Research Articles (Conservation Ecology and Entomology)

Seed survival of Australian Acacia in the Western Cape of South Africa in the presence of biological control agents and given environmental variation

Strydom, Matthys; Veldtman, Ruan; Ngwenya, Mzabalazo Z.; Esler, Karen J. (PeerJ, 2019)

Studies of invasive Australian Acacia have shown that many seeds are still produced and accumulate in soil stored seed banks regardless of the presence of seed-targeting biological control agents. This is despite claims ...

Invasive Australian Acacia seed banks: Size and relationship with stem diameter in the presence of gall-forming biological control agents

Strydom, Matthys; Veldtman, Ruan; Ngwenya, Mzabalazo Z.; Esler, Karen J. (Public Library of Science, 2017)

Australian Acacia are invasive in many parts of the world. Despite significant mechanical and biological efforts to control their invasion and spread, soil-stored seed banks prevent their effective and sustained removal. ...

Including irrigation in niche modelling of the invasive wasp Vespula germanica (Fabricius) improves model fit to predict potential for further spread

De Villiers, Marelize; Kriticos, Darren J.; Veldtman, Ruan (Public Library of Science, 2017)

The European wasp, Vespula germanica (Fabricius) (Hymenoptera: Vespidae), is of Palaearctic origin, being native to Europe, northern Africa and Asia, and introduced into North America, Chile, Argentina, Iceland, Ascension ...

The metabolic costs of sexual signalling in the chirping katydid Plangia graminea (Serville) (Orthoptera: Tettigoniidae) are context dependent : cumulative costs add up fast

Doubell, Marcee; Grant, Paul B. C.; Esterhuizen, Nanike; Bazelet, Corinna S.; Addison, Pia; Terblanche, John S. (The Company of Biologists, 2017)

Katydids produce acoustic signals via stridulation, which they use to attract conspecific females for mating. However, direct estimates of the metabolic costs of calling to date have produced diverse cost estimates and are ...

Learning to starve : impacts of food limitation beyond the stress period

McCue, Marshall D.; Terblanche, John S.; Benoit, Joshua B. (The Company of Biologists, 2017)

Starvation is common among wild animal populations, and many individuals experience repeated bouts of starvation over the course of their lives. Although much information has been gained through laboratory studies of acute ...

Direct environmental impacts of solar power in two arid biomes : an initial investigation

Rudman, Justine; Gauche, Paul; Esler, Karen J. (Academy of Science of South Africa, 2017)

According to recent national energy plans and policy documents, the number of renewable energy developments is expected to increase in South Africa, thus contributing to the diversification of the country’s energy system. ...

Analysis of the global warming potential of biogenic CO₂ emission in life cycle assessments

Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; Von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun (Nature Research, 2017-01-03)

Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO2 (GWPbio). ...

Down, but not out : recent decline of Berg–Breede River whitefish (Barbus andrewi) in the upper Hex River, South Africa

Shelton, Jeremy M.; Impson, N. Dean; Graham, Shaun; Esler, Karen J. (AOSIS Publishing, 2017)

he Berg–Breede River whitefish, Barbus andrewi, an endangered Cape Floristic Region endemic, was once widespread in both the Berg and Breede River catchments. However, its distribution has been strongly reduced, apparently ...

Adapting the Dragonfly Biotic Index to a katydid (Tettigoniidae) rapid assessment technique : case study of a biodiversity hotspot, the Cape Floristic Region, South Africa

Thompson, Aileen C.; Bazelet, Corinna S.; Naskrecki, Piotr; Samways, Michael J. (Pensoft Publishers, 2017)

Global biodiversity faces many challenges, with the conservation of invertebrates among these. South Africa is megadiverse and has three global biodiversity hotspots. The country also employs two invertebrate-based rapid ...

Foliar application of steinernema yirgalemense to control planococcus ficus : assessing adjuvants to improve efficacy

Platt, T.; Stokwe, N. F.; Malan, A. P. (South African Society for Enology and Viticulture, 2018)

The vine mealybug (Planococcus ficus) is regarded as a key mealybug pest of grapevines in South Africa, with entomopathogenic nematodes (EPNs) being touted as a potential alternative to chemical control, although their ...

Plant functional trait data and reflectance spectra for 22 palmiet wetland species

Rebelo, Alanna J.; Somers, Ben; Esler, Karen J.; Meire, Patrick (Elsevier, 2018)

We provide reflectance spectra for 22 South African palmiet wetland species collected in spring 2015 from three wetlands throughout the Cape Floristic Region. In addition, we provide summarized plant functional trait data, ...

Potential of local entomopathogenic nematodes for control of the vine mealybug, planococcus ficus

Platt, T.; Stokwe, N. F.; Malan, A. P. (South African Society for Enology and Viticulture, 2018)

Planococcus ficus, the vine mealybug, is the dominant mealybug pest of grapes in South Africa. To provide an alternative for chemical control, entomopathogenic nematodes (EPNs) were investigated as a biological control ...

Woody encroachment as a social-ecological regime shift

Luvuno, Linda; Biggs, Reinette; Stevens, Nicola; Esler, Karen (MDPI, 2018-06-28)

African savannas are increasingly affected by woody encroachment, an increase in the density of woody plants. Woody encroachment often occurs unexpectedly, is difficult to reverse, and has significant economic, cultural ...

Biologically based methods for pest management in agriculture under changing climates : challenges and future directions

Chidawanyika, Frank; Mudavanhu, Pride; Nyamukondiwa, Casper (MDPI, 2012)

The current changes in global climatic regimes present a significant societal challenge, affecting in all likelihood insect physiology, biochemistry, biogeography and population dynamics. With the increasing resistance of ...

Cold tolerance is unaffected by oxygen availability despite changes in anaerobic metabolism

Boardman, Leigh; Sørensen, Jesper G.; Koštál, Vladimir; Šimek, Petr; Terblanche, John S. (Springer Nature, 2016)

Insect cold tolerance depends on their ability to withstand or repair perturbations in cellular homeostasis caused by low temperature stress. Decreased oxygen availability (hypoxia) can interact with low temperature ...

Potential synergies between nature-based tourism and sustainable use of marine resources : insights from dive tourism in territorial user rights for fisheries in Chile

Biggs, Duan; Amar, Francisca; Valdebenito, Abel; Gelcich, Stefan (Public Library of Science, 2016-03)

Novel solutions to conserve biodiversity whilst allowing for resource harvesting are urgently needed. In marine systems, Territorial User Rights for Fisheries (TURFs) are promoted to enable sustainable use of resources. ...