Larval habits and host plants of Neotropical Hylobiina (Curculionidae: Molytinae)

The subtribe Hylobiina belongs to the tribe Molytini (Curculionidae: Molytinae). Alonso-Zarazaga and Lyal (1999) listed 29 Neotropical genera within what was then recognized as the tribe Hylobiini. The revised classification proposed by Mendivil-Nieto and Morrone (2026) recognizes 28 Neotropical genera, for 11 of which published information on larval habits and plant associations was located. Host plants are defined here as plants reported to support larval feeding or development. Records involving dead plant tissues are distinguished from those involving living tissues, and probable or incompletely documented associations are explicitly identified. Reports of adults feeding on, resting on, or collected from a plant are not, by themselves, considered evidence of a larval host association. Such observations may nevertheless help identify plants for further investigation.

Most of the available information concerns larvae feeding within trunks, stems, roots, or branches of trees, shrubs, and herbaceous plants. Some species attack living plants, whereas others develop in standing dead trees, fallen trunks or stems, or dead plant tissues. Development in seeds has been reported in two genera, while an additional historical record in another genus requires clarification. In several of the species reviewed, larval growth and pupation occur within plant tissues (Fig. 1), from which the adults subsequently emerge. Adults have been reported feeding on leaves, buds, tender shoots, unlignified stems and branches, flowers, and fruits. When feeding on fruits, adults may scrape the skin or also consume the pulp, without damaging the seeds. Much of our knowledge of these genera comes from their associations with cultivated plants, including fruit trees, timber trees, and ornamentals. The following accounts summarize reported larval associations and identify cases where the evidence remains incomplete.

Arniticus Pascoe. In Brazil, Sánchez-Soto and Nakano (2003) identified adults of A. brevicollis Pascoe damaging leaves of Morus alba L. (Moraceae: Rosales). They also summarized earlier reports of larvae living in mulberry stems and of females making holes in the stems for oviposition. These reports suggest a larval association with M. alba, although the study did not directly demonstrate complete larval development in this plant.

Byzes Pascoe. In Brazil, B. nodifer (Boheman) was reported to develop in seeds of “manga brava” and Swartzia sp. (Fabaceae: Fabales) (Silva et al. 1968). The botanical identity of the plant reported as “manga brava” requires confirmation.

Calvertius Sharp. In Argentina and Chile, larvae of C. tuberosus (Fairmaire & Germain) (Fig. 2A) feed on the phloem of Araucaria araucana (Molina) K.Koch (Araucariaceae: Pinales) (Morrone 1997). This species often occurs together with Araucarius medius and A. minor (Curculionidae: Cossoninae) in fallen trees and standing dead trees (Kuschel 2000). According to Morrone (1997), C. tuberosus is a secondary colonizer: rather than attacking healthy tissues of A. araucana, it enters branches previously attacked by bark beetles or species of Araucarius.

Epistrophus Kirsch. In a wet páramo in Chingaza National Natural Park, Colombia, larvae of E. cristulatus Faust were documented feeding on soft, living tissues at the leaf bases and growing point of Espeletia killipii Cuatrec. var. killipii (Asteraceae: Asterales). Larvae were found mainly in the rosette and were reared to adults in the laboratory (Trujillo-Motta et al. 2002).

Heilipodus Kuschel. In Argentina, larvae of H. ventralis (Hustache) bore into the root crown and roots of Grindelia chiloensis (Cornel.) Cabrera, Gutierrezia solbrigii Cabrera, and occasionally species of Baccharis L. (Asteraceae) (Cordo et al. 1999). Larvae of H. erythropus (Klug) (Fig. 2B) damage the stem and root of Eryngium eburneum Decne. ex Hérincq (Montero et al. 2013) and bore into the flowering stalk of E. horridum Malme (Campos and Fernández 2011) (Apiaceae: Apiales). In Uruguay, larvae of H. erythropus and H. scabripennis (Klug) bore into the flowering stalk and rhizome of E. horridum (Pazos 2008). In Brazil, Silva et al. (1968) reported larvae of H. erythrorhynchus (Germar) boring into “assa-peixe” and larvae of H. ocellatus (Olivier) developing in “ingazeiro” (Inga sp.; Fabaceae), without specifying the plant organ occupied. The botanical identity of the plant reported as “assa-peixe” requires confirmation. Mecke and Galileo (2004) also reported that larvae of H. tuberculatus (Boheman) develop beneath the bark of felled trees and dead branches of Araucaria angustifolia (Bertol.) Steud. (Araucariaceae).

