Discrepancy Between Antennal and Behavioral Responses for Enantiomers of a-Pinene: Electrophysiology and Behavior of Helicoverpa Armigera (Lepidoptera)

The ability of adult cotton bollworm, Helicoverpa armigera (Hubner), to distinguish and respond to enantiomers of α-pinene was investigated with electrophysiological and behavioral methods. Electroantennogram recordings using mixtures of the enantiomers at saturating dose levels, and single unit electrophysiology, indicated that the two forms were detected by the same receptor neurons. The relative size of the electroantennogram response was higher for the (−) compared to the (+) form, indicating greater affinity for the (−) form at the level of the dendrites. Behavioral assays investigated the ability of moths to discriminate between, and respond to the (+) and (−) forms of α pinene. Moths with no odor conditioning showed an innate preference for (+)-α-pinene. This preference displayed by naıve moths was not significantly different from the preferences of moths conditioned on (+)-α-pinene. However, we found a significant difference in preference between moths conditioned on the (−) enantiomer compared to naıve moths and moths conditioned on (+)-α-pinene, showing that learning plays an important role in the behavioral response. Moths are less able to distinguish between enantiomers of α-pinene than different odors (e.g., phenylacetaldehyde versus (−)-α-pinene) in learning experiments. The relevance of receptor discrimination of enantiomers and learning ability of the moths in host plant choice is discussed.

The impact of dry matter, ripeness and internal defects on consumer perceptions of avocado quality and intentions to purchase.

Insights into the relative importance of various aspects of product quality can be provided through quantitative analysis of consumer preference and choice of fruit. In this study, methods previously used to establish taste preferences for kiwifruit (Harker et al., 2008) and conjoint approaches were used to determine the influence of three key aspects of avocado quality on consumer liking and willingness to purchase fruit: dry matter percentage (DM), level of ripeness (firmness) and internal defects (bruising). One hundred and seven consumers tasted avocados with a range of DM levels from ~20% (minimally mature) to nearly 40% (very mature), and at a range of fruit firmness (ripeness) stages (firm-ripe to soft-ripe). Responses to bruising, a common quality defect in fruit obtained from the retail shelf, were examined using a conjoint approach in which consumers were presented with photographs showing fruit affected by damage of varying severity. In terms of DM, consumers showed a progressive increase in liking and intent to buy avocados as the DM increased. In terms of ripeness, liking and purchase intent was higher in avocados that had softened to a firmness of 6.5 N or below (hand-rating 5). For internal defects, conjoint analysis revealed that price, level of bruising and incidence of bruising all significantly lowered consumers' future purchase decision, but the latter two factors had a greater impact than price. These results indicate the usefulness of the methodology, and also provide realistic targets for Hass avocado quality on the retail shelf.

VG10024 Consumer insights into vegetable consumption phase two

To develop the psychological concepts identified in Horticulture Australia Limited (HAL) study VG08000 into a survey instrument. To conduct a quantitative study that provides a psychological understanding of consumer segments.

Late Autumn Winter Spring strawberries for profit and consumer appeal

Improved cultivar.

