Anagrapha falcifera Kirby Lepidoptera Noctuidae

Natural History

Distribution. Celery looper is found throughout the United States and southern Canada. There is some question whether this native species overwinters in the northern United States and Canada. Research conducted in Iowa suggested that celery looper did not overwinter successfully, but was carried into the area in the spring when the appropriate weather patterns developed (Peterson et al., 1988). This is highly plausible, as many other noctuids similarly overwinter in the south and disperse northward annually. However, there also are reports of this insect overwintering in the north in the larval stage, and adult activity was reported in New York from April to November (Chapman and Lienk, 1981).

Host Plants. The host range of this insect is poorly known, but it appears that celery looper feeds on a wide variety of plants. Among vegetables damaged are celery, beet, cabbage, carrot, lettuce, and pea. Corn has been reported to be a host plant, but this is questionable. It is an occasional pest of sugarbeet and has been reported to feed on cranberry and hollyhock. Weeds fed upon include dandelion, Taraxacum officinale; plantain, Plantago sp.; and a burdock, Arctium lappa. Coquillett (1881) reported oviposition on grass, so larvae also may develop on unknown grasses. Adults have been observed taking nectar from clover and lilac blossoms. Moths have also been found to be contaminated with pollen from several plant taxa, including Quercus, Rosaceae, and Pyrus, indicating an extensive range of adult host plants (Lingren et al., 1993).

Natural Enemies. Little is known concerning the insect enemies of celery looper. A nuclear polyhedro-sis virus is widespread and highly pathogenic to celery looper, and may be the key factor that limits abundance of this insect. This virus is unusual in that it is also pathogenic to numerous other species of Lepi-doptera, affecting over 30 species in 10 families (Hostetter and Puttler, 1991).

Life Cycle and Description. Most reports suggest 2-3 generations annually in northern states (Knutson, 1944). However, the generations overlap and it is difficult to discern population dynamics solely from capture rates of adults. For example, Chapman and Lienk (1981) presented data from New York showing continuous occurrence of moths in all but the coldest months. Peterson et al. (1988) conducted a study in Iowa that included determination of ovary development, which aids in assessing the age of insects. Based on these studies, there were four generations annually.

  1. The eggs are milky white, and measure about 0.5 mm in diameter. They are somewhat flattened, and bear vertical ridges. They may be deposited singly or in small groups on either the upper and lower surfaces of vegetation. Duration of the egg stage is 4-6 days.
  2. There likely are five instars, with each of about 3-5 days duration. Total larval development time is usually about 21 days, and larvae attain a length of about 35 mm. The larvae are green, and tend to have a weak dark longitudinal line dorsally, accompanied by three narrow whitish lines on each side of the dorsal line. The thoracic legs are pale colored, and the abdominal tubercles located above the lateral spiracles are not black. The most distinctive marking is a narrow white line on each side, running through the lateral spiracles. The skin bears numerous minute spines, called microspines, over most of its surface. The spiracles are ringed with black pigment. If there is a dark bar on the head, it is indistinct. The caterpillar is more robust posteriorly, and bears three pairs of prolegs. It is easily confused with other common loopers. Celery looper can be distinguished from bilobed looper, Megalographa biloba (Stephens), and alfalfa looper, Autographa californica (Speyer) by its pale thoracic legs and absence of pronounced dark, lateral bars on the head; the latter species generally have dark bars and dark thoracic legs. Celery looper can be distinguished from cabbage looper, Trichoplusia ni (Hubner) by the presence of small, nipple-like structures located ventrally on the third and fourth abdominal segments, and the absence of dark microspines on the abdomen of the latter. (See color figure 46.)
  3. The mature larva spins a thin, white silken cocoon on the underside of a leaf or amongst debris, and pupates within. The pupa is blackish brown, and measures 13-15 mm long. Duration of the pupal stage is 10-20 days.
  4. The moth measures 3.5-5 cm in wingspan. The front wings are dark, usually purplish brown and reddish brown, but the wings are marked distally with a silvery band. Many members of the noctuid subfamily Plusinae bear a spot near the center of the forewing, and this species is no exception. For celery looper, however, the spot is silver, and is drawn out into a curving line that terminates at the posterior margin of the wing. Although not completely unique to celery looper, this pattern can serve to differentiate this moth from other common vegetable pest such as cabbage looper, alfalfa looper, and bilobed looper. The front wings are also abnormally widened distally, due to a conical projection on the trailing edge of the forewing. The hindwings are yellowish brown, with darker brown bands and a whitish border. (See color figures 232 and 233.)

The biology of celery looper is poorly documented. Some elements of the biology were given by Coquillett (1881), Chittenden (1902), and Peterson et al. (1988). Information on rearing and artificial diet were found in Treat and Halfhill (1973). Keys for the differentiation of celery looper moths from related species were given by Rings (1977a), Eichlin and Cunningham (1978), and Capinera and Schaefer (1983). Larvae are included in the keys of Crumb (1956), Capinera (1986), and in a key to common vegetable-feeding loopers in Appendix A.

Vegetable Lepidoptera
Adult celery looper.

Damage

The larva is a defoliator, eating holes in the leaves of lettuce, celery, and other crops. It has been known to be destructive in Florida (Ball et al., 1932), but generally this insect is considered to be a minor pest. It sometimes is a serious contaminant of peas harvested for canning and freezing.

Management

Moths of this species can be monitored with a blacklight trap. Butler et al. (1977) provided information on trapping celery looper with a sex pheromone. Insecticides applied to commercial or home garden crops for other insect pests are adequate to keep celery looper at very low levels of abundance. The microbial insecticide Bacillus thuringiensis is effective.

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