Nutritional ecology of predaceous Tetanocera elata larvae and the physiological effects of alternative prey utilisation

Tetanocera elata (Fabricius) (Diptera: Sciomyzidae) is an obligate mesoparasitoid of pestiferous Deroceras spp. slugs in the first and second larval instars and then emerges to become a free-living predator of terrestrial slugs in the third instar. To determine the biological control potential of T. elata, naïve third-instar larvae were exposed to a range of prey slug species (Deroceras reticulatum, Arion hortensis, and Tandonia budapestensis) in no-choice, pairwise two-choice, and three-choice feeding assays. While larvae showed little prey preference, typically attacking the first individual with which they came into contact, A. hortensis was significantly preferred over T. budapestensis in two-choice trials (P = 0.048). Larvae were also more efficacious at predating D. reticulatum, in that significantly fewer larval attacks preceding feeding were required for D. reticulatum than for A. hortensis or T. budapestensis (P = 0.0008 and P = 0.0059, respectively). Larvae reared on D. reticulatum in culture following trials also experienced the greatest survivorship to the start of pupariation. While these results suggest that D. reticulatum may remain the ideal prey for third instar T. elata larvae, they also demonstrate the ability of larvae to survive on alternative species. The implications of these findings in the context of using T. elata as a biocontrol agent are discussed. © 2020, International Organization for Biological Control (IOBC)

Biological control of pestiferous slugs using Tetanocera elata (Fabricius) (Diptera: Sciomyzidae): Larval behavior and feeding on slugs exposed to Phasmarhabditis hermaphrodita (Schneider, 1859)

While the larval stage of Tetanocera elata (Diptera: Sciomyzidae) is a known parasitoid and predator of pestiferous slugs, its biology and predatory behavior as well as its interaction with slug parasitic nematodes requires further investigation. In this study, survival of larvae fed from the neonate stage on Deroceras reticulatum Müller (a previously known prey species) was significantly greater (P = 0.023) than for larvae fed on Deroceras invadens Reise with 100% and 40% survival respectively. However, when fed solely on D. reticulatum which were previously exposed to P. hermaphrodita, only 20% of neonate larvae pupariated successfully. Ninety percent of neonate larvae maintained without food for the first four days and subsequently fed on D. reticulatum pupariated successfully although this decreased to below 50% for ≥6 days without food. Predatory third instar T. elata larvae appeared to select nematode-exposed D. reticulatum over non-exposed slugs with the continued feeding on nematode-exposed slugs also reducing the chances of successful pupariation by 25%. Records of maximum egg-laying by laboratory-reared female adults were greater (487 eggs) than previously recorded for field-caught adults (3 7 3). The implications of these results for the potential use of T. elata as a biological control agent of pestiferous slugs are discussed. © 2019 Elsevier Inc

Habitat requirements of Tetanocera elata (Diptera: Sciomyzidae): case study of a dry meadow in western Ireland

Terrestrial slugs are pervasive pests of agriculture throughout temperate regions and have the potential to disrupt the germination of seedlings, cause damage to fruiting bodies of crops, and vector plant pathogens. Tetanocera elata Fabricius (Diptera: Sciomyzidae), a widely distributed Palaearctic species, is an obligate mesoparasitoid and predator of pestiferous slugs including Deroceras reticulatum Müller (Stylommatophora: Agriolimacidae). It has the potential to be developed as a native natural enemy in a conservation biological control programme as an alternative to chemical molluscicides. To better understand the ecological requirements of this species, a detailed observational study was conducted at a site in the west of Ireland possessing naturally occurring T. elata populations. Comparison of local patches where T. elata were recovered revealed no association with plant community composition. Taller dead vegetation was associated with T. elata presence throughout the site. Within the area of greatest T. elata aggregation, there was a significantly greater percentage cover of dead vegetation where T. elata occurred. Abundance of T. elata was also significantly correlated to hedgerow proximity. Results of this study are directly applicable for the design of a conservation biological control programme, which effectively satisfies the principal habitat requirements of T. elata populations

Parallel genome-scale loss of function screens in 216 cancer cell lines for the identification of context-specific genetic dependencies

Using a genome-scale, lentivirally delivered shRNA library, we performed massively parallel pooled shRNA screens in 216 cancer cell lines to identify genes that are required for cell proliferation and/or viability. Cell line dependencies on 11,000 genes were interrogated by 5 shRNAs per gene. The proliferation effect of each shRNA in each cell line was assessed by transducing a population of 11M cells with one shRNA-virus per cell and determining the relative enrichment or depletion of each of the 54,000 shRNAs after 16 population doublings using Next Generation Sequencing. All the cell lines were screened using standardized conditions to best assess differential genetic dependencies across cell lines. When combined with genomic characterization of these cell lines, this dataset facilitates the linkage of genetic dependencies with specific cellular contexts (e.g., gene mutations or cell lineage). To enable such comparisons, we developed and provided a bioinformatics tool to identify linear and nonlinear correlations between these features

Achilles_QC_v2.4.3.rnai.Gs.gct

Achilles_QC_v2.4.3.rnai.Gs.gct is the ATARiS-processed, gene level file for 216 cancer cell lines undergoing shRNA pooled screening

cBOTv8_sbsv3_allreps_log.gct

<p>cBOTv8_sbsv3_allreps_log.gct is the raw normalized and logged read counts for the second group of cancer cell lines undergoing pooled shRNA screening.</p

Achilles_Analysis_README_v2.4.3.txt

<p>Achilles_Analysis_README_v2.4.3.txt is the file describing data processing steps of pooled shRNA screening of 216 cancer cell lines.</p