1. Wheat Insect Pest Management by Dr. Jack Baldwin Dept. of Entomology LSU AgCenter

2. True Armyworm Fall Armyworm Both have four abdominal prolegs and are about 1.5 inches in length when full grown.

3. Fall Armyworm Reported to be a pest on seedling wheat in the fall. Reported to be a pest on seedling wheat in the fall. Brownish color, but varies from green to almost black. Brownish color, but varies from green to almost black. Dark head with prominent inverted Y on front. Dark head with prominent inverted Y on front. Spines and hairs on body. Spines and hairs on body. 4 black spots arranged in square on top of 8 th abdominal segment. 4 black spots arranged in square on top of 8 th abdominal segment.

4. Worm Damage to Seedling Wheat in Fall Suspected Pest/s: Fall Armyworm and Cutworm Stand loss (November) Clipped seedlings

5. True Armyworm Greenish color, but varies. Brownish head with honeycombed markings. Smooth body, no hairs or spines. Orange stripes on both sides of body. Each proleg has brownish or dark colored band on outer sides.

6. True Armyworm Primarily an early season (spring) pest. Primarily an early season (spring) pest. Strong preference for grass crops: Strong preference for grass crops: Known to infest wheat and corn in LA Known to infest wheat and corn in LA Source of infestation: Source of infestation: Overwinters in larva stage Overwinters in larva stage Migration Migration Life cycle: egg to adult requires 41-66 days. Eggs laid in masses of 25 or more Life cycle: egg to adult requires 41-66 days. Eggs laid in masses of 25 or more

7. True Armyworm Observations and Conventional Trends Bigger problem in cool, wet springs Bigger problem in cool, wet springs Prefers fields with lush, rank growth and lodging. Moth like to lay eggs in moist shady areas. Prefers fields with lush, rank growth and lodging. Moth like to lay eggs in moist shady areas. In LA, infestations usually develop in April. In LA, infestations usually develop in April. Feeds at night. During day it hides under soil or under surface debri and thatch. Feeds at night. During day it hides under soil or under surface debri and thatch. Scout for pest during early am and late pm, or look for larvae on and under the ground surface. Scout for pest during early am and late pm, or look for larvae on and under the ground surface. Feeds on foliage. Appears as notches on leaf margin, or in extreme cases complete defoliation. Feeds on foliage. Appears as notches on leaf margin, or in extreme cases complete defoliation. Frass appears as black, pepper-like droppings. Frass appears as black, pepper-like droppings. Feeding on the heads (beards) and/or clipped heads Feeding on the heads (beards) and/or clipped heads

8. True Armyworm When to treat: 5 or more larvae per square foot and foliage loss is occurring. When to treat: 5 or more larvae per square foot and foliage loss is occurring. Protect crop/foliage until physiological maturity (hard dough stage). Protect crop/foliage until physiological maturity (hard dough stage). Head clipping: Head clipping: Theory 1: Clip heads after defoliating Theory 1: Clip heads after defoliating leaves. leaves. Theory 2: Some years heads clipped Theory 2: Some years heads clipped and some years they are not. and some years they are not. Suggested threshold of 2-3% clipped Suggested threshold of 2-3% clipped heads. heads.

9. Stink Bugs Rice Stink Bug and Southern Green Stink Bug Occasional pest, more so in south LA. Occasional pest, more so in south LA. Damage developing seed grain with piercing- sucking mouthparts. Damage developing seed grain with piercing- sucking mouthparts. At milk stage or earlier (flowering): treat when 10% of seed heads have stink bugs. At milk stage or earlier (flowering): treat when 10% of seed heads have stink bugs. At soft dough stage, treat when 25% of seed heads have stink bugs. At soft dough stage, treat when 25% of seed heads have stink bugs.

