Green lacewings are insects in the large family Chrysopidae of the order Neuroptera. There are about 85 genera and (differing between sources) 1,300–2,000 species in this widespread group. Members of the genera Chrysopa and Chrysoperla are very common in North America and Europe; they are very similar and many of their species have been moved from one genus to the other time and again, and in the nonscientific literature assignment to Chrysopa and Chrysoperla can rarely be relied upon. Since they are the most familiar neuropterans to many people, they are often simply called "lacewings". Since most of the diversity of Neuroptera are properly referred to as some sort of "lacewing", common lacewings is preferable. Description and ecology Green lacewings are delicate insects with a wingspan of 6 to over 65 mm, though the largest forms are tropical. They are characterized by a wide costal field in their wing venation, which includes the cross-veins. The bodies are usually bright green to greenish-brown, and the compound eyes are conspicuously golden in many species. The wings are usually translucent with a slight iridescence; some have green wing veins or a cloudy brownish wing pattern. The vernacular name "stinkflies", used chiefly for Chrysopa species but also for others (e.g. Cunctochrysa) refers to their ability to release a vile smell from paired prothoracic glands when handled. Adults have