which diseases are spread by them?
Chagas disease
Hemiptera
Chagas disease 
what is a unique characteristics of insects in the order hemiptera check all that apply The group is very diverse. The majority of species are terrestrial, including a number of important agricultural pests, but some are found in freshwater habitats. how do they produce sound? Many hemipterans can produce sound for communication. 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. can they swim? Yes, several families of Heteroptera are "water bugs", adapted to an aquatic lifestyle
wiki:19554250
Hemiptera [SEP] As human parasites and disease vectors
Chagas disease is a modern-day tropical disease caused by "Trypanosoma cruzi" and transmitted by kissing bugs, so-called because they suck human blood from around the lips while a person sleeps. The bed bug, "Cimex lectularius", is an external parasite of humans. It lives in bedding and is mainly active at night, feeding on human blood, generally without being noticed. Bed bugs mate by traumatic insemination; the male pierces the female's abdomen and injects his sperm into a secondary genital structure, the spermalege. The sperm travel in the female's blood (haemolymph) to sperm storage structures (seminal conceptacles); they are released from there to fertilise her eggs inside her ovaries.