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
Insect significantly; most noticeably, they do not have the six-legged characteristic of adult insects. The higher-level phylogeny of the arthropods continues to be a matter of debate and research. In 2008, researchers at Tufts University uncovered what they believe is the world's oldest known full-body impression of a primitive flying insect, a 300-million-year-old specimen from the Carboniferous period. The oldest definitive insect fossil is the Devonian "Rhyniognatha hirsti", from the 396-million-year-old Rhynie chert. It may have superficially resembled a modern-day silverfish insect. This species already possessed dicondylic mandibles (two articulations in the mandible), a feature associated with winged insects, suggesting that