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Two Mexican leaf-feeding beetles, Zygogramma piceicollis (Stål) and Zygogramma signatipennis (Stål) (Coleoptera: Chrysomelidae), were released in South Africa for the biological control of the invasive species Tithonia rotundifolia (Mill.) S.E. Blake (Asteraceae: Heliantheae). The aim of this study was to predict the potential of these beetles to establish and spread in South Africa, using MaxEnt climate modelling that incorporated locality data recorded in Mexico between 2008 and 2019 and data from the Global Biodiversity Information Facility. Zygogramma signatipennis displayed a wider distribution than Z. piceicollis in Mexico, with some overlap between the two species. The average receiver operating characteristic curves obtained for Z. piceicollis and Z. signatipennis predicted high mean area under curve values of 0.910 and 0.885, respectively. Jackknife tests revealed that mean annual temperature had the highest gain when used in isolation for Z. piceicollis, compared with minimum precipitation of the driest month for Z. signatipennis. These tests also revealed that the highest and lowest contributing environmental variables for Z. piceicollis and Z. signatipennis were minimum precipitation of the driest month (37.9 and 46.7%) and maximum annual temperature of the warmest month (3.8 and 12.3%), respectively. MaxEnt modelling predicted that at least six of South Africa's nine provinces provide regions that would support the proliferation of both beetles, with conditions best suited for Z. piceicollis. Despite predictions that both beetles should establish throughout the range of T. rotundifolia in South Africa, their realized establishment has so far been poor. Other factors, besides climate, including release size, site destructions, drought, soil moisture and texture could be constraining establishment. [ABSTRACT FROM AUTHOR]

Maize is one of the most important sources of protein and starch for humans, however, low soil nitrogen may affect important grain quality traits. The objective of this study was to determine the chemical composition and pasting properties of 11 quality protein maize (QPM) hybrids with one non-QPM hybrid check, grown under optimal and low nitrogen stress conditions. Maize hybrids grown under low nitrogen compared to optimal environments had higher values of starch (56.71 and 54.50%), amylose (33.41 and 30.99%), β- (1.39 and 1.36%) and γ-zeins (68.53% and 53.78) as well as final (3004.56 and 1465.88 cP), setback (2110.48 and 1035.17 cP), trough (958.32 and 430.71 cP), breakdown (237.23 and 68.19 cP) and peak (1217.0 and 499.0 cP) viscosities. Lower amounts of protein (7.08% and 10.22) and α-zein content (29.94% and 44.96), as well as lower temperatures of pasting (50.89 and 51.21 °C) and peak time (5.89 and 6.91 min) of the pasting curves, were observed under low nitrogen conditions. The environment had a large effect on protein, viscosity and amylose content, while starch, zein and pasting temperature were largely determined by genotype. [ABSTRACT FROM AUTHOR]

The information and communication technology (ICT) sector within the Netherlands is a major driver of globalization, the country's economic growth and innovation. The Dutch ICT sector's performance is increasingly becoming dependent upon employee driven innovations in order to address the needs of the sectors they service. In other words, the ICT sector within the Netherlands is largely dependent upon the performance and innovative capacity of its employees; both of which are functions of employee engagement. Given the high demand, and low supply of talent within this sector, ICT organizations need to develop innovative ways to enhance the performance capacities of its people. Developing an engaged and highly innovative workforce seems to be an efficient way to activate employees' performance. As such, the aim of this paper was to investigate the mediating function of employee driven innovative work behaviors in the relationship between work engagement and task performance within the a Dutch ICT consulting firm. A cross-sectional survey-based research design, employing a census-based sampling method, was employed to obtain data from a global ICT consulting firm within the Netherlands (n = 232). The Utrecht Work Engagement Scale, the Innovative Work Behavior Scale and the Task Performance Scale was used to assess the associative subjective experiences of ICT employees. The results showed that work engagement is a significant driver for innovative work behaviors, which in turn affects the task performance of employees. Further, innovative work behaviors are therefore important to translate the engaging energies of employees into performance. This paper discusses the theoretical and practical implications of these findings. [ABSTRACT FROM AUTHOR]

