Copyright: Shofner, Ryan
Copyright: Shofner, Ryan
Agricultural systems are increasingly faced with the emergence of novel pests. Within the last decade, the macadamia lace bug, Ulonemia decoris Drake, 1942, became established in macadamia orchards in northern New South Wales and southern Queensland. This study provides the first comprehensive overview of the genus and its status in Australia. This study had three broad goals: 1) to describe the relationship between Ulonemia and other tingids in Australia using genetics; 2) to redefine the genus Ulonemia using the results from part 1; 3) to examine the population genomics of U. decoris to determine the dispersal rate of individuals between populations. Analysis of four genes (two mitochondrial and two nuclear) by Maximum Likelihood and Bayesian estimation returned a paraphyletic Ulonemia with three strongly supported clades; a combined morphological and molecular analysis with parsimony failed to resolve any relationships. Two new genera and five new species, Cercotingis (C. croajingolong sp. nov., C. namadgi sp. nov., C. tasmaniensis sp. nov.) and Proteatingis (P. astibosetes sp. nov., P. howardi sp. nov.), are described to account for the observed molecular phylogenies. One species of Tingis and U. decoris were transferred into Cercotingis, and three species of Ulonemia were transferred to Proteatingis. The capability of lace bugs to disperse between orchards is critical in developing better control methods, because determining dispersal ability can provide valuable information on the geographic extent over which control must be coordinated. Single-nucleotide polymorphism (SNP) data were obtained for C. decoris for 204 individuals over 7 localities in northern NSW. Each sample locality had an excess of homozygous individuals and there was minimal genetic differentiation over geographic distance. This evidence points to selection against heterozygotes, recent extensive mixing, non-random mating, parthenogenesis, or cryptic species within C. decoris. The high dispersal and possible rapid reproduction due to parthenogenesis would make C. decoris difficult to manage. There is also a need to monitor for other emergent pest species, because there are multiple lace bug lineages on the Proteaceae, with three of these lineages containing verified pests. In summary, optimal management of the species will likely require region-wide coordination.