Understanding Heliothine (Lepidoptera: Heliothinae) pests: What is a host plant?

Heliothine moths (Lepidoptera: Heliothinae) include some of the world's most devastating pest species. Whereas the majority of nonpest heliothinae specialize on a single plant family, genus, or species, pest species are highly polyphagous, with populations often escalating in size as they move from one crop species to another. Here, we examine the current literature on heliothine host-selection behavior with the aim of providing a knowledge base for research scientists and pest managers. We review the host relations of pest heliothines, with a particular focus on Helicoverpa armigera (Hubner), the most economically damaging of all heliothine species. We then consider the important question of what constitutes a host plant in these moths, and some of the problems that arise when trying to determine host plant status from empirical studies on host use. The top six host plant families in the two main Australian pest species (H. armigera and Helicoverpa punctigera Wallengren) are the same and the top three (Asteraceae, Fabaceae, and Malvaceae) are ranked the same (in terms of the number of host species on which eggs or larvae have been identified), suggesting that these species may use similar cues to identify their hosts. In contrast, for the two key pest heliothines in the Americas, the Fabaceae contains approximate to 1/3 of hosts for both. For Helicoverpa zea (Boddie), the remaining hosts are more evenly distributed, with Solanaceae next, followed by Poaceae, Asteraceae, Malvaceae, and Rosaceae. For Heliothis virescens (F.), the next highest five families are Malvaceae, Asteraceae, Solanaceae, Convolvulaceae, and Scrophulariaceae. Again there is considerable overlap in host use at generic and even species level. H. armigera is the most widely distributed and recorded from 68 plant families worldwide, but only 14 families are recorded as a containing a host in all geographic areas. A few crop hosts are used throughout the range as expected, but in some cases there are anomalies, perhaps because host plant relation studies are not comparable. Studies on the attraction of heliothines to plant odors are examined in the context of our current understanding of insect olfaction, with the aim of better understanding the connection between odor perception and host choice. Finally, we discuss research into sustainable management of pest heliothines using knowledge of heliothine behavior and ecology. A coordinated international research effort is needed to advance our knowledge on host relations in widely distributed polyphagous species instead of the localized, piecemeal approaches to understanding these insects that has been the norm to date.

The functional significance of fruit exocarp on host selection and oviposition by Queensland fruit fly, Bactrocera tryoni (Froggatt) (Tephritidae: Diptera)

Queensland fruit fly is Australia's most serious insect pest of horticulture. The fly lays its eggs into fruit, where they hatch into maggots which destroy the fruit. Understanding egg laying behaviour, known as oviposition, is a critical but under-researched aspect of fruit fly biology. This thesis focused on three aspects of oviposition: the role of fruit peel as a physical barrier to oviposition; the quality of fruit for maggot development; and the structure and wear of the egg laying organ – the ovipositor. Results showed that flies selected fruit based on their suitability for offspring survival, not because of the softness or hardness of fruit peel. Previously reported use of holes or wounds in fruit peel by ovipositing females was determined to be a mechanism which saved the female time, not a mechanism to reduce ovipositor wear. The results offer insights into the evolution of host use by fruit flies and their sustainable management.

Effects of artificial shade on attack by the mahogany shoot borer, Hypsipyla robusta (Moore)

