Innovating out of the Fishmeal Trap: The role of Insect-Based Fish Feed in Consumers’ Preferences for Fish Attributes

The purpose of the study was to examine the potential market impacts of the use of insect-based protein for fish feed as an innovative approach out of the fish-meal trap. An online questionnaire was used to elicit information on fish consumption choices among 610 German consumers using a Discrete Choice Experiment. Mixed logit and latent class logit models were used to model consumers’ preference heterogeneity. Results showed, that consumers’ preferences for fish attributes such as filets, freshness, ecolabelling and domestic production are heterogeneous and important in consumption choices. The minor share of the respondents was sensitive, while the remaining was indifferent regarding the use of insect based protein as feed in trout production. For this sensitive segment, consumption would be expected to be reduced unless the price is reduced or other attributes such as convenience aspects are improved. The implication is that firms can substitute without a significant impact on the market demand given that the majority of consumers are indifferent regarding feed sources for trout production. As a result, it provides an innovative way to ensure sustainable use of resources and reduces the threat of fish meal trap while reducing pressure on the already over-exploited marine life. The results provide first insights into the market impact of using insects in the animal protein value chain. It is important especially with Europe’s recent lift of the ban on using insect-based protein in the animal food industry

Feeding Preference Studies of Adult \u3ci\u3eNezara Viridula\u3c/i\u3e (Hemiptera: Pentatomidae) Morphs from India and the United States

Nezara viridula (Linnaeus) morphs from India and the United States were studied in a laboratory comparison of feeding preferences for pods of soybeans, Glycine max, and green beans, Phaseolus vulgaris. Adults of a morph from the U.S. apparently selected pods at random, while three sympatric morphs from India generally preferred green bean pods

Conservation of Olfactory Avoidance in Drosophila Species and Identification of Repellents for Drosophila suzukii.

Flying insects use olfaction to navigate towards fruits in complex odor environments with remarkable accuracy. Some fruits change odor profiles substantially during ripening and related species can prefer different stages. In Drosophila species attractive odorants have been studied extensively, but little is understood about the role of avoidance pathways. In order to examine the role of the avoidance cue CO2 emitted from fruit on behavior of two species with different ripening stage preferences, we investigated the CO2-detection pathway in Drosophila melanogaster and Drosophila suzukii, a harmful pest of fruits. Avoidance to CO2 is not conserved in D. suzukii suggesting a behavioral adaptation that could facilitate attraction to younger fruit with higher CO2 emission levels. We investigated known innate avoidance pathways from five species at different evolutionary distances: D. melanogaster, D. yakuba, D. suzukii, D. pseudoobscura and D. virilis. Surprisingly, only DEET shows strong repellency across all species, whereas CO2, citronellal and ethyl 3-hydroxybutyrate show only limited conservation. These findings guide us to test recently discovered safe DEET substitutes, and we identify one that protects fruits from D. suzukii thus providing a new behavioral strategy for controlling agricultural pests

Odour-mediated orientation of beetles is influenced by age, sex and morph

The behaviour of insects is dictated by a combination of factors and may vary considerably between individuals, but small insects are often considered en masse and thus these differences can be overlooked. For example, the cowpea bruchid Callosobruchus maculatus F. exists naturally in two adult forms: the active (flight) form for dispersal, and the inactive (flightless), more fecund but shorter-lived form. Given that these morphs show dissimilar biology, it is possible that they differ in odour-mediated orientation and yet studies of this species frequently neglect to distinguish morph type, or are carried out only on the inactive morph. Along with sex and age of individual, adult morph could be an important variable determining the biology of this and similar species, informing studies on evolution, ecology and pest management. We used an olfactometer with motion-tracking to investigate whether the olfactory behaviour and orientation of C. maculatus towards infested and uninfested cowpeas and a plant-derived repellent compound, methyl salicylate, differed between morphs or sexes. We found significant differences between the behaviour of male and female beetles and beetles of different ages, as well as interactive effects of sex, morph and age, in response to both host and repellent odours. This study demonstrates that behavioural experiments on insects should control for sex and age, while also considering differences between adult morphs where present in insect species. This finding has broad implications for fundamental entomological research, particularly when exploring the relationships between physiology, behaviour and evolutionary biology, and the application of crop protection strategies

Behavioral Ecology of an Invasive Species: Habitat and Mate Preference(s) in Drosophila Suzukii

The invasive Spotted-Wing fruit fly, Drosophila suzukii, has inflicted substantial economic losses to the soft-fruit agriculture industry worldwide due to the ability of females in this species to use a large, serrated ovipositor to cut the fruit’s skin and lay eggs directly into the mesocarp of ripening fruit. Once the eggs hatch, larvae consume the fruit flesh, ultimately leaving the fruit unmarketable. This species parasitizes numerous commercial fruit types (including blueberries, blackberries, strawberries, raspberries and occasionally grapes) as well as fruits from a variety of wild plant species. Since fruit types vary in their nutritional composition, as well as their spatial and temporal availability, this suggests that D. suzukii experiences considerable environmental heterogeneity. The environment can have a large influence on the development and evolution of morphological, physiological, and behavioural phenotypes and, thus, can have significant implications for individual variation and population growth and change over time. Thus to better understand success if this invasive species we have examined the behavioural and developmental and reproductive performance of D. suzukii as it relates to their local environment. Specifically we focused on the role of the nutritional developmental history (NDH), which can either hinder or support offspring growth and survival, and may be an important factor when selecting habitats. Secondly, as the juvenile NDH has the potential to greatly influence adult phenotypes, and consequently individual reproductive potential, we also examined if NDH influenced the operation of sexual selection. Here we report evidence that NDH is an important factor for D. suzukii females when choosing oviposition sites, and can have dramatic consequences for offspring development, mate-choice, offspring fitness, and ultimately population growth. Information on these two subject areas (habitat and mate choice) is of great potential importance to bettering future management strategies (e.g. by manipulating fly numbers based on host preference and reproductive strategies), which are currently limited by lack of knowledge on the biology of this species

