Garden Fleahopper Halticus Bractatus Say Hemiptera Miridae

Natural History

Distribution. Garden fleahopper is a native insect occurring widely in the eastern United States and Canada. It is known to occur as far west as the Rocky Mountain region, but it is relatively uncommon in the Great Plains. Its distribution extends southward through Central and South America to Argentina.

Host Plants. This fleahopper has a known host range that exceeds 40 different plants, but leguminous crops are most frequently damaged. Vegetable crops that host garden fleahopper include bean, beet, cabbage, celery, cowpea, cucumber, eggplant, lettuce, pea, pepper, potato, pumpkin, squash, sweet potato, and tomato. Field crops injured include alfalfa, clover, and sweet clover. Some of the common weeds that support garden fleahopper are beggartick, Bidens sp.; bindweed, Convolvulus spp.; burdock, Arctium minus; mallow, Malva spp.; pigweed, Amaranthus spp.; plantain, Plantago spp.; ragweed, Ambrosia spp.; smart-

weed, Polygonum spp.; prickly lettuce, Lactuca serriola; thistle, Carduus spp.; and wood sorrel, Oxalis stricta.

Mirids often are facultative predators, occasionally feeding on small insects or eggs. However, garden fleahopper has only infrequently been observed in this role (Day and Saunders, 1990). (See color figure 16.)

Natural Enemies. Natural control has been poorly studied, but parasitic wasps can inflict high rates of mortality. In the United States, 50% mortality caused by Leiophron uniformis (Gahan) (Hymenoptera: Braco-nidae) has been observed, and this parasitoid was believed to be regulating bug densities in New Jersey. Leiophron uniformis attacks principally the nymphal stages. In Canada, Peristenus clematidis Loan (Hyme-noptera: Braconidae) is known to parasitize garden fleahopper. An unidentified nematode and predatory mite also have been detected in the United States (Beyer, 1921; Day and Saunders, 1990). Beyer also reported several egg parasitoids, including Anaphes perdubius Girault and Anagrus sp. (both Hymenoptera: Mymaridae), and Oligosita americana Girault and Para-centrobia subflava Howard (both Hymenoptera: Tricho-grammatidae), but gave no data on their effectiveness.

Life Cycle and Description. There appear to be five generations annually in Virginia, though there is considerable overlap among the generations, and all stages can be found through the warmer months. A life cycle can be completed in about 30 days. Overwintering occurs in the egg stage, with hatch of overwintering eggs occurring in April. In Florida, flea-hoppers are present earlier in spring, and it has not been determined whether eggs hatch earlier or whether adults are the predominant overwintering form. However, adults have been captured over all months of the year except December, so overwintering of eggs is not essential under Florida's warm winter conditions. Temperatures above 32°C are reported to be unsuitable for fleahopper survival.

Egg. The eggs are normally inserted into the stems of vegetation. They are white to yellow, and measure about 0.7 mm long and 0.2 mm wide. The egg is curved in shape, with one side convex and the opposite side concave. The female deposits the eggs in feeding punctures. The end inserted into the plant tissue is rounded, whereas the end that is flush with the plant surface is truncate and level with the surface of the plant tissue. The female commences egg production about four days after mating, and deposits most of them during the evening hours. She produces 80-100 eggs during her life span, which averages about 30-50 days. Duration of the egg stage is about 14 days (range about 10-30 days).

Halticus Bractatus
Garden fleahopper egg.
  1. The nymphs are green. Initially they are pale-green, but by the fifth and final instar they become dark-green. First and second instars are difficult to distinguish, differing principally in size. In the third instar, however, a black dot is present on the sides of the prothoracic segment; the black spots persist through the remaining nymphal stages. In the fourth instar, wing pads are apparent, and extend back over the first abdominal segment. During the last instar the wing pads extend over about half of the abdominal segments. In females which are brachyp-terous (short-winged) as adults, the wings pads in the fifth instar tend to be slightly less than one-half the length of the abdomen. In males, or females which are macropterous (long-winged) as adults, the wing pads in the fifth instar tend to be slightly longer than one-half the length of the abdomen. The mean duration (range) of each instar is about 8.3 (3-16), 9.9 (515), 7.8 (4-14), 5.8 (3-9), and 7.2 (5-12) days, respectively. Body length of each instar is about 0.7, 0.8, 1.0,1.2, and 2.0 mm, respectively.
  2. The adults are shiny black, with some yellow on the antennae and legs. Garden fleahopper adults occur in three forms: brachypterous (short-
  3. females, macropterous (long-winged) females, and macropterous males. The males are thin, measuring about 1.9-2.1 mm long and 0.7 mm wide. The females are more robust, the brachypterous form measuring about 1.6 mm long and the macropterous about 2.2 mm long, with both forms about 1.0 mm wide. Females generally are brachypterous. The adults of all forms have greatly expanded hind femora and hop when disturbed. Thus, in both behavior and form (especially the brachypterous females) the fleahoppers resemble flea beetles. The long antennae of fleahop-pers, which exceed the length of the body, help to distinguish fleahoppers from flea beetles, which have antennae less than half the length of the body. Flea-hoppers and flea beetles also differ in their mouthpart configuration, having piercing-sucking and chewing mouthparts, respectively. Females normally mate within a day of attaining the adult state. (See color figures 138 and 139.)

The biology of garden fleahopper was given by Beyer (1921) and Cagle and Jackson (1947). Keys to plant bug genera can be found in Slater and Bara-nowski (1978) and keys to the species of Halticus in Henry (1983).

Male garden fleahopper.

Garden fleahopper nymph.

Garden fleahopper female, short-winged form.

Damage

Nymphs and adults frequent the stems and both the lower and upper surfaces of plant leaves, sucking the sap from individual cells and and causing their death. The result is a whitish or yellowish speckling on the foliage. Extensive feeding may cause stunting of plant growth and death of seedlings. Deposition of fecal material on the plant by both nymphs and adults also detracts from the appearance and marketability of vegetables.

This insect is rarely a pest of commercial vegetable crops because it is easily controlled with insecticides. However, it is commonly an early season nuisance in home gardens, especially those grown near wooded or in shaded areas of gardens.

Management

Suppression, when necessary, is easily accomplished with insecticides. Because fleahoppers commonly frequent weeds, where they may attain great abundance, such host plants should be monitored and sprayed or destroyed, if necessary. Also, garden fleahoppers sometimes build to high number in legume crops such as alfalfa and clover, so nearby vegetables may be at risk when the legume forage crops are harvested.

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