Sweetpotato consumer research: insights to increasing consumption

This report provides an evaluation of the behaviours and purchasing drivers of key sweetpotato consumers defined by Nielsen consumer research as Established Couples (two or more adults with no children 17 and under, and head of house 35-59), Senior Couples (two or more adults with no children 17 or under, and head of house 60 or over), and Independent Singles (one person household 35 or over, no children 17 or under). Research was qualitative in nature. Methods used included focus groups, depth interviews and shop-a-longs. The report found that preferences for sweetpotato amongst these groups were varied. In general a smaller torpedo shaped vegetable was valued for ease of preparation and the convenience of being of sufficient size for a meal for two. Satisfaction with sweetpotato was high with negative comments on quality exceedingly rare within discussions. However, shop-a-longs revealed that some quality issues were apparent at retail such as withered product, pitting and occasionally damage. A display with stock resting in any amount of water was a barrier to purchase for consumers and this was apparent on two out 15 occasions. A high quality sweetpotato was of a deep orange/red colour, had a smooth skin and was extremely dense and hard. An inferior sweetpotato was wrinkly, spongy, pitted and damaged. Awareness of sweetpotato was a relatively recent phenomenon amongst the respondents of this study with most recalling eating the vegetable in the last five to 10 years. Life-time eating patterns emerged as a consequence of childhood food experiences such as growing up with a ‘meat and three’ veg philosophy and traditional Australian meals. However, this was dependent on cultural background and those with ties to diverse cultures were more likely to have always known of the vegetable. Sweetpotato trial and consumption coincided with a breaking away from these traditional patterns, or was integrated into conventional meals such as a baked vegetable to accompany roasts. Increased health consciousness also led to awareness of the vegetable. A primary catalyst for consumption within the Established and Senior Couples groups was the health benefits associated with sweetpotato. Consumers had very little knowledge of the specific health properties of the vegetable and were surprised at the number of benefits consumption provided. Sweetpotato was important for diabetics for its low Glycemic Index status. Top-of-the-mind awareness of the vegetable resulted from the onset of the disease. Increasing fibre was a key motive for this demographic and this provided a significant link between consumption and preventing bowel cancer. For those on a weight loss regime, sweetpotato was perceived as a tasty, satisfying food that was low in carbohydrates. Swapping behaviours where white potato was replaced by sweetpotato was often a response to these health concerns. Other health properties mentioned by participants through the course of the research included the precursor β-carotene and Vitamins A & C. The sweetpotato was appreciated for its hedonic and timesaving qualities. For consumers with a high involvement in food, the vegetable was valued for its versatility in meals. These consumers took pride in cooking and the flavour and texture of sweetpotato lent itself to a variety of meals such as soups, salads, roasts, curries, tagines and so on. Participants who had little time or desire to prepare and cook meals valued sweetpotato because it was an easy way to add colour and variety to the plate and because including an orange vegetable to meals is a shortcut to ensuring vitamin intake. Several recommendations are made to the sweetpotato industry. • Vigorously promote the distinct nutritional and health properties of sweetpotatoes, particularly if they can be favourably compared to other vegetables or foods • Promote the salient properties to specific targets such as diabetics, those that are at risk to bowel cancer, and those embarking on a weight-loss regime. Utilise specialist channels of communication such as diabetic magazines and websites • Promote styles of cooking of sweetpotato that would appeal to traditionalists such as roasts and BBQs • Promote the vegetable as a low maintenance vegetable, easy to store, easy to cook and particularly focusing on it as a simple way to boost the appearance and nutritional value of meals. • Promote the vegetable to high food involvement consumers through exotic recipes and linking it to feelings of accomplishment with cooking • Promote the versatility of the vegetable • Devise promotions that link images and tone of communications with enjoying life to the fullest, having time to enjoy family and grandchildren, and of partaking in social activities • Educate retailers on consumer perceptions of quality and ensuring moisture and mould is not present at displays Qualitative information while providing a wealth of detail cannot be extrapolated to the overall target population and this may be considered a limitation to the research. However, within research theory, effective quantitative design is believed to stem from the insights developed from qualitative studies. • Develop and implement a quantitative study on sweetpotato attitudes and behaviours based on the results of this study.

Effect of physiological and experiential state of Bactrocera tryoni flies on intra-tree foraging behavior for food (bacteria) and host fruit

Using caged guava trees in Queensland, Australia, provided with food and oviposition sites, the foraging behaviour of females of the tephritid Bactrocera tryoni was investigated in relation to hunger for protein, the presence or absence of bacteria as a source of protein, the degree of prior experience with host fruit and quality of host fruit for oviposition. One aim was to evaluate whether it is immature or mature B. tryoni females that are responsible for initially inoculating host fruit surfaces with "fruit-fly-type" bacteria, the odour of which is known to attract B. tryoni females. Three-week-old immature females provided with sucrose but deprived of protein from eclosion had a much greater propensity than 3-week-old protein-fed mature females to visit vials containing fruit-fly-type bacteria, irrespective of whether vials were associated with adjacent host fruit or not. In the absence of associated bacteria in vials, immature females had a much lower propensity than mature females to visit host fruit. In the presence of bacteria in vials, however, propensity of immature and mature females to visit fruit was about equal. Mature (but not immature) females were more inclined to visit fruit that ranked higher for oviposition (nectarines) than fruit that ranked lower (sweet oranges). Mature females that attempted oviposition during a single 3-min exposure period to a nectarine prior to release were much more likely to find a nectarine than were mature females naive to fruit or immature females with or without prior contact with fruit. Exposure to a nectarine before release did not affect the propensity of either mature or immature females to alight on an odourless visual model of a nectarine, however. As judged by numbers of leaves visited, protein-deprived immature females were more active than protein-fed mature females, irrespective of the sorts of resources on a tree. It was concluded that: the 1st B. tryoni females to arrive on the fruit of a host tree and therefore inoculate the fruit with fruit-fly-type bacteria were unlikely to be sexually immature, but to be mature as a result of having earlier acquired protein elsewhere; the odour of colonies of fruit-fly-type bacteria when associated with host fruit attracted protein-hungry but not protein-fed females; and the odour of the fruit itself attracted mature females (especially experienced ones) but not immature females.

