An occasional series by AntLab Parataxonomist: Brittany Benson
Cicadellidae
Hind tibiae with 1 or more rows of small spines – this is the main thing separating this family from the other Cicadoidea families.
Commonly called leafhoppers, there are about 3,000 North American species, around 22,000 worldwide. They can vary in size from 2mm to 30mm, but most stay under 13mm. These are hemimetabolous insects, so their nymphs look like miniature versions of the adults, but with different proportions (usually larger heads), and the wings have not developed yet – again, do not mistake the developing wing pads for wings. Wings will be as long or longer than the body, where the wing pads leave much or most of the abdomen exposed.
Occurring on nearly all types of plants – trees, shrubs, grasses, fields, gardens – the leafhoppers can be found in about every habitat that has vascular plants, as varied as deserts and wetlands.
They feed mainly on the leaves of their host plant, most species being quite specific, so habitat for a species can also be well defined. Many act as vectors for plant diseases.
Plenty of them emit honeydew from their anus. Yummy! It’s a cocktail made from unused plant sap and the insect’s own special waste products. Surprisingly, there are few known instances of ants tending these fru fru drink specialists. One Brazilian species was observed to be tended by up to 21 different ant species, but it seems as though it is an opportunistic relationship. But another example, that of Dalbulus quinquenotatus, shows that some are complete myrmecophiles – this species will allow ants to approach, and when the ants stroke them with their antennae, the leafhopper nymphs will secrete a honeydew droplet and hold it in place until an ant takes it. Nonattended species of Dalbulus will avoid ants by walking away, hopping, or jumping. The droplets of the ant-loving species are also much larger and more frequently excreted than in other species.
Many can produce sound, but they are weak sounds (at least to us, and we should totally judge the strength of other and utterly different creatures to that of our own). These sounds are produced by vibrating timbals on the dorsolateral base of the abdomen. Tymbals are thin-walled bits of the body wall. They can be sounds of disturbance, courtship, and lady sounds, but all the sounds appear to be species specific.