was similar between the 2 Neoseiulus species but lower for G. occidentalis. Prey killed per day was greatest for G. occidentalis > N. fallacis > N. californicus. For overwintering abilities, N. fallacis and G. occidentalis are indigenous to the Pacific Northwest and will survive winter assuming overwintering sites are available, but survival of N. californicus is unlikely. Neoseiulus californicus has the widest prey range, G. occidentalis the narrowest, with N. fallacis intermediate. When inoculated into spider mite infested landscape plants, N. fallacis was equally effective at suppressing spider mites as G. occidentalis in either Malus rootstock or Acer shade trees. Further tests with N. fallacis or N. californicus on Spiraea and Rhododendron plants suggested that N. fallacis is equally or more effective at suppressing pest mites, respectively. Compared with the other candidates, N. fallacis was equally effective at controlling pest mites and has a wider prey range than G. occidentalis. Neoseiulus fallacis appears to be the best candidate for biological control of multiple spider mite species on landscape plants in these parts of the Pacific Northwest.

scholarly journals Banker Plants: Evaluation of Release Strategies for Predatory Mites

2000 ◽  
Vol 18 (4) ◽  
pp. 211-217 ◽  
Author(s):  
P.D. Pratt ◽  
B.A. Croft
Keyword(s):  
Spider Mite ◽  
Predatory Mites ◽  
Spider Mites ◽  
Predatory Mite ◽  
Wind Integration ◽  
Landscape Plant ◽  
Banker Plant ◽  
Predaceous Mites ◽  
Plant Foliage ◽  
Commercial Landscape

Abstract Spider mites (Tetranychidae) are among the most injurious pests of commercial landscape plant nurseries. The introduction of predaceous mites (Phytoseiidae) into nursery crops for control of spider mites can be an effective alternative to pesticides. We sought to evaluate the use of banker plants as a method of rearing and dispersing predatory mites for the control of spider mites in landscape nursery systems. Banker plants include any plant addition that aids in development and dispersal of predators for control of herbivorous pests. Addition of the predatory mite Neoseiulus fallacis (Garman) into spider mite infested arborvitae and rhododendron banker plants held in replicated greenhouse cubicles resulted in more predatory mites dispersing to spider mite infested plants downwind than were originally inoculated. To improve persistence and subsequent dispersal of predatory mites in an arborvitae banker plant, we evaluated the use of adding supplemental prey (spider mites) and applying a portion of the plant foliage with a pyrethroid to provide a refuge for the prey. Reintroduction of prey increased the dispersal duration of N. fallacis but the pyrethroid-based refuge did not. Predatory mites dispersing from arborvitae banker plants of approximately 1.25 m (4.1 ft) tall were collected from receiver plants at 10, 20 and 30 m (10.9, 21.9 and 32.8 yd) down wind. Integration of a banker plant system into a landscape nursery operation is discussed.

First Report of Powdery Mildew of Nandina domestica Caused by Microsphaera berberidis (Erysiphe berberidis) in the Pacific Northwest

2003 ◽  
Vol 4 (1) ◽  
pp. 30 ◽  
Author(s):  
Dean A. Glawe
Keyword(s):  
Powdery Mildew ◽  
Pacific Northwest ◽  
Host Species ◽  
Puget Sound ◽  
First Report ◽  
Landscape Plant ◽  
Landscape Plants ◽  
The Pacific ◽  
Microscopic Features ◽  
Plant Grown

Nandina domestica is a bamboo-like landscape plant grown widely in the Pacific Northwest. In 2000 through 2002, powdery mildew was observed on landscape plants of N. domestica in cities in the Puget Sound region. Microscopic features of the fungus present in these specimens fit those of Microsphaera berberidis, previously reported from this host species in Scotland and California. Accepted for publication 29 September 2003. Published 23 October 2003.

