Insect bites and stings Insect bites and stings Insect bites and stings occur when an insect is agitated and seeks to defend itself through its natural defense mechanisms, or when an insect seeks to feed off the bitten person. Some insects inject formic acid, which can cause an immediate skin reaction often resulting in redness and swelling in the injured area. Stings from fire ants, bees, wasps and hornets are usually painful, and may stimulate a dangerous allergic reaction called anaphylaxis for at-risk patients, and some wasps can also have a powerful bite along with a sting. Bites from mosquitoes and fleas are more
Insect diuretic hormones Insect diuretic hormones Insect diuretic hormones are hormones that regulate water balance through diuretic action. The insect excretory system, responsible for regulating water balance in the insect, comprises the Malpighian tubules and the hindgut (the ileum and rectum). Malpighian tubules secrete primary urine, most of which is passed into the hindgut where water, ions and essential metabolites are reabsorbed before the fluid is excreted. Excretion is under the control of diuretic and anti-diuretic factors, or hormones, comprehensively reviewed by Coast et al. (2002). These factors are produced in neurosecretory cells in the insect nervous system, and stored and released from