pulse insect issues · pea leaf weevil •sitona lineatus –adults emerge in spring •temp >20...
TRANSCRIPT
Pulse Insect Issues
James Tansey PhD
Provincial Specialist, Insect/Pest Management
Pea Leaf Weevil
• Sitona lineatus– Adults emerge in spring
• Temp >20° C for more than a few days in late April/early May, weevils arrive in fields early, higher yield losses
• Notch feeding on alfalfa, clover, dry beans, faba beans, field peas
• Can kill plants, reduce pod production• 1000-1500 eggs/female• Egg to adult in 10 weeks with new generation
adults late July through August
– Larvae• Will complete development on peas, faba• Consume Rhizobium leguminosarum in
nodules• Reduces N fixation• 27% yield loss
Photo: C. Herle, AAFC-Lethbridge
Photo: Saskatchewan Ministry of Agriculture
Photo: Saskatchewan Ministry of Agriculture
Pea Leaf Weevil
– Scouting• 3-6 node stage (late May to
mid June)
• 10 locations/field, 25m apart
• 10 seedlings per location
• Look for notches in leaves and damage to ‘clam’ leaf– Yield loss: 30% of seedlings
have damage to ‘clam’ leaf
– six node stage: take no actionFigure: Modified from Prairie Pest Monitoring Network
Pea Leaf Weevil– “…pea crops in soils with high levels of soil N are unlikely to be
affected by this herbivore and should not require insecticide inputs” (Carcamo et al 2015)
• Cultural– Crop rotation– Recent evidence that N fertilization can help– Seed inoculation with R. leguminosarum– Zero-till– Early-planted border strips as a trap crop
• Chemical– Seed treatments (Peas and Faba)
» Cruiser Maxx Vibrance Pulses (N - thiamethoxam), Cruiser 5FS (N -thiamethoxam), Stress Shield 600 (N - imidacloprid)
» Base treatment on previous year’s local pressure
– Foliar insecticides – Peas only» Matador/Silencer (P - lambda-cyhalothrin)
» Mixed results
Pea Leaf Weevil– Natural enemies
• Small ground beetles eat eggs
– E.g. Bembidion quadrimaculatum
• Large ground beetles eat adult and larval weevils
– E.g. Pterostichus melanarius
• Wolf spiders eat adult weevils
– E.g. Hogna frondicola
Photo: Coleoptera.org
Photo: bugguide.netPhoto: bugguide.net
Pea Aphid
• Acrythosiphon pisum– Peas, lentil, chickpea, faba
– Piercing-sucking mouthparts• Feed on lower leaf surfaces, pods – yellowing, wilting
• Reduce yield but not quality
• Vector plant diseases
– Adults 3-4 mm (large by aphid standards)
– 15 generations per year• Females only in spring/summer
– Parthenogenesis – clones
– 4-12/young day
– 7-12 days for adult from birth
Photo: USDA
Photo: MB Agriculture
Photo: influential points.com
Pulse Pests
Photo: USDA
Photo: influential points.com
Photo: influential points.com
Figure: Modified from Jaqueiry et al. (2013)
Winged females at any time if crowded or poor host quality
Shorter day lengths – sexual reproduction
Pea Aphid• Scouting
– Check at the beginning of flowering– 5 locations per field, approx 50 m apart– 20 sweeps per location
• Aphid counts• Aphid volume (field peas)
– Control if» Moderate to heavy» <10% parasitized» Few natural enemies
– Examine 5 plant tips (20 cm)• Aphid counts
Ph
oto
: USD
A
Photo: influential points.com
Photo: Government of Western Australia
Table: Perdue Field Crops IPM
Pea Aphid
• Lentils– Consider insecticide
• 30-40 aphids/sweep
• Few natural enemies
• Population sustained or increases over 2 days
• Field pea– Consider insecticide
• 2-3 aphids per plant tip or 9-12 aphids per sweep
• Apply when 50% of plants have produced some young pods
• Assumes – crop is worth $0.21/kg ($5.71 / bushel)
– cost of control is $16.63 - $22.86/ha ($6.73-$9.25/acre)
– ‘Century’ field peas – other varieties may be more tolerant
Photo: USDA
Photo: influential points.com
Perdue Field Crops IPM; Gavloski 2017
Aphid Control Products
• Chickpea: Beleaf (F), Movento (TT), Matador/Silencer (P), Voliam Xpress (D+P)
