Cabbage looper

Scientific name

Trichoplusia ni (Lepidoptera: Noctuidae)

Similar species

soybean looper, Pseudoplusia includens

The soybean looper can be differentiated from the cabbage looper using wing characteristics. The forewingforewing:
the anterior (closest to the head) pair of wings in insects
of the cabbage looper has centrally-positioned, silvery-white spots that resemble a "V" or "figure 8". In contrast, the forewingforewing:
the anterior (closest to the head) pair of wings in insects
of the soybean looper has two centrally positioned brown spots that have a thick, silvery white outline.

Distribution

United States: Widespread almost everywhere host plants are grown; overwinters in Arizona, Florida, Hawaii, and Texas.

Worldwide: Canada, Central America, Mexico, and South America.

Native to North America.

Diagnostic characteristics

Adults

• Mottled dark gray brown in color with silvery white spots located centrally on forewingforewing:
  the anterior (closest to the head) pair of wings in insects
  .
• White spot on forewingforewing:
  the anterior (closest to the head) pair of wings in insects
  resembles a "V" or "figure 8."
• Hindwings light brown at the base and dark brown distally.
• Wing span of 33 - 38 mm (1.5 in.).

Pupae

• Pupa initially green, but turns dark brown before pupation.
• 19 mm (0.75 in.) in length.

Larvae

• Number of larval instars varies from four to seven.
• Young larvae are white or green and have hairs that decrease as the larvae matures.
• Mature larvae are green with a white stripe on both sides of the caterpillarcaterpillar:
  common name for larval lepidopterans (butterflies and moths)
  .
• 30.5 - 40.6 mm (1.2 - 1.6 in.) in length at maturity.

Eggs

• Eggs are hemispherical in shape with the flat side fixed to foliage.
• Eggs are usually deposited singly but can be in clusters of 6 - 7.
• Eggs are yellowish-white to light green in color.
• Eggs have longitudinal ridges.
• 0.6 mm (0.02 in.) in diameter and 0.4mm (0.015 in.) in height.

Hosts

Citrus hosts

All Citrus species and their hybrids.

Non-citrus hosts

Broad host rangehost range:
the range of species that a particular organism can feed on to achieve successful growth and reproduction
, including weeds as well as vegetable, field, and flower crops. A partial list includes:

• all cruciferous vegetables, Brassica oleracea
• bean, Phaseolus vulgaris
• Celery, Apium graveolens
• chrysanthemum, Chrysanthemum spp.
• cotton, Gossypium hirsutum
• dandelion, Taraxacum officinale
• dock, Rumex crispus
• lambsquarters, Chenopodium album
• lettuce, Lactuca sativa
• melon, Cucumis spp.
• pepper, Piper nigra
• potato, Solanum tuberosum
• soybean, Glycine max
• squash, Cucurbita spp.
• sweet potato, Ipomoea batatas
• tobacco, Nicotiana tabacum
• tomato, Solanum lycopersicum
• watermelon, Citrullus lanatus
• wild lettuce, Lactuca spp.

Host damage

Flowers

• Feeds on blossoms.

Fruits

• Feeds on young fruit.

Leaves

• Prefer to feed on new growth flushes.
• First three larval instars feed on the lower leaf surface, leaving the upper leaf surface intact.
• Fourth and fifth instars chew large holes through foliage and can consume entire leaf.
• Larvae can consume 3 times their weight in plant material daily.

Biology

Adults are nocturnal but can also be found at dusk and will live for 10 - 12 days. A female will lay 300 - 600 eggs in her lifetime. Eggs hatch in 3 - 4 days. Only larvae are responsible for damage to plants. There are 4 - 7 larval instars. They are referred to as loopers because they walk in a "looping" manner. Larvae pupate in soil or cocoons on host planthost plant:
the plant the provides sustenance for an insect
fruit and leaves. It takes 18 - 25 days for development from eggs to adult. These moths are sexually dimorphic, and the males have tufts of gold hair at the tip of abdomenabdomen:
one of the three body segments in insects; the most posterior segment containing the heart, reproductive organs, and digestive organs
. There are 2 - 7 overlapping generations per year, depending on temperature. Year round activity and reproduction occurs south of Orlando, Florida.

Comments

Not considered a major pest of citrus and rarely require treatment.

References

University of California, IPMOnline. 2008. UC IPM Pest Management Guidelines: Citrus. (http://www.ipm.ucdavis.edu/PMG/r107302211.html).

Capinera, J.L. 2005. Featured creatures fact sheet: Trichoplusia ni (Hübner). Publication EENY-116. University of Florida. (http://entnemdept.ufl.edu/creatures/veg/leaf/cabbage_looper.htm).

Authors

Weeks, J.A., A.C. Hodges, and N.C. Leppla