Alternatively, it might suggest that a quasi-equilibrium between 7DHC and its photoproducts had been reached, as occurs in vertebrate skin to prevent overproduction of previtamin D, or that photodegradation of formed vitamin D was taking place 6 , Future studies should determine which vitamin D metabolites are formed and whether these metabolites have a function in insects. This study indicates that: 1 migratory locusts, house crickets and yellow mealworms can synthesise vitamin D 3 de novo after UVb exposure, but attain different concentrations, 2 higher vitamin D levels can be attained with exposure to higher UVb intensities, and 3 vitamin D 3 levels in yellow mealworms increase until a maximum concentration is reached during prolonged UVb exposure.
Three experiments were conducted. In the first experiment, four insect species were exposed to a lamp which emitted a low UVb irradiance. In the second experiment, these four species were exposed to a lamp which emitted a higher UVb irradiance. In the third experiment, one insect species was exposed to the same UVb lamp as in the second experiment, but for different durations.
In the first two experiments migratory locusts Locusta migratoria L. The first two species were provided by a commercial insect rearing company Kreca, Ermelo, the Netherlands and the latter two species were obtained from colonies maintained at the Laboratory of Entomology, Wageningen University, Wageningen, the Netherlands. In both these experiments the insects were subjected to one of two treatments; UVb exposed or UVb unexposed. In the third experiment only yellow mealworms were used. All species were housed in enclosures proven suitable in prior investigations and provided with amounts of feed that allowed ad libitum feeding throughout the study 53 , Due to differences in housing and nutrient requirements, both the enclosures and provided diets differed between species.
Five replicates were used per treatment. Grass that had dried out was removed. The locusts developed large wings indicating adulthood after 21days in the first experiment and after 33 days in the second experiment. They were then manually taken from their cages. In the first experiment the crickets were provided with a chicken feed diet Opfokmeel farmfood; Agruniek Rijnvallei Voer B.
Drinking water was provided via a water dispenser Gebroeders de Boon, Gorinchem, the Netherlands with a piece of paper tissue placed in the opening to prevent drowning. In both experiments most crickets reached the adult stage as indicated by the formation of large wings, after 31 days. They were then taken from their cages by hand. Five replicates per treatment were used in the first experiment, and three replicates were used in the second experiment.
In the first experiment the larvae were provided with a chicken feed diet Opfokmeel farmfood; Agruniek Rijnvallei Voer B. In both experiments the first BSF reached the pre-pupal stage after seven days, as shown by the darkening of their integument. All BSF were then taken from their container rinsed with tap water to remove adhering feed residues, and subsequently dried on paper towels. Half of the specimens for each of the four species in experiment 1 and 2 were allocated to a treatment exposed to UVb, whereas the other half were allocated to a control treatment not exposed to UVb.
The lamps used in all three experiments had a similar spectral power distribution across visible wavelengths, but the UV irradiance was higher in the lamps used in the second and third experiment Fig. The minimum distance between the UV lamps and the insects differed between species due to differences in cage dimensions; for the migratory locusts and BSFL this was 8. The outside of all enclosures were covered with dark plastic to prevent stray light, including UVb, from entering.
For the migratory locusts, house crickets and yellow mealworms, the UV compact lamps were randomly rotated between the experimental treatment cages every three days, to correct for potential differences in UVb output between individual lamps. For the BSFL, which have a shorter life cycle, lamps were rotated daily. In the third experiment the influence of UVb exposure time on vitamin D content was determined. For this, One sample was analysed per time point. UVb irradiance and UV index of all lamps were determined every five days.
Measurements were taken perpendicular to the lamps at the minimum distance between the insects and the lamps See Animal housing and feeding. Enclosure temperatures during the day were measured by means of an infrared thermometer Model DTG, Reptile Technologies, Gorinchem, the Netherlands. At the start of the experiments samples were taken from all four species and their feed, and analysed in duplo for vitamin D 2 and D 3.
