Insects in Vegetables: A Review of 2011 and What to Know for 2012

Transcription

1 1/3/12 Insects in Vegetables: A Review of 211 and What to Know for 212 CABBAGE CATERPILLARS Rick Foster Purdue University Diamondback Moth 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 Imported Cabbageworm Imported Cabbageworm Adults are white butterflies Larvae are velvety green, 1 inch long Relatively easy to control 1

2 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 Broccoli, Cauliflower Thresholds Stage Diamondback Moth ICW and Loopers Transplant to cupping 5% with > 5 larvae/plant 3% Cupping to early head 5% with > 5 larvae/plant 2% Early head to harvest 1% with > 1 larva/plant 1% Stage Diamondback Moth ICW and Loopers Seedbed 1 % 1% Transplant to first curd 4% 2% First curd to harvest 1% 1% 2

3 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 211 Chemical Rate/acre Loopers ICW DBM Yield Untreated 3. ab a 24. ab 1.8 e Coragen 5 fl. oz c 8.5 c bc 85. a Radiant 1 fl. oz. 7. c 8.5 c 8.5 c 77.5 abc Proclaim 4.8 oz abc bc 17. abc 81.7 ab Agree 2 lb a 9. c c 71.7 bcd Avaunt 3.5 oz abc bc bc 65.8 cd Entrust 2. oz ab b 1.5 c 64.2 d Intrepid 1 fl. oz bc bc 3.5 a 65. cd Mustang Max 4 fl. oz abc 16.5 bc 18.5 bc 65.8 cd Crymax 2 lb. 23. abc 1.5 bc 17. 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 European Corn Borer Management Treatment at pre row tassel is the key Pyrethroid insecticides work well especially Brigade, Mustang Max, Hero and Warrior

4 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 25, significant moth captures in Illinois 26, first moths captured in Indiana 27, first damage documented in NW Indiana 29, significant damage documented in NW Indiana WBC Moth Trapping 211 WBC, 21 Documented Damage 4

5 Western Bean Cutworm 211 Moth emergence was 2 weeks later than in 21 Temperatures were very high at peak emergence Egg masses were very difficult to find Damage was greatly reduced compared to ????? First Documented Case of WBC Damage To Sweet Corn In Indiana - 29 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 5

6 WBC Treatment Foliar insecticides Early instar larvae easy to control Timing is critical whorl stage/ pre row tassel Pyrethroids have provided good control 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 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 7%) Treat if catching more than 1 moths per night 6

7 Corn Earworm Management Make treatments every 2 5 days from 7% 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 (7% 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 2 gallons per acre or more RELATIONSHIP BETWEEN CORN EARWORM PHEROMONE TRAP CATCH AND EGG LAYING 7

8 Relationship Between Pheromone Trap Catch and Egg Laying Nightly Relationship Between Trap Catch and Egg Laying What Affects Trap Catch? Full moon suppresses trap catch High relative humidity (5 8%) 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 1 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. 8

9 CEW Pheromone Trap Catch TOMATOES HIGH TUNNELS Moths Per Week Pinney Lafayette 5 6 Jun 13 Jun 2 Jun 27 Jun 4 Jul 11 Jul 18 Jul 25 Jul 1 Aug 8 Aug 15 Aug 22 Aug 29 Aug 5 Sep Hornworms Hornworms are generally a minor problem in field grown tomatoes 9

10 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 Hornworms High Tunnels vs. Field A 1.15 Hornworms/ Plant A.32.2 HT Field Brown Marmorated Stink Bugs Found in Indiana Brown Marmorated Stinkbug, Halyomorpha halys (Stal) First discovery in Elkhart County in November, 21 Confirmed in 6 counties Likely present in many other locations All confirmed counties are along interstate 1

11 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 21 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 11

12 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 211 Brown Marmorated Stink Bug Trapping 211 Blacklight Trap and Pyramid Traps Blacklight Trap Only Pyramid Trap Only Brown Marmorated Stink Bug Trapping 211 Blacklight Trap and Pyramid Traps Blacklight Trap Only Pyramid Trap Only 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 12

13 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? 13