(X 20.) order, showing affinities on the one hand with the Corrodentia (book-lice and biting lice) and on the other with the Hemiptera (cicads, bugs, &c.) .
The nervous system is remarkably concentrated in some beetles, the abdominal ganglia showing a tendency to become shifted forward and crowded together, and in certain chafers all the thoracic and abdominal ganglia are fused into a single nervecentre situated in the thorax, - a degree of specialization only matched in the insectan class among the Hemiptera and some muscid flies.
Other genera of the family are parasitic on Hemiptera - bugs and frog-hoppers - but nothing is known as to the details of their life-history.
Injurious insects occur among the following orders: Coleoptera, Hymenoptera, Lepidoptera, Diptera, Hemiptera (both heteroptera and homoptera), Orthoptera, Neuroptera and Thysanoptera.
By far the most destructive insects in warm climates belong to the Hemiptera, especially to the Coccidae or scale insects.
How would you define hemiptera? Add your definition here.