Insect samples stemming from each replicate in the three experiments were analysed in simplo for vitamin D 2 and D 3. In short, after the addition of an internal standard vitamin D 2 and basic hydrolysis, vitamin D 3 was extracted with di-isopropyl ether. A separate test portion was analysed in parallel to confirm the absence of endogenous vitamin D 2.
In short, an internal standard solution with deuterated vitamin D 2 and vitamin D 3 was added to a ground, homogenised sample. The sample was hydrolysed with ethanolic potassium hydroxide and vitamin D was extracted with di-isopropyl ether. The extract was evaporated, re-dissolved in methanol and vitamin D 2 and D 3 were analysed simultaneously using UPLC with tandem mass-spectrometry.
The two methods above provide information on total vitamin D concentrations without distinguishing between their esterified and non-esterified forms. No tachysterol was detected, and peak purity of vitamin D was confirmed. Temperature and UV data were analysed with a paired sample t-test.
Vitamin D data which were normally distributed and had equal variances were analysed via an independent sample t-test, else a Mann-Whitney U test was used. If vitamin D concentrations were below the limit of detection, this detection limit was used for statistical analysis. Reichrath, J. Vitamins as hormones. Holick, M. Vitamin D: a millenium perspective. Norman, A. From vitamin D to hormone D: fundamentals of the vitamin D endocrine system essential for good health. Huldschinsky, K. Curing rickets by artificial UV radiation.
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Kamen, D. Vitamin D and molecular actions on the immune system: modulation of innate and autoimmunity. Vitamin D deficiency. New Engl. Vitamin D and the skin: an ancient friend, revisited. Finke, M. Complete nutrient content of three species of wild caught insects, pallid-winged grasshopper, rhinoceros beetles and white-lined sphinx moth. Melo-Ruiz, V. Assessment of nutrients of escamoles ant eggs Limotepum apiculatum M.
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Entomophagy - Wikipedia
Buchala, A. Vitamin D and its analogues as a new class of plant growth substances affecting rhizogenesis. We are taught to be careful as children; we are cautioned that wasps will sting us, that flies carry diseases, and that beetles can bite. Even bees are to be treated with caution: their honeyed gifts are paired with a non-so-sweet stinger. These messages are often reinforced through chance encounters with insect members of the natural world.
For example, at the age of three, I disturbed a nest of red ants. I was insatiably curious even at early age and I wanted to know where the ants went after they went into the ground. So I dug the nest up. Or tried to. The red ants swarmed angrily out of the ground and over my chubby, bare feet. My screams brought half the neighborhood running. I learned that insects—all insects—are generally bad and harbor a general dislike for ants. I also learned that observation would get me farther in nature but that is a story for another day.
These ideas carry over into popular culture. In The Deadly Mantis a foot long praying mantis awakes from a frozen slumber and requires military intervention to bring down. A bevy of insects descend from a parallel world in small-town Maine to plague residents in The Mist And then there is of course Empire of the Ants. We aren't culturally inclined to distinguish between good insects and bad insects.
And I don't know that we care to make this distinction. Insects are different —they're like miniature monsters with their antennae and pincers and multiple appendages. By casting them all as "bad," they're easier to deal with. It wasn't until I began gardening this year that I really began to recognize the beneficial insects living in my backyard. Or understand the ways they respond to the ecology that I am cultivating.
Research by Heather Looy suggests that I am in a minority: most American farmers view insects as pests. When faced with concerns about productivity, any possible pestilent threat to the harvest needs to be eradicated, which often means pesticides. And while chemical products work, they don't discriminate. Consequently, good bugs and bad bugs are eliminated together which can cause devastating ecological shifts.
We know that pesticides can accumulate and trickle down the food chain, but entomophagy often drives the most extreme solutions. In non-Western cultures insects are an important food source, providing proteins, fats, vitamins, minerals, and fiber. Where eating insects is a norm, people can tell the difference between good insects and bad insects and identify seasonal differences in arthropodal food choices when to harvest larval states, which adults to avoid, etc.
