A Review of Corn Earworm and Other Insect Problems in 2011 Rick Foster Purdue University
Corn Earworm Pest of sweet corn, seed corn and tomato Two generaeons 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 Ep Once inside the ear, the larvae are protected from insececides
Corn Earworm Control Must have insececide present on silk when larvae hatches from egg Pyrethroids have been primary control opeons, especially Capture, Mustang Max, Hero, and Warrior Some concerns about resistance Coragen and Radiant appear to be good alternaeves
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 unel silks are brown; generally 3-4 treatments Shorten interval if temperatures are high Shorten interval if moth catches are high
Corn Earworm Management First generaeon populaeons may or may not reach economic levels During much of the season, few earworms present Once the second generaeon hits, populaeons will likely be high for the rest of the season Date of arrival of second generaeon is variable A pheromone trap is a criecal management tool
2006 Meigs Farm CEW Pheromone Trap Catches 1200 1000 Moths per Week 800 600 400 200 0 6/15/2006 6/22/2006 6/29/2006 7/6/2006 7/13/2006 7/20/2006 7/27/2006 8/3/2006 8/10/2006 8/17/2006 8/24/2006 8/31/2006 9/7/2006 9/14/2006 Week Ending
2008 Meigs Farm CEW Pheromone Trap Catches 300 250 Moths per Week 200 150 100 50 0 6/16/2008 6/23/2008 6/30/2008 7/7/2008 7/14/2008 7/21/2008 7/28/2008 8/4/2008 8/11/2008 8/18/2008 8/25/2008 9/1/2008 9/8/2008 Week Ending
CEW Management Tips The first applicaeon (70% silks) is the most criecal, with each succeeding spray being less important Ge[ng good coverage of the silks is imperaeve consider drop nozzles. Test with water sensieve paper. High gallonage is preferred 20 gallons per acre or more
RELATIONSHIP BETWEEN CORN EARWORM PHEROMONE TRAP CATCH AND EGG LAYING
RelaEonship Between Pheromone Trap Catch and Egg Laying
Nightly RelaEonship Between Trap Catch and Egg Laying
What Affects Trap Catch? Full moon suppresses trap catch High relaeve 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 conenue 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.
CEW Pheromone Trap Catch - 2010 1400 1200 Moths Per Week 1000 800 600 400 Pinney Lafayette 200 0
CEW Pheromone Trap Catch - 2011 300 250 Moths Per Week 200 150 100 Pinney Lafayece 50 0
CABBAGE CATERPILLARS
Diamondback Moth
Diamondback Moth Most serious pest worldwide - $1 billion annually Resistant to many insececides 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 bucerflies Larvae are velvety green, 1 inch long RelaEvely 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 RelaEvely difficult to control
Caterpillar Damage Chew holes in leaves; bore into head Young plants killed Older plants stunted Heads abort or are unmarketable ContaminaEon
Management OpEons Method DBM ICW CL Natural enemies +++ ++ + Early planting --- + ++ Bt insecticides +++ +++ ++ Chemical insecticides +++ +++ +++ Overhead irrigation ++ --- --- Crop destruction --- + ---
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%
InsecEcides Pyrethroids Ambush, Asana, Baythroid, Brigade, Hero, Mustang Max, Pounce, Warrior Bt Avaunt Confirm, Intrepid, Rimon Coragen Radiant, Entrust, SpinTor Proclaim Larvin, Lannate
Cabbage InsecEcide 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
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
Hornworms High Tunnels vs. Field Hornworms/ Plant 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0-0.2 A 1.15 HT A 0.32 Field Hornworms / Plant 7 6 5 4 3 2 1 0 A 4.73 High Tunnel A 1.88 Field Plot 2010 2011
Brown Marmorated SEnk Bugs Found in Indiana First discovery in Elkhart County in November, 2010 Confirmed in 6 counees Likely present in many other locaeons All confirmed counees are along interstate
Brown Marmorated Stinkbug, Halyomorpha halys (Stal)
Why should we care about brown marmorated senk 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 senk
History Important pest in naeve 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 aceve in May First acack trees and orchards Later vegetables and soybeans Probably 2 or more generaeons per year
IdenEficaEon
Management No good sampling methods available yet Blacklight traps Pyramid trap Direct observaeons No economic thresholds No cultural methods No biological control No organic control solueons Several pyrethroids and a number of older insececides 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
ImplicaEons 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 pesecide 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
QuesEons?