• Dry Bean: Movento (TT), Matador/Silencer (P), VoliamXpress (D+P), Lannate (C), Malathion 85E (OP), Lagon/Cygon 480 EC (OP), Dibrom (OP)
• Faba: Beleaf (F), Matador/Silencer (P), Voliam Xpress (D+P)
• Lentil: Movento (TT), Matador/Silencer (P), VoliamXpress (D+P)
• Peas: Movento (TT), Matador/Silencer (P), Voliam Xpress (D+P), Lannate (C), Malathion 85E (OP), Lagon/Cygon 480 EC (OP)
Soybean Aphid• Aphis glycines
– Soybean aphid
– Yellow-green, black cornicles
– Invasive - N. America 2000• Does not overwinter in Canada
– Appear as early as late June• Occasional economic pest
– Colonies can double in 1.3 days
– Honeydew • Substrate for sooty mould
Photo: MB Agriculture
Photo: Tilmon et al. 2011
Soybean Aphid• Feeding
– Reduces plant growth, pod and seed number
– Seed weight and oil concentration
– Yield by 40% under high pressures
– Phloem feeding• Interferes with photosynthetic pathway
• Vectors viruses (e.g. soybean mosaic virus)
• Stunted, yellow plants
• Leaf distortion
Photo: MB Agriculture
Photo: Tilmon et al. 2011
Soybean aphid• Scouting
– Monitor weekly R1-R5– Count aphids on 20 whole plants at 5 locations/field
• 20 m apart • W pattern recommended
• Action threshold– 250 aphids/plant– >80% plants have aphids– Plants not yet R6 (full seed)– Populations on the rise
• Economic Injury– 675 aphids/plant
• Products– Movento (TT), Matador/Silencer (P), Voliam Xpress (D+P), Concept (N
+ P), Lagon 480 E /Cygon 480 EC/Cygon 480-AG (OP)
Photo: MB Agriculture
Ragsdale et al. 2007; Guide to Crop Protection 2018
Lacewing larva
Lacewing adult
Lacewing eggs
Hoverfly larva
Predatory mite
Minute pirate bug
Damsel bug
Photo: Hobby Farms
Photo: TC Permaculture Photo: Flickr
Photo: NC Extension
Photo: Oregon State
Generalist Natural Enemies
Hoverfly adult
Photo: NC Extension
Ladybug adultPhoto: Cornell Extension Collops
Ladybug larvaPhoto: Flickr
Ladybug pupa
Photo: Flickr
Wireworms
• Click beetle larvae (Elateridae)
– Hypnoides and Selatosomus spp prefer non-irrigated land
– Limonius spp prefer irrigated land
– Can live 4 to 11 years in the soil
– Can survive for at least two years without any food other than humus
• Feed on underground parts causing wilting and plant death
Wireworms
• The longer a field is in cereals or pasture, the higher the pest population and potential for greater crop damage
• If crop grown in newly broken light soils, wireworm control is usually necessary
• Previous crop damage indicates large wireworm population
• Seed treatments– Chickpea, Faba, Lentil, Peas
• Cruiser Maxx Vibrance Pulses (N), Cruiser 5FS (N), Stress Shield 600 (N)
– Dry Bean• Cruiser Maxx Vibrance Beans (N), Cruiser 5FS (N), Stress Shield 600 (N)
– Soybean• Fortenza (D), Cruiser Maxx Vibrance Beans (N), Cruiser 5FS (N), Stress Shield
600 (N), Alias 240 SC (N), Sombrero 600 FS (N)
Two-spotted Spider Mite
• Tetranychus urticae
– Very broad host range
– Very small, can be very numerous
– Characteristic webbing
– Feeding destroys cells, produces chlorotic, mottled leaves, leaf senescence
Photo: Cornell Extension
Photo: U Nebraska Extension
Photo: Iowa State University
Two-spotted spider mite
• Scouting– Look under leaves
– Webbing is conspicuous
– Tap sample • place a clip board or tray below plant and give it a few taps to
dislodge mites
– No thresholds for field crops• Products
– Dry bean: Oberon (TT), Cygon 480-AG (OP)
– Soybean: Lagon 480 E /Cygon 480 EC / Cygon 480-AG (OP)
• Chemical control of mites can result in flare-ups due to effects on natural enemies
Cutworms• Larvae feed on weeds before seedlings
emerge • Root and surface feeding• Pale western cutworm
– Agrotis orthogonia– Prefer cereals– Southern Prairies– Dry May and June– Overwinter as eggs laid in soil – Eggs hatch in spring
• Redbacked cutworm– Euxoa ochrogaster– Overwinter as eggs laid in soil – Eggs hatch in spring
Photo: J. Capinera
Photo: J. Gavloski
Cutworms
