Drosophila suzukii, a vinegar fly originated from Southeast Asia, has recently invaded western countries, and it has been recognized as an important threat of a wide variety of several commercial soft fruits. This review summarizes the current information about the biology and dispersal of D. suzukii and discusses the current status and prospects of control methods for the management of this pest. We highlight current knowledge and ongoing research on innovative environmental-friendly control methods with emphasis on the sterile insect technique (SIT) and the incompatible insect technique (IIT). SIT has been successfully used for the containment, suppression or even eradication of populations of insect pests. IIT has been proposed as a stand-alone tool or in conjunction with SIT for insect pest control. The principles of SIT and IIT are reviewed, and the potential value of each approach in the management of D. suzukii is analyzed. We thoroughly address the challenges of SIT and IIT, and we propose the use of SIT as a component of an area-wide integrated pest management approach to suppress D. suzukii populations. As a contingency plan, we suggest a promising alternative avenue through the combination of these two techniques, SIT/IIT, which has been developed and is currently being tested in open-field trials against Aedes mosquito populations. All the potential limiting factors that may render these methods ineffective, as well as the requirements that need to be fulfilled before their application, are discussed.

Non-ribosomal peptide synthetases (NRPS) and type-I polyketide synthases (PKS-I) are multimodular enzymes involved in biosynthesis of oligopeptide and polyketide secondary metabolites produced by microorganisms such as bacteria and fungi. New findings regarding the mechanisms underlying NRPS and PKS-I evolution illustrate how microorganisms expand their metabolic potential. During the last decade rapid development of bioinformatics tools as well as improved sequencing and annotation of microbial genomes led to discovery of novel bioactive compounds synthesized by NRPS and PKS-I through genome-mining. Taking advantage of these technological developments metagenomics is a fast growing research field which directly studies microbial genomes or specific gene groups and their products. Discovery of novel bioactive compounds synthesized by NRPS and PKS-I will certainly be accelerated through metagenomics, allowing the exploitation of so far untapped microbial resources in biotechnology and medicine.

Since its recent invasion of the European and American continents, the spotted wing Drosophila Drosophila suzukii has become a burden of the fruit industry. Armed with a highly sclerotized ovipositor, females can lay eggs in a wider variety of ripening and healthy fruits than other Drosophila species. Economic losses due to D. suzukii reach millions of dollars annually and methods to control natural populations in the field mainly rely on the use of chemical pesticides. We tested if Wolbachia bacteria represents a potential ally to control this pest. These symbionts are naturally present in many insects and often induce a form of conditional sterility called cytoplasmic incompatibility (CI): the offspring of infected males die, unless the eggs are rescued by the compatible infection, inherited from the mother that protects the embryo. A long‐recognized strategy called the incompatible insect technique (IIT) makes use of the CI phenotype to control insect populations through the mass release of infected males. To implement this technique in D. suzukii, we used back and forth Wolbachia transfers between D. suzukii and Drosophila simulans to identify Wolbachia strains that can sterilize D. suzukii females despite the presence of wSuz, a natural Wolbachia infection in this species. We identified two Wolbachia strains as potential candidates for developing IIT in D. suzukii. Both induce a very high level of CI in this pest which is not attenuated by the presence of wSuz in females. Moreover, the newly transferred Wolbachia do not affect the fitness or the mating competitiveness of the sterilizing males. Synthesis and applications. However, several critical steps still need to be tested and developed outside the laboratory to achieve the control of Drosophila suzukii using Incompatible Insect Technique. By an experimental approach in large population cages, we showed that releases of transinfected males limit population size. Thus, we provide in this study the proof of concept that this technique can be a very promising approach to control Drosophila suzukii populations.

