Growth exoskeletons

Insect Growth Regulators. These compounds (40—45), unlike most conventional insecticides, interfere with biochemical processes that are unique to arthropods eg, molting, ecdysis, and formation of the chitinous exoskeleton. Therefore, they are selective insecticides with very low mammalian toxicity. 

Christiansen, M.E. and J.D. Costlow, Jr. 1982. Ultrastructural study of the exoskeleton of the estuarine crab Rithropanopeus harrisii effect of the insect growth regulator dimilin (diflubenzuron) on the formation of the larval cuticle. Mar. Biol. 66 217-226. 

Daphnid, Daphnia pulex, daily exposure to crab, 340 in gills, and 70 in exoskeleton 50% elimination in 55 days Increased growth rate 1... 

An inventory of known biomacromolecules is provided in Table 22.3. Many of these play essential metabolic roles in enabling growth and reproduction, such as the carbohydrates, lipids, proteins, and polynucleotides. Others are components of cell walls and exoskeletons. Some organisms, such as bacteria, plankton, plants, and lower invertebrates, synthesize biomolecules, called secondary metabolites, that are used to control ecological relationships, including predator/prey, host/symbiont, mating/spawning, and competition for food or space. 

Structure of /3-ecdysone and juvenile hormone. These hormones play major roles in the growth and maturation of insects by controlling the timing for molting of the insect exoskeleton. 

Chitin Synthesis Inhibitors. These are insect growth regulators that prevent the formation of the insect chitinous exoskeleton and thus produce a critical biochemical lesion during hatching, ecdysis, or pupation (44). These complex biochemical and physiological processes are unique to arthropods therefore, the benzoyl phenyl ureas are highly specific insecticides (44). 

Buddemeier, R.W., Maragos, J.E. and Knutson, D.W., 1974. Radiographic studies of coral reef exoskeletons Rates and patterns of coral growth. J. Exp. Mar. Biol. Ecol., 14 179—200. 

Insects and other arthropods obtain structural support and protection from a cuticular exoskeleton secreted by a single layer of epidermal cells. The stages of growth and development are delineated by deposition, expansion, stabilization and pigmentation of... 

The active ingredient in Sentricon is hexaflumuron, an insect growth regulator that interferes with termites synthesis of chitin, the material that makes up the exoskeleton of insects. Although toxic to fish and not advisable for use where it could be washed out of the bait station into water, the potential for adverse effects on the ecosystem is dramatically reduced compared to previous methods because it is present only in very small quantities in stations with termite activity. 

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