First Report of Powdery Mildew of Lycium chinense (Chinese Matrimony Vine) Caused by Arthrocladiella mougeotii in the Pacific Northwest

2004 ◽  
Vol 5 (1) ◽  
pp. 16
Author(s):  
Dean A. Glawe
Keyword(s):  
North America ◽  
Powdery Mildew ◽  
Medicinal Plant ◽  
Pacific Northwest ◽  
Morphological Features ◽  
Lycium Chinense ◽  
First Report ◽  
Landscape Plant ◽  
The Pacific ◽  
Plant Grown

Chinese matrimony-vine (Lycium chinense Mill.) is a traditional medicinal plant grown in China and used as a perennial landscape plant in North America. This report documents the presence of powdery mildew on L. chinense in the Pacific Northwest and describes and illustrates morphological features of the causal agent. It appears to be the first report of a powdery mildew caused by Arthrocladiella in the Pacific Northwest. Accepted for publication 10 November 2004. Published 8 December 2004.

scholarly journals Temporal Asynchrony of Adult Emergence Between Leucopis argenticollis and Leucopis piniperda (Diptera: Chamaemyiidae), Predators of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae), with Implications for Biological Control

2020 ◽  
Vol 49 (4) ◽  
pp. 823-828
Author(s):  
Alex N Neidermeier ◽  
Darrell W Ross ◽  
Nathan P Havill ◽  
Kimberly F Wallin
Keyword(s):  
Biological Control ◽  
North America ◽  
Pacific Northwest ◽  
Adult Emergence ◽  
Hemlock Woolly Adelgid ◽  
Adelges Tsugae ◽  
Tsuga Heterophylla ◽  
Eastern North America ◽  
Biological Control Agents ◽  
The Pacific

Abstract Two species of silver fly, Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) (Diptera: Chamaemyiidae), from the Pacific Northwest region of North America have been identified as potential biological control agents of hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) in eastern North America. The two predators are collectively synchronized with A. tsugae development. To determine whether adult emergence of the two species of silver fly are also synchronized with one another, we collected adult Leucopis which emerged from A. tsugae-infested western hemlock [Pinaceae: Tsuga heterophylla (Raf.) Sarg.] from four sites in the Pacific Northwest over a 29-d period. Specimens were collected twice daily in the laboratory and identified to species using DNA barcoding. The study found that more adult Leucopis were collected in the evening than the morning. Additionally, the daily emergences of adults over the 29-d sampling period exhibited sinusoidal-like fluctuations of peak abundance of each species, lending evidence to a pattern of temporal partitioning. This pattern could have logistical implications for their use as biological control agents in eastern North America, namely the need to release both species for maximum efficacy in decreasing A. tsugae populations.

METZNERIA PAUCIPUNCTELLA ZELLER (LEPIDOPTERA: GELECHIIDAE), A MOTH INTRODUCED AGAINST SPOTTED KNAPWEED: ITS FEEDING STRATEGY AND IMPACT ON TWO INTRODUCED UROPHORA SPP. (DIPTERA: TEPHRITIDAE)

1991 ◽  
Vol 123 (5) ◽  
pp. 1001-1007 ◽  
Author(s):  
J.M. Story ◽  
K.W. Boggs ◽  
W.R. Good ◽  
P. Harris ◽  
R.M. Nowierski
Keyword(s):  
Biological Control ◽  
Seed Dispersal ◽  
Pacific Northwest ◽  
Biocontrol Agent ◽  
Feeding Strategy ◽  
Centaurea Maculosa ◽  
Spotted Knapweed ◽  
Seed Head ◽  
The Pacific ◽  
Normal Seed

AbstractMetzneria paucipunctella Zeller is a seed head moth introduced for biological control of spotted knapweed, Centaurea maculosa Lamarck, in the Pacific Northwest. A cage study was conducted in Montana in 1987 and 1988 to assess the feeding strategy of the M. paucipunctella larva and its impact on two seed head flies, Urophora spp., also introduced on spotted knapweed. Each moth larva destroyed an average of 8.13 knapweed seeds. Most of the seeds were destroyed prior to seed dispersal in early September but the remaining seeds were attacked in the spring of the following year. Each larva tied an average of 7.0 seeds with silk webbing which allowed for feeding long after normal seed dispersal. Seed survival in cages containing both the moth and the two fly species (4.71 seeds per head) was significantly less than in fly-only cages (9.75 seeds per head). The moth larvae caused extensive mortality to the two Urophora species, especially during the spring months. Moth-caused mortality to U. affinis larvae increased from 19% during June through October to 67% in May of the following year. Mortality to U. quadrifasciata also occurred but did not increase significantly in the spring. Data from 10 field sites showed very little association between M. paucipunctella and the two Urophora species which suggests that the unnatural conditions associated with the cages did not increase the incidence of joint moth and fly attack to individual seed heads. The moth is a valuable biocontrol agent as it is contributing significantly to the overall consumer pressure on spotted knapweed seed heads.