The spotted wing Drosophila, Drosophila suzukii, has recently invaded Europe and the Americas, and it is a major threat for a wide variety of commercial soft fruits both in open field and greenhouse production systems. D. suzukii infests a wide range of ripening fruits, leading to substantial yield and revenue losses. As the application of insecticides close to the harvest period poses great concerns, the development of an efficient environment-friendly control approach to fight D. suzukii is necessary. In this study, we exploited the sterile insect technique (SIT) in combination with Wolbachia symbiosis as a population suppression approach that can constitute a potential component of an area-wide integrated pest management program. We aimed to establish a combined SIT/incompatible insect technique (IIT) protocol that would require lower irradiation doses as a complementary tool for D. suzukii management. Two D. suzukii lines trans-infected with the Wolbachia wHa and wTei strains were irradiated at doses four times less than usual (e.g., 45 Gy), and the egg hatching and adult emergence were determined. Our results indicated that wHa and wTei females as well as wHa males were sterile at this low dose. The longevity, adult emergence and flight ability of adults were evaluated, and no major effect caused by irradiation was detected. Our data indicate that a SIT/IIT protocol can be a competent approach for D. suzukii management. Keywords Wolbachia • Spotted wing Drosophila • Biological control • Area-wide integrated pest management Key message • Wolbachia-trans-infected D. suzukii lines were irradiated with 45-60-90 Gy irradiation doses, and egg hatch rate and F1 progeny production were significantly affected. • Longevity emergence rate and flight ability were not affected after irradiation at 45 Gy. • A combined SIT/IIT strategy is proposed for the population suppression of D. suzukii populations as part of an area-wide integrated pest management program.

Paper documents in archives, libraries, and museums often undergo biodeterioration by microorganisms. Fungi and less often bacteria have been described to advance paper staining, so called “foxing” and degradation of paper substrates. In this study, for the first time, the fungal and bacterial diversity in biodeteriorated paper documents of Hellenic General State Archives dating back to the 19th and 20th century has been assessed by culture‐dependent and independent methods. The internally transcribed spacer (ITS) region and 16S rRNA gene were amplified by PCR from fungal and bacterial isolates and amplicons were sequenced. Sequence analysis and phylogeny revealed fungal phylotypes like Penicillium sp., Cladosporium sp., Penicillium citrinum, Alternaria infectoria, Alternaria alternata, Epicoccum nigrum, and Penicillium chrysogenum which are often implicated in paper deterioration. Bacterial phylotypes closely related to known biodeteriogenic bacteria such as Bacillus spp., Micrococcus spp., Kocuria sp. in accordance with previous studies were characterized. Among the fungal phylotypes described in this study are included well‐known allergens such as Penicillium spp., Alternaria spp., and Cladosporium spp. that impose a serious health threat on staff members and scholars. Furthermore, fungal isolates such as Chalastospora gossypii and Trametes ochracea have been identified and implicated in biodeterioration of historical paper manuscripts in this study for the first time. Certain new or less known fungi and bacteria implicated in paper degradation were retrieved, indicating that particular ambient conditions, substrate chemistry, or even location might influence the composition of colonizing microbiota.

Mass releases of sterilized male insects, in the frame of sterile insect technique programs, have helped suppress insect pest populations since the 1950s. In the major horticultural pests Bactrocera dorsalis, Ceratitis capitata, and Zeugodacus cucurbitae, a key phenotype white pupae (wp) has been used for decades to selectively remove females before releases, yet the gene responsible remained unknown. Here, we use classical and modern genetic approaches to identify and functionally characterize causal wp− mutations in these distantly related fruit fly species. We find that the wp phenotype is produced by parallel mutations in a single, conserved gene. CRISPR/Cas9-mediated knockout of the wp gene leads to the rapid generation of white pupae strains in C. capitata and B. tryoni. The conserved phenotype and independent nature of wp− mutations suggest this technique can provide a generic approach to produce sexing strains in other major medical and agricultural insect pests.

