Effect of Indoor Climate and Habitat Change on Museum Insects during COVID-19 Closures

COVID-19 spread globally and, as there was little immunity, quarantine, isolation, and social distancing became widely practiced. As people were restricted to their homes in many countries, public venues, such as museums, galleries, and historic houses, were typically closed. This allowed insect abundance, under changed conditions, to be explored using traps from the Technical Museum, Schönbrunn Palace, Hofburg Museum, and Weltmuseum in Vienna. The trap contents reveal an increase in Lepisma saccharinum, the common silverfish, as well as in the Zygentoma Ctenolepisma longicaudatum and C. calvum at some museums. Other insects such as Tineola bisselliella, Anthrenus verbasci, and Attagenus smirnovi, though found in reasonable numbers, did not increase. Museum interiors were likely a little cooler and drier during lockdown, but this difference is too small to explain the increased silverfish activity. The larger rooms were certainly quieter, which allowed insects freedom to range more widely. Nevertheless, museums did not observe increased damage to collections from the larger numbers. The infestations during the closures suggest a need for low level cleaning and regular inspections, with an initial focus examining those areas frequented by insects in the past.

Next-Generation Sequencing Analysis of the Tineola bisselliella Larval Gut Transcriptome Reveals Candidate Enzymes for Keratin Digestion

The clothes moth Tineola bisselliella is one of a few insects that can digest keratin, leading to the destruction of clothing, textiles and artwork. The mechanism of keratin digestion is not yet fully understood, partly reflecting the lack of publicly available genomic and transcriptomic data. Here we present a high-quality gut transcriptome of T. bisselliella generated from larvae reared on keratin-rich and keratin-free diets. The overall transcriptome consists of 428,221 contigs that were functionally annotated and screened for candidate enzymes involved in keratin utilization. As a mechanism for keratin digestion, we identified cysteine synthases, cystathionine β-synthases and cystathionine γ-lyases. These enzymes release hydrogen sulfite, which may reduce the disulfide bonds in keratin. The dataset also included 27 differentially expressed contigs with trypsin domains, among which 20 were associated with keratin feeding. Finally, we identified seven collagenases that were upregulated on the keratin-rich diet. In addition to this enzymatic repertoire potentially involved in breaking down keratin, our analysis of poly(A)-enriched and poly(A)-depleted transcripts suggested that T. bisselliella larvae possess an unstable intestinal microbiome that may nevertheless contribute to keratin digestion.

Larvae of the Clothing Moth Tineola bisselliella Maintain Gut Bacteria that Secrete Enzyme Cocktails to Facilitate the Digestion of Keratin

The evolutionary success of insects is promoted by their association with beneficial microbes that enable the utilization of unusual diets. The synanthropic clothing moth Tineola bisselliella provides an intriguing example of this phenomenon. The caterpillars of this species have adapted to feed on keratin-rich diets such as feathers and wool, which cannot be digested by most other animals and are resistant to common digestive enzymes. Inspired by the hypothesis that this ability may be conferred by symbiotic microbes, we utilized a simple assay to detect keratinase activity and a method to screen gut bacteria for candidate enzymes, which were isolated from feather-fed larvae. The isolation of DNA from keratin-degrading bacterial strains followed by de novo genome sequencing resulted in the identification of a novel bacterial strain related to Bacillus sp. FDAARGOS_235. Genome annotation identified 20 genes with keratinase domains. Proteomic analysis of the culture supernatant from this gut bacterium grown in non-nutrient buffer supplemented with feathers revealed several candidate enzymes potentially responsible for keratin degradation, including a thiol-disulfide oxidoreductase and multiple proteases. Our results suggest that the unusual diet of T. bisselliella larvae promotes their association with keratinolytic microorganisms and that the ability of larvae to feed on keratin can at least partially be attributed to bacteria that produce a cocktail of keratin-degrading enzymes.

Susceptibility of Environmentally Friendly Sheep Wool Insulation Panels to the Common Clothes Moth Tineola bisselliella in Laboratory Assays

In this study the resistance opposed to Tineola bisselliella larvae by a commercial sheep-wool panel incorporating borate salts was determined under laboratory conditions. The susceptibility of clothes moth larvae to different concentrations of disodium octaborate tetrahydrate (DOT) incorporated in pure wool was also determined. The commercial wool panel showed a remarkable resistance to moth attack compared with pure untreated wool, and the damage to panel samples was limited to their surface. As a result of bioassays exposing larvae to pure wool treated with DOT, a concentration dependent effect was observed, achieving a good efficacy at an application rate between 40–100 mg/mL. This study highlights the need to protect wool-based construction material with appropriate insecticidal (antifeedant or repellent) substances and supports the development of eco-sustainable solutions.

Evaluation of the larvicidaleffectof the essential oils extracted from five aromatic plants of Algeria: test on the miteTineola bisselliella (Lepidoptera:Tineidae)

The essential oils extracted by hydrodistillation from fivearomatic plants from Algerian West –Ammoїdes verticillata (Apiacae), Origanum glandulosum (Lamiacae), Thymus capitatus (Lamiacae), Rosmarinus officinalis (Lamiacae), Artemisia herba-alba (Asteracae), were tested with various amounts on the larvaeof Tineola bisselliella, under the conditions of laboratory (Temperature of 26°C and with a relative humidity of 75 %). These oilscaused a significant larvicidalactivity. The essential oils extracted from Artemisia herba-alba, Rosmarinus officinalis, Origanum glandulosum are most toxic with LD50of 5,92μL/50,24cm², 6,66μL/50,24cm², and 7,16μL/50,24cm² respectively, Ammoїdes verticillata present alittle variable toxicity with LD50= 7,95μL/50,24cm², whereas the essential oil of Thymus capitatus is the least toxic on the larves of T. bisselliella with one LD50de 9,81μL/50,24cm².The analysis of the chemical composition shows the richness of five essential oils in compounds known for their insecticidal properties like α-pinène, β-pinène, p-cymène, carvacrol, camphre, γ-terpinène, and1,8-cineole, what explains the results obtained.

Tinea altaica sp. nov. and new records of some small moths from the Russian Altai (Lepidoptera: Meessiidae, Tineidae, Douglasiidae, Epermeniidae, Glyphipterigidae: Acrolepiinae)

The paper summarizes the results of our study of selected Microlepidoptera families (Meessiidae, Tineidae, Douglasiidae, Epermeniidae, Glyphipterigidae: Acrolepiinae) collected in the Russian Altai. Tinea altaica sp. nov. is described from the vicinity of Tashanta on the Russian-Mongolian border and from Mongolia. The new species distantly resembles Tinea semifulvella Haworth, 1828 and T. semifulvelloides Petersen, 1973. The up to now unknown females of Klimeschia biarmatella Budashkin, 2003 and Monopis luteocostalis Gaedike, 2006 are described. Scardia boletella (Fabricius, 1794), Crassicornella crassicornella (Zeller, 1847), Trichophaga ziniella Zagulajev, 1960, Tineola bisselliella (Hummel, 1823), Monopis laevigella (Denis & Schiffermüller, 1775), M. pallidella Zagulajev, 1955, Epermenia ochreomaculella asiatica Gaedike, 1979, and Acrolepiopsis sapporensis (Matsumura, 1931) are recorded from the Altai Republic for the first time. Tinea hongorella Zagulajev, 1975 and Klimeschia biarmatella Budashkin, 2003, so far known only from the holotypes, are new species for Russia. Tinea hongorella is also a new species for Europe.