The complexities of knowing what it is you are trapping

The effectiveness of any trapping system is highly dependent on the ability to accurately identify the specimens collected. For many fruit fly species, accurate identification (= diagnostics) using morphological or molecular techniques is relatively straightforward and poses few technical challenges. However, nearly all genera of pest tephritids also contain groups of species where single, stand-alone tools are not sufficient for accurate identification: such groups include the Bactrocera dorsalis complex, the Anastrepha fraterculus complex and the Ceratitis FAR complex. Misidentification of high-impact species from such groups can have dramatic consequences and negate the benefits of an otherwise effective trapping program. To help prevent such problems, this chapter defines what is meant by a species complex and describes in detail how the correct identification of species within a complex requires the use of an integrative taxonomic approach. Integrative taxonomy uses multiple, independent lines of evidence to delimit species boundaries, and the underpinnings of this approach from both the theoretical speciation literature and the systematics/taxonomy literature are described. The strength of the integrative approach lies in the explicit testing of hypotheses and the use of multiple, independent species delimitation tools. A case is made for a core set of species delimitation tools (pre- and post-zygotic compatibility tests, multi-locus phylogenetic analysis, chemoecological studies, and morphometric and geometric morphometric analyses) to be adopted as standards by tephritologists aiming to resolve economically important species complexes. In discussing the integrative approach, emphasis is placed on the subtle but important differences between integrative and iterative taxonomy. The chapter finishes with a case study that illustrates how iterative taxonomy applied to the B. dorsalis species complex led to incorrect taxonomic conclusions, which has had major implications for quarantine, trade, and horticultural pest management. In contrast, an integrative approach to the problem has resolved species limits in this taxonomically difficult group, meaning that robust diagnostics are now available.

Complete genome sequence of Colocasia bobone disease-associated virus, a putative cytorhabdovirus infecting taro

We report the first genome sequence of a Colocasia bobone disease-associated virus (CBDaV) derived from bobone-affected taro [Colocasia esculenta L. Schott] from Solomon Islands. The negative-strand RNA genome is 12,193 nt long, with six major open reading frames (ORFs) with the arrangement 3′-N-P-P3-M-G-L-5′. Typical of all rhabdoviruses, the 3′ leader and 5′ trailer sequences show complementarity to each other. Phylogenetic analysis indicated that CBDaV is a member of the genus Cytorhabdovirus, supporting previous reports of virus particles within the cytoplasm of bobone-infected taro cells. The availability of the CBDaV genome sequence now makes it possible to assess the role of this virus in bobone, and possibly alomae disease of taro and confirm that this sequence is that of Colocasia bobone disease virus (CBDV).