We present restriction site-associated DNA sequencing (RAD-seq) genomic data for 2,292 specimens, which unequivocally supports the delimitation of two new species, here described as Bactrocera borneoensis sp. n. Doorenweerd & San Jose and B. incognita sp. n. Doorenweerd & San Jose.
Under concatenation, both datasets suggest identical species relationships with mostly high statistical support. However, multispecies coalescent and multispecies network approaches suggest markedly different hypotheses and detected significant gene flow.
As the amount of genomic data for nonmodel taxa grows, it is increasingly clear that gene flow across species barriers in insects is much more common than previously thought.
In the E. rubivora complex, ddRAD data resolved all four species, contrary to morphological and COI data, which supports a potential scenario of host plant-driven speciation where the host plant specialization provides an ecological barrier to hybridization.
Our results show that the morphological differences between B. frauenfeldi and B. albistrigata (de Meijere) are part of a continuum that cannot be phylogenetically separated into monophyletic groups.
To further our understanding of the relationships between populations, both the Alpine and the extra Alpine ones, we sequenced 1,496 bp of the COI gene in 16 Alpine and Jurassian populations and analysed them in combination with published Pyrenean and Carpathian sequences.
Dating analyses indicate a mid-Cretaceous (105.3 Ma) origin of the family, followed by a rapid diversification into the nine subfamilies predating the Cretaceous–Palaeogene extinction. We hypothesize that advanced larval behaviours, such as making keeled or tentiform blotch mines, rolling leaves and galling, allowed gracillariids to better avoid larval parasitoids allowing them to further diversify.
Using traps baited with the male lures cue-lure, methyl eugenol, and zingerone, 30 of the 48 species previously known to occur in the Solomon Islands were collected. Six species are newly described.