Evaluating Volatile Plant Compounds of Psidium galapageium (Myrtales: Myrtaceae) as Repellents Against Invasive Parasitic Diptera in the Galapagos Islands

Author(s):  
C Martina ◽  
L Krenn ◽  
L Krupicka ◽  
H Yamada ◽  
R Hood-Nowotny ◽  
...  

Abstract Plant-based repellents represent a safe, economic, and viable alternative to managing invasive insects that threaten native fauna. Observations of self-medication in animals can provide important cues to the medicinal properties of plants. A recent study in the Galapagos Islands found that Darwin’s finches apply the leaves of Psidium galapageium (Hooker 1847) to their feathers, extracts of which were repellent to mosquitoes and the parasitic fly Philornis downsi (Dodge & Aitkens 1968; Diptera: Muscidae). Introduced mosquitoes are suspected vectors of avian pathogens in the Galapagos Islands, whereas the larvae of P. downsi are blood-feeders, causing significant declines of the endemic avifauna. In this study, we investigated the volatile compounds found in P. galapageium, testing each against a model organism, the mosquito Anopheles arabiensis (Patton 1905; Diptera: Culicidae), with the aim of singling out the most effective compound for repelling dipterans. Examinations of an ethanolic extract of P. galapageium, its essential oil and each of their respective fractions, revealed a mixture of monoterpenes and sesquiterpenes, the latter consisting mainly of guaiol, trans-nerolidol, and β-eudesmol. Of these, trans-nerolidol was identified as the most effective repellent to mosquitoes. This was subsequently tested at four different concentrations against P. downsi, but we did not find a repellence response. A tendency to avoid the compound was observed, albeit significance was not achieved in any case. The lack of repellence suggests that flies may respond to a combination of the volatile compounds found in P. galapageium, rather than to a single compound.

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Daniel Escobar-Camacho ◽  
Paulina Rosero ◽  
Mauricio Castrejón ◽  
Carlos F. Mena ◽  
Francisco Cuesta

AbstractThe unique marine and terrestrial ecosystems of the Galapagos Islands are highly vulnerable to human-based drivers of change, including the introduction of invasive species, unsustainable tourism, illegal fishing, overexploitation of ecosystem services, and climate change. These drivers can interact with climate-based drivers such as El Niño-Southern Oscillation (ENSO) at multiple temporal and spatial scales, exacerbating their negative impacts on already fragile ecosystems and the socioeconomic system of the Archipelago. In this review, we performed a literature review based on published literature from 1945 to 2020 and local and global climate databases to analyze drivers of change in the Galapagos. We developed and applied a spatial impact assessment model to identify high-ecological value areas with high sensitivity and exposure scores to environmental change drivers. We identified 13 priority HEVA that encompass ca. 23% (14,715 km2) of the Galapagos Archipelago, distributed in nearly 3% of the Galapagos Marine Reserve and 20% Galapagos National Park. Current and future impacts are likely to concentrate on the inhabited islands’ highlands, whereas marine impacts concentrate along most of the Galapagos Islands’ shorelines. These results are important for guiding the design and implementation of adaptation measures aimed at increasing ecosystem resilience and human adaptive capacity in the face of global environmental change. Overall, these results will be valuable in their application for preserving Galapagos biota, securing the provision of vital ecosystem services for resident human populations, and sustaining the nature-based tourism industry.


2021 ◽  
pp. 100180
Author(s):  
William F. Vásquez ◽  
Nejem Raheem ◽  
Diego Quiroga ◽  
Valeria Ochoa-Herrera

2011 ◽  
Vol 65 (4) ◽  
pp. 507-513 ◽  
Author(s):  
Mark S. Hoddle ◽  
Laurence A. Mound

Author(s):  
Polpass Arul Jose ◽  
Michael Ben‐Yosef ◽  
Paola Lahuatte ◽  
Charlotte E. Causton ◽  
George E. Heimpel ◽  
...  

Author(s):  
A. Cano ◽  
Paul Arévalo ◽  
F. Jurado

This research compared different sizing methods to improve the current autonomous hybrid system in the Galapagos Islands in 2031, analyzing the loss of power supply probability (LPSP).


Radiocarbon ◽  
1993 ◽  
Vol 35 (2) ◽  
pp. 245-251 ◽  
Author(s):  
T. A. Brown ◽  
G. W. Farwell ◽  
P. M. Grootes ◽  
F. H. Schmidt ◽  
Minze Stuiver

We report AMS 14C measurements on subannual samples of coral from the Galapagos Islands that span the period, 1970–1973. Both the major 1972 El Niño/Southern Oscillation event and intra-annual changes in regional upwelling of 14C-depleted waters associated with alternation of surface-ocean current patterns are evident in the record. Our data show that the corals preserve a detailed record of past intra-annual variations of the 14C content of surface ocean water.


1994 ◽  
Vol 118 (2) ◽  
pp. 191-208 ◽  
Author(s):  
P. W. Glynn ◽  
S. B. Colley ◽  
C. M. Eakin ◽  
D. B. Smith ◽  
J. Cortés ◽  
...  

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