Rhopalapion longirostre

Distinguished from congeners by combination of elongate body, elongate antennal club, and strong sexual dimorphism in rostrum length. Females have markedly longer rostra than males. Distinguished from Rhopalapion celatum by morphological study of populations; R. celatum occurs in Turkey, Armenia, Azerbaijan, Syria, Iraq, Iran, Uzbekistan, Kyrgyzstan and Kazakhstan. Presence in hollyhock (Alcea) flowers and fruits is strongly indicative. Two distinct pupal size morphs (large: 3.00–3.50 mm; small: 1.75–2.30 mm) are notable features.

Heliophilic and xerothermophilous; occurs in pastures, meadows, roadsides, ruderal communities, and gardens. Found in mountain regions up to 2150 m elevation. Patchy distribution in residential areas indicates anthropogenic expansion. Strongly associated with presence of host plants from genus Alcea.

Native to central Asia. Since the 1960s, rapidly expanded to Middle East, Mediterranean region, across Europe (except Scandinavia) to British Isles. Introduced to North America, spreading from east to west; recorded from Canada (British Columbia, Nova Scotia, Ontario, Quebec) and United States. In France, documented from Gard (1980), Ardèche (1982), Loire, Isère, Haute-Loire, Vendée, and Hautes-Pyrénées. Also recorded from Serbia.

Adults active March to November, potentially year-round in suitable conditions. Oviposition occurs May to July. First instar larvae appear 3–4 days after egg laying. Pupation lasts 2–6 weeks depending on weather. Whole developmental period 7–10 weeks. Multiple generations may coexist in single season. Adult emergence observed in August.

Specialized seed predator of Alcea species. Larvae consume seeds inside hollyhock pericarps, forming chambers within individual seeds. Adults feed on host plant tissues; specific adult diet details not provided in sources.

• Alcea digitata - larval hostlarvae develop in seeds
• Alcea dissecta - larval hostlarvae develop in seeds
• Alcea rosea - primary hostmain host for reproduction and development; also known as hollyhock or Rose trémière
• Alcea setosa - larval hostlarvae develop in seeds

Eggs laid in holes bored in flower buds. Larva hatches after 3–4 days, migrates to ovary, enters single pericarp, and consumes seed while forming a chamber. Larva bores escape hole and seals it with protective secretion. Pupation occurs inside pericarp lasting 2–6 weeks. Developmental period from egg to adult: 7–10 weeks. Multiple generations may coexist in single season. Overwintering occurs under plant remains near host plant.

Females are efficient, active fliers. Females use elongated rostra to bore holes in flower buds for oviposition. Larvae seal escape holes in pericarps with protective secretion. Developmental behavior includes strict association with single seeds within pericarps. Competition with Pexicopia malvella (hollyhock seed moth) for development niche in hollyhock fruit has been observed.

Specialized seed predator of Alcea species. Competes with Pexicopia malvella caterpillars for hollyhock seed development niche; this competition acts as a pathogenic factor limiting population numbers. Regarded as pest of ornamental plants in some countries. Role in broader ecosystem food webs not documented in available sources.

Regarded as pest of ornamental hollyhock plants in some countries. Rapid range expansion since 1960s cited as expression of response to climate change. Anthropogenic dispersal evident from patchy distribution in residential areas. Subject of extensive research with over 300 scientific papers published on various aspects of its biology.

• Rhopalapion celatumFormerly confused with R. longirostre; distinguished by morphological study of populations; occurs in Turkey, Armenia, Azerbaijan, Syria, Iraq, Iran, Uzbekistan, Kyrgyzstan and Kazakhstan
• Pexicopia malvellaNot a congener but shares ecological niche; hollyhock seed moth caterpillars develop sympatrically in hollyhock fruit and compete for same resource, limiting R. longirostre numbers

• seed predator
• pest
• sexual dimorphism
• range expansion
• climate change response
• hollyhock
• Malvaceae

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Quelques observations sur la biologie de Rhopalapion longirostre (Olivier) (Coleoptera, Curculionidae, Apioninae)
• Immature Stages and Breeding Behaviour of the Hollyhock Weevil–Rhopalapion longirostre (Olivier 1807) (Coleoptera, Brentidae, Apioninae)
• Taxonomic revision of the genus Rhopalapion Schilsky, 1906 (Coleoptera, Apionidae) with description of Rhopalapion celatum n. sp. from the Turanian Region