As in other animals, the color of insects serves to conceal them from predators (some- THE INTEGUMENT times through mimicry), frighten or "warn" predators that potential prey is distasteful, or facilitate intraspecific and/or sexual recognition. It may be used also in thermoregulation. The color of an insect generally depends on the integument. Rarely, an insect's color may be the result of pigments in tissues or hemolymph below the integument. For example, the red color of Chironomus larvae is caused by hemoglobin in solution in the hemolymph. Integumental colors may be produced in two ways. Pigmentary colors are produced when pigments in the integument (usually the cuticle) absorb certain wavelengths of light and reflect others (Fuzeau-Bresch, 1972). Physical (structural) colors result when light waves of a certain length are reflected as a result of the physical features of the surface of the integument.

Pigmentary colors result from the presence in molecules of particular bonds between atoms. Especially important are double bonds such as C=C, C=O, C=N, and N=N which absorb particular wavelengths of light (Hackman, 1974; Kayser, 1985). The integument may contain a variety of pigment molecules that produce characteristic colors. Usually the molecule, known as a chromophore, is conjugated with a protein to form a chromo-protein. The brown or black color of many insects results usually from melanin pigment. Melanin is a molecule composed of polymerized indole or quinone rings. Typically, it is located in the cuticle, but in Carausius it occurs in the epidermis, where it is capable of movement and may be concerned with thermoregulation as well as concealment. Carotenoids are common pigments of phytophagous insects. They are acquired through feeding as insects are unable to synthesize them. Carotenoids generally produce yellow, orange, and red colors, and, in combination with a blue pigment, mesobiliverdin, produce green. Examples of the use of carotenoids include the yellow color of mature Schistocerca and the red color of Pyrrhocoris and Coccinella. Pteridines, which are purine derivatives, are common pigments of Lepidoptera, Hymenoptera, and the hemipteran Dysdercus, and produce yellow, white, and red colors. Ommochromes, which are derivatives of trypto-phan, an amino acid, are an important group of pigments that produce yellow, red, and brown colors. Examples of colors resulting from ommochromes are the pink of immature adult Schistocerca, the red of Odonata, and the reds and browns of nymphalid butterflies. In some insects the characteristic red or yellow body color is the result of flavones originally present in the foodplant. Uric acid, the major nitrogenous excretory product of insects (Chapter 18, Section 3.1), is deposited in specific regions of the epidermis in some insects. For example, in Dysdercus it is responsible for the white areas of the integument.

Physical colors are produced by scattering, interference, or diffraction of light though the latter is extremely rare. Most white, blue, and iridescent colors are produced using the first two methods. White results from the scattering of light by an uneven surface or by granules that occur below the surface. When the irregularities are large relative to the wavelength of light, all colors are reflected equally, and white light results. An interference color is produced by laminated structures when the distance between successive laminae is similar to the wavelength of light that produces that particular color. As light strikes the laminae light waves of the "correct" length will be reflected by successive surfaces, and the color they produce will therefore be reinforced. Light waves of different lengths will be out of phase. Changing the angle at which light strikes the surface (or equally the angle at which the surface is viewed) is equivalent to altering the distance between laminae. In turn,

370 this will alter the wavelength that is reinforced and color that is produced. This change of color in relation to the angle of viewing is termed iridescence. Iridescent colors are common CHAPTER 11 . , „ ..

in many Coleoptera and Lepidoptera.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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