Seeking Alfalfa Resistance to a Rhizophagous Pest, the Clover Root Curculio (Sitona hispidulus F.)

Since the cancellation of broad-spectrum soil-active insecticides in alfalfa (Medicago sativa L.) production, clover root curculio (Sitona hispidulus F.) (CRC) larval root damage has increased. Current CRC management practices are limited in their ability to suppress larval feeding belowground. First, we field screened developmental alfalfa populations for CRC damage. Subsequently, we developed a soil-less arena to observe nodule feeding and development (head capsule width) of larvae in the lab. This method was used to evaluate five alfalfa populations (two CRC-susceptible (control) and three CRC-resistant populations) against larvae. Further, one CRC-resistant population paired with its genetically similar susceptible population were tested against adult leaf consumption and oviposition in the greenhouse. Field screening revealed that the alfalfa populations selected for little or no larval root feeding damage were more resistant to CRC larval feeding than their corresponding unselected cultivars and significantly more resistant than populations selected for susceptibility. The development of a soil-less arena provided a useful method for evaluation of root-larva interactions. Although larval development was similar across susceptible and resistant alfalfa populations, one CRC-resistant population (NY1713) displayed overall increased nodulation and, thus, had a significantly lower proportion of nodules consumed by larvae. Adult feeding and oviposition aboveground were similar across all populations tested. These results provide possible candidates and screening method for the development and evaluation of alfalfa cultivars that may reduce the impacts of larval feeding and that offer an additional option for CRC management.

Biological relevance unites, semantics divides: a comment on Ruther et al (2021)

Ruther et al (2021) evaluated fatty acid synthesis in several parasitic wasp species to test if the general finding that lipogenesis in parasitoids is lacking is upheld (Visser et al 2010 PNAS). As proposed by Visser & Ellers (2008), parasitoids can readily assimilate the triglyceride stores produced by their host. When large triglyceride stores are carried over from larval feeding into adulthood (i.e., up to 30 to 40% of the parasitoid’s dry body weight; Visser et al., 2018, 2021), de novo lipid synthesis from adult feeding is either unnecessary or too costly to maintain, leading to trait loss (Ellers et al., 2012). To test the hypothesis that many parasitoids do not synthesize substantial quantities of fat stores as adults, a previous study used feeding experiments on a wide taxonomic range of insects, including parasitoid wasps, parasitoid flies, a parasitoid beetle, and 65 non-parasitoid species (Visser et al., 2010 and references therein). What is striking is that when compared to non-parasitoid insects, 24 out of 29 evolutionarily distinct parasitoid lineages (Coleoptera, Diptera and Hymenoptera; Visser et al., 2010) did not accumulate significant lipid quantities in adulthood even when fed surplus carbohydrates. When little to no lipids are synthesized de novo by adult parasitoid wasps, this can lead to significant constraints on energy allocation toward key adult functions, such as maintenance, dispersal, and reproduction (Jervis et al., 2008). To our minds, the most important question is ‘why don’t parasitoids accumulate substantial quantities of fat as adults like other insects do, and what does this mean for their life histories?’

Relationships between pest density and associated leaf necrosis for an invasive leaf-mining weevil, Orchestes fagi L., on American beech (Fagus grandifolia Ehrh.)

Pest density-plant damage relationships are essential guides for decision-making in Integrated Pest Management. In this article, we established pest density-leaf damage relationships for the beech leaf-mining weevil,<i></i> Orchestes fagi <i></i>(L.) (formerly <i></i>Rhynchaenus fagi<i></i>, Coleoptera: Curculionidae) in its invasive range of Nova Scotia, Canada. Outbreaks of<i> O. fagi</i> cause tree-wide leaf necrosis in American beech (<i>Fagus grandifolia</i> Ehrh.), which can eventually result in tree mortality. In 2014 and 2016, we collected weekly samples in stands with American beech and assessed leaves for densities during different life stages (eggs, larvae, and pupae), population proxy measures (adult feeding damage, egg slits, and larval galleries), and percent necrosis. In general, feeding damage and leaf necrosis plateaued soon after end of budburst, but before larval mine expanded. This strongly suggested that leaf necrosis may be linked to damage caused by adults or mine initiation rather than that caused by larval mine expansion and gallery development. Density of <i>O. fagi</i> per leaf for life stages and population proxies all significantly explained ~ 42–81% of the variation in end-of season percent leaf necrosis. Results from this study provide a variety of relationships that could be used in both short- and long-term monitoring efforts for <i>O. fagi</i>.