Despite potential negative interactions between biological control agents, the release of multiple agents against invasive alien weeds is often justified. The leaf-feeding beetle Mada polluta Mulsant (Coleoptera: Coccinellidae), released against Tecoma stans (L.) Juss ex Kunth var. stans in South Africa, has so far been unable to contain the weed. Consequently, the root-feeding flea beetle Heikertingerella sp. (Coleoptera: Galerucinae) was introduced to complement M. polluta. The effects of the interaction between the two beetles on their performance and on the target weed were studied on potted T. stans plants in a quarantine glasshouse to assess whether they were additive, synergistic or negative. There was no significant difference in the percentage survival of the P1 adults of either beetle when tested alone or in combination. Mada polluta produced significantly more F1 adult progeny than Heikertingerella sp. when tested alone, while both beetles produced significantly fewer offspring when tested in combination. Leaf damage by M. polluta alone was higher than that caused by Heikertingerella sp. alone, but in combination was not significantly higher than damage by M. polluta alone. Although both beetles on their own caused a significant reduction in leaf density relative to the control, leaf density was significantly lower when in combination. Despite significant reductions in plant height relative to the control, the differences between the three beetle treatments were not significant. Although competitive interactions caused a trade-off between agent proliferation and their impact on the growth of T. stans, these data need to be confirmed in the field. [ABSTRACT FROM AUTHOR]

The invasive tree Solanum mauritianum Scopoli remains one of the world’s most widespread environmental weeds. Despite biocontrol providing one of the few viable long-term solutions to tackling S. mauritianum invasions globally, only South Africa and, more recently, New Zealand, have programmes in place. Ongoing biocontrol efforts against S. mauritianum are reviewed here with particular reference to South Africa. The South African programme has suffered a troubled history, with considerable research efforts culminating in the eventual release and establishment of only two insect agents, Gargaphia decoris Drake and Anthonomus santacruzi Hustache. The difficulties experienced have hindered research into new agents, causing apprehension in using biocontrol internationally. However, recent studies have demonstrated that biocontrol may be deserving of renewed investment, particularly within an integrated management context. In this review, we advocate for the revival of the S. mauritianum biocontrol programme in South Africa, and discuss possible avenues for future research internationally. [ABSTRACT FROM AUTHOR]

Several invasive Asteraceae have been targeted for biological control worldwide, with variable success. Senecio madagascariensis Poiret, which invades agricultural lands in Australia and Hawaii, is a recent target. Since several potential insect agents were recorded in the plant's native range in South Africa, we assessed biocontrol efforts against asteraceous weeds to determine those most likely to deliver success. Some 108 insect species, from five orders and 23 families, were deployed against 38 weed taxa, mostly in the mainland USA, Canada, Australia and New Zealand. Coleoptera (mainly Curculionidae and Chrysomelidae), Diptera (Tephritidae) and Lepidoptera (Tortricidae) featured the most. Despite high establishment success (73% of releases across countries), only 37% of successful releases achieved meaningful impact. Although root-feeding and stem-feeding insects appeared to be the best candidates, neither insect family nor feeding guild significantly influenced the probability of success. This synthesis of the global contribution of different guilds of specialist herbivores to the management of invasive Asteraceae is guiding the selection of candidate agents for the biocontrol of S. madagascariensis in Australia. [ABSTRACT FROM AUTHOR]

The flower-galling mite Aceria lantanae (Cook) (Trombidiformes: Eriophyidae) was released for the biological control of Lantana camara L. (Verbenaceae) in South Africa in 2007, but has displayed variable and patchy establishment throughout the weed's range. Surveys were undertaken in 2013-2014, both seasonally and during the mite's peak infestation periods, to determine the influence of climatic factors on its performance. Although there were seasonal differences in the percentages of mite-infested inflorescences, these did not differ significantly between altitudinal zones. There were also no significant relationships between the percentages of mite-infested inflorescences and either of annual rainfall, temperature or relative humidity. A field inoculation trial revealed significant differences between 10 common South African L. camara varieties in their susceptibility to A. lantanae. Only three varieties displayed appreciable susceptibility (50-61% of inflorescences infested), whereas six displayed only slight to moderate susceptibility (8-21%) and one displayed a lack of susceptibility (no infestation). These data support the contention that differential varietal susceptibility and not climate is responsible for the variable performance of A. lantanae on L. camara in South Africa. Complementing the current biotype of A. lantanae, originally sourced from Florida (USA), with other biotypes from different L. camara genotypes in Central and South America could increase the mite's impact on the weed. [ABSTRACT FROM AUTHOR]

