The non-infectious diseases are those in which no living micro-organism is involved. Such diseases are often considered as injuries caused by:
The mechanical injuries that may affect insects are usually of two types:
Distension results when a digestive tract or Malpighian tubules is obstructed to prevent the flow of its contents.
Trauma results from the cutting, crushing and tearing of tissues and organs. The wounds or injuries usually affect the insect by damage to the tissues and organs, loss of blood (hemolymph), and exposure to pathogens at the site of injury. There are various kinds of trauma, such as bruises from injurious contact with a blunt object, concussions through jarring, crushing due to excessive pressure, cutting by sharp instruments, tearing by the forceful pulling apart of structures and puncturing from sharp or pointed objects.
Amputations of important structures, such as antennae, may to a considerable extent alter the insect's behaviour.