However, what's becoming clear is that as Western cultural ideas have spread, the potential for this food option is shrinking. In the West African country of Mali, it was common for children to forage for grasshoppers among the crops grown by their families. Their diets consist of millet, sorghum, maize, peanuts and some fish, so grasshoppers were an important source of protein Looy However, when their families began to grow surplus crops and make use of pesticides, parents began to actively discourage their children from eating grasshoppers, which means that they're now short of an important protein option.
Elsewhere in the ethnographic record, Looy documents hesitation by locals to discuss their entomophagic tendencies with outsiders out of fear of being judged or misunderstood. The United Nations Food and Agriculture Organization reports that between an estimated million people suffered from undernourishment. This number largely represents the populations of developing countries, where economic and political tensions contribute to limited access to food resources more so than scarcity.
In light of this, are we overlooking an important food source in insects? Sorkin was quick to note the squeamishness of some audience members as he worked his way through slides showing infestations—though he did try to assure the group that most would be quite tasty if cooked in light oil with garlic, salt, and pepper.
Or infused with some sort of citrus. Not too many people seemed convinced, which was hardly surprising given our relationship with food. Food plays a huge role in cultural and social identity. For example, following the dismantling of the Soviet Union the emergence of the Soviet sausage in Lithuania was a reminder of a shared history. In Eastern Europe, the "Soviet period" was regarded locally and globally as an era of oppression and want, and minimal cultural growth.
Seeking to distance themselves from this past, new governing bodies and their citizenry changed street names, laws and history. Nonetheless, anthropologist Neringa Klumbyte reports that in the face of this public denouncement, "Soviet sausages" began appearing on dinner tables in They were fully advertised as a "Soviet" product—and all the things that the Soviet Union represented were wrapped in that casing. While politicians opposed the meats and cast them as threat to the values of the emerging state, Lithuanian customers swore that these were the tastiest option available to them.
Their enthusiasm crafted a niche for the sausages, which were held as symbols of innovation and luxury in the face of stark conditions. As a mass produced food, the humble sausage was an accessible food item, made under consistent conditions regardless of the person who purchased them. In the s and s they were viewed as symbols of modernity and marketed to the bourgeois under the label of pleasure and well-being. When "Soviet sausages" emerged in the post-Soviet era, Lithuanians claimed a piece of themselves as they navigated the boundaries of what it meant to be Lithuanian in the eyes of a non-Soviet global community.
You can read more about Soviet sausages and identity here.
It's a pattern that's repeated throughout the world: food plays a strong part in social and cultural identity. Daniel Miller has written extensively about the relationship Trinidadians have with Solo-brand soft drinks. These sweetened soft drinks have a niche market among Trinidadians, who are exposed to them from an early age.
In Trinidadian immigrant communities, these drinks are a staple in shops, helping to connect people with their homelands, beliefs, and the family and friends they have left behind. And reminding them of what they believe to be "Trinidadian". We take in nutrients from our foodstuffs, but we also absorb the associations connected with it.
It is not that sausages make you more Lithuanian or Solo brand drinks make you more Trinidadian, but they have become linked to local culture and local experiences. These items can instantly connect you with friends and family and experiences in ways that are meaningful to a larger collective. Hot dogs and hamburgers help us identify with popular American activities such as baseball and cook-outs. Steak and oysters can suggest wealth because they are expensive to produce and purchase.
Organic foods may help communicate a commitment to environmental awareness. In this context eating insects seems base. It's a last resort act that suggests you don't have the means to access sanctioned food items. There is a mythology around prepackaged food. It's clean and packaged attractively. It's sanctioned—someone has approved it for consumption. Who that someone is matters less for some.
Related Insect Diets : Science and Technology, Second Edition
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