Slugs Mice / voles Crows Moles turf

Transcription

1 ENT 695 Lync #4 Vertebrates and crop damage stretching diagnosis Soil / Early crop stand and turf pests Slugs Mice / voles Crows Moles turf Slugs Phylum Mollusca Soft body Head foot, body mass, mantle Radula toothed tongue Radula slug scraper or rasp Tears at plant tissue Slime trails left by slugs Movement Defense Moisture control Trail finding Life cycle Eggs or juveniles are over wintering stages Juveniles Adults 1

2 Predisposing conditions Reduced tillage no till protects eggs in soil, greater survival other stages, keeps soil cool and moist Corn stubble Rasped foliage surface scraping Meadow slug Cotyledon and stem damage to soybeans Plants clipped below cotyledon will die Seedlings clipped above cotyledon normally survive with almost no yield loss Girdling damage effect varies Elongate lesions on corn leaves Note heavy grass cover Armyworm feeding comes in from edges 2

3 Armyworm feeding Damage above growing point less important Cool temperatures slow plant growth slugs still active Early planted rows escaped slugs Slugs are not affected by insecticides Residue and plants compete with bait Urea application sporadic success at best may not harm crop, unlikely to be available Slug management row crops Slug management row crops Surface residue reduction especially with predicted mild winter Slugs in landscape Delayed planting cool, moist spring Row sweep / cleaner 3

4 Habitat modification More sunlight pruning Dry air drip irrigation Remove shelter boards, stones, ground covers Vegetation modification Slugs like: Seedlings Succulent foliage Vegetation modification Slugs don t like: Grasses Plants with stiff leaves Highly scented foliage Woody ornamentals Steep vertical sides Fermenting bait beer, sugar water + yeast Collection area a few feet Compete with available shelter Traps We ve licked the slug problem, Stan. No need for a beer trap tonight! I think I just saw one out of the corner or my eye. I ll go get another can. Shelter traps Tin pan with brick or weight Shelter 4

5 Barriers Slugs avoid crossing dry, dusty surfaces, scratchy surfaces Dry ashes Sand Diatomaceous earth DE Barriers Copper reacts with slime to disrupt nervous system causes shock 1 inch high, 3 inches wide lose effectiveness when wet Pennies Bands Slug baits pellets Metaldehyde (Deadline ag product toxic to dogs and cats; attractive to dogs, equipment Best when warm & sunny cause desiccation Iron phosphate (Slug go, Escar go) safer, slugs stop eating better on snails, in more humid situations Compete with available food Field mice / voles Live in colonies populations can explode mild winters Eat green surface vegetation seeds if vegetation is sparse 30 mice per acre can cause 80% to 100% stand reductions 5 colonies per acre 30 days before planting Managment Remove hay or graze before planting Low mowing in fall Controlled burn of cover in late winter Early preplant herbicides Check fields in late winter for vole activity Managment Predators hawks, owls, coyotes, foxes, etc. No registered toxicants Broadcast alternative food before planting coarse cracked corn Protect corn until 8 tall 5

6 Mice Factoids Require full canopy cover for protection against predators Feed day and night do not hibernate Favored habitat rolling hill field or dry ridge Feeding range 10 to 15 feeding range if food is plentiful ¼ acre more normal No till corn into sod Note pattern Heavy grass cover Long gaps in row no kernels Gnawed stalk Field mouse hole 6

7 Crow damage Seedlings pulled kernel missing Thiram fungicide Crow damage Crows respond to visual clues, other birds See seedlings in open areas, not is high overgrowth Moles Crumbled soil No visible entrance Preferences Moist, sandy, loamy soils irrigated, fertilized lawns Main characteristics refuge habitat and food source Move in response to food supply and soil moisture Male ranges over 2 ac; female < 3/4 ac Big Eater Food primarily earthworms also eats insect larvae, slugs, etc. 25% to 50% of body weight per day 5 oz mole eats estimated 45 lbs of earthworms worms and insects/year 7

8 What s the difference? Deep runs deep and fairly straight, connect feeding areas Subsurface runs stem in all directions Deep runs Straight often follow borders Used daily Soil from deep tunnels deposited on surface thru short vertical tunnels Subsurface runs Few or no mounds produced Just below surface May be used daily, weekly, or only once Life cycle Breeding late March or early April Gestation 28 to 45 days Litters 2 to 5 Pups independent in 30 to 40 d Mature by next breeding season Life span unknown < 3 yrs Baits Kaupt Mole Gel Bait warfarin anticoagulant Talpirid bromethalin not an anticoagulant 8

9 Talpirid Label Use in lawns, parks, around homes, golf courses, ornamental gardens, nurseries, and other non crop grasslands Apply underground in main runways or subsurface feeding tunnels Puncture top of subsurface runway with narrow rod bait those sealed within 72 hrs Wear gloves when handling Oral LD 50 2,000 mg/kg Dermal LD 50 > prolonged or frequent skin contact can cause allergic reaction Toxic to fish, birds, and other wildlife Others Molexit castor oil based repellent. Scattered over surface Mole Chaser Sonic repeller may have temporary effect Yellowstriped armyworm Lepidoptera: Noctuidae Cutworm armyworm family Bare body, stripes Yellow Y on head like FAW Black spot on side of thorax 1 1/4 inches mature Yellow lateral stripe on each side Black spot on side of 4 th segment behind head Black triangles along back Body color gray brown green black Multivoltine 3 to 4 generations/yr Found in field and greenhouse Broadleafed plants Greens, tomatoes & peppers (leaves and fruit), beans, cucurbits, cole crops, tobacco, soybeans, corn 9

10 Life cycle Winters as pupa in soil About 200 eggs / mass on underside of leaves Young larvae feed in groups and skeletonize leaves Disperse and chew irregular holes in leaves Tomato fruit Larval feeding stage about 10 days life cycle about 1 month Control Organic control Bt products (Bacillus thuringiensis) for small larvae stomach only Entrust (spinosad) stomach or contact Capt Jack s Dead Bug Brew Pyrethrins contact or stomach 10