Background The Mediterranean fruit fly, Ceratitis capitata, is a cosmopolitan agricultural pest of worldwide economic importance and a model for the development of the Sterile Insect Technique (SIT) for fruit flies of the Tephritidae family (Diptera). SIT relies on the effective mating of laboratory-reared strains and natural populations, and therefore requires an efficient mass-rearing system that will allow for the production of high-quality males. Adaptation of wild flies to an artificial laboratory environment can be accompanied by negative effects on several life history traits through changes in their genetic diversity and symbiotic communities. Such changes may lead to reduced biological quality and mating competitiveness in respect to the wild populations. Profiling wild populations can help understand, and maybe reverse, deleterious effects accompanying laboratory domestication thus providing insects that can efficiently and effectively support SIT application. Results In the present study, we analyzed both the genetic structure and gut symbiotic communities of natural medfly populations of worldwide distribution, including Europe, Africa, Australia, and the Americas. The genetic structure of 408 individuals from 15 distinct populations was analyzed with a set of commonly used microsatellite markers. The symbiotic communities of a subset of 265 individuals from 11 populations were analyzed using the 16S rRNA gene-based amplicon sequencing of single individuals (adults). Genetic differentiation was detected among geographically distant populations while adults originated from neighboring areas were genetically closer. Alpha and beta diversity of bacterial communities pointed to an overall reduced symbiotic diversity and the influence of the geographic location on the bacterial profile. Conclusions Our analysis revealed differences both in the genetic profile and the structure of gut symbiotic communities of medfly natural populations. The genetic analysis expanded our knowledge to populations not analyzed before and our results were in accordance with the existing scenarios regarding this species expansion and colonization pathways. At the same time, the bacterial communities from different natural medfly populations have been characterized, thus broadening our knowledge on the microbiota of the species across its range. Genetic and symbiotic differences between natural and laboratory populations must be considered when designing AW-IPM approaches with a SIT component, since they may impact mating compatibility and mating competitiveness of the laboratory-reared males. In parallel, enrichment from wild populations and/or symbiotic supplementation could increase rearing productivity, biological quality, and mating competitiveness of SIT-important laboratory strains.

The Joint FAO/IAEA Centre (formerly called Division) of Nuclear Techniques in Food and Agriculture was established in 1964 and its accompanying laboratories in 1961. One of its subprograms deals with insect pest control, and has the mandate to develop and implement the sterile insect technique (SIT) for selected key insect pests, with the goal of reducing the use of insecticides, reducing animal and crop losses, protecting the environment, facilitating international trade in agricultural commodities and improving human health. Since its inception, the Insect Pest Control Laboratory (IPCL) (formerly named Entomology Unit) has been implementing research in relation to the development of the SIT package for insect pests of crops, livestock and human health. This paper provides a review of research carried out between 2010 and 2020 at the IPCL. Research on plant pests has focused on the development of genetic sexing strains, characterizing and assessing the performance of these strains (e.g., Ceratitis capitata), elucidation of the taxonomic status of several members of the Bactrocera dorsalis and Anastrepha fraterculus complexes, the use of microbiota as probiotics, genomics, supplements to improve the performance of the reared insects, and the development of the SIT package for fruit fly species such as Bactrocera oleae and Drosophila suzukii. Research on livestock pests has focused on colony maintenance and establishment, tsetse symbionts and pathogens, sex separation, morphology, sterile male quality, radiation biology, mating behavior and transportation and release systems. Research with human disease vectors has focused on the development of genetic sexing strains (Anopheles arabiensis, Aedes aegypti and Aedes albopictus), the development of a more cost-effective larvae and adult rearing system, assessing various aspects of radiation biology, characterizing symbionts and pathogens, studying mating behavior and the development of quality control procedures, and handling and release methods. During the review period, 13 coordinated research projects (CRPs) were completed and six are still being implemented. At the end of each CRP, the results were published in a special issue of a peer-reviewed journal. The review concludes with an overview of future challenges, such as the need to adhere to a phased conditional approach for the implementation of operational SIT programs, the need to make the SIT more cost effective, to respond with demand driven research to solve the problems faced by the operational SIT programs and the use of the SIT to address a multitude of exotic species that are being introduced, due to globalization, and established in areas where they could not survive before, due to climate change.