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Orchardgrass billbug. Orchardgrass, bluegrass and timothy hay 35% (451,500 acres) of grass hay acreage (2004) Estimated value: $158 million Two key pests of orchardgrass: Bluegrass billbug (BB) and Japanese beetle (JB)
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Orchardgrass billbug • Orchardgrass, bluegrass and timothy hay 35%(451,500 acres) of grass hay acreage (2004) • Estimated value: $158 million • Two key pests of orchardgrass: Bluegrass billbug (BB) and Japanese beetle (JB) • 2005 survey on over 800 acres of orchardgrassshowed 40-100% damage from BB & JB • Economic loss estimated at $63 million for 2005(assuming 40% loss per acre)
Billbug species (Family: Curculionidae) • Bluegrass billbug, Sphenophorus parvulus Gyllenhal • Hunting billbug, S. venatus vestitus Chittenden • Orchardgrass billbug, S. venatus confluens Chittenden
Eggstage • Female lay eggs from April-June • Eggs deposited in stems or crown region • 1 female can lay up to 200 eggs over 2-wk period
Larval orgrub stage • About ½ inches long, legless, white in color with brown head, and slightly curved • Early instars feed in stems hollowing them out and leaving sawdust-like frass and excrement around crown • Later instars feed in crown or on roots, 2-3 in below surface
Pupal stage • Occurs during mid-July • About 1-2 inches deep in soil • Appearance similar to adult, but soft and white in color • Pupal stage lasts for 2-3 weeks
Adult stage • 1/4-1/2 in long, distinctive snout, gray to black with tapered abdomen • Emerge from pupa in mid-late July, feed for brief period, followed by overwintering phase • Reemerges in spring, remains active from March through May (temperature dependent, 68-69 °F)
Adult feeding damage • Paired feeding holes starting from late April • Active in late April or May (temperature dependent) • Adults are dormant during fall and winter around grassy areas
Management • Egg-laying female is weak link for targeting management decisions • Only available insecticides are contact insecticides • Sevin XLR Plus, malathion, and methyl parathion • Stubble spray: Apply insecticide immediately after first cutting of hay (3-5 inches of grass stubble) • Begin monitoring for adult weevils before first cutting, or as soon as soil temperatures ≥ 67°F • Look for paired leaf feeding holes in addition to pitfall trap counts of adult weevils
Japanese beetle, Popillia japonica Newman, (Coleoptera: Scarabaeidae)
Japanese beetle • Adult 1/3-1/2 in long, shiny metallic green with copper-brown wing covers • Presence of 5 tufts of white hairs under wing covers with 2 additional tufts of white hairs on abdomenal tip • Fully-developed grub is off-white or grayish in color, about 1/2 - 1 in long, and typically curls into a “C” shape when disturbed • Grub has a distinct head capsule that is brown to orange in color and 3 pairs of true legs
Japanese beetle life history • One generation per year • Egg-laying period from mid-July to early August • Grubs continue to feed on roots until soil temp’s decline below 60°F • Move down 6 inches in soil to escape freezing • Grubs resume feeding in spring and pupate in late May-early June, 1-3 in. deep in soil • Adults emerge in 3 wks, from late June-early July
Japanese beetle management • Early August best time to treat when young grubs are close to soil surface • No insecticides labeled for Japanese beetle in grass hay and pastures • High rate of Sevin XLR Plus • Japanese beetle pheromone trap also an effective way to lure & disrupt the mating cycle of beetles
Bt corn hybrid technology against corn rootworm (CRW) and European corn borer (ECB)
Refuge management (RM) plan for European corn borer (ECB) targeted Bt plants • In non-cotton growing areas, up to 80% with Bt seeds, remaining 20% corn refuge with non-Bt seeds • In cotton growing areas, up to 50% with Bt seeds, remaining 50% corn refuge • Refuge within, adjacent, or up to 1/2 mile from Bt field • Refuge up to 1/2 mile from Bt cornfield, if not treated with insecticide for ECB • Refuge up to 1/4 mile from Bt cornfield, if later treated with insecticide for ECB
Contd…. • A refuge must be planted for every Bt-planted field and must be under farmer’s control • Refuge should be planted at same time as Bt field • Seed mixing not allowed • Refuge and Bt seeds should be planted on fields with similar agronomic and cropping history • Refuge can be planted as strips (min 6-row strips, 12-row strips preferable) within the field, or as blocks within, adjacent, or away from Bt cornfield • Refuge can also be planted along field perimeter or as end rows
RM plan for corn rootworm (CRW)targeted Bt plants • 80% with Bt seeds, remaining 20% corn refuge with non-Bt seeds • Refuge can be treated with soil-, seed-, and foliar-applied non-Bt insecticides • For ECB, non-Bt insecticides can be used in both Bt and refuge fields • Refuge must be within or adjacent to Bt field • Corn refuge can include Bt seeds for ECB, Roundup Ready corn, and conventional corn
Contd…. • A refuge must be planted for every Bt-planted field and must be under farmer’s control • Refuge should be planted at same time as Bt field • Seed mixing not allowed • Refuge and Bt seeds should be planted on fields with similar agronomic and cropping history • Refuge can be planted as strips (min 6-row strips, 12-row strips preferable) within the field, or as blocks within or adjacent to Bt cornfield • Field perimeters or end rows to corn refuge
Refuge management for ECB and corn rootworm targeted Bt plants (Stacked Bt hybrids) Strategy 1 - Common refuge areas • Refuge area at least 50% of stacked hybrid acreage • As adjacent block, perimeter strips, or in-field strips • If strips, at least 6 rows wide, preferably 12 rows wide • Refuge area can be treated with soil-, seed-, and foliar-applied non-Bt insecticides • If corn rootworm adults present in refuge at time of overhead or aerial insecticide application, same treatment must be made to stacked Bt corn acreage
Refuge management for ECB and corn rootworm targeted Bt plants (Stacked Bt hybrids) Strategy 2 - Separate refuge areas • ECB refuge area within ½ mile & at least 50% of stacked Bt corn acreage • Corn rootworm refuge area at least 20% of stacked Bt corn acreage • As adjacent block, perimeter strips, or in-field strips • Refuge area can be treated with soil-, seed-, and foliar-applied non-Bt insecticides • If corn rootworm adults present in refuge at time of overhead or aerial insecticide application, same treatment must be made to stacked Bt corn acreage
Layout of the refuge area Adjacent fields Blocks in fields Strips in fields Perimeter in fields Bt-planted area Non-Bt planted refuge area