Molecular and cytogenetic differentiation within the Lariophagusdistinguendus (Förster, 1841) species complex (Hymenoptera, Pteromalidae).

Christian König,Vladimir E Gokhman,Justus Weber,Cornelia Gantert,Lars Krogmann,Marie Pollmann,Sina Paschke,Johannes L.M Steidle,Ronja Reinisch

doi:10.3897/compcytogen.v13i2.34492

Abstract

Several strains of the apparently well-known cosmopolitan synanthropic parasitoid of coleopteran stored-product pests, Lariophagusdistinguendus (Förster, 1841) from Western Europe, were studied using DNA sequencing and chromosomal analysis. The presence of at least two cryptic species with different COI sequences and chromosome numbers (n = 5 and 6) was supported. The species with n = 6 is associated with the drugstore beetle Stegobiumpaniceum (Linnaeus, 1758), whereas the other one with n = 5 mostly develops on the granary weevil Sitophilusgranarius (Linnaeus, 1758). A phylogenetic study revealed that the karyotype with n = 6 represents an ancestral character state in this complex. Consequently, the chromosome set with n = 5 which is characteristic of a particular internal clade, apparently originated via chromosomal fusion which was probably preceded by a pericentric inversion. If this is true, inverted chromosome segments could accumulate a number of genetic loci responsible for certain interspecific differences.

Highlights

Parasitoid Hymenoptera are among the most diverse, taxonomically complicated and economically important insect groups (Heraty 2017, Forbes et al 2018)
We report relative lengths (RL: 100 × length of each chromosome divided by total length of the set) and centromeric indices (CI: 100 × length of shorter arm divided by total length of a chromosome) for both species
Three main clades (Stegobium Clade 1, Sitophilus Clade 1, Stegobium Clade 2) were recovered within the L. distinguendus species complex (Fig. 1), including a particular one (Stegobium Clade 2) which can be considered as an outgroup to all previously studied strains (König et al 2015)

Summary

Introduction

Parasitoid Hymenoptera are among the most diverse, taxonomically complicated and economically important insect groups (Heraty 2017, Forbes et al 2018). Over 80 thousand species of parasitoid wasps have already been described (Huber 2017). At least one million parasitoid species might still be unknown (Bebber et al 2014, see Quicke 1997). In addition to the poor knowledge of tropical fauna of parasitoid wasps, this high number of undescribed species apparently results from the phenomenon of the so-called cryptic lineages (Quicke 2002, Heraty 2017), which are very similar or virtually identical in morphology but differ considerably in genetic, ecological, behavioral, and other characteristics. Successful resolution of cryptic species complexes has important implications both for parasitoid wasp taxonomy and biological pest control (Heraty 2017)

Methods

Results

Conclusion