Psychological ownership is a cognitive-affective construct based on individuals' feelings of possessiveness towards and of being psychologically tied/attached to objects that are material (e.g. tools or work) and immaterial (e.g. ideas or workspace) in nature. Research suggests that psychological ownership could be influenced by various individual, organisational and contextual factors. The South African Employment Equity Act, which was implemented to grant equitable opportunities to previously disadvantaged employees, could be a significant contextual factor affecting psychological ownership, due to perceptions associated with inequality. Ethnicity may also act as a moderator for the relationship between perceptions of employment equity and psychological ownership. The objective of this study was to investigate the relationship between employment equity perceptions and psychological ownership and to explore whether ethnicity plays a moderating role in the relationship. A cross-sectional survey design was employed with a purposeful sample of 202 respondents employed in a large South African mining house. Pearson product-moment correlations and structural equation modelling confirmed that employment equity perceptions could predict the five components of psychological ownership. However, the results revealed that ethnicity has no moderating effect on the relationship between perceptions of employment equity and the emergence of psychological ownership. By implication, organisations that seek to retain employees targeted through equity initiatives need to find ways to enhance and develop the psychological ownership of these employees. The research contributes new insights into and knowledge of how contextual factors could influence employees' psychological ownership. [ABSTRACT FROM AUTHOR]

Chromolaena odorata (L.) King & H.E. Robins. (Asteraceae) threatens several economic and environmental activities in the eastern subtropical regions of South Africa and is a target for biological control. Three populations of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae) originating from Florida (USA), Cuba and Jamaica were released at 30 separate sites in KwaZulu-Natal, South Africa. Subsequent overlapping of two of these populations in the field and the likelihood of interbreeding posed a potential risk of establishment failure. To explore the genetic diversity of the different P. insulata populations and test for the existence of pre- and post-zygotic reproductive isolation between them, molecular analyses and cross-mating experiments were conducted. Mitochondrial DNA sequences revealed significant genetic similarity between them. Cross-mating trials between Floridian and Jamaican populations of P. insulata revealed no significant pre- and post-zygotic isolation, with no demonstrable differences in measured parameters between the 'parental' populations, the F 'hybrids' and the backcrosses. These results suggest that P. insulata populations released in South Africa are part of the same 'parental' population. Genetic incompatibility is, therefore, relatively unlikely to be the cause of any failure in establishment of P. insulata at any of the release sites. [ABSTRACT FROM AUTHOR]

Type II diabetes mellitus is currently globally one of the fastest growing non-communicable diseases, especially in developing countries. This investigation reports on a meta-analysis undertaken of the C-11377G locus within the adiponectin gene in a black South African, a Cuban Hispanic and a German Caucasian cohort. Genotyping was performed via a real-time PCR strategy. Both fixed- and random-effects models were tested to describe the diabetes risk at both the cohort and population levels. The 2,2 genotype may only be associated with increased diabetes risk in the Cuban Hispanic cohort. Population-specific effects may have masked these associations upon meta-analytical analysis, as no significant odds ratio could be determined. Thus, to examine diabetes risk, a more global approach including the design of population-specific experimental strategies should be used, which will be crucial in developing health education and policies in a global health programme.The Pharmacogenomics Journal (2009) 9, 42–48; doi:10.1038/tpj.2008.2; published online 4 March 2008 [ABSTRACT FROM AUTHOR]

