Insects in Vegetables: A Review of 2011 and What to Know for 2012 Rick Foster Purdue University
CABBAGE CATERPILLARS
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Diamondback Moth Most serious pest worldwide $1 billion annually Resistant to many insecticides in some places Appear early in growing season Larvae are small (5/16 inch), light green, tapered, and wiggle when disturbed
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Imported Cabbageworm Adults are white butterflies Larvae are velvety green, 1 inch long Relatively easy to control
Cabbage Looper
Cabbage Looper Does not overwinter; late season pest Larvae loop when they crawl Pale green; 1 1/2 inch long Relatively difficult to control
Caterpillar Damage Chew holes in leaves; bore into head Young plants killed Older plants stunted Heads abort or are unmarketable Contamination
Management Options
Cabbage Thresholds Stage Diamondback Moth ICW and Loopers Transplant to cupping 50% with > 5 larvae/plant 30% Cupping to early head 50% with > 5 larvae/plant 20% Early head to harvest 10% with > 1 larva/plant 10%
Broccoli, Cauliflower Thresholds Stage Diamondback Moth ICW and Loopers Seedbed 10 % 10% Transplant to first curd 40% 20% First curd to harvest 10% 10%
Insecticides Pyrethroids Ambush, Asana, Baythroid, Brigade, Hero, Mustang Max, Pounce, Warrior Bt Avaunt Confirm, Intrepid, Rimon Coragen Radiant, Entrust, SpinTor Proclaim Larvin, Lannate
Cabbage Insecticide Trial 2011 Chemical Rate/acre Loopers ICW DBM Yield Untreated 30.0 ab 103.25 a 24.0 ab 10.8 e Coragen 5 fl. oz. 4.25 c 8.5 c 14.25 bc 85.0 a Radiant 10 fl. oz. 7.0 c 8.5 c 8.5 c 77.5 abc Proclaim 4.8 oz. 20.25 abc 16.25 bc 17.0 abc 81.7 ab Agree 2 lb. 35.25 a 9.0 c 12.25 c 71.7 bcd Avaunt 3.5 oz. 16.5 abc 14.75 bc 15.75 bc 65.8 cd Entrust 2.0 oz. 27.5 ab 21.25 b 10.5 c 64.2 d Intrepid 10 fl. oz. 13.75 bc 13.75 bc 30.5 a 65.0 cd Mustang Max 4 fl. oz. 21.25 abc 16.5 bc 18.5 bc 65.8 cd Crymax 2 lb. 23.0 abc 10.5 bc 17.0 bc 67.5 cd
Caterpillars Attacking Sweet Corn Ears European Corn Borer Western Bean Cutworm Corn Earworm
European Corn Borer Two generations per year Declining in importance due to Bt corn
European Corn Borers Per Untreated Ear in Insecticide Trials Lafayette, IN 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 1990 1992 1994 1995 1996 1997 1998 1999 2001 2002 2003 2004 2005 2006 2007 2008 2009
European Corn Borer Management Treatment at pre row tassel is the key Pyrethroid insecticides work well especially Brigade, Mustang Max, Hero and Warrior
Western Bean Cutworm Native to North America, first described in Arizona in 1887 Long time pest of dry land beans and corn Gradual migration to the east, CO, NE, IA 2005, significant moth captures in Illinois 2006, first moths captured in Indiana 2007, first damage documented in NW Indiana 2009, significant damage documented in NW Indiana
WBC Moth Trapping
2011
WBC, 2010 Documented Damage
Western Bean Cutworm 2011 Moth emergence was 2 weeks later than in 2010 Temperatures were very high at peak emergence Egg masses were very difficult to find Damage was greatly reduced compared to 2010 2012?????
