Highlights from Gene McAvoy's PD Hotline newsletter:
Around SW Florida, worm pressure increased around the full moon but has dropped off in recent days and reports indicate that a mix of beet, southern and fall armyworms are present in mostly low numbers. Respondents indicate they are seeing a few more loopers in tomatoes as well as an increase in tomato fruitworm numbers. Melonworms are still active in cucurbits.
The different armyworms especially the younger instars are similar in color, size and markings and can be difficult to tell apart. The following information was excerpted from the Florida Tomato Scouting Guide to help growers identify these different worms.
¥ Beet armyworm: (Spodoptera exigua) is generally less numerous than southern armyworm but is more difficult to control. The larva is generally green, mottled with white spots with black spot over the middle pair of true legs. 1 - 1 1/4 in. long at maturity. The adults have light brownish gray front wings with indistinct lines and are active at night. The eggs are laid in masses of 50 75 eggs covered with a felt like mass of scales from female's body. Eggs are generally found on underside of leaves and hatch in 3 days.
¥ Southern armyworm: (Spodoptera eridania) The larva is a dark caterpillar with a yellowish brown head and a yellowish line along the side of body that is interrupted by a large dark spot on first abdominal segment. Approximately 2 in. long at maturity. Large larvae have 2 rows of dark triangles on dorsal surface. The young larvae feed on under surface of leaflets leaving upper epidermis intact to give a "window pane" appearance. The adult has the front wing streaked with cream, gray, light brown and black and hind wing white with some dark on margins. Large masses of 100 200 eggs covered with moth body scales are found on underside of leaves
¥ Tomato fruitworm: (Helicoverpa zea) Larval color is variable, ranging from very dark to light green or pink with alternating longitudinal dark and light stripes. The skin is covered with short sharp micro spines. Adults are active at night, with a 1-½ in. wingspan. Males display a cream colored forewing with orange or olive cast, while females have a light yellow brown forewing with indistinct vertical lines. Eggs are waxy white and ribbed, with a flat base, and are deposited singly usually on lower surfaces of leaves adjacent to or near flowers. Eggs hatch in 2 3 days.
¥ Cabbage or soybean looper: (Trichoplusia ni or Pseudoplusia includens) Larva is pale green with white line alongside of body and only 3 pair of prolegs. Mature size 1 – 1 1/4 in. Adult is a grayish brown moth that is active at night. Front wings marked near center with a figure 8 shaped, silver white spot. Eggs are greenish white, ridged but flattened laterally and are found singly on upper or lower leaf surfaces of upper canopy leaves.
The Florida Tomato Scouting Guide has excellent color photographs to help you identify these and other common tomato pests. It can be found on the web at http://erec.ifas.ufl.edu/
Thanks as always Gene for your informative newsletters.