Nutritional and Defensive Chemistry of Three North American Ash Species: Possible Roles in Host Performance and Preference by Emerald Ash Borer Adults

Black ash (Fraxinus nigra), green ash (F. pennsylvanica), and white ash (F. americana) are the three most abundant ash species in the northeastern USA. We compared emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), adult performance and preference among seedlings of the three ash species, and then related performance and preference to foli- age nutritional quality and defensive compounds. Longevity of EAB adults reared on green and white ash was found to be greater than on black ash. EAB adult females also seemed to show feeding preference among the three species of ash trees because the total foliage area consumption was greater on green ash and white ash compared to black ash in dual-choice tests; however, the total mass of foliage consumed did not differ. The foliage of all ash species was high in nitrogen and in most macro- and micro-nutrients studied. The patterns of EAB performance and preference did not correspond to any of the individual chemical compounds tested (nitrogen, proteins, most macro- and micro-nutrients, or putative defensive compounds of ash seedlings). Never- theless, greater longevity of EAB adults on green and white ash compared to black ash was probably related to unbalanced nutrients (total nitrogen/total non-structural carbohydrate ratio) of black ash. Putative defensive compounds (i.e., phenolics and protease inhibitors) did not contribute to EAB longevity in this study, probably because (1) EAB adults were able to excrete most of these compounds and (2) their effects were alleviated by high nitrogen levels. More research is needed to elucidate the interactions of nitrogen and carbohydrate levels, and the interactions of nutrient balance and defensive plant allelochemicals on EAB performance and preference

Effects of contaminants of emerging concern on Megaselia scalaris (Lowe, Diptera: Phoridae) and its microbial community.

Drought, rising temperatures, and expanding human populations are increasing water demands. Many countries are extending potable water supplies by irrigating crops with wastewater. Unfortunately, wastewater contains biologically active, long-lived pharmaceuticals, even after treatment. Run-off from farms and wastewater treatment plant overflows contribute high concentrations of pharmaceuticals to the environment. This study assessed the effects of common pharmaceuticals on a cosmopolitan saprophagous insect, Megaselia scalaris (Diptera: Phoridae). Larvae were reared on artificial diets spiked with contaminants of emerging concern (CECs) at environmentally relevant concentrations. Female flies showed no oviposition preference for treated or untreated diets. Larvae exposed to caffeine in diets showed increased mortality, and larvae fed antibiotics and hormones showed signs of slowed development, especially in females. The normal sex ratio observed in M. scalaris from control diets was affected by exposure to caffeine and pharmaceutical mixture treatments. There was an overall effect of treatment on the flies' microbial communities; notably, caffeine fed insects displayed higher microbial variability. Eight bacterial families accounted for approximately 95% of the total microbes in diet and insects. Our results suggest that CECs at environmentally relevant concentrations can affect the biology and microbial communities of an insect of ecological and medical importance

Lack of correlation between constitutive and induced resistance to a herbivore in crucifer plants: real or flawed by experimental methods?

The correlation between constitutive and induced resistance to herbivores in plants has long been of interest to evolutionary biologists, and various approaches to determining levels of resistance have been used in this field of research. In this study, we examined the relationship between constitutive and induced resistance to the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), in 11 closely related species of wild crucifers. We assessed the survival, development, and reproduction of the test insects and calculated their intrinsic rate of increase as an indicator of constitutive and induced resistance for the plants. We used larvae of P. xylostella and jasmonic acid as elicitors of the induced response. We failed to find a correlation between constitutive and induced resistance in these crucifer plants when the induction of resistance was initiated by either herbivory or jasmonic acid application. Analysis of the results suggests that the failure to detect a relationship between the two types of resistance could be caused by flaws in measuring constitutive resistance, which was apparently confounded with induced resistance. We discuss the difficulties and pitfalls in measuring constitutive resistance and ways to improve the methodology in investigating the relationships between constitutive and induced resistance in plant

Visual ecology of aphids – a critical review on the role of colours in host finding

We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms. Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region. We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours that are not likely to hold. Finally we also discuss the implications for developing and optimising strategies of aphid control and monitoring

Diversity and Community Structure of Stream Insects in a Minimally Disturbed Forested Watershed in Southern Illinois

The Lusk Creek Watershed, located in Pope County, IL, long has been rec- ognized as a high quality area of biological significance, but surveys of the stream macroinvertebrate fauna have been limited. Thus, a survey of the benthic insect community at 11 sites in the upper portion of Lusk Creek was conducted from May 2003 to April 2005. A total of 20,888 specimens, mostly immatures, were examined during the study and represented eight orders. The Diptera, by far, was the most abundant order, with 18,590 specimens, almost all of which were members of the Chironomidae or Simuliidae. Members of the EPT (Ephemer- optera, Plecoptera, Trichoptera) contributed 1,550 specimens. The Coleoptera was represented by 647 specimens, most of which were members of Stenelmis (Elmidae) (n = 612). The Shannon diversity index (H ́) ranged from 1.07-2.01 for individual sites and was indicative of relatively undisturbed streams in this region. Jackknife analyses of richness estimated that as many as 37 taxa were unobserved in this survey. Results provide information on reference conditions in the region and a foundation for future monitoring