Sunflower Production Field Guide - Your "Home Page"

32
■ Cutworms
Species:
Darksided cutworm Euxoa messoria (Harris)
Redbacked cutworm Euxoa ochrogaster (Guenee)
Dingy cutworm Feltia jaculifera (Walker)
Description: Darksided cutworm — Forewings
of the adult darksided cutworm are usually light,
powdery and grayish brown with indistinct markings
(Figure 22). The larvae are pale brown dorsally and
white on the ventral areas (Figure 23 ). Sides have numerous
indistinct stripes. At maturity, they are about
1.25 to 1.5 inches (32 to 38 mm) long and 0.19 inch (5
mm) wide.
Redbacked cutworm — The forewings of the adult
redbacked cutworm are reddish brown with characteristic
bean-shaped markings (Figure 24). The larvae are
dull gray to brown with soft, fl eshy bodies and may be
1 to 1.25 inches (25 to 32 mm) long when fully grown
(Figure 25). Larvae can be distinguished by two dull
reddish stripes along the back.
Dingy cutworm — Forewings are dark brown with
bean-shaped markings as in the redbacked cutworm
adults (Figure 26). Hind wings in the male are whitish
with a broad, dark border on the outer margin; in the
female they are uniform dark gray. The larvae have
a dull, dingy, brown body mottled with cream color.
The dorsal area is pale with traces of oblique shading
(Figure 27).
Life Cycles: The female darksided and redbacked cutworm
moths deposit eggs in the soil in late July and
early August. The eggs remain dormant until the onset
of warm weather the following spring. The larvae of
both species emerge from late May to early June. They
continue to feed and grow until about the end of June,
when fully grown larvae pupate in earthen cells near
the soil surface. The pupal period lasts about three
weeks. Both species have one generation per year.
The adult dingy cutworms emerge in August and are
active until mid-October, with peak activity in September.
Eggs are deposited in plants in the Compositae
family in the fall. The larvae develop to the second
or third instar in the fall and overwinter in the soil.
Pupation occurs in the spring to early summer. One
generation of this species is produced per year.
■ Figure 22. Adult - Darksided cutworm
Euxoa messoria. (Extension Entomology)
■ Figure 23. Larva - Darksided cutworm
Euxoa messoria. (Extension Entomology)
■ Figure 24. Adult - Redbacked cutworm
Euxoa ochrogaster. (Extension Entomology)
■ Figure 25. Larva - Redbacked cutworm
Euxoa ochrogaster. (Extension Entomology)