Swietenia macrophylla King (Meliaceae: Swietenioideae) provides one of the premier timbers of the world. The mahogany shoot borer Hypsipyla robusta Moore (Lepidoptera: Pyralidae) is an economically important pest of S. macrophylla throughout Asia, Africa and the Pacific. No viable method of controlling this pest is known. Previous observations have suggested that the presence of overhead shade may reduce attack by H. robusta, but this has not been investigated experimentally. This research was therefore designed to assess the influence of light availability on shoot-borer attack on S. macrophylla, by establishing seedlings under three different artificial shade regimes, then using these seedlings to test oviposition preference of adult moths, neonate larval survival and growth and development of shoot borer larvae. Oviposition preference of shoot borer moths was tested on leaves from seedlings grown under artificial shade for 63 weeks. A significant difference in choice was recorded between treatments, with 27.4 ± 1.5 eggs laid under high shade and 87.1 ± 1.8 under low shade. Neonate larval survival on early flushing leaflets of S. macrophylla did not differ significantly between shade treatments. Larval growth rate, estimated by measuring daily frass width, was significantly higher for those larvae fed on seedlings from the high and medium shade treatments (0.1 mm/day), than the low shade treatment (0.06 mm/day). In laboratory-reared larvae, the total mass of frass produced was significantly higher in the high shade treatment (0.4 g) than under the low shade treatment (0.2 g). Longer tunnel lengths were bored by larvae in plants grown under high shade (12.0 ± 2.4 cm) than under low shade (7.07 ± 1.9 cm). However, pupal mass under low shade was 48% higher than that under the high shade treatment, suggesting that plants grown under high shade were of lower nutritional quality for shoot borer larvae. These results indicate that shading of mahogany seedlings may reduce the incidence of shoot borer attack, by influencing both oviposition and larval development. The establishment of mahogany under suitable shade regimes may therefore provide a basis for controlling shoot borer attack using silvicultural approaches.

Resistance or covert infection : baculovirus studies re-examined

Recently, Boots & Begon (1993) described the development of resistance to granulosis virus (GV) (Baculoviridae) infection in the moth Plodia interpunctella, following prolonged exposure to virus in laboratory cultures. Resistant insects exhibited reduced fitness in other respects, namely slower development and reduced egg viability, compared to control insects. These results were interpreted as pleiotropic effects of selection at the loci controlling resistance. Similar results have been described in a previous study: Fuxa & Richter (1989) used artificial selection to increase resistance to nuclear polyhedrasis virus (NPV) (Baculoviridae) infection in the moth Spodoptera frugiperda. The resulting gain in resistance they interpreted as the result of an increase in the frequency of alleles conferring resistance. Again, resistant insects exhibited maladaptive traits compared to controls, including a shorter adult life span, reduced number of eggs and reduced egg viability. In both studies the suggestion is made that selection against maladaptive traits will result in a decline in resistance, once selection for resistance is removed. Boots & Begon (1993) described a decrease in development time (towards that of control insects) within two generations of removing selection for resistance. Fuxa & Richter (1989) describe a decrease in resistance, so that within two generations of relaxing selection, previously resistant lines were not significantly more resistant than control insects. . .

We need to talk : feminism and food (GOMA Harvest Picnic)

This collaborative, participatory work by feminist collective LEVEL took place at the Gallery of Modern Art (GOMA) as part of the official program of activities surrounding the exhibition 'Harvest', 2014. It took the form of a public picnic, where women and their friends were invited to share cooking recipes while also discussing the possible recipe for a gender revolution. Groups discussed their ideas, before a public reading of potential 'ingredients' and 'methods' outside the museum on the Maiwar Green.

Combustion analysis of microalgae methyl ester in a common rail direct injection diesel engine