Figure from Floate 2017
Cutworms
• Scouting
– Growing areas of bare soil after crop emergence
– Inspect bare patches, margins for larvae
– Count larvae on surface and in top 2-6 cm soil (dig)• 50 cm x 50 cm
• Count x 4 = /m2 count
• Repeat 5-10 times at 50 m intervals
• Thresholds
– 2-3 larvae/m2
– 25-30% stand reductions
Cutworms• Products
– Chickpea, Dry bean, Soybean: Coragen (D), Matador/Silencer (P)
– Faba: Coragen (D)
– Lentil: Coragen (D), Decis 5EC/Poleci (P), Matador/Silencer (P), Pounce 384EC/Perm-UP (P) Ambush (P), Chlorpyrifos (pale western cutworm only) (OP)
– Peas: Coragen (D), Matador/Silencer (P), Pounce 384EC/Perm-UP (P) Ambush (P)
Photo: Bugguide.net
Cutworms• Natural enemies of cutworms
– Consider when controlling with insecticide
Photo: Bugguide.net
Photo: Canola digest
Photo: USDA
Photo: Bugguide.net
Photo: Alberta Farmer Express
Photo: Vincent Hervet, AAFC
Lygus spp.• Lygus lineolaris, L. elisus and L. borealis in
Parkland Ecoregion• L. elisus, L. keltoni dominant species in drier
areas– Move into crops from other plants in July. Edge
effects– Piecing-sucking feeders
• Can cause quality loss in faba (move from canola after harvest)
• Can cause chalk spot in peas, lentil• ETs
– Lentil: ET 7-10 adults/25 sweeps during blooming and podding
• Products– Faba: Beleaf 50SG (F), Matador/Silencer (P)– Lentil: Matador/Silencer (P)– Dry beans: Beleaf 50SG (F), Matador/Silencer (P), Sevin
XLR (C), Cygon 480-AG (OP)
Lygus lineolaris adult
Photo: J. Gavloski
Lygus nymph
Photo: D. Johnson
Lygus elisus adult
Photo: H. Kim
Lygus spp.
Necrotic seed perforations in faba beans
Photo: M. Dolinski
Photo: D. Johnson
Photo: J. Knodel Chalk spot in pea
Chalk spot in lentil
Photo: J. Knodel
Potato leafhopper• Empoasca fabae
– Very small (1-2 mm)
– Blow in from USA in spring
– Lay eggs on main stems, petioles
– Piecing-sucking feeders
– Foliage becomes dwarfed, crinkled, and curled
– Small triangular brown areas appear at the tips of leaves, gradually spreading around the entire leaf margin
– ET• Dry bean: 1/per trifoliate leaf at fourth trifoliate stage; 2/ trifoliate at
bloom
– Products• Chickpea, Faba, Lentil: Matador/Silencer (P)
• Peas: Malathion 85E (OP)
• Dry bean: Matador/Silencer (P), Sevin XLR (C), Cygon 480-AG (OP)
Potato leafhopper adultPhoto: Ohio State University
Photo: MSU
Photo: Michigan State University Photo: University of Vermont Extension
Grasshoppers• 600 spp. N America, 85 spp. SK
– Few species are pests
– Cereals preferred
– Scouting
• Walk a line from one corner of field to middle, turn and walk straight out to one side
• Count GH that jump from a square foot – Average of 20 sites /2 = GH/ m2)
• ET – 12/ m2 in peas
– 2/m2 in lentils
– 35% defoliation occurs before bloom and 15% after bloom in dry beans
– Products• Peas, chickpeas: Coragen (D), Matador/Silencer (P)
• Dry beans: Coragen (D), Ecobran (C)
• Faba: Coragen (D)
• Lentil: Coragen (D), Matador/Silencer (P), Decis 5E /Poleci (P)
Photo: Bugguide.net
Packard’s
Two-striped
Clear winged
Photo: Bugguide.netMigratory
• 2018 Survey
– 1200 sites
Bean Weevil
• Acanthoscelides obtectus– Not a weevil at all, Chrysomelidae– Adults 6-7 mm
• Last abdominal segments exposed• Feed on foliage and seeds
– Larvae and adults feed on pulses in field and in storage• Adults emerge in spring, feed for 2 weeks• Eggs laid on pods • Larvae burrow into pod, feed on seeds• Larvae chew out after 40 d
– Canada, USA, Africa and Europe• Not widespread in India• India requiring fumigation of pulses coming
from Canada
Photo: Canadian Grain Commission
Photo: Canadian Grain Commission
Photo: Government of Western Australia
QUESTIONS?
Thanks for listening
Ministry of Agriculture websitesPrairie Pest Monitoring Network BlogField HeroesSaskatchewan Guide to Crop ProtectionCutworm Pests of Crops on the Canadian Prairies SaskPulse