First Documented Case of WBC Damage To Sweet Corn In Indiana - 2009
WBC Scouting Egg masses on upper leaves
WBC Scouting Egg masses on upper leaves Hatched larvae in whorl or leaf axils
WBC Threshold No threshold yet My recommendation is to treat if you see larvae
WBC Treatment Foliar insecticides Early instar larvae easy to control Timing is critical whorl stage/ pre row tassel Pyrethroids have provided good control
Corn Earworm Pest of sweet corn, seed corn and tomato Two generations per year where it overwinters 2 nd is usually most important Does not overwinter in large numbers in northern 2/3 of Indiana
Corn Earworm Biology Females prefer to lay eggs on green silks
Corn Earworm Biology Females prefer to lay eggs on green silks When larvae hatch, they move directly into the ear tip Once inside the ear, the larvae are protected from insecticides
Corn Earworm Control Must have insecticide present on silk when larvae hatches from egg Pyrethroids have been primary control options, especially Capture, Mustang Max, Hero, and Warrior Some concerns about resistance Coragen and Radiant appear to be good alternatives
Corn Earworm Management Treat when fresh, green silks are present (start at 70%) Treat if catching more than 10 moths per night
Corn Earworm Management Make treatments every 2 5 days from 70% silks until silks are brown; generally 3 4 treatments Shorten interval if temperatures are high Shorten interval if moth catches are high
Corn Earworm Management First generation populations may or may not reach economic levels During much of the season, few earworms present Once the second generation hits, populations will likely be high for the rest of the season Date of arrival of second generation is variable A pheromone trap is a critical management tool
CEW Management Tips The first application (70% silks) is the most critical, with each succeeding spray being less important Getting good coverage of the silks is imperative consider drop nozzles. Test with water sensitive paper. High gallonage is preferred 20 gallons per acre or more
RELATIONSHIP BETWEEN CORN EARWORM PHEROMONE TRAP CATCH AND EGG LAYING
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What Affects Trap Catch? Full moon suppresses trap catch High relative humidity (50 80%) increased trap catch
What Affects Egg Laying? Egg laying was suppressed during full moon High humidity suppressed egg laying Egg laying was increased (per moth caught in pheromone trap) in early season sweet corn
So, how do we use threshold? In general, we should continue to use 10 moths per night as the threshold for most of the season For early season sweet corn (before nearby field corn in silking, use a threshold of 1.
300 CEW Pheromone Trap Catch 2011 250 Moths Per Week 200 150 100 Pinney Lafayette 50 0
TOMATOES HIGH TUNNELS
Hornworms Hornworms are generally a minor problem in field grown tomatoes
Insects in High Tunnels Popular literature says that most insects will be less serious in high tunnels than in field Hightunnels.org decreased incidence of pest and disease problems Vermont High Tunnel Guide Insect pests generally cause less damage in high tunnels than they do in the field Not supported by research data Our research shows that most insects can be as bad or worse in high tunnels
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Brown Marmorated Stink Bugs Found in Indiana First discovery in Elkhart County in November, 2010 Confirmed in 6 counties Likely present in many other locations All confirmed counties are along interstate
Brown Marmorated Stinkbug, Halyomorpha halys (Stal)
Why should we care about brown marmorated stink bugs? Serious pest of vegetables such as tomatoes, peppers, sweet corn, green beans, etc. Serious pest of fruit crops such as peaches, apples, grapes, etc. Pest of corn and soybeans Pest of many ornamental plants They like to overwinter inside homes They are difficult to control They stink
History Important pest in native range of Korea, China, and Japan First detected in Allentown, PA in 2001 Now a serious problem along most of the eastern seaboard Problems usually appear in homes for several years prior to becoming a serious crop pest Find in Elkhart Co. was in a home large numbers
Biology Overwinters as adult (inside) Become active in May First attack trees and orchards Later vegetables and soybeans Probably 2 or more generations per year
Identification
Management No good sampling methods available yet Blacklight traps Pyramid trap Direct observations No economic thresholds No cultural methods No biological control No organic control solutions Several pyrethroids and a number of older insecticides seem to provide good control
Brown Marmorated Stink Bug Trapping 2011
Brown Marmorated Stink Bug Trapping 2011 Blacklight Trap and Pyramid Traps Blacklight Trap Only Pyramid Trap Only
Brown 0 0 0 Blacklight Trap and Pyramid Traps Blacklight Trap Only Marmorated Stink Bug Trapping 0 0 0 0 0 Pyramid Trap Only 2011 0 0 0 0
Implications We probably have a few years before BMSB becomes a serious crop pest Growing organic fruits and vegetables will become increasingly difficult Vegetable growers will likely increase pesticide use
What should you do? Stay calm; it s not a problem yet If you think you see BMSB, collect some and report to your county Extension educator
Questions?