Adult Feeding Preference and Fecundity in the Large Pine Weevil, Hylobius abietis (Coleoptera: Curculionidae)

Adult feeding preferences of Hylobius abietis on Picea abies, Larix decidua, Pinus sylvestris, Pseudotsuga menziesii, Abies alba and Betula pendula were tested in outdoor conditions. The preferred food source was P. menziesii, and the mean bark area consumed per seedling was 440.8 ± 147.9 mm2. The second most preferred host was P. abies. The coniferous species that suffered the least damage was A. alba (76.8 ± 62.56 mm2 per seedling). B. pendula was the least preferred source of food, and it caused mortality of 60% of weevils that fed on it. Weevils exhibited large differences in fecundity when fed with different tree species in a laboratory experiment. The largest number of eggs was laid by females fed with P. abies. Mean egg numbers reached 26.4 ± 24.89 eggs per experiment for P. abies. Similar fecundity was observed in weevils fed with twigs of P. sylvestris. Oviposition was approximately six times lower in females fed with L. decidua and P. menziesii. The maximum number of eggs laid by a single female during a one-month experiment was 90. The results are discussed in relation to management of H. abietis.

BEHAVIORAL RESPONSE OF BEMISIA TABACI (HEMIPTERA: ALEYRODIDAE) TOWARDS METARHIZIUM ANISOPLIAE VOLATILES

The aim of this study was to investigate the behavioral response of Bemisia tabaci towards Metarhizium anisopliae (isolates PR1 and GT3) volatiles. Behavioral response of B. tabaci was investigated based on adult feeding and oviposition preference in eggplant Solanum melongena L. The highest mean number of adult (87) and egg (418) of B. tabaci were observed in the control plant, while the lowest mean number of adult (26) and egg (107) of B. tabaci were deposited in the PR1-treated plant. There were 8 and 5 compounds identified from the isolates PR1 and GT3, respectively. The highest amount of compounds of 1-Hydroxy-2-aminopropane (61.96%) and 1, 4-Dioxane-2-ol (54.18%) were released by PR1 and GT3 respectively. The results obtained so far revealed that whitefly avoided the eggplants provided with cultures of the M. anisopliae isolates emanating the volatile organic compounds and suitability largely depended upon the volatile profile.

Simple steps to prevent hospital-acquired pneumonia in non-intubated patients: a quality improvement project

Background: Hospital-acquired pneumonia (HAP) affects approximately 1.5% of UK inpatients. As well as leading to significant morbidity and mortality, HAP increases burden on hospitals by lengthening hospital stay. At a district general hospital in Kent, a quality improvement project (QIP) was designed that introduced simple preventive measures that could be implemented by ward nurses and allied health professionals. Methods: Three audit cycles studying a total of 222 inpatients on elderly care wards were undertaken over a 6-month period to assess staff compliance at various stages of the project, with interventions between each cycle. Actions included raising bedheads to 30°, sitting patients out of bed for meals, discouraging use of drinking straws, and regular mouth care. Results: Overall, improvements were seen in three of the measures. Considering the percentage of patients, there was a 23% increase in patients with bedheads >30°, 21% increase in use of adult feeding cups rather than straws, and 26% rise in patients sitting out of bed for meals. Conclusion: The main objective of this QIP was to show that these simple yet potentially life-saving interventions are easy to implement on a busy ward, and the results have shown this to be true.