Host selection and parasitism behavior of lysiphlebus testaceipes: Role of plant, aphid species and instar

The aphid parasitoid Lysiphlebus testaceipes is a potentially valuable biological control agent of Aphis gossypii a major worldwide pest of cotton. One means of increasing the abundance of a biological control agent is to provide an alternative host habitat adjacent to cropping, from which they can provide pest control services in the crop. Host selection and parasitism rate of an alternative host aphid, Aphis craccivora by L. testaceipes were studied in a series of experiments that tested its host suitability relative to A. gossypii on cotton, hibiscus and mungbean. Host acceptance, as measured by number of ovipositions was much greater in A. craccivora compared to A. gossypii, while more host aphids were accepted on mungbean than cotton. When given a choice L. testaceipes attacks more 4th instar and adult stages (63% and 70%, respectively) of both hosts than 2nd instar nymphs (47%). In a switching (host choice) experiment, L. testaceipes preferentially attacked A. craccivora on mungbean over A. gossypii on cotton. Observations of parasitoid contact with A. gossypii cornicle secretion suggest it provides a useful deterrent against parasitoid attack. From these experiments it appears L. testaceipes has a preference for A. craccivora and mungbean compared to A. gossypii and cotton, in this respect using A. craccivora and mungbean as alternative habitat may not work as the parasitoid is unlikely to switch away from its preferred host. © 2012.

Elevated CO2 affects the behavior of an ecologically and economically important coral reef fish

We tested the effect of near-future CO2 levels (a parts per thousand 490, 570, 700, and 960 mu atm CO2) on the olfactory responses and activity levels of juvenile coral trout, Plectropomus leopardus, a piscivorous reef fish that is also one of the most important fisheries species on the Great Barrier Reef, Australia. Juvenile coral trout reared for 4 weeks at 570 mu atm CO2 exhibited similar sensory responses and behaviors to juveniles reared at 490 mu atm CO2 (control). In contrast, juveniles reared at 700 and 960 mu atm CO2 exhibited dramatically altered sensory function and behaviors. At these higher CO2 concentrations, juveniles became attracted to the odor of potential predators, as has been observed in other reef fishes. They were more active, spent less time in shelter, ventured further from shelter, and were bolder than fish reared at 490 or 570 mu atm CO2. These results demonstrate that behavioral impairment of coral trout is unlikely if pCO(2) remains below 600 mu atm; however, at higher levels, there are significant impacts on juvenile performance that are likely to affect survival and energy budgets, with consequences for predator-prey interactions and commercial fisheries.

Sweetcorn colour change and consumer perception associated with increasing zeaxanthin for the amelioration of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. Increasing dietary intake of lutein- and zeaxanthin-rich foods is a potential means of preventing, or at least slowing the progression of AMD. Zeaxanthin levels in tropical super-sweetcorn was increased from 1.1 to 11.9 µg/g FW through conventional breeding and selection, associated with both an increase in the proportion of zeaxanthin relative to other carotenoids, and a general increase in carotenoid synthesis. Increasing zeaxanthin was associated with a colour shift from traditional ‘canary-yellow’ kernels to a golden-orange colour. Kernel colour was most closely correlated (r2=69%) with an increase in beta-arm carotenoid concentration. Consumer analysis revealed that prior to any knowledge of zeaxanthin-related health benefit, consumers would readily purchase both yellow and gold cobs. Once the health benefit was explained, this extended to deep-gold cobs. Colour difference between regular yellow sweetcorn and high-zeaxanthin sweetcorn could potentially be used as a visual means of differentiating high-zeaxanthin sweetcorn in the marketplace.