Bee pollination services and the burden of biogeography.

Native bees augment pollination services in the Northern Hemisphere, especially cultivated apple crops, yet Southern Hemisphere contexts are poorly known. We observed the foraging behaviour of 69 354 invertebrate flower visitors in Australian orchards (two regions, 3 years) to assess the efficacy of pollination service (Peff). Native stingless bees and introduced honey bees were the most abundant visitors and most efficacious pollinators (Tetragonula Peff = 6.16; Apis Peff = 13.02), with Tetragonula becoming important service providers above 22°C. However, visits by tree-nesting stingless bees decreased with distance from native forest (less than 200 m) and their tropical/subtropical distribution precludes pollination service in other major Australian apple-producing regions. More broadly distributed native allodapine and halictine bees transferred the most pollen per-visit, but their low abundances reduce efficacies (Exoneura Peff = 0.03; Lasioglossum Peff = 0.06), resulting in a general dependence on honey bees. This reliance is a burden of biogeography, since key Northern Hemisphere pollinators of apple (Andrena, Apis, Bombus, Osmia) do not naturally occur in Australasia-where there is only 15% generic overlap with Central Asian bees sympatric with wild apple distributions (cf. Palaearctic 66% and Nearctic 46% generic overlaps). The historical biogeography of bees therefore drives an extreme dependence on one introduced species for apple pollination in Australia.

The frequency and framing of cognitive lapses in healthy adults.

OBJECTIVE: Many people present to health services with concern about cognitive symptoms. In a significant proportion those symptoms are not the result of pathologically defined brain disease. In some they are part of a functional cognitive disorder (FCD). We assessed the frequency of cognitive lapses in a non-clinical sample in order to consider the utility of frequency of cognitive lapses in diagnosing cognitive disorders. METHODS: Healthy adults, who had never sought help for cognitive symptoms, completed a questionnaire, distributed via social media, about self-evaluation of cognitive function, frequency of cognitive lapses, and use of memory aids, including Schmitdke and Metternich's functional memory disorder (FMD) inventory. RESULTS: One hundred and twenty-four adults, aged 18-59 (median 23), most with further or higher education, responded. Thirty-one (25%) reported "fair" or "poor" memory. Forty-eight (39%) reported memory worse than 5 years ago, and 30 (24%) reported memory worse than others the same age. Participants endorsed a mean 13/18 specific cognitive lapses at least monthly. One hundred and eleven (89%) scored ≥4, the suggested cutoff for the FMD inventory. CONCLUSIONS: Cognitive lapses described in FCDs are common in highly educated adults. The high frequency of lapses in this healthy population suggests self-reported frequency of lapses alone cannot discriminate FCDs from "normal" experiences. Further research is required to clarify the role of abnormal metacognition in FCD. Better understanding of the factors moderating subjective interpretation of cognitive failures will also aid development of better clinical risk-stratification methods in people concerned about future dementia.