Initial studies of mating disruption of the tomato moth, Tuta absoluta (Lepidoptera : Gelechiidae) using synthetic sex pheromone

The potential of the synthetic major component of T. absoluta (Meyrick) sex pheromone for mating disruption was studied in small plots (0.01 hectares) with fresh-market tomato crop. The effects of the application of the sex pheromone 3E,8Z,11Z-14: Ac (from 0 to 80 g a. i./ha) were assessed on male orientation to pheromone baited traps, mating in cages and plant damage. The highest levels of interruption in male orientation (60-90%) were found in plots treated with 35 to 50 g/ha of sex pheromone. However, no treatment with pheromone was capable of significantly reducing the percentage of mined leaflets or bored fruits or the frequency of mating in cages compared to the control plots. The failure in mating disruption technique may be attributed to the composition of the synthetic pheromone, doses used, high pest population density, and mated female migration to the area treated

What's in the Gift? Towards a Molecular Dissection of Nuptial Feeding in a Cricket.

Journal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Nuptial gifts produced by males and transferred to females during copulation are common in insects. Yet, their precise composition and subsequent physiological effects on the female recipient remain unresolved. Male decorated crickets Gryllodes sigillatus transfer a spermatophore to the female during copulation that is composed of an edible gift, the spermatophylax, and the ampulla that contains the ejaculate. After transfer of the spermatophore, the female detaches the spermatophylax and starts to eat it while sperm from the ampulla are evacuated into the female reproductive tract. When the female has finished consuming the spermatophylax, she detaches the ampulla and terminates sperm transfer. Hence, one simple function of the spermatophylax is to ensure complete sperm transfer by distracting the female from prematurely removing the ampulla. However, the majority of orally active components of the spermatophylax itself and their subsequent effects on female behavior have not been identified. Here, we report the first analysis of the proteome of the G. sigillatus spermatophylax and the transcriptome of the male accessory glands that make these proteins. The accessory gland transcriptome was assembled into 17,691 transcripts whilst about 30 proteins were detected within the mature spermatophylax itself. Of these 30 proteins, 18 were encoded by accessory gland encoded messages. Most spermatophylax proteins show no similarity to proteins with known biological functions and are therefore largely novel. A spermatophylax protein shows similarity to protease inhibitors suggesting that it may protect the biologically active components from digestion within the gut of the female recipient. Another protein shares similarity with previously characterized insect polypeptide growth factors suggesting that it may play a role in altering female reproductive physiology concurrent with fertilization. Characterization of the spermatophylax proteome provides the first step in identifying the genes encoding these proteins in males and in understanding their biological functions in the female recipient.Max Planck GesellschaftNational Science FoundationBBSRRoyal Societ

Plant-based natural product chemistry for integrated pest management of Drosophila suzukii

Since the first reports of damage by Drosophila suzukii, the spotted-wing Drosophila (SWD), over a decade ago in Europe, widespread efforts have been made to understand both the ecology and the evolution of this insect pest, especially due to its phylogenetic proximity to one of the original model organisms, D. melanogaster. In addition, researchers have sought to find economically viable solutions for the monitoring and management of this agricultural pest, which has now swept across much of Europe, North America and Asia. In a new direction of study, we present an investigation of plant-based chemistry, where we search for natural compounds that are structurally similar to known olfactory cues from parasitoid wasps that in turn are welldescribed ovipositional avoidance cues for many Drosophila species. Here we test 11 plant species across two plant genera, Nepeta and Actinidia, and while we find iridoid compounds in both, only those odorants from Actinidia are noted to be detected by the insect antenna, and in addition, found to be behaviorally active. Moreover, the Actinidia extracts resulted in oviposition avoidance when they were added to fruit samples in the laboratory. Thus we propose the possible efficacy of these plants or their extracted chemistry as a novel means for establishing a cost-effective integrated pest management strategy towards the control of this pest fly

Plectranthus zeylanicus: A rich source of secondary metabolites with antimicrobial, disinfectant and anti-inflammatory activities

