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(1) Background: Insect pathogenic fungi of the genus Metarhizium are under study and in application as highly solicited, more eco-system friendly substitutes for chemical insecticides in many countries and in different agricultural contexts. In Cuba and Florida, Metarhizium strains have previously been isolated from economically important coffee and sugar cane pests. (2) Methods: Unambiguous species delineation within the Metarhizium anisopliae species complex is methodologically challenging. Recently, a species-discriminating PCR approach has been developed based on ribosomal intergenic spacer (rIGS) sequences that covered the prominent four "PARB" species within the complex. This approach is combined here with further genetic markers and is extended to a further species. (3) Results: Metarhizium isolates from Cuba, found to be more naturally associated with the coffee berry borer, Hypothenemus hampei, were morphologically, microscopically and molecular taxonomically characterized. Multilocus sequence analysis based on 5TEF, MzIGS3 and rIGS markers delineated these weevil-associated strains from all previously established Metarhizium species. (4) Conclusions: The isolates under study represent a new fungal taxon proposed to be designated Metarhizium caribense. The rIGS-based species-discriminating diagnostic PCR is a suitable tool for the identification of new Metarhizium species and can be productively combined to approaches using further genetic markers. [ABSTRACT FROM AUTHOR]

The control of olive tree insect pests has mostly been performed for several decades by chemical means. However, in an attempt to develop more natural treatments, two Providencia entomophila Ksentini et al. (Enterobacterales Morganellaceae) strains (IO-6 and IO-20) previously isolated from the olive tree insect pests Prays oleae Bernard (Lepidoptera Hyponomeutidae) and Bactrocera oleae (Rossi) (Diptera Tephritidae), respectively, were tested and were found to be effective against B. oleae. The side effects of both strains on beneficial insects were evaluated on the preimaginal stages and the adults of the egg parasitoid Trichogramma oleae Voegele et Pointel (Hymenoptera Trichogrammatidae) at concentrations ranging from 105 to 109 cfu/ml. The results showed that all IO-6 tested concentrations harmed T. oleae larvae, as well as the concentration 109 cfu/ml on prepupae. In contrast, different concentrations of strain IO-20 were found to be harmless for all developmental stages but slightly harmful at concentrations of 109 and 106 cfu/ml on larvae and prepupae, respectively. Nevertheless, none of the tested strains and concentrations were found to be persistent even 2 days after treatment application, as T. oleae adult survival was not negatively affected by any bacterial strain. However, when treatments were applied during developmental stages, some side effects on females external appearance, as brachypterous, two-male-antennae and single-male-antenna, were detected. Thus, taking into consideration all the aforementioned parameters, only P. entomophila IO-20 at a concentration of 105 cfu/ml guarantees perfect respect to all T. oleae developmental stages and offspring appearance. [ABSTRACT FROM AUTHOR]

Simple Summary: The peach fruit fly is an economically relevant agricultural insect pest infesting many types of fruit and vegetables. It originated from the Indian subcontinent and was spread across the Middle East to Egypt and Sudan. Due to changing climatic conditions, its further spread in the Mediterranean region is highly probable. The present study demonstrated that the peach fruit fly has adapted to olives as a new host plant. This poses a potentially serious threat to olive cultivation in Northern African and Southern European countries. The present study used molecular genetic methods to investigate the diversity of peach fruit fly populations from Egyptian olive orchards in order to understand if adaptation to the new host plant occurred once or several times. Moreover, as it is well known that fruit flies carry symbiotic bacteria, termed "bacterial microbiome", that help them to adapt to changing environmental conditions, the present study has compared the bacterial microbiome of peach fruit flies developing in olives and in other fruits. Several changes in the microbiome composition were identified. This knowledge can help to understand how similar adaptations happen and to develop agents or strategies for biological control of the peach fruit fly. The peach fruit fly, Bactrocera zonata (Tephritidae), is economically relevant as a highly polyphagous pest infesting over 50 host plants including commercial fruit and horticultural crops. As an invasive species, B. zonata was firmly established in Egypt and holds potential to spread further across the Mediterranean basin. The present study demonstrated that the peach fruit fly was found multiplying in olive orchards at two distant locations in Egypt. This is the first report of B. zonata developing in olives. COI barcoding has revealed evidence for high diversity across these peach fruit fly populations. These data are consistent with multiple rather than a single event leading to both peach fruit fly invasion to Egypt and its adaptation to olive. Comparative microbiomics data for B. zonata developing on different host plants were indicative for microbiome dynamics being involved in the adaptation to olive as a new niche with a potential adaptive role for Erwinia or Providencia bacteria. The possibility of symbiont transfer from the olive fruit fly to the peach fruit fly is discussed. Potentially host switch relevant bacterial symbionts might be preferred targets of symbiosis disruption strategies for integrated pest management or biological control of B. zonata. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate biological and molecular characteristics of Lecanicillium strains isolated from Hemipteran hosts in Argentina. Morphology‐based taxonomic characterization together with molecular taxonomy based on rRNA operon internal transcribed spacer (ITS), mitochondrial nad1 gene, and nuclear ef1a gene sequences resulted in the assignment of nine out of ten isolates to the Lecanicillium lecanii sensu lato complex. However, whereas several isolates were thus unequivocally characterized as Lecanicillium muscarium or Lecanicillium longisporum, species assignment was not possible for three isolates that might represent a new species within the L. lecanii s.l. complex. We found two group‐I introns on 18S and 28S rRNA gene on only one isolate. Pathogenicity tests were conducted against the peach aphid using conidial suspensions (1 × 107 conidia/ml), and the Kaplan–Meier analysis was performed to evaluate the survival of Myzus persicae. Lecanicillium longisporum CEP 155 and L. muscarium CEP 182 were significantly more pathogenic to M. persicae than all the Lecanicillium isolates causing aphid mortalities >85%. Determination of susceptibility to the benzimidazole fungicide benomyl revealed important differences between Lecanicillium strains. The inhibitory effect of benomyl appeared less pronounced for the L. muscarium fungal isolates than for those belonging to a different taxon. Based in our results, the best candidate strain as microbial biological control agent against M. persicae is L. muscarium CEP 182. However, further research under field conditions in greenhouses should be done in order to confirm the compatibility of entomopathogenic fungi and fungicides within an IPM strategy. [ABSTRACT FROM AUTHOR]