In this study, the biodiesel properties and effects of blends of oil methyl ester petroleum diesel on a CI direct injection diesel engine is investigated. Blends were obtained from the marine dinoflagellate Crypthecodinium cohnii and waste cooking oil. The experiment was conducted using a four-cylinder, turbo-charged common rail direct injection diesel engine at four loads (25%, 50%, 75% and 100%). Three blends (10%, 20% and 50%) of microalgae oil methyl ester and a 20% blend of waste cooking oil methyl ester were compared to petroleum diesel. To establish suitability of the fuels for a CI engine, the effects of the three microalgae fuel blends at different engine loads were assessed by measuring engine performance, i.e. mean effective pressure (IMEP), brake mean effective pressure (BMEP), in cylinder pressure, maximum pressure rise rate, brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), heat release rate and gaseous emissions (NO, NOx,and unburned hydrocarbons (UHC)). Results were then compared to engine performance characteristics for operation with a 20% waste cooking oil/petroleum diesel blend and petroleum diesel. In addition, physical and chemical properties of the fuels were measured. Use of microalgae methyl ester reduced the instantaneous cylinder pressure and engine output torque, when compared to that of petroleum diesel, by a maximum of 4.5% at 50% blend at full throttle. The lower calorific value of the microalgae oil methyl ester blends increased the BSFC, which ultimately reduced the BTE by up to 4% at higher loads. Minor reductions of IMEP and BMEP were recorded for both the microalgae and the waste cooking oil methyl ester blends at low loads, with a maximum of 7% reduction at 75% load compared to petroleum diesel. Furthermore, compared to petroleum diesel, gaseous emissions of NO and NOx, increased for operations with biodiesel blends. At full load, NO and NOx emissions increased by 22% when 50% microalgae blends were used. Petroleum diesel and a 20% blend of waste cooking oil methyl ester had emissions of UHC that were similar, but those of microalgae oil methyl ester/petroleum diesel blends were reduced by at least 50% for all blends and engine conditions. The tested microalgae methyl esters contain some long-chain, polyunsaturated fatty acid methyl esters (FAMEs) (C22:5 and C22:6) not commonly found in terrestrial-crop-derived biodiesels yet all fuel properties were satisfied or were very close to the ASTM 6751-12 and EN14214 standards. Therefore, Crypthecodinium cohnii- derived microalgae biodiesel/petroleum blends of up to 50% are projected to meet all fuel property standards and, engine performance and emission results from this study clearly show its suitability for regular use in diesel engines.

Dewatering of microalgal culture for biodiesel production : exploring polymer flocculation and tangential flow filtration

Background: Conventional biodiesel production relies on trans-esterification of lipids extracted from vegetable crops. However, the use of valuable vegetable food stocks as raw material for biodiesel production makes it an unfeasibly expensive process. Used cooking oil is a finite resource and requires extra downstream processing, which affects the amount of biodiesel that can be produced and the economics of the process. Lipids extracted from microalgae are considered an alternative raw material for biodiesel production. This is primarily due to the fast growth rate of these species in a simple aquaculture environment. However, the dilute nature of microalgae culture puts a huge economic burden on the dewatering process especially on an industrial scale. This current study explores the performance and economic viability of chemical flocculation and tangential flow filtration (TFF) for the dewatering of Tetraselmis suecicamicroalgae culture. Results: Results show that TFF concentrates the microalgae feedstock up to 148 times by consuming 2.06 kWh m-3 of energy while flocculation consumes 14.81 kWhm-3 to concentrate the microalgae up to 357 times. Economic evaluation demonstrates that even though TFF has higher initial capital investment than polymer flocculation, the payback period for TFF at the upper extreme ofmicroalgae revenue is ∼1.5 years while that of flocculation is ∼3 years. Conclusion: These results illustrate that improved dewatering levels can be achieved more economically by employing TFF. The performances of these two techniques are also compared with other dewatering techniques.

Identification of the sources of primary organic aerosols at urban schools : a molecular marker approach

Children are particularly susceptible to air pollution and schools are examples of urban microenvironments that can account for a large portion of children’s exposure to airborne particles. Thus this paper aimed to determine the sources of primary airborne particles that children are exposed to at school by analyzing selected organic molecular markers at 11 urban schools in Brisbane, Australia. Positive matrix factorization analysis identified four sources at the schools: vehicle emissions, biomass burning, meat cooking and plant wax emissions accounting for 45%, 29%, 16% and 7%, of the organic carbon respectively. Biomass burning peaked in winter due to prescribed burning of bushland around Brisbane. Overall, the results indicated that both local (traffic) and regional (biomass burning) sources of primary organic aerosols influence the levels of ambient particles that children are exposed at the schools. These results have implications for potential control strategies for mitigating exposure at schools.