The South American tree Solanum mauritianum, a major environmental weed in the high-rainfall regions of South Africa, has proved to be a difficult target for biological control. Artificially expanded host ranges of candidate agents during quarantine host-specificity tests, have resulted in the release of only one agent species which has so far had a negligible impact on the weed. The necessity for additional agents resulted in the importation of a leaf-mining flea beetle, an unidentified species of Acallepitrix, from Brazil in 1997. No-choice tests in quarantine showed that potential host plants are confined to the genus Solanum. Although several non-target plants, including cultivated eggplant (aubergine) and some native South African Solanum species, sustained feeding, oviposition and the development of larval leaf mines, most of these were inferior hosts. These results were confirmed by paired choice tests, where Acallepitrix sp. nov. displayed significant feeding and oviposition preferences for S. mauritianum and where, with few exceptions, more larval leaf mines were initiated on S. mauritianum. Interpretation of the host-specificity tests was facilitated by a risk assessment matrix which suggested that the risk of feeding and oviposition on non-target Solanum plants, including eggplant cultivations, was relatively low. These and other considerations, such as the lack of evidence of damage inflicted on cultivated Solanaceae in South America, suggest that Acallepitrix sp. nov. could be considered for release against S. mauritianum in South Africa. However, the results of the host-specificity tests remain ambiguous and until more compelling evidence is obtained from field surveys and open-field trials in Brazil, an application for permission to release the flea beetle in South Africa will not be considered. [ABSTRACT FROM AUTHOR]

The South American tree Solanummauritianum is a major environmental weed in thehigh-rainfall regions of South Africa and has beentargeted for biological control since 1984. Althoughhost ranges of imported agents determined duringquarantine tests have resulted in the rejection ofeight of the 11 candidate agents tested so far, theleaf-sucking lace bug Gargaphia decoris,imported from Argentina in 1995, displayed anacceptably narrow host range in captivity. No-choicetests showed that G. decoris is confined to Solanum species and cannot survive on solanaceouscrops outside that genus. Although these tests alsoindicated that G. decoris colonies could surviveand reproduce on cultivated eggplant (aubergine) andat least five native South African Solanumspecies, all but one native species proved to beinferior hosts in terms of adult survival andoviposition potential. During paired choice andmultichoice tests in small and larger cagesrespectively, G. decoris displayed very strongfeeding and oviposition preferences for S. mauritianum. Analyses of the risk of attack onnon-target Solanum plants revealed that, withone possible exception, none were likely to suffermore than incidental damage in the field. Host recordsfrom South America have also indicated that G. decoris has not been recorded on any Solanumspecies other than S. mauritianum, providingfurther evidence of its host specificity. The resultsof this study were accepted by the regulatoryauthorities and in February 1999, G. decorisbecame the first agent to be released in South Africafor the biological control of S. mauritianum. [ABSTRACT FROM AUTHOR]

The South American tree Solanum mauritianum is a major environmental weed in the high-rainfall regions of South Africa and has been targeted for biological control. Potential agents included five species of the genus Platyphora, which were imported from South America in 1994. Platyphora species associated with Solanaceae reputedly have very specific habitat requirements and host plant preferences in the field. Despite this, host-specificity tests on one species, Platyphora semiviridis, revealed a broad physiological host range. Although laboratory tests showed that P. semiviridis is confined to Solanum species and cannot survive on solanaceous crops outside that genus, it developed on potato and cultivated eggplant (aubergine) as well as on 10 native South African Solanum species. With few exceptions, there were no consistent differences in survival and duration of development on these compared with S. mauritianum. Furthermore, at least six of these non-target species, including potato and eggplant, supported breeding colonies of the beetles in cages. During choice tests in both small and larger cages, P. semiviridis avoided potato but did not consistently discriminate between S. mauritianum, eggplant and six native solanums for larviposition. Despite these findings, P. semiviridis has never been recorded on either potato or eggplant in South America, where it was only observed to feed on S. mauritianum. Although there are several reasons why P. semiviridis is unlikely to attack non-target Solanum species in the field, it will not be released in South Africa because there are other imported agents which have displayed narrower physiological host ranges and which may be more effective. [ABSTRACT FROM AUTHOR]