Plectranthus zeylanicus Benth is used in Sri Lankan folk medicine as a remedy for inflammatory conditions and microbial infections. Our previous investigations revealed potent 5-lipoxygenase (5-LO) inhibitory activity in lipophilic extracts of this plant, supporting its anti-inflammatory potential. In-depth studies on the antimicrobial activity have not been conducted and the bioactive ingredients remained elusive. As a continuation of our previous work, the present investigation was undertaken to evaluate the antimicrobial activity of different extracts of P. zeylanicus and to isolate and characterize bioactive secondary metabolites. Different organic extracts of this plant were analyzed for their antibacterial activity, and the most active extract, i.e., dichloromethane extract, was subjected to bioactivity-guided fractionation, which led to the isolation of 7α-acetoxy-6β-hydroxyroyleanone. This compound displayed strong antibacterial activity against methicillin-resistant Staphylococcus aureus with a minimum inhibitory concentration of 62.5 µg/mL, and its disinfectant capacity was comparable to the potency of a commercial disinfectant. Moreover, 7α-acetoxy-6β-hydroxyroyleanone inhibits 5-LO with IC50 values of 1.3 and 5.1 µg/mL in cell-free and cell-based assays, respectively. These findings rationalize the ethnopharmacological use of P. zeylanicus as antimicrobial and anti-inflammatory remedy

Mate discrimination among subspecies through a conserved olfactory pathway.

Communication mechanisms underlying the sexual isolation of species are poorly understood. Using four subspecies of Drosophila mojavensis as a model, we identify two behaviorally active, male-specific pheromones. One functions as a conserved male antiaphrodisiac in all subspecies and acts via gustation. The second induces female receptivity via olfaction exclusively in the two subspecies that produce it. Genetic analysis of the cognate receptor for the olfactory pheromone indicates an important role for this sensory pathway in promoting sexual isolation of subspecies, in combination with auditory signals. Unexpectedly, the peripheral sensory pathway detecting this pheromone is conserved molecularly, physiologically, and anatomically across subspecies. These observations imply that subspecies-specific behaviors arise from differential interpretation of the same peripheral cue, reminiscent of sexually conserved detection but dimorphic interpretation of male pheromones in Drosophila melanogaster. Our results reveal that, during incipient speciation, pheromone production, detection, and interpretation do not necessarily evolve in a coordinated manner

Metabolomic and transcriptomic data on major metabolic/biosynthetic pathways in workers and soldiers of the termite Prorhinotermes simplex (Isoptera: Rhinotermitidae) and chemical synthesis of intermediates of defensive (E)-nitropentadec-1-ene biosynthesis

Production of nitro compounds has only seldom been recorded in arthropods. The aliphatic nitroalkene (E)-nitropentadec-1-ene (NPD), identified in soldiers of the termite genus Prorhinotermes, was the first case documented in insects in early seventies. Yet, the biosynthetic origin of NPD has long remained unknown. We previously proposed that NPD arises through the condensation of amino acids glycine and/or l-serine with tetradecanoic acid along a biosynthetic pathway analogous to the formation of sphingolipids. Here, we provide a metabolomics and transcriptomic data of the Prorhinotermes simplex termite workers and soldiers. Data are related to NPD biosynthesis in P. simplex soldiers. Original metabolomics data were deposited in MetaboLights metabolomics database and are become publicly available after publishing the original article. Additionally, chemical synthesis of biosynthetic intermediates of NPD in nonlabeled and stable labeled forms are reported. Data extend our poor knowledge of arthropod metabolome and transcriptome and would be useful for comparative study in termites or other arthropods. The data were used for de-replication of NPD biosynthesis and published separately (Jirošová et al., 2017) [1]

How organic farmers view their own practice: results from the Czech Republic

This paper addresses the development of organic agriculture in the Czech Republic, which is seen as a success story among post-communist countries. The relatively short history of organic farming and specific contextual factors raises questions about the nature and meaning of Czech organic farming. The goal of this study was to find out how farmers view their own practice, interpret its symbolic value, and construct its content. This empirical study uses Q methodology aimed at the identification of the collectively-shared perspectives belonging engaged actors. Data were gathered through semi-standardized interviews with Czech farmers registered in official organic scheme. The analysis emphasized three components, which are considered as three distinct perspectives possessed by organic farmers; that is, (1) organic farming as a way of life, (2) as an occupation, and (3) as a production of food of an alternative quality compared to conventional food. Each viewpoint entails a different understanding of what organic farming means; each then—when considered together—comprises the meaning of organic agriculture in the Czech Republic. The presented classification of the farmers holding the viewpoints contributes to the ongoing theoretical discussion regarding the nature of the current organic sector, its development and potential conventionalization