Gall-inducing insect Gall-inducing insect A gall-inducing insect is any insect that can cause the growth of galls within plants. The term gall fly is also used to cover these species, although most are not true flies. There are several groups of insects that meet this description. They include the gall wasps, scales, gall midges, aphids, psyllids and certain species of leafminer flies. Galls are growth deformities induced in certain plants by various insects which are mostly species-specific. The gall's form or type depends on what organism is attacking the plant and where the plant is being attacked. Based on the form, there
Ant to burst from the anterior region of its head, spraying a poisonous, corrosive secretion containing acetophenones and other chemicals that immobilise small insect attackers. The worker subsequently dies. Suicidal defences by workers are also noted in a Brazilian ant, "Forelius pusillus", where a small group of ants leaves the security of the nest after sealing the entrance from the outside each evening. In addition to defence against predators, ants need to protect their colonies from pathogens. Some worker ants maintain the hygiene of the colony and their activities include undertaking or "necrophory", the disposal of dead nest-mates. Oleic acid has