scholarly journals Functional response of two Neoseiulus species preying on Tetranychus urticae Koch 

2017 ◽  
Vol 22 (7) ◽  
pp. 1059 ◽  
Author(s):  
Yuan Zheng ◽  
Patrick De Clercq ◽  
Zi-Wei Song ◽  
Dun-Song Li ◽  
Bao-Xin Zhang
Keyword(s):  
Biological Control ◽  
Tetranychus Urticae ◽  
Spider Mite ◽  
Rate Coefficient ◽  
Handling Time ◽  
Spider Mites ◽  
Functional Responses ◽  
Combined Use ◽  
Mite Infestations ◽  
Tetranychus Urticae Koch

Neoseiulus californicus and N. cucumeris are both potential candidates for the biological control of key pests in China. Whereas N. californicus has mainly been used to control spider mites, N. cucumeris has been released for the control of thrips and spider mites. To understand the potential of the combined use of N. californicus and N. cucumeris to suppress outbreaks of Tetranychus urticae, the predatory performance of these Neoseiulus species against different stages of T. urticae, either separately or in combination, was evaluated by assessing their functional responses in the laboratory. The values of the attack rate coefficient (α) of N. californicus to each stage of T. urticae exceeded those of N. cucumeris, whereas the handling time (Th) of N. californicus was longer than that of N. cucumeris, except when attacking the larvae of T. urticae. Especially at the higher prey densities, N. cucumeris consumed more eggs per day than N. californicus, whereas N. californicus consumed more larvae. Both predators killed similar numbers of nymphs at each density when tested singly. The searching efficiency of the Neoseiulus species decreased with increasing prey densities, and for all stages of T. urticae, the searching efficiency of the Neoseiulus species tested singly was lower than when they were tested together. The study indicates the potential of mixed releases of N. californicus and N. cucumeris for the management of spider mite infestations.

scholarly journals Ecological Characteristics of Ventenata dubia in the Intermountain Pacific Northwest

2015 ◽  
Vol 8 (1) ◽  
pp. 57-71 ◽  
Author(s):  
John M. Wallace ◽  
Pamela L. S. Pavek ◽  
Timothy S. Prather
Keyword(s):  
Life History ◽  
Soil Moisture ◽  
Pacific Northwest ◽  
Seed Bank ◽  
Life History Traits ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Habitat Types ◽  
Wide Range

AbstractVentenata dubia is an exotic winter annual grass that has invaded Conservation Reserve Program (CRP) lands, improved pastures, intensively managed hay fields, and rangelands within the Intermountain Pacific Northwest (PNW). Currently, producers are attempting to develop V. dubia management strategies with little knowledge of its life history traits. We conducted several studies to characterize V. dubia life history patterns. Preliminary germination trials were completed to describe primary and secondary dormancy characteristics. Field studies were conducted to evaluate (1) seed bank persistence patterns, (2) seedling emergence patterns under V. dubia litter, and (3) seedling emergence and phenological development patterns within timothy hay, CRP, and rangeland habitats. Preliminary germination trials suggest that the after-ripening period required for loss of dormancy does not exceed 30 d and that dormancy breakdown peaks at approximately 90 d, after which germination occurs over a wide range of temperatures (9 to 29 C). A small fraction (< 1%) of the seed bank remained germinable up to 3 yr after burial at 2 cm depth in a grassland habitat. Seedling emergence and survival was significantly greater under high V. dubia litter layers (100% cover) compared with bare surface during the drier study year because of higher soil moisture levels maintained under litter. Across habitat types, mean seedling emergence (50% of total) occurred between 33 and 94 growing degree days (GDD) after soil moisture rose above the permanent wilting point in the fall. Seedling emergence periodicity varied among habitat types in relation to spring seedling emergence, ranging from 0 to 13% of total emergence per year. Phenological development differed across sites and years by up to several hundred GDDs but was closely aligned to Julian days. This collection of studies improves our understanding of V. dubia life history traits and will aid integrated weed management strategies in the Intermountain PNW.

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