Heilipus Germar. Heilipus is one of the most species-rich genera of Hylobiina and has comparatively well-documented larval habits and host plants. It has traditionally been recognized for the damage caused by some of its species to the seeds, trunks, and branches of avocado trees (Persea americana Mill.; Lauraceae: Laurales) (Fig. 1). The compilation by Díaz-Grisales et al. (2024) documented ten species associated with avocado: three seed borers and seven trunk and branch borers, with records from Brazil, Colombia, Costa Rica, Mexico, Nicaragua, Panama, and the United States. However, Heilipus host associations extend to other genera of Lauraceae and to Annonaceae. Of the 90 species currently grouped in the genus, information on larval habits and host plants was available for 24: 12 seed borers and 12 trunk and branch borers. Their hosts comprise 33 species of Lauraceae belonging to Aiouea Aubl., Aniba Aubl., Beilschmiedia Nees, Caryodaphnopsis Airy Shaw, Cinnamomum Schaeff., Clinostemon Kuhlm. & Samp., Damburneya Raf., Mespilodaphne Nees, Mezilaurus Kuntze ex Taub., Nectandra Rol. ex Rottb., Ocotea Aubl., and Persea Mill., as well as five taxa of Annona L. (Annonaceae: Magnoliales). Host plant species and details of the associations, biology, and distribution are provided by Díaz-Grisales et al. (2024).

Heilus Kuschel. In southern Florida, USA, a larva of H. bioculatus (Boheman) was extracted from a fallen trunk of Bursera simaruba (L.) Sarg. (Burseraceae: Sapindales) (Anderson 1992). In Brazil, H. ochrifer (Boheman) was reported “in seeds” of an unidentified member of Annonaceae (Costa-Lima 1956). This historical record does not specify the developmental stage or explicitly describe feeding, and therefore requires clarification before it can be treated as confirmed evidence of larval seed feeding.

Marshallius Kuschel. All records assembled here for this genus are from Brazil. Costa-Lima (1956) reported M. multisignatus (Boheman) as a trunk and branch borer of unhealthy cashew trees (Anacardium occidentale L.; Anacardiaceae: Sapindales). Marshallius anacardii Almeida-Lima (Fig. 3A) and M. bondari Rosado-Neto also bore into cashew trunks and roots, although the latter is more often associated with roots than with trunks (Carvalho et al. 2024). Larvae of M. bonellii (Boheman) (Fig. 3B) bore into the trunks and branches of fig trees (“figueira”; Ficus carica L.) and “gameleira” (Ficus sp.; Moraceae) (Silva et al. 1968).

Plethes Pascoe. This genus is endemic to Colombia and has been recorded in páramo ecosystems. Craw (1999) reported rearing Plethes from Asteraceae based on specimen label data in the New Zealand Arthropod Collection (NZAC), without specifying the weevil species or the plant's identity. Adults of P. unguiculatus (Boheman) (Fig. 3C) have also been recorded on living leaves (Sturm and Rangel 1985) and flowers (Sturm 1989) of Espeletia grandiflora Bonpl. (Asteraceae). These observations suggest that the Asteraceae mentioned by Craw (1999) might belong to Espeletia, whose species are commonly known as “frailejones”. This possibility remains unconfirmed and requires examination of the original rearing data or targeted sampling for immature weevils.

Pseudanchonus Faust. In a wet páramo in Chingaza National Natural Park, Colombia, larvae of Pseudanchonus sp. were documented feeding on the bases of dead leaves that remain attached to the stems of Espeletia killipii Cuatrec. var. killipii (Asteraceae). This consumption of dead leaf material occurs on the lower portions of living plants and on fallen stems. The authors reared the larvae to adults in the laboratory (Trujillo-Motta et al. 2002). This record concerns dead plant tissue as a larval feeding substrate.

Whiteheadlobius Mendivil-Nieto. Eight species formerly assigned to Heilipodus were transferred to this new genus as part of the revised classification of Hylobiina proposed by Mendivil-Nieto and Morrone (2026). Two of these species have documented larval habits and host plants. In Brazil, W. destructor (Olivier) was reported as a stem and root borer of peppers (Capsicum spp.; Solanaceae: Solanales) (França et al. 1984). In Ecuador, Cedeño and Flowers (2012) found larvae and newly emerged adults of W. unifasciatus (Champion) in roots of Ochroma pyramidale (Cav. ex Lam.) Urb. (Malvaceae: Malvales).

This preliminary compilation highlights the predominance of trunk, stem, branch, and root boring among the genera reviewed. Other documented larval habits include feeding on living leaf bases and growing points and on dead leaf bases. Seed feeding appears less widely documented: development in seeds has been reported in Byzes and Heilipus, while the historical record for Heilus requires confirmation. Heilipus has the largest number of species documented as larval seed borers among the genera reviewed; all confirmed host plants of its seed-boring larvae belong to Lauraceae. Further research and targeted field sampling are needed to determine whether seed feeding occurs in additional genera. Published records do not necessarily reflect the full range of larval habits within Hylobiina.

