Haplorhynchites aeneus

(Boheman, 1829)

sunflower headclipping weevil, head-clipping weevil

Haplorhynchites aeneus is a in the , commonly known as the sunflower headclipping . are metallic black, approximately 6–8 mm long, with a prominent elongated snout. Females sunflower stems just below the flower , causing the head to fall to the ground where develop and overwinter. The is prairie- and found across North America, with documented in Canada (Manitoba, Ontario, Saskatchewan) and the United States. to commercial sunflowers is generally minor, though occasional can affect 2–3 percent of a .

Haplorhynchites aeneus by (c) Even Dankowicz, some rights reserved (CC BY), uploaded by Even Dankowicz. Used under a CC-BY license.

Haplorhynchites aeneus (40471266933) by Christina Butler from Georgia, United States. Used under a CC BY 2.0 license.

Silphium laciniatum-Haplorhynchites aeneus by Peterwchen. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Haplorhynchites aeneus: /ˌhæpləˈrɪnkaɪtiːz ˈiːniəs/

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

Identification

Metallic black coloration with long, slender snout () characteristic of . measure approximately 6–8 mm in body length. Distinguished from other sunflower-associated weevils by the combination of: metallic black , elongated rostrum, and association with girdled sunflower . Similar to weevils but placed in based on morphological and phylogenetic characters. develop within fallen sunflower heads rather than in standing tissue.

Images

Habitat

prairie ; associated with sunflower (Helianthus) plants. Occurs in agricultural settings where sunflowers are cultivated, as well as in stands of native sunflowers.

Distribution

North America; prairie-. Documented in Canada: Manitoba, Ontario, Saskatchewan. Present throughout the United States in prairie regions.

Seasonality

emerge in mid-summer. Females active during sunflower blooming period for girdling and . overwinter in fallen , with adults emerging the following summer.

Host Associations

Helianthus annuus - common sunflower; cultivated and wild used for and larval development
Helianthus spp. - sunflower in prairie

Life Cycle

. laid in girdled sunflower . feed and develop within the head after it falls to the ground. occurs in soil. Single per year with emerging the following summer.

Behavior

Females perform distinctive -clipping : girdling the sunflower stem 1–2 inches below the flower head, causing the head to detach and fall. This behavior prepares the site and provides protected for larval development. feed on pollen and nectar.

Ecological Role

specializing on sunflowers; contributes to natural and in prairie . Minor pest in agricultural contexts.

Human Relevance

Occasional pest of commercial sunflower production. Economic rare; typically affects 2–3 percent of in problem years. In Kansas, considered when 10 percent or more of flower clipped and remain active. Head-clipping can reduce seed yield directly and predispose plants to secondary issues.

Similar Taxa

Cylindrocopturus adspersussunflower stem ; also in but differs in boring within standing stalks rather than -clipping, and has -and- mottled coloration versus metallic black
Smicronyx fulvusred sunflower seed ; smaller (2.5–3 mm), reddish- with rust-colored , feeds on developing seeds rather than clipping
Smicronyx sordidusgray sunflower seed ; gray coloration, similar size to S. fulvus, also seed-feeding rather than -clipping
Baris strenuasunflower ; larger (6 mm), dull black with short downward snout, feed on roots rather than
Dectes texanus (); stalks at base for but much larger (16 mm), pale gray with extremely long , bore in stems rather than