Comparative nutritional ecology of grass-feeding in a sub-Antarctic beetle: the impact of introduced species on Hydromedion sparsutum from South Georgia

Oecologia ◽  
1997 ◽  
Vol 111 (2) ◽  
pp. 216-224 ◽  
Author(s):  
S. L. Chown ◽  
W. Block
2010 ◽  
Vol 26 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Jannie Fries Linnebjerg ◽  
Dennis M. Hansen ◽  
Nancy Bunbury ◽  
Jens M. Olesen

Disruption of ecosystems is one of the biggest threats posed by invasive species (Mack et al. 2000). Thus, one of the most important challenges is to understand the impact of exotic species on native species and habitats (e.g. Jones 2008). The probability that entire ‘invasive communities’ will develop increases as more species establish in new areas (Bourgeois et al. 2005). For example, introduced species may act in concert, facilitating one another's invasion, and increasing the likelihood of successful establishment, spread and impact. Simberloff & Von Holle (1999) introduced the term ‘invasional meltdown’ for this process, which has received widespread attention since (e.g. O'Dowd 2003, Richardson et al. 2000, Simberloff 2006). Positive interactions among introduced species are relatively common, but few have been studied in detail (Traveset & Richardson 2006). Examples include introduced insects and birds that pollinate and disperse exotic plants, thereby facilitating the spread of these species into non-invaded habitats (Goulson 2003, Mandon-Dalger et al. 2004, Simberloff & Von Holle 1999). From a more general ecological perspective, the study of interactions involving introduced and invasive species can contribute to our knowledge of ecological processes – for example, community assembly and indirect interactions.


2021 ◽  
Vol 210 (07) ◽  
pp. 35-46
Author(s):  
Gyul'nar Bagirova ◽  
Hokuma Kulieva

Abstract. The purpose of this study is the ascertainment of to the physiological responses to exogenous exposure to aqueous solutions of the drug “Violet-K” (C24H28N3Cl) in the phase of wintering eggs of the local and introduced silkworm species. Methods. The research was carried out according to the methodology developed by us for the content, selection and processing of material [9], [10]. Statistical analysis was performed according to G. F. Lakin [11]. Results. It was found that in the absence of sharp fluctuations of the temperature and air humidity, the effect of exposure to water and 0.01% and 0.001 % aqueous solutions of the “Violet-K” preparation on hibernating eggs causes a response of caterpillars at younger ages during molting, by the fifth age this effect diminishes. A strong response to the impact in terms of weight of caterpillars was revealed for the introduced silkworm species: against the background of minor fluctuations in the “Oragase” variant for caterpillars “Sverico-sari” the difference with the control by age is 16,4 % (III), 143,3 % (IV) and 27,3 % (V). The introduced species “Oragase” often differs from the “Sverico-sari” and the local breed “Veten” by the presence of negative responses: the weight of caterpillars after exposure compared to the control corresponds to + 43.7 % (III), + 65.0 % (IV), –36.2 % (V). It was found that the content of wintering grains in water and aqueous solutions of the “Violet-K” preparation leads to the weight increase of the silk shell: by 54.4–80.5 % (p < 0.05 and 0.001) in the local species, as well as by 11.4–16.1 % (0.001 %) and 2.7 % (0.01 % solution “Violet K”) p < 0.05 and 0.001. The species “Oragase” differs in this effect compared with the control, particularly, in the comparison with control, the impact promotes to a significant decrease in the weight of the silk shell by 33 % (–78.5 mg) and 22.5 % (–49.0 mg), p < 0.001. The impact is reflected in the date of departure of butterflies and the number of laid eggs, and only in introduced species: the positive effect compared to the control, on average on 1 female was 3.6–4.8 times higher (“Sverico-sari”) and 1.1 times (“Oragase”).


Biology ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 462
Author(s):  
Zuzanna M. Filipiak ◽  
Michał Filipiak

Bee nutrition studies have focused on food quantity rather than quality, and on details of bee biology rather than on the functioning of bees in ecosystems. Ecological stoichiometry has been proposed for studies on bee nutritional ecology as an ecosystem-oriented approach complementary to traditional approaches. It uses atomic ratios of chemical elements in foods and organisms as metrics to ask ecological questions. However, information is needed on the fitness effects of nutritional mismatches between bee demand and the supply of specific elements in food. We performed the first laboratory feeding experiment on the wild bee Osmia bicornis, investigating the impact of Na, K, and Zn scarcity in larval food on fitness-related life history traits (mortality, cocoon development, and imago body mass). We showed that bee fitness is shaped by chemical element availability in larval food; this effect may be sex-specific, where Na might influence female body mass, while Zn influences male mortality and body mass, and the trade-off between K allocation in cocoons and adults may influence cocoon and body development. These results elucidate the nutritional mechanisms underlying the nutritional ecology, behavioral ecology, and population functioning of bees within the context of nutrient cycling in the food web.


2019 ◽  
Vol 10 (5) ◽  
pp. 731-738 ◽  
Author(s):  
John Finley ◽  
Lindsay M Jaacks ◽  
Christian J Peters ◽  
Donald R Ort ◽  
Ashley M Aimone ◽  
...  