Despite the records assembled here, information on the biology and larval habits of Neotropical Hylobiina remains limited: no reliable information on larval habits or host plants was located for 17 of the 28 genera. The literature contains numerous records of adults feeding on or merely resting on plants. Although some of these plants may also support larval development, confirming these associations requires targeted sampling for immature stages within plant tissues and rearing them to adulthood. Distinguishing these records from larval associations also draws attention to native or endemic plants used by these weevils, such as Espeletia killipii in Colombia and Araucaria araucana in Argentina and Chile. Some documented host plants are threatened: A. araucana is assessed as Endangered (Premoli et al. 2013) and A. angustifolia as Critically Endangered (Thomas 2013) on the IUCN Red List. How might the decline or loss of these native plants affect the weevils that use them? Addressing this question requires a better understanding of host specificity, alternative host plants, and the availability of suitable larval feeding and development substrates.

Dedication

I dedicate this note to the memory of Germán Amat García, a prominent Colombian coleopterist and coauthor of the study documenting the biology of Epistrophus cristulatus and Pseudanchonus sp. on Espeletia killipii var. killipii in Chingaza National Natural Park, Colombia.

Acknowledgments

Remembering those we have lost reminds us how important it is to express our gratitude while we still have the opportunity to do so. I am grateful to Dr. Jennifer Girón for her feedback, which helped improve this note, and for her ongoing support. I also thank Humberto Lezama and the iNaturalist users who generously allowed me to use their photographs.

References

• Alonso-Zarazaga MA, Lyal CHC (1999) A world catalogue of families and genera of Curculionoidea (Insecta: Coleoptera) (excepting Scolytidae and Platypodidae). Entomopraxis, Barcelona, 315 pp.

• Anderson RS (1992) Curculionoidea of southern Florida: An annotated checklist (Coleoptera: Curculionoidea [excluding Curculionidae: Scolytinae, Platypodinae]). Insecta Mundi 6(3–4): 193–248. https://digitalcommons.unl.edu/insectamundi/428/  

• Campos RE, Fernández LA (2011) Coleopterans associated with plants that form phytotelmata in subtropical and temperate Argentina, South America. Journal of Insect Science 11: 147.

• Carvalho YL de, Teixeira PBS, Gonçalves NGG, Silva GA da, Mota MSCS, Mesquita ALM (2024) Insetos broqueadores associados ao cajueiro: uma revisão. In: Andrade JKB de (Org) Fundamentos e pesquisas em Ciências Ambientais e Agrárias. Licuri, Campina Grande,  90–103. https://doi.org/10.58203/Licuri.22717  

• Cedeño PE, Flowers RW (2012) Heilipodus unifasciatus (Champion) (Coleoptera: Curculionidae: Molytinae: Hylobiini) attacking plantations of Ochroma pyramidale (Cavanilles Ex Lamarck) Urban (Malvaceae) in Ecuador. The Coleopterists Bulletin 66(4): 344–346. https://doi.org/10.1649/072.066.0408

• Cordo HA, DeLoach CJ, Habeck DH (1999) Biology of Heilipodus ventralis (Coleoptera: Curculionidae), an Argentine weevil for biological control of snakeweeds (Gutierrezia spp.) in the United States. https://doi.org/10.1006/bcon.1999.0721  

• Costa-Lima AM da (1956) Insetos do Brasil, 10.º Tomo, Coleópteros, 4.ª e última parte. Escola Nacional de Agronomia Série Didática N.º 12, 373 pp.

• Craw RC (1999) Molytini (Insecta: Coleoptera: Curculionidae: Molytinae). Fauna of New Zealand 39.  Manaaki Whenua Press, Lincoln, 68 pp. https://www.landcareresearch.co.nz/assets/Publications/Fauna-of-NZ-Series/FNZ39Craw1999.pdf

• Díaz-Grisales V, Caicedo AM, Carabalí A (2017) Ciclo de vida y descripción morfológica de Heilipus lauri Boheman (Coleoptera: Curculionidae) en Colombia. Acta Zoológica Mexicana (n.s.) 33: 231–242. https://doi.org/10.21829/azm.2017.3321063

• Díaz-Grisales V, Romero-Nápoles J, González-Hernández H, Girón Duque JC, Bautista-Martínez N, Castañeda-Vildózola Álvaro, Anzaldo S, Lourenção AL (2024) Host plants of the weevil genus Heilipus Germar, 1824 (Coleoptera, Curculionidae, Molytinae, Molytini, Hylobiina). Contributions to Entomology 74(2): 217–234. https://doi.org/10.3897/contrib.entomol.74.e129094  

