Anastatus semiflavidus

Gahan, 1914

Anastatus semiflavidus is a minute in the Eupelmidae. It is a parasitoid of the range caterpillar (Hemileuca oliviae), a pest of rangeland grasses in western North America. The exhibits arrhenotokous , with females developing from fertilized eggs and males from unfertilized eggs. Laboratory studies demonstrate strong temperature-dependence in its development and .

Anastatus semiflavidus by the Smithsonian. Used under a CC0 license.Anastatus semiflavidus by the Smithsonian. Used under a CC0 license.Anastatus semiflavidus by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Anastatus semiflavidus: /ˌænəˈsteɪtəs ˌsɛmɪˈfleɪvɪdəs/

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Identification

Members of the Anastatus are distinguished from similar eupelmid genera by females having a distinct pattern of bands on the forewings, thought to enhance mimicry. The wings adhere closely to the body when not flying, giving a wingless appearance at first glance. The ovipositor is almost entirely concealed. Females possess modified middle legs adapted for powerful jumping, a trait shared with other Eupelminae. Males lack these modifications and fly readily. Specific identification of A. semiflavidus requires microscopic examination; the was described by Gahan in 1914.

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Distribution

Recorded from Arizona, California, Kansas, Louisiana, New Mexico, and Texas. The distribution corresponds to the range of its , the range caterpillar Hemileuca oliviae, which inhabits rangeland areas of the southwestern and south-central United States.

Diet

of Hemileuca oliviae (range caterpillar, Lepidoptera: Saturniidae).

Host Associations

  • Hemileuca oliviae - obligate ; laboratory studies confirm development only in of this

Life Cycle

Development from to ranges from 35.6 days at 15°C to 12.4 days at 35°C. The preoviposition period ranges from 3.4 days at 30°C to 8.8 days at 15°C. Arrhenotokous : mated females produce both sexes, unmated females produce only male offspring. Sex ratio is female-biased across all temperatures tested. is highest at intermediate temperatures (approximately 100 offspring per female at 25°C).

Behavior

Females exhibit powerful jumping ability using modified middle legs, powered by large dorso-longitudinal thoracic muscles and energy stored in blocks. This jumping is thought to be an escape response from such as ants and spiders. Females prefer over flying until disturbed.

Ecological Role

agent of the range caterpillar, a significant pest of rangeland grasses that can cause economic damage to grazing lands.

Human Relevance

Investigated as a potential agent for management of range caterpillar in rangeland . No direct economic importance beyond this biocontrol context.

Similar Taxa

  • Anastatus orientalisBoth are in the Anastatus investigated for of pests; A. orientalis targets spotted lanternfly while A. semiflavidus targets range caterpillar
  • Anastatus reduviiCongeneric of wheel bug (Arilus cristatus) eggs; shares -level traits including female jumping ability and -mimic wing patterns
  • Anastatus disparisIntroduced congeneric for spongy moth (Lymantria dispar) biocontrol; shares arrhenotokous and general eupelminae

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