ABSTRACT Efforts to promote health through improved diet and nutrition demand an appreciation of the nutritional ecology that accounts for the intersection of agriculture, food systems, health, disease and a changing environment. The complexity and implications of this ecology is exemplified by current trends and efforts to address nutrition-related non-communicable diseases (NCDs), most prominently type 2 diabetes. The global prevalence of type 2 diabetes continues to rise unabated. Of particular concern is how to address the unhealthy dietary patterns that are contributing to this pandemic in a changing environment. A multi- disciplinary approach is required that will engage those communities that comprise the continuum of effort from research to translation and implementation of evidence-informed interventions, programs and policies. Using the prevention of type 2 diabetes by increasing fruit and vegetable consumption as an exemplar, we argue that the ability to effect positive change in this and other persistent nutrition-related problems can be achieved by moving away from siloed approaches that limit the integration of key components of the diet–health continuum. Ultimately the impact of preventing type 2 diabetes via increased fruit and vegetable consumption will depend on how the entire diet changes, not just fruits and vegetables. In addition, the rapidly changing physical environment that will confront our food production system going forward will also shape the interventions that are possible. Nonetheless, the proposed “team science” approach that accounts for all the elements of the nutrition ecology will better position us to achieve public health goals through safe and sustainable food systems.


2001 ◽  
Vol 58 (12) ◽  
pp. 2513-2525 ◽  
Author(s):  
Anthony Ricciardi

A widely cited hypothesis in ecology is that species-rich communities are less vulnerable to invasion than species-poor ones, owing to competition for limiting resources (the "biotic resistance" model). However, evidence for biotic resistance in aquatic ecosystems is equivocal. Contrary to the view that communities become more resistant to invasion as they accumulate species, the rate of invasion has increased over the past century in areas that have received frequent shipping traffic. Furthermore, introduced species may facilitate, rather than compete with, one another. A review of invasions in the Great Lakes indicates that direct positive (mutualistic and commensal) interactions among introduced species are more common than purely negative (competitive and amensal) interactions. In addition, many exploitative (e.g., predator–prey) interactions appear to be strongly asymmetric in benefiting one invading species at a negligible cost to another. These observations, combined with an increasing invasion rate in the Great Lakes, tentatively support the Simberloff – Von Holle "invasional meltdown" model. The model posits that ecosystems become more easily invaded as the cumulative number of species introductions increases, and that facilitative interactions can exacerbate the impact of invaders. It provides a theoretical argument for substantially reducing the rate of species introductions to the Great Lakes.


Marine Policy ◽  
2021 ◽  
Vol 131 ◽  
pp. 104618
Author(s):  
M.A. Collins ◽  
P.R. Hollyman ◽  
J. Clark ◽  
M. Soeffker ◽  
O. Yates ◽  
...  

Oryx ◽  
2017 ◽  
Vol 53 (1) ◽  
pp. 27-35 ◽  
Author(s):  
A. R. Martin ◽  
M. G. Richardson

AbstractThe Subantarctic island of South Georgia lost most of its birds to predation by rodents introduced by people over 2 centuries. In 2011 a UK charity began to clear brown rats Rattus norvegicus and house mice Mus musculus from the 170 km long, 3,500 km2 island using helicopters to spread bait containing Brodifacoum as the active ingredient. South Georgia's larger glaciers were barriers to rodent movement, resulting in numerous independent sub-island populations. The eradication could therefore be spread over multiple seasons, giving time to evaluate results before recommencing, and also reducing the impact of non-target mortality across the island as a whole. Eradication success was achieved in the 128 km2 Phase 1 trial operation. Work in 2013 (Phase 2) and early 2015 (Phase 3) covered the remaining 940 km2 occupied by rodents. By July 2017, 28 months after baiting was concluded, there was no sign of surviving rodents, other than one apparently newly introduced by ship in October 2014. A survey using detection dogs and passive devices will search the Phase 2 and Phase 3 land for rodents in early 2018. Seven (of 30) species of breeding birds suffered losses from poisoning, but all populations appear to have recovered within 5 years. The endemic South Georgia pipit Anthus antarcticus was the first bird to breed in newly rat-free areas, but there were also signs that cavity-nesting seabirds were exploring scree habitat denied them for generations. Enhanced biosecurity measures on South Georgia are needed urgently to prevent rodents being reintroduced.


1977 ◽  
Vol 109 (4) ◽  
pp. 555-564 ◽  
Author(s):  
L. A. Lyons

AbstractFour species of Exenterus were reared from the European pine sawfly, Neodiprion sertifer (Geoff.), in Ontario. An introduced species, E. abruptorius (Thunb.), last reported in Ontario in 1948, was recovered in very small numbers at one location. The native E. affinis Roh. (= E. walleyi Cush.) parasitized a small proportion of N. sertifer but was the main species attacking feeding larvae. The native E. nigrifrons (formerly called E. canadensis Prov.) and the introduced E. amictorius (Panz.) occurred at all sampled locations. Both species were more numerous in high than in low density populations of N. sertifer, but E. nigrifrons was more destructive, and E. amictorius less destructive, at high than at low density.About 60% of adults of E. amictorius and 6% of those of E. nigrifrons eclosed in the same summer that attack occurred. Most were unlikely to have reproduced, owing to the scarcity of hosts. In both species females were more frequent in female than in male hosts.Samples of N. sertifer cocoons in July were superior to larval samples in June and cocoon samples in August and the following May for measuring the rate of parasitism and the relative abundance of Exenterus spp. However, because of mortality of Exenterus before and after sampling, data based on the rearing of cocoons seriously underestimated the impact of the parasites.


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