Wild bacterial probiotics fed to larvae of mass‐reared Queensland fruit fly [Bactrocera tryoni (Froggatt)] do not impact long‐term survival,mate selection,or locomotor activity

Queensland fruit fly [Bactrocera tryoni (Froggatt), Diptera, Tephritidae] is the most devastating insect pest impacting Australian horticulture. The Sterile Insect Technique (SIT) is an important component of tephritid pest management programs. However, mass‐rearing and irradiation (to render insects sterile) may reduce the fitness and performance of the insect, including the ability of sterile males to successfully compete for wild females. Manipulation of the gut microbiome, including the supplementation with bacterial probiotics shows promise for enhancing the quality of mass‐reared sterile flies, however there are fewer published studies targeting the larval stage. In this study, we supplemented the larval stage of mass‐reared B. tryoni with bacterial probiotics. We tested several individual bacteria that had been previously isolated and characterized from the gut of wild B. tryoni larvae including Asaia sp., Enterobacter sp., Lactobacillus sp., Leuconostoc sp. We also tested a consortium of all four of these bacterial isolates. The fitness parameters tested included adult survival in field cages, laboratory mate selection of bacteria supplemented males by bacteria nonsupplemented females, and laboratory locomotor activity of adult flies. None of the bacterial probiotic treatments in the current study was significantly different to the control for field survival, mate selection or locomotor activity of adult B. tryoni, which agree with some of the other studies regarding bacterial probiotics fed to the larval stage of tephritids. Future work is needed to determine if feeding the same, and/or other probiotics to adults, as opposed to larvae can positively impact survival, mating performance, mating competitiveness and locomotor activity of B. tryoni. The bacterial group(s) and function of bacterial species that increase fitness and competitiveness is also of interest to tephritid mass‐rearing programs.     

Long-term bird colonization and turnover in restored woodlands

The long-term effectiveness of restored areas for biodiversity is poorly known for the majority of restored ecosystems worldwide. We quantified temporal changes in bird occurrence in restoration plantings of different ages and geometries, and compared observed patterns with a reference dataset from woodland remnants on the same farms as our plantings. Over time, bird species richness remained unchanged in spring but exhibited modest increases in winter. We found that wider plantings supported significantly greater bird species richness in spring and winter than narrow plantings. There was no evidence of a significant interaction between planting width and time. We recorded major temporal changes in the occurrence of a range of individual species that indicated a clear turnover of species as plantings matured. Our results further revealed marked differences in individual species occurrence between plantings and woodland remnants. Life-history attributes associated with temporal changes in the bird assemblage were most apparent in winter survey data, and included diet, foraging and nesting patterns, movement behaviour (e.g. migratory vs. dispersive), and body size. Differences in bird assemblages between plantings of different ages suggest that it is important that farms support a range of age classes of planted woodland, if the aim is to maximize the number of native bird species in restored areas. Our data also suggest that changes in the bird species occupying plantings of different ages can be anticipated in a broadly predictable way based on planting geometry (especially width) and key life-history attributes, particularly movement patterns and habitat and diet specialisation.