New records of parasitism of the Fuller's rose weevil Naupactus cervinus (Coleoptera, Curculionidae) in Argentina.

CABRIO, V.; RODRIGUERO, M.S; FERNANDEZ GOYA, L.; LANTERI A.A.; CONFALONIERI, V.A.

Ciudad de Buenos Aires

Congreso; II Virtual Meeting of Systematics, Biogeography, and Evolution; 2021

Naupactus cervinus is an invasive species native to South America and distributed throughout the world. It is considered a pest of citrus in several countries because of root herbivory. Also, eggs on fruit have been a quarantine barrier for exports of citrus and kiwifruit to markets in East Asia. Study of natural parasitoids of this weevil is important in order to develop possible biological control strategies.We studied two parasitoids found in adult females of N. cervinus collected in Entre Ríos province, Argentina. DNA was extracted and the mitochondrial COI gene was amplified and sequenced. Wolbachia infection was diagnosed through PCR and characterized through MLST genotyping. BLAST analysis suggested one of the parasitoids was 85-91% similar to several Braconidae (order Hymenoptera).The other parasitoid shared a 93-97% identity with the COI sequences of several Tachinidae (order Diptera). Then, for each parasitoid we performed a family-level analysis by retrieving sequences of several related genera from GenBank and BOLD databases. MRMODELTEST v.2.4 was used to establish the best fit model of nucleotide substitution and MRBAYES v.3.2.7a was used to perform Bayesian inference. We also compared COI genetic distances between our samples and putative congeneric species by pairwise comparisons using MEGA v.6, thus testing whether our genus-level identification was compatible in terms of genetic variability. The hymenopteran parasitoid fell within the genus Microctonus with high nodal support. A previous study by Rodriguero et al. (2014) first reported a Micronoctus sp. parasitoid for N. cervinus but the species herein studied would be different from the former. Until present, none of them could be identified based on COI gene sequences (they do not match with those of known species), or by morphology of the larvae (we did not obtain adult specimens of the parasitoid). This wasp was infected with the wNau5 strain, the same present in N. cervinus. This enforces the ongoing hypothesis that parasitoids are vehicles for Wolbachia horizontal transmission.The other parasitoid here reported belongs to the genus Oestrophasia within the family Tachinidae. The Tachinids gather several endoparasitoids of insects, and Oestrophasia is associated with some Neotropical broad-nosed weevils, e.g. Oestrophasia sabroskyi in Artipus floridanus. Until present we could not identify the species associated with N. cervinus. In this case, the parasitoid was not infected with Wolbachia.