The subfamily Heliothinae contains many, globally important crop pest species. As a group, these moths can be light tan-colored with various degrees of patterning on the wings, or brightly colored. Individuals of the same species can exhibit extreme morphological variation, which makes identification difficult.
Further confusion comes from common names that have been used for decades; Helicoverpa zea is called tomato fruitworm, corn earworm, and cotton bollworm, whereas flax bollworm, tobacco budworm, and false corn earworm all refer to different Heliothis spp.
It is important to recognize similarities and differences between these two Heliothine moths. Confusion over ID in traps can affect spray decisions.
Corn earworm (Helicoverpa zea) activity tends to peak later in the season, coinciding with corn silking. However, early spring flights are possible, and since this species has a wide host range, it can feed on fruiting tomatoes, peppers, etc.
False corn earworm (Heliothis phloxiphaga), on the other hand, is common throughout the year. It can be a major pest of mint and outbreaks have been known to occur in the Willamette Valley (2008 and 2010).
| False Corn Earworm Heliothis phloxiphaga | Corn Earworm Helicoverpa zea |
|
|---|---|---|
| Wingspan | 28-35mm | 32-45mm |
| ID (adult moth) (FW-forewing, HW-hindwing) | green eyes FW: tan with intricate patterning, however this can be rubbed off as wing scales are damaged in traps. Reniform spot not well defined. HW: cream colored, HW margin dark with white patch and discal spot thick and PROMINENT | green eyes FW: pale yellow to olive green with dots at scalloped edge, dark grey reniform (kidney-bean shaped) spot present. HW: cream colored with dark veins, HW margin dark with white patch but discal spot light or ABSENT |
| Larval hosts | mint, gumweed, columbine, apple, pear, peach, elms, ornamentals | corn, tomato, cabbage, pea, pepper, snap bean, many others |
| Flight activity in PNW | APR-SEPT with 2 evident peaks. Usually sporadic, but outbreak years can occur, such as 2008. Widespread in U.S., does overwinter in PNW | usually mid-AUG to OCT, but may have activity in JUN, depending on year. A Washington trapping study found CEW became active ~6 weeks after PHX in spring, and the pattern was consistent over many years. Considered migratory, but overwintering in PNW is unknown |
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