Bangasternus orientalis

Capiomont, 1873

yellow starthistle bud weevil

Bangasternus orientalis is a small true () used as a agent against the weed starthistle (Centaurea solstitialis). to southern Europe and the Mediterranean, it was to the United States in 1985 and has become established throughout the western United States. feed on leaves and flower , while develop within flower and consume developing seeds, destroying 50-60% of seeds in infested heads.

Pronunciation

How to pronounce Bangasternus orientalis: /bæŋ.ɡəˈstɜːrnəs ɔːr.iˈɛn.teɪ.lɪs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other starthistle seed (Eustenopus villosus and Larinus curtus) by its much shorter and blunt snout. Body hairs are shorter than those of E. villosus. The compact size and mottled coloration with short are also characteristic.

Appearance

are with a thin coat of light mottled hairs, approximately 6 millimeters in length. The body is covered with short, blunt hairs. The snout is notably shorter and blunter than that of related seed .

Habitat

Associated with starthistle (Centaurea solstitialis) ; found in grasslands, rangelands, disturbed sites, and areas where the weed grows. are found on bolting host plants in spring and early summer.

Distribution

to southern Europe and the Mediterranean region. to the United States in 1985; now established throughout the western United States wherever starthistle occurs, including California and other western states.

Seasonality

appear on plants from mid-May through early summer. Adults of summer emerge from seed from late July to mid-September. begins about one week after overwintered adults appear and continues for approximately 2.5 months.

Diet

feed on young leaves and flower of starthistle. feed on developing seeds and flower parts within the flower , destroying 50-60% of seeds in infested heads.

Host Associations

Centaurea solstitialis - primary starthistle; primary target for
Centaurea calcitrapa - secondary purple starthistle; occasionally attacked

Life Cycle

(one per year). overwinter and emerge in spring. are laid singly on or near young and covered with a protective cap of dark mucilage. mine into flower , feed on developing seeds, then construct a from flower and seed remnants and pupate within the flower head. New adults exit to overwinter.

Behavior

Females glue to tissue using dark-colored mucilage. tunnel into flower and develop concealed within. are host-specific and do not attack plants. In its native range, high egg and larval mortality (up to 98.7% and 84% respectively) due to limits buildup; in the range without , populations can reach higher .

Ecological Role

and agent that reduces seed production of starthistle. Helps limit spread of this weed, though it is considered less effective than other agents such as Eustenopus villosus. Contributes to integrated weed management programs but does not provide sufficient control alone.

Human Relevance

Used as a agent for starthistle, a noxious weed in western North rangelands and grasslands. First released in the United States in 1985. Redistribution is generally unnecessary as it is already present at most starthistle sites. can be collected from spring through early summer for purposes.

Similar Taxa

Eustenopus villosusAlso a starthistle seed ; distinguished by longer, more pointed snout and longer body hairs. E. villosus is more common and effective as a agent.
Larinus curtusAnother starthistle seed ; B. orientalis has a much shorter and blunter snout.

More Details

Biocontrol efficacy

Considered less effective than Eustenopus villosus; its impacts are usually secondary. High mortality from in its range limits growth, but it can achieve higher in the range.

Host specificity testing

Field and laboratory studies confirm restriction to Centaurea; ornamental and plants were not used as sites. Atrophied were found in females caged on safflower (Carthamus tinctorius) with no oviposition occurring.