Biology and host preference of Selitrichodes neseri: A potential biological control agent of the Eucalyptus gall wasp,Leptocybe invasa

Selitrichodes neseri (Hymenoptera: Eulophidae) is a parasitoid of the invasive gall-forming wasp Leptocybe invasa (Hymenoptera: Eulophidae), which has caused serious damage to Eucalyptus plantations in many parts of the world. S. neseri is a recently discovered parasitoid considered to be a potentially important biological control agent of L. invasa. The aim of this study was to provide the first basic data on the biology of S. neseri, which is essential for its application in biological control. S. neseri was shown to be a biparental ectoparasitoid. Observation from dissected galls indicated that the parasitoid developed on late larvae, pupae and callow adults, although development did occur in a range of gall ages. Observed nominal parasitism in captivity ranged from 9.7% to 71.8%. Adult S. neseri specimens, fed with honey-water and galled Eucalyptus leaves, survived an average of 26 days at 26 °C. The average developmental time from oviposition to emergence was 19.3 days ± 0.2 days. There was no pre-oviposition period. A single female produced a maximum of thirty-nine offspring, with a maximum of ten per day. Dissection of the ovaries showed that twelve ovarioles were present. The sex ratio of S. neseri observed in this study was 1:3.43 males:females. Galls of native insects most closely related to L. invasa and to galls of similar morphology to L. invasa-induced galls, were not suitable for S. neseri oviposition. S. neseri showed considerable potential as a biological control agent of L. invasa due to its relatively short developmental time, long adult life span when supplemented with carbohydrates, ability to utilize a range of gall ages and the fact that it has a high level of host specificity.     

In Vitro Cultivation of Borrelia duttonii on Cultures of SflEp Cells

Borrelia duttonii strain 406 K, a causative agent of relapsing fever, could not be cultivated in vitro in currently available media for borreliae. We have developed an in vitro cultivation system by using SflEp cell cultures. The average increases of the number of borreliae, when inoculated with 1.0 × 10⁵ organisms per ml from infected mice, were 23-fold and 150-fold in the primary culture and the 3rd subculture, respectively. Even a single borrelia could propagate in this cultivation system. This system will be useful for immunological and physiological studies on uncultivable Borrelia strains.     

The effect of temperature on reproduction in three species of cyclopoid copepods

Megacyclops viridis (Jurine), Macrocyclops albidus (Jurine), and Acanthocyclops vernalis (Fischer) were raised in the laboratory at six temperatures (5, 8, 10, 12, 15 and 20°) and fed a mixture of ciliates (Paramecium caudatum and Colpidium campylum). Data were taken on clutch size, embryonic development time, interclutch period, time to first clutch, sex ratio and longevity.Clutch size, time to first clutch, embryonic development time, interclutch period and longevity are inversely related to temperature. The ratio of males to females in a cohort is independent of temperature.     

Computational method for the real-time calculation of the full-body muscle load distribution

A method is described for minimising a quadratic function subject to equality and inequality constraints. This approach is applicable to solving the full-body muscle load distribution problem and calculating joint contact loads. It has been found that this approach can provide the solution on modest computing facilities and in significantly less time than using active set and interior point quadratic programming techniques. Hence the approach is suitable for providing real-time feedback to subjects undergoing biomechanical analysis of muscle, skeletal and joint loadings.     

Cox model with interval‐censored covariate in cohort studies

In cohort studies the outcome is often time to a particular event, and subjects are followed at regular intervals. Periodic visits may also monitor a secondary irreversible event influencing the event of primary interest, and a significant proportion of subjects develop the secondary event over the period of follow‐up. The status of the secondary event serves as a time‐varying covariate, but is recorded only at the times of the scheduled visits, generating incomplete time‐varying covariates. While information on a typical time‐varying covariate is missing for entire follow‐up period except the visiting times, the status of the secondary event are unavailable only between visits where the status has changed, thus interval‐censored. One may view interval‐censored covariate of the secondary event status as missing time‐varying covariates, yet missingness is partial since partial information is provided throughout the follow‐up period. Current practice of using the latest observed status produces biased estimators, and the existing missing covariate techniques cannot accommodate the special feature of missingness due to interval censoring. To handle interval‐censored covariates in the Cox proportional hazards model, we propose an available‐data estimator, a doubly robust‐type estimator as well as the maximum likelihood estimator via EM algorithm and present their asymptotic properties. We also present practical approaches that are valid. We demonstrate the proposed methods using our motivating example from the Northern Manhattan Study.     

