Towards the development of a chemical lure to improve the management of invading rat populations

<p>Introduced species, such as Rattus norvegicus and Rattus rattus,have contributed to the extinction of many native animals and plants in New Zealand(NZ). Current strategies exist to monitor, manage and eradicate pest species. However, these haven’t always been completely successful and tools to detect small or invading densities remain to be developed. One possible new method to address this problem is the application of chemical attractants (lures). Recently, a major urinary protein (MUP) has been shown in male miceto act as a sexual attractant. MUPs modulate the release of volatile attractants and have potential to act as attractants themselves. Our aim was to determine if a similar MUP(s) and associated volatiles are present in the urine of rats, with the prospect of creating a chemical lure to use in rat detection and eradication. Using Gas Chromatography/Mass Spectrometry, potential volatiles in rat urine have been identified. Analysis of rat urine by gel electrophoresis has shown MUPs present in both sexes. A 22.4 kDa MUP in Rattus norvegicushas been synthesised and expressed in E.coliusing recombinant DNA technology. Preliminary steps have been made towards the production of a MUP based on ship rat DNA sequence. Future behavioral trials are needed to investigate whether the synthesised protein, in the presence or absence of the urinary-derived volatiles, is a sexual attractant.</p>

Towards the development of a chemical lure to improve the management of invading rat populations

<p>Introduced species, such as Rattus norvegicus and Rattus rattus,have contributed to the extinction of many native animals and plants in New Zealand(NZ). Current strategies exist to monitor, manage and eradicate pest species. However, these haven’t always been completely successful and tools to detect small or invading densities remain to be developed. One possible new method to address this problem is the application of chemical attractants (lures). Recently, a major urinary protein (MUP) has been shown in male miceto act as a sexual attractant. MUPs modulate the release of volatile attractants and have potential to act as attractants themselves. Our aim was to determine if a similar MUP(s) and associated volatiles are present in the urine of rats, with the prospect of creating a chemical lure to use in rat detection and eradication. Using Gas Chromatography/Mass Spectrometry, potential volatiles in rat urine have been identified. Analysis of rat urine by gel electrophoresis has shown MUPs present in both sexes. A 22.4 kDa MUP in Rattus norvegicushas been synthesised and expressed in E.coliusing recombinant DNA technology. Preliminary steps have been made towards the production of a MUP based on ship rat DNA sequence. Future behavioral trials are needed to investigate whether the synthesised protein, in the presence or absence of the urinary-derived volatiles, is a sexual attractant.</p>

Designing a species-selective lure based on microbial volatiles to target Lobesia botrana

Sustainable, low impact control methods, including mating disruption and microbial insecticides against L. botrana have been available for decades. Yet, successful implementation has been restricted to only a few grapevine districts in the world. A limiting factor is the lack of a female attractant to either monitor or control the damaging sex. Volatile attractants for both female and male insects can be used to assess when L. botrana populations exceed economic thresholds, and to decrease the use of synthetic pesticides within both conventional and pheromone programs. Rather than using host-plant volatiles, which are readily masked by background volatiles released by the main crop, we tested the attractiveness of volatiles that signify microbial breakdown and more likely stand out against the background odour. A two-component blend of 2-phenylethanol (2-PET) and acetic acid (AA) caught significant numbers of both sexes. Catches increased with AA and, to a minimal extent, 2-PET loads. However, a higher load of 2-PET also increased bycatches, especially of Lepidoptera and Neuroptera. Major (ethanol, ethyl acetate, 3-methyl-1-butanol) or minor (esters, aldehydes, alcohols and a ketone) fermentation volatiles, did surprisingly not improve the attraction of L. botrana compared to the binary blend of 2-PET and AA alone, but strongly increased bycatches. The most attractive lure may thus not be the best choice in terms of specificity. We suggest that future research papers always disclose all bycatches to permit evaluation of lures in terms of sustainability.

The Colonization of Necrophagous Larvae Accelerates the Decomposition of Chicken Carcass and the Emission of Volatile Attractants for Blowflies (Diptera: Calliphoridae)

The decomposition of a living being involves a series of changes produced by a number of interacting abiotic and biotic factors. In this study, we analyzed the effect of the colonization of blowflies on the decomposition of chicken carcasses and on the emission of sulfur compounds. The loss of the mass of carcasses and the release rate of sulfur compounds were compared for 30 d in chicken carcasses with and without blowflies in field conditions. The tissue degradation was slower in the carcasses without insects compared to those colonized by blowflies. The decomposition stages of fresh, bloated, active decay, and advanced decay were observed in the carcasses without flies; while the decomposition stages of fresh, active decay, advanced decay, and dry remains were identified in carcasses with flies. Two sulfur compounds, dimethyl disulfide and dimethyl trisulfide, were present during the entire decomposition process. The emission of these compounds is not directly associated with the presence of the blowflies’ immature stages during the whole decomposition process. However, in cadavers with insects, the highest emission of both compounds occurred in day 2, while in cadavers without insects, the peak of emission was observed in day 4. In addition, the presence of the larval stages I and II of Lucilia eximia (Wiedemann, 1819) (Diptera: Calliphoridae), Chrysomya rufifacies (Macquart, 1842) (Diptera: Calliphoridae), Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae), and Cochliomyia macellaria Fabricius, 1775 (Diptera: Calliphoridae) matched with the peak of emission of both compounds.

A Low-Cost, Passive Release Device for the Surveillance and Control of Mosquitoes

Mosquitoes continue to be a major threat to global health, and the ability to reliably monitor, catch, and kill mosquitoes via passive traps is of great importance. Global, low-cost, and easy-to-use outdoor devices are needed to augment existing efforts in mosquito control that combat the spread of disease, such as Zika. Thus, we have developed a modular, portable, non-powered (passive), self-contained, and field-deployable device suitable for releasing volatiles with a wide range of applications such as attracting, repelling, and killing mosquitoes. This unique device relies on a novel nested wick and two-reservoir design that achieves a constant release of volatiles over several hundred hours. Devices loaded with one of either two compounds, geraniol or 1-methylpiperazine (MP), were tested in a controlled environment (32 °C and 70% relative humidity), and both compounds achieved a constant release from our devices at a rate of 2.4 mg/h and 47 mg/h, respectively. The liquid payload can be volatile attractants or repellants as well as mosquitocide-containing feeding solutions for capture and surveillance. This low-cost device can be utilized for both civilian and military mosquito control purposes, but it will be particularly important for protecting those in economically repressed environments, such as sub-Saharan Africa and Central and South America.

PIM-related kinases selectively regulate sensory functions in C. elegans

ABSTRACTThe mammalian PIM family of serine/threonine kinases regulate several cellular functions, such as cell survival and motility. Since we have observed PIM expression in the olfactory epithelium and other sensory organs of mice, this has raised the question of whether PIM kinases regulate also sensory cell functions. As our model organism to investigate this question, we used the Caenorhabditis elegans nematodes, which express two PIM-related kinases, PRK-1 and PRK-2. We demonstrated them to be true PIM orthologs with similar substrate specificity as well as sensitivity to PIM-inhibitory compounds. Furthermore, we obtained evidence to indicate that PRKs are selectively involved in regulation of olfactory sensations via AWB or AWCON neurons to volatile attractants or repellants, but do not affect gustatory sensations.