10. Aphids Yellow sugarcane aphid Greenbug Russian wheat aphid English grain aphid Oat bird cherry aphid Corn leaf aphid

11. Aphids General Biology Generation – about a week from birth to mature aphid Generation – about a week from birth to mature aphid Adult females give birth to living young; 2-3 per day for 2-3 weeks Adult females give birth to living young; 2-3 per day for 2-3 weeks Piercing-sucking mouthparts; remove plant juices Piercing-sucking mouthparts; remove plant juices Winged or wingless Winged or wingless Soft bodied insects Soft bodied insects Identification Legs Antennae Siphunculi (cornicles)

12. Aphids Potential pests, but normally not a major problem in LA. Inject Toxin Inject Toxin Russian wheat aphid – does not occur in LA. Russian wheat aphid – does not occur in LA. Greenbug – usually does not develop high populations. Greenbug – usually does not develop high populations. Yellow sugarcane aphid – Not as toxic to wheat as to sorghum. Yellow sugarcane aphid – Not as toxic to wheat as to sorghum. Do Not Inject Toxin Corn leaf aphid Oat bird cherry aphid English grain aphid – clusters on grain heads. Transmit BYDV Corn leaf aphid Oat bird cherry aphid English grain aphid Greenbug

13. Oat Bird Cherry Aphid Color ranges from green to black Color ranges from green to black Tips of siphunculi, legs and antennae are black. Tips of siphunculi, legs and antennae are black. Reddish-orange colored patch on rear of abdomen Reddish-orange colored patch on rear of abdomen Direct feeding usually not damaging Direct feeding usually not damaging

14. Corn Leaf Aphid Blue green color; can appear black Blue green color; can appear black Black siphunculi, legs and antennae Black siphunculi, legs and antennae More common on grain sorghum than wheat More common on grain sorghum than wheat Direct feeding usually not a problem. Direct feeding usually not a problem.

15. English Grain Aphid Long, black siphunculi Long, black siphunculi Black antennae that extend straight back over the abdomen. Black antennae that extend straight back over the abdomen. Dark legs or leg bands Dark legs or leg bands Direct feeding can cause damage; usually in flowering/ early grain formation. Dark hit areas in field from flag leaf damage and fungal infected heads. Thresholds are available in some states.

16. Greenbug Light green with dark green stripe down the back Light green with dark green stripe down the back Dark tips on siphunculi (tail pipes) and legs Dark tips on siphunculi (tail pipes) and legs Present in wheat all winter and can reproduce at temperatures lower than natural enemies. Present in wheat all winter and can reproduce at temperatures lower than natural enemies. Injects toxin; results in yellowish spot with dark lesion; ultimately death. Damaged areas first appear as N deficiency/ moisture stress.

17. Yellow Sugarcane Aphid Long, oval, hairy body shape. Long, oval, hairy body shape. Lemon yellow to mint green color Lemon yellow to mint green color Siphunculi, legs and antennae are light colored. Siphunculi, legs and antennae are light colored. Injects toxin and can cause serious damage. Injects toxin and can cause serious damage. More damaging to grain sorghum than wheat. More damaging to grain sorghum than wheat.

18. Russian Wheat Aphid Present in 16 western states on wheat and barley Present in 16 western states on wheat and barley First US detection was in Muleshoe, TX in 1986 First US detection was in Muleshoe, TX in 1986

19. Aphid Mummies Aphids that have been parasitized by small wasps. Aphids that have been parasitized by small wasps. Greenbug mummies

20. Hessian Fly Important pest of wheat, but rarely a problem in the deep south states. Important pest of wheat, but rarely a problem in the deep south states. Outbreaks in the southeast in 1984-1985 and 1985-1986. Outbreaks in the southeast in 1984-1985 and 1985-1986. Outbreak in Alabama in 1989. Outbreak in Alabama in 1989. Detected in southwest Alabama in 2006. Detected in southwest Alabama in 2006. Detected in collections taken from Louisiana in 2000. Detected in collections taken from Louisiana in 2000. Pupa (Flaxseed) Larva (Maggot)

21. Insecticide Seed Treatments Gaucho and Cruiser have wheat labels. Gaucho and Cruiser have wheat labels. Labeled for aphid control and Hessian fly control Labeled for aphid control and Hessian fly control No current LA data at this time to support their use, but they will be looked at this year. No current LA data at this time to support their use, but they will be looked at this year.

22. Questions