#WednesdaysWeeklyWeevil (2) – Lissoderes cecropiae
Natural History. As the species name suggests, this weevil utilizes cecropia trees (Cecropia Löfling; Urticaceae) as its host plant. Lissoderes adults can be easily found on the underside of cecropia leaves throughout the Neotropics, along with the members of conoderine genus Pseudolechriops and some species of Eulechriops and Lechriops, among other weevils. Lissoderes cecropiae is found at mid elevations (~ 1,000-1,600 m) on the tree Cecropia angustifolia. Larvae are endophytic in the internodes, feeding on the parenchyma tissue while moving around on their dorsum. However, the specific oviposition site on the host plant, mating behavior, and adult feeding behavior for this species remain unknown.
Other comments & fun facts. The mutualism between Cecropia and Azteca ants (Hymenoptera: Formicidae) is well documented, where the ants protect the plant from herbivory and in return the plant provides the colony with shelter and food in the hollow internodes of the stem. The extent to which the weevils are parasites of this mutualism is unclear. However, C. angustifolia is a cecropia species that does not have ant colonists. As a possible evolutionary corollary, the parenchyma in the internodes is thinner than in ant-inhabited species. The larvae of L. cecropiae move between internodes during their development, whereas other species of Lissoderes in ant-inhabited trees (and typically with thicker parenchyma) do not.
Although rostral sexual dimorphism is relatively rare in conoderine weevils, it is present to some degree in most members of the two main cecropia-inhabiting genera of Lissoderes and Pseudolechriops. The most extreme example of dimorphism in the genus is in L. cecropiae. Pictured below is the male – the function of the rostral keel and enlarged mandibles is yet to be discovered. The keel of the male rostrum varies from a truncate to a rounded projection.
Taxonomic name. Lissoderes cecropiae Hespenheide 1987: 48
Classification. Curculionoidea: Curculionidae: Conoderinae: Zygopini Lacordaire 1866
Reference. Bouchard et al. 2011. Family-group names in Coleoptera (Insecta). ZooKeys 88: 1-972. Link
Common Name. Not available.
Relevant Taxonomic Treatment. Hespenheide, H.A. 1987. A revision of Lissoderes Champion (Coleoptera: Curculionidae: Zygopinae). Coleopterists Bulletin 41: 41-55. Link
Diagnosis. Lissoderes is easily distinguished from other conoderine genera by the antennal insertions, which are in the distal half of the rostrum. Additional characters: eyes large and round, head globose, prothorax cylindrical, body largely glabrous (often shiny black or reddish-brown), and hind tibia laterally compressed. L. cecropiae is among the larger Lissoderes species, with males 3.2-4.9 mm and females 3.6-5.45 mm. It is further distinguishable from the other six described species by the combination of the following characters: a strongly sexually dimorphic rostrum, a slightly convex pronotum in profile, and the absence of long golden setae on the hind tibiae (Hespenheide 1987, 2007).
Phylogenetic treatment. Not available.
- Weng, J.-L., K. Nishid, P. Hanson & L. LaPierre. 2007. Biology of Lissoderes Champion (Coleoptera, Curculionidae) in Cecropia saplings inhabited by Azteca ants. Journal of Natural History 41: 1679-1695. Link
- Hespenheide, H.A. 2007. Two new species of Lissoderes Champion, 1906 (Coleoptera: Curculionidae: Conoderinae) with comments on the ecology of the genus. Coleopterists Bulletin 61: 604-610. Link