A number of aposematic butterfly and diurnal moth species sequester unpalatable or toxic substances from their host plants rather than manufacturing their own defensive substances. Despite a great diversity in their life histories, there are some general features in the selective utilization of plant secondary metabolites to achieve effective protection from predators. This review illustrates the biochemical, physiological, and ecological characteristics of phytochemical-based defense systems that can shed light on the evolution of the widely developed sequestering lifestyles among the Lepidoptera.

Sequestration of defensive substances from plants by Lepidoptera.

Sequestration of Plant Natural Products by Insects

This chapter is concerned with physiological factors that control levels of flavonoids accumulating in plants and with the biological implications of these accumulations both within the plant and in plant-animal (1ncluding man) interactions. Levels of flavonoids within plants are a reflection of the efficiency of biosynthesis (see Chapter 16) tempered by turnover and degradation (Chapter 17) during growth and development. These are all influenced by the external environment. The functions of flavonoids may be approached by a consideration of their general reactivity when introduced into biochemical systems, the many implications of their pigment characteristics, their possible mediation in plant growth and development, and their effects on animals and microorganisms.

https://link.springer.com/content/pdf/10.1007%2F978-1-4899-2909-9_18.pdf

Physiology and Functions of Flavonoids

A variety of commercially raised insects are fed to insectivorous reptiles, but information concerning appropriate diets used to feed these insects is limited. In the present study, house crickets (Acheta domesticus adults and nymphs), mealworms (Tenebrio molitor larvae), and silkworms (Bombyx mori larvae) were fed diets containing graded levels of calcium (Ca) and/or vitamin A–nutrients that are low or absent in most insects. Diets and insects were analyzed for moisture, Ca, phosphorus (P), and vitamin A. For adult crickets and cricket nymphs, body Ca and vitamin A concentrations increased in a linear fashion with increasing levels of dietary Ca or vitamin A. Ca concentrations of silkworms also increased in a linear fashion with increasing levels of dietary Ca. For mealworms, body Ca and vitamin A concentrations increased in a nonlinear fashion with increasing levels of dietary Ca or vitamin A. These regression equations, in conjunction with insect nutrient composition, allow for the calculation of the optimum nutrient concentration for gut-loading diets. Final recommendations were based on National Research Council (NRC) requirements for rats, adjustments for the energy content of the insects, and nutrient overages as appropriate. Gut-loading diets for crickets (adults and nymphs) should be supplemented to contain the following nutrients, respectively: Ca (51 and 32 g/kg), vitamin A (8,310 and 5,270 mg retinol/kg), vitamin D (300 and 190 mg cholecalciferol/kg), vitamin E (140 and 140 mg RRR-a-tocopherol/kg), thiamin (31 and 21 mg/kg), and pyridoxine (20 and 10 mg/kg). Gut-loading diets for mealworms should be supplemented to contain the following nutrients: Ca (90 g/kg), iron (51 mg/kg), manganese (31 mg/ kg), vitamin A (13,310 mg retinol/kg), vitamin D (460 mg cholecalciferol/kg), vitamin E (660 mg RRR-a-tocopherol/kg), thiamin (5 mg/kg), vitamin B12 (650 mg/kg), and methionine (29 g/kg). Gut-loading diets for silkworms should be supplemented to contain the following nutrients: Ca (23 g/kg), iodine (0.7 mg/kg), vitamin D (140 mg cholecalciferol/kg), vitamin E (70 mg RRR-a-tocopherol/kg), and vitamin B12 (226 mg/kg). Zoo Biol 22:147–162, 2003. � c 2003 Wiley-Liss, Inc.

Gut loading to enhance the nutrient content of insects as food for reptiles: A mathematical approach

Flavonoids and insects

Carotenoids in 38 species of Lepidoptera have been examined qualitatively and quantitatively. Comparisons are made between cryptic and aposematic species, pupae and adult, dried and fresh material, males and females, and certain polymorphic species. Although some selective storage is demonstrated, Lepidoptera chiefly store the carotenoids present in their food plants unchanged. It was found that the Large White (Pieris brassicae), a toxic species, stored more carotenoids than the less toxic Small White (P. rapae) while ab. coerulea (P. brassicae) contained only 25 % of the carotenoids found in typical specimens.

Carotenoids in thirty‐eight species of Lepidoptera

FLAVONOIDS are rare in the animal kingdom, but Ford1, using a simple colour test, suggested that they were present in a number of butterflies. A difficulty in characterizing the pigments is the fact that a large number of specimens, of the order of hundreds, is required, and it is not always possible to obtain one species in such large numbers. Morris and Thomson2, using some 400 specimens, identified tricin and a glycoside of this flavone as well as a glycoside of another flavone, orientin, from the wings of the marble white butterflies Melanargia galathea. They found3 that the small heath butterflies Coenonympha pamphilus contained tricin both free and as glycoside but not orientin. The flavonoids seem to be obtained by the insects through the caterpillars feeding on a particular food host. Carotenoids, on the other hand, are well known in animals, and Goodwin4 has suggested that insects accumulate their dietary carotenoids as such or that they may be altered to form other carotenoids not found in the insects' food. A number of specimens of the common blue butterfly Polyommatus icarus Rott. were collected both in France and in England with a view to characterizing the flavonoids and the carotenoids and to comparing these with their food plants. One hundred specimens of P. icarus from Box Hill, Surrey, were feeding on rest harrow Ononis repens and those from St Martial, France (800 specimens), on a species of Anthyllis; both plants are members of the Leguminosae.

Plant Pigments identified in the common blue butterfly.

http://portlandpress.com/biochemsoctrans/article-pdf/2/5/1061/507545/bst0021061.pdf

John Feltwell

Papers

Carotenoids in thirty‐eight species of Lepidoptera

Plant Pigments identified in the common blue butterfly.

The Relationship between Carotenoids of Certain Lepidoptera and Coleoptera and of their Food Plants