A. Hiromi Cule

While the word “bug” is used colloquially to refer to many different types of arthropod, and often used within the common names of un-related arthropods as well, scientists only refer to insects within this order as bugs. Sometimes, to make the distinction between Colloquial Bug and Scientific Bug, the term “true bug” is used. Once, my sister asked me to identify a Leaf-footed Bug (family Coreidae) that was crawling up the wall. I looked at its mouthparts and said “well, it’s definitely a bug” very matter-of-factly, referring to the fact that it was a Hemipteran. I got made fun of for that for a long time after. I still hold common names in a bit of contempt for it (among other reasons). *shakes fist*

The "song" of male cicadas, the loudest of any insect, is produced by tymbal organs on the underside of the abdomen, and is used to attract mates. The tymbals are drumlike disks of cuticle, which are clicked in and out repeatedly, making a sound in the same way as popping the metal lid of a jam jar in and out.

Cicadas have featured in literature since the time of Homer's Iliad, and as motifs in decorative art from the Chinese Shang dynasty (1766–1122 B.C.). They are described by Aristotle in his History of Animals and by Pliny the Elder in his Natural History; their mechanism of sound production is mentioned by Hesiod in his poem Works and Days "when the Skolymus flowers, and the tuneful Tettix sitting on his tree in the weary summer season pours forth from under his wings his shrill song".

Hemipterans that feed on plant sap are sometimes specialized to feed on either plant phloem or plant xylem, so much so that this is a part of their classification. Phloem feeding bugs typically have symbiotic micro-organisms in their gut that help to convert amino acids. Phloem feeders produce honeydew from their anus. A variety of organisms that feed on honeydew form symbiotic associations with phloem-feeders. Phloem sap is a sugary liquid low in amino acids, so bugs have to process large quantities to meet their nutritional requirements. Xylem sap is even lower in amino acids and contains monosaccharides rather than sucrose, as well as organic acids and minerals. No digestion is required (except for the hydrolysis of sucrose) and 90% of the nutrients in the xylem sap can be utilised.

Some leafhoppers (suborder Auchenorrhyncha) are "milked" by ants. In the Corcovado Rainforest of Costa Rica, wasps compete with ants to protect and milk leafhoppers. The leafhoppers preferentially give more honeydew, and more often, to the wasps, which are larger and may offer them better protection.

Several Heteropteran families are adapted to an aquatic lifestyle, such as the water boatmen (Corixidae), water scorpions (Nepidae), and backswimmers (Notonectidae). They are mostly predatory, and have legs adapted as paddles to help the animal move through the water. Water bugs in the genus Microvelia (Veliidae) can travel at up to 17 cm/s, twice as fast as they can walk on land, by releasing a soap-like surfactant on the water surface. The water striders (Gerridae) are also associated with water, but use the surface tension of standing water to keep them above the surface; they include the sea skaters in the genus Halobates: the only truly marine group of insects.

Parental care is found in many species of Hemiptera, especially in members of the Membracidae and numerous Heteroptera. In many species of shield bug, females stand guard over their egg clusters to protect them from egg parasitoids and predators. In the aquatic Belostomatidae, females lay their eggs on the back of the male, who guards the eggs.

I am making a conscious choice to not include Bug Sex Facts™ about bed bugs; y’all can do that on your own…

While many of the plant-sucking bugs are considered pests in agriculture, some of the predatory species are used as biological pest control, including some species of assassin bug (family Reduviidae), damsel bugs (family Nabidae), and big-eyed bugs (genus Geocoris) who predate on many types of crop pest.

While scale insects (infraorder Coccomorpha) are often considered serious pests in both the farming and houseplant industry, some species have long been used by humans for commercially valuable substances. The Indian Lac Bug (Kerria lacca) is the main source of lac, a resin which can be refined into shellac and other products. Female Lac Bug nymphs crawl along the branches of their host plants and feed on the phloem. As they pierce the branches to reach the phloem, they cover the holes with their wax secretions. Raw shellac, which contains bark shavings and Lac Bugs, is scraped off of trees, placed in canvas tubes, and heated over a fire. This causes the shellac to liquefy, and it seeps out of the canvas, leaving the bark and bugs behind. The thick, sticky shellac is then dried into a flat sheet and broken into flakes, or dried into "buttons", then bagged and sold. The user can then crush it into a fine powder and mix it with ethyl alcohol before use, to dissolve the flakes and make liquid shellac. Shellac can be used as a brush-on collorant, food glaze, wood finish, primer, sanding sealant, tannin-blocker, odor-blocker, stain, and high-gloss varnish. Shellac was once used in electrical applications as an insulator to seal out moisture, and phonograph and 78 rpm gramophone records were made of shellac until it was replaced by vinyl. The True Cochineal Bug (Dactylopius coccus) is a scale insect that feeds on prickly pear cacti (genus Opuntia). The insect produces carminic acid that deters predation by other insects. Carminic acid, typically 17–24% of dried insects' weight, is extracted from the body and eggs, and mixed with aluminium or calcium salts to make carmine dye, also known as cochineal. It takes about 70,000 Cochineal Bugs to make 1 pound (0.45 kilograms) of carmine dye. Today, carmine is primarily used as a colorant in food and in lipstick (where it is labeled as E120 or Natural Red 4). Carmine replaced Kermes, a red dye derived from Kermes vermilio and other scale bugs in the genus Kermes. These insects were used as a red dye since antiquity by the ancient Egyptians, Mesopotamians, Indians, Greeks, Romans, and Iranians. The dye also served a number of ritual and practical purposes in the Hebrew Bible. Kermes has good colour fastness in silk and wool. It was much esteemed in the medieval era for dyeing silk and wool, particularly scarlet cloth.

Many aphids (family Aphididae) are capable of parthenogenesis: producing young from unfertilised eggs. A typical life cycle involves flightless females giving live birth to female nymphs, who may also be already pregnant, an adaptation scientists call telescoping generations, without the involvement of males. This allows females to breed profusely and make full use of a resource in times of plenty. Later in the season, once resources begin to dwindle, winged females may begin to develop, allowing the population to colonize new plants. In temperate regions, sexual reproduction will begin to occur in the autumn, with the last generation of aphids laying eggs that will overwinter to hatch the next year’s brood.