• França FH, Barbosa S, Ávila AC (1984) Pragas do pimentão e da pimenta: características e métodos de controle. Informe Agropecuário 10(113): 61–67. https://www.alice.cnptia.embrapa.br/alice/bitstream/doc/767150/1/Pragadopimentaocaracteristicas.pdf   

• Kuschel G (2000) La fauna curculiónica (Coleoptera: Curculionoidea) de la Araucaria araucana. Revista Chilena de Entomología 27: 41–51. https://www.biodiversitylibrary.org/page/33097891#page/47/mode/1up  

• Mecke R, Galileo MHM (2004) A review of the weevil fauna (Coleoptera, Curculionoidea) of Araucaria angustifolia (Bert.) O. Kuntze (Araucariaceae) in South Brazil. Revista Brasileira de Zoologia 21(3): 505–513. https://doi.org/10.1590/S0101-81752004000300013

• Mendivil-Nieto JA, Morrone JJ (2026) Phylogenetic relationships of the Neotropical genera of Hylobiina (Coleoptera: Curculionidae: Molytinae: Molytini): seventy years after Kuschel's proposal. Cladistics 42(4): 321–357. https://doi.org/10.1111/cla.70032  

• Montero GA, Barberis I, Fernández C, Freire R, Montero Bulacio N (2013) Insectos herbívoros asociados a Eryngium eburneum Decne (Apiaceae) y a Dipsacus fullonum L. (Dipsacaceae) en el sur de Santa Fe. In: López CE, Bulacio L, Migliaro M (Coords.) Ciencia y tecnología 2013: divulgación de la producción científica y tecnológica de la UNR. UNR Editora, Rosario, 193–196. http://hdl.handle.net/2133/19003

• Morrone JJ (1997) Weevils (Coleoptera: Curculionoidea) that feed on Araucaria araucana (Araucariaceae) in southern Chile and Argentina, with annotated checklist. Folia Entomológica Mexicana 100: 1–14.

• Pazos JL (2008) Factibilidad de control biológico de malezas de pasturas en el Uruguay. Serie FPTA 20. Instituto Nacional de Investigación Agropecuaria, Montevideo, 40 pp. https://ainfo.inia.uy/digital/bitstream/item/2818/1/18429130709162450.pdf  

• Premoli A, Quiroga P, Gardner M (2013) Araucaria araucana. The IUCN Red List of Threatened Species 2013: e.T31355A2805113. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T31355A2805113.en. Accessed on 15 October 2026.

• Sánchez-Soto S, Nakano O (2003) Arniticus brevicollis Pascoe (Coleoptera: Curculionidae), Praga da Amoreira em São Paulo. Neotropical Entomology 32(3): 513–514. https://doi.org/10.1590/S1519-566X2003000300023

• Silva AG d’A, Gonçalves CR, Galvão DM, Gonçalves AJL, Gomes J, Silva MN, Simoni L (1968) Família Curculionidae, subfamília Hylobiinae. In: Lima AM da C, Silva AG d’A (Eds) Quarto catálogo dos insetos que vivem nas plantas do Brasil; seus parasitos e predadores, Tomo 1, pt. 2. Ministério da Agricultura, Rio de Janeiro, 510–514.

• Sturm H (1989) Beziehungen zwischen den Blüten einiger hochandiner Wollschopfpflanzen (Espeletiinae, Asteraceae) und Insekten. Studies on Neotropical Fauna and Environment 24(3): 137–155. https://doi.org/10.1080/01650528909360784

• Sturm H, Rangel JO (1985) Ecología de los páramos andinos: una visión preliminar integrada. Biblioteca José Jerónimo Triana 9. Universidad Nacional de Colombia, Instituto de Ciencias Naturales, Bogotá, 292 pp. https://www.researchgate.net/publication/339750662_ECOLOGIA_DE_LOS_PARAMOS_ANDINOS_Una_vision_preliminar_integrada  

• Thomas P (2013) Araucaria angustifolia. The IUCN Red List of Threatened Species 2013: e.T32975A2829141. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T32975A2829141.en. Accessed on 15 October 2026.

• Trujillo-Motta DM, Amat-García G, Vargas O (2002) Efecto de disturbios antrópicos en las interacciones bióticas de un páramo húmedo de Colombia. In: Ange Jaramillo C (Ed.) Congreso Mundial de Páramos: estrategias para la conservación y sostenibilidad de sus bienes y servicios ambientales. Memorias, Tomo II. Ministerio del Medio Ambiente, CAR, IDEAM y Conservación Internacional Colombia, Bogotá, 969–982. https://www.researchgate.net/publication/262915574_EFECTO_DE_DISTURBIOS_ANTROPICOS_EN_LAS_INTERACCIONES_BIOTICAS_DE_UN_PARAMO_HUMEDO_DE_COLOMBIA