Microbial biofilm inoculants benefit growth and yield of chrysanthemum varieties under protected cultivation through enhanced nutrient availability

Protected cultivation of ornamental flowers, as a commercial venture, becomes less profitable with excessive use of fertilizers. The present study examined the influence of microbial biofilm inoculants (Anabaena–Azotobacter, Anabaena–Trichoderma and Trichoderma–Azotobacter) on the availability of soil nutrients and structure of rhizosphere microbial communities in three varieties of chrysanthemum (var. White Star, Thai Chen Queen and Zembla). Varietal-specific responses in growth, enzyme activities, flower yield of plants and availability of soil nutrients were recorded. Dehydrogenase activity was highest in var. White Star treated with the Anabaena–Trichoderma biofilm inoculants. The Anabaena–Azotobacter inoculant enhanced the availability of nitrogen, phosphorus and micronutrients in the soil, besides 40–50% increase in soil organic carbon, as compared to carrier alone or no inoculation. PCR-DGGE profiling of the cyanobacterial communities and qPCR quantification of 16S rRNA abundance of bacteria, archaea and cyanobacteria in the rhizosphere soils, revealed the stronger influences of these inoculants, especially in var. Zembla. Principal Component Analysis (PCA) helped to illustrate that the enhanced microbe-mediated availability of soil macro-and micronutrients, except iron content (Fe), was the most influential factor facilitating improved plant growth and yield parameters. The Anabaena–Azotobacter, and Anabaena–Trichoderma biofilm inoculants, proved superior in all three chrysanthemum varieties.     

Increase in body size is correlated to warmer winters in a passerine bird as inferred from time series data

Climate change is expected to affect natural populations in many ways. One way of getting an understanding of the effects of a changing climate is to analyze time series of natural populations. Therefore, we analyzed time series of 25 and 20 years, respectively, in two populations of the citril finch (Carduelis citrinella) to understand the background of a dramatic increase in wing length in this species over this period, ranging between 1.3 and 2.9 phenotypic standard deviations. We found that the increase in wing length is closely correlated to warmer winters and in one case to rain in relation to temperature in the summer. In order to understand the process of change, we implemented seven simulation models, ranging from two nonadaptive models (drift and sampling), and five adaptive models with selection and/or phenotypic plasticity involved and tested these models against the time series of males and females from the two population separately. The nonadaptive models were rejected in each case, but the results were mixed when it comes to the adaptive models. The difference in fit of the models was sometimes not significant indicating that the models were not different enough. In conclusion, the dramatic change in mean wing length can best be explained as an adaptive response to a changing climate.     

Artificial cultivation of true morels: current state,issues and perspectives

Morels (Morchella, Ascomycota), which are some of the most highly prized edible and medicinal mushrooms, are of great economic and scientific value. Morel cultivation has been a research focus worldwide for more than 100 years, and the outdoor cultivation of morels has succeeded and expanded to a large scale in China in recent years. In this study, we review the progress in recent research regarding the life cycle and reproductive systems in the genus Morchella and the current state of outdoor cultivation. Sclerotia formation and conidia production are two important phases during the life cycle. The morel species cultivated commercially in America is M. rufobrunnea based on molecular phylogenetic analysis. The species currently cultivated in China are black morels, including M. importuna, M. sextalata and M. eximia. The field cultivation of morels expanded in the majority of the provinces in China with a yield of fresh morels of 0–7620?kg per ha. The key techniques include spawn production, land preparation and spawning, the addition of exogenous nutrition, fruiting management and harvesting. The application of exogenous nutrition is the most important breakthrough in the field of morel cultivation, but the mechanism remains unclear. It was estimated that the total amount of field cultivated fresh morels was ～500 t in 2015–2016. We also discuss the potential issues remaining in the current literature and suggest directions for future studies.