A ‘Big Data’ Approach to Mapping the Australian Twittersphere

This chapter discusses the methodological aspects and empirical findings of a large-scale, funded project investigating public communication through social media in Australia. The project concentrates on Twitter, but we approach it as representative of broader current trends toward the integration of large datasets and computational methods into media and communication studies in general, and social media scholarship in particular. The research discussed in this chapter aims to empirically describe networks of affiliation and interest in the Australian Twittersphere, while reflecting on the methodological implications and imperatives of ‘big data’ in the humanities. Using custom network crawling technology, we have conducted a snowball crawl of Twitter accounts operated by Australian users to identify more than one million users and their follower/followee relationships, and have mapped their interconnections. In itself, the map provides an overview of the major clusters of densely interlinked users, largely centred on shared topics of interest (from politics through arts to sport) and/or sociodemographic factors (geographic origins, age groups). Our map of the Twittersphere is the first of its kind for the Australian part of the global Twitter network, and also provides a first independent and scholarly estimation of the size of the total Australian Twitter population. In combination with our investigation of participation patterns in specific thematic hashtags, the map also enables us to examine which areas of the underlying follower/followee network are activated in the discussion of specific current topics – allowing new insights into the extent to which particular topics and issues are of interest to specialised niches or to the Australian public more broadly. Specifically, we examine the Twittersphere footprint of dedicated political discussion, under the #auspol hashtag, and compare it with the heightened, broader interest in Australian politics during election campaigns, using #ausvotes; we explore the different patterns of Twitter activity across the map for major television events (the popular competitive cooking show #masterchef, the British #royalwedding, and the annual #stateoforigin Rugby League sporting contest); and we investigate the circulation of links to the articles published by a number of major Australian news organisations across the network. Such analysis, which combines the ‘big data’-informed map and a close reading of individual communicative phenomena, makes it possible to trace the dynamic formation and dissolution of issue publics against the backdrop of longer-term network connections, and the circulation of information across these follower/followee links. Such research sheds light on the communicative dynamics of Twitter as a space for mediated social interaction. Our work demonstrates the possibilities inherent in the current ‘computational turn’ (Berry, 2010) in the digital humanities, as well as adding to the development and critical examination of methodologies for dealing with ‘big data’ (boyd and Crawford, 2011). Out tools and methods for doing Twitter research, released under Creative Commons licences through our project Website, provide the basis for replicable and verifiable digital humanities research on the processes of public communication which take place through this important new social network.

Household food insecurity, diet, and weight status in a disadvantaged district of Ho Chi Minh City, Vietnam: A cross-sectional study

Background Food security exists when all people, at all times, have physical, economic and socially acceptable access to safe, sufficient, and adequately nutritious food in order to meet their dietary needs for an active and healthy life. For high income countries and those experiencing the nutrition transition, food security is not only about the quantity of available food but also the nutritional quality as related to over- and under-nutrition. Vietnam is currently undergoing this nutrition transition, and as a result the relationship between food insecurity, socio-demographic factors and weight status is complex. The primary objective of this study was to therefore measure the prevalence of household food insecurity in a disadvantaged urban district in Ho Chi Minh City (HCMC) in Vietnam using a more comprehensive tool. This study also aims to examine the relationships between food insecurity and socio-demographic factors, weight status, and food intakes. Methods A cross-sectional study was conducted using multi-stage sampling. Adults who were mainly responsible for cooking were interviewed in 250 households. Data was collected on socioeconomic and demographic factors using previously validated tools. Food security was assessed using the Latin American and Caribbean Household Food Security Scale (ELCSA) tool and households were categorized as food secure or mildly, moderately or severely food insecure. Questions regarding food intake were based on routinely used and validated questions in HCMC, weight status was self-reported. Results Cronbach’s alpha coefficient was 0.87, showing the ELCSA had a good internal reliability. Approximately 34.4% of households were food insecure. Food insecurity was inversely related to total household income (OR = 0.09, 95% CI = 0.04 - 0.22) and fruit intakes (OR = 2.2, 95% CI 1.31 - 4.22). There was no association between weight and food security status. Conclusions Despite rapid industrialization and modernization, food insecurity remains an important public health issue in large urban areas of HCMC, suggesting that strategies to address food insecurity should be implemented in urban settings, and not just rural locations. Fruit consumption among food insecure households may be compromised because of financial difficulties, which may lead to poorer health outcomes particularly related to non-communicable disease prevention and management.

‘Beyond all the trends’: Torres Strait Island foods, past, present and future

While trends are cyclical, Indigenous perspectives offer continuity to life’s pathways. One of the current trends is the increasing culinary interest in Indigenous Australian foods, not just in restaurants, but also in home kitchens. This is a recent trend despite Indigenous foods being nutritious and wholesome, and sustaining Indigenous peoples for thousands of years. Home Economics can support, foster and affirm Indigenous foods both within this current mainstream trend and in the future in life sustaining ways. In order to do so, Home Economics need’s to ensure it is prepared, and skilled, with the appropriate knowledge and regard for Indigenous ingredients, foods and foodways. This paper will focus on Torres Strait Islander foods from the Torres Strait and from mainland Australia. It will showcase Torres Strait foods is the past, present and the future. Some of what is presented here is part of a research case study, which involves a literature review, data collection, and photography. In documenting the history of Torres Strait Island food and foodways, the traditions and customs will be kept alive for future generations, and beyond any trends or fashions.

Environmental health risk assessment of dioxin in foods at the two most severe dioxin hot spots in Vietnam

Background Bien Hoa and Da Nang airbases were bulk storages for Agent Orange during the Vietnam War and currently are the two most severe dioxin hot spots. Objectives This study assesses the health risk of exposure to dioxin through foods for local residents living in seven wards surrounding these airbases. Methods This study follows the Australian Environmental Health Risk Assessment Framework to assess the health risk of exposure to dioxin in foods. Forty-six pooled samples of commonly consumed local foods were collected and analyzed for dioxin/furans. A food frequency and Knowledge–Attitude–Practice survey was also undertaken at 1000 local households, various stakeholders were involved and related publications were reviewed. Results Total dioxin/furan concentrations in samples of local “high-risk” foods (e.g. free range chicken meat and eggs, ducks, freshwater fish, snail and beef) ranged from 3.8 pg TEQ/g to 95 pg TEQ/g, while in “low-risk” foods (e.g. caged chicken meat and eggs, seafoods, pork, leafy vegetables, fruits, and rice) concentrations ranged from 0.03 pg TEQ/g to 6.1 pg TEQ/g. Estimated daily intake of dioxin if people who did not consume local high risk foods ranged from 3.2 pg TEQ/kg bw/day to 6.2 pg TEQ/kg bw/day (Bien Hoa) and from 1.2 pg TEQ/kg bw/day to 4.3 pg TEQ/kg bw/day (Da Nang). Consumption of local high risk foods resulted in extremely high dioxin daily intakes (60.4–102.8 pg TEQ/kg bw/day in Bien Hoa; 27.0–148.0 pg TEQ/kg bw/day in Da Nang). Conclusions Consumption of local “high-risk” foods increases dioxin daily intakes far above the WHO recommended TDI (1–4 pg TEQ/kg bw/day). Practicing appropriate preventive measures is necessary to significantly reduce exposure and health risk.

Food literacy

The term 'food literacy' is increasingly being used to describe the knowledge, skills and behaviours needed to feed yourself. In the last five years the use of this specific term has more than tripled in the research literature. The term is now commonly used in food and nutrition policy(Department of Agriculture Fisheries and Forestries, 2013; Glickman, Parker, Sim, Del Valle Cook, & Miller, 2012; Vandenbroeck, Goossens, & Clemens, 2007) and by a range of different industries, including, health, education and sustainable agriculture (Colatruglio, 2015; Piscopo, 2015; Voget-Kleschin, 2014). This article will look at what has led to the emergence of this term and then go on to define it based on the author's own PhD research which involved two studies, one of food experts and one of 16-25 year olds which aimed to identify the components of food literacy.