Morphological and molecular inference of immature stages of Larinus hedenborgi (Col: Curculionidae), a trehala-constructing weevil

Trehala manna is the edible and trehalose-rich cocoons of a few Larinus species (Coleoptera: Curculionidae: Lixinae: Lixini), and manufactured by the feeding activity of larvae on the Echinops plants. Knowledge on the morphological and molecular properties of immature stages of Larinus species, especially trehala-constructing ones, is still very limited. Herein, the mature larva and pupa of Larinus hedenborgi Boheman, 1845, are morphologically described for the first time, illustrated and compared with known immature stages of other Larinus species. Morphological identification keys prepared for all known immature stages of Larinus species. The DNA sequences of three mitochondrial (COI, Cytb, and 16S RNA) and four nuclear (enolase, histon 4, 18S rRNA, and 28S rRNA) markers were generated for L. hedenborgi and compared with the available sequences in the GenBank. Comparative morphology revealed the affinity of L. hedenborgi with the L. vulpes, L. inaequalicollis, and L. capsulatus based on five larval and two pupal characters. Molecular analysis based on 1859 bp of mtDNA and 1618 bp of nDNA sequences indicated a close association between the L. hedenborgi and other Lixinae namely Larinus species. Although both morphological and molecular descriptions supported the taxonomic status of L. hedenborgi within weevils, sufficient molecular data must be available to allow further comparisons. This pioneering study can be expanded to a large-scale zoogeographic study using morpho-molecular characters, simultaneously with population-level sampling of all trehala-constructing Larinus species.

Automated summary

The study provides morphological descriptions of the mature larva and pupa of Larinus hedenborgi for the first time and compares them with other Larinus species. Both morphological and molecular analysis reveal the close association between L. hedenborgi and other Lixinae namely Larinus species. The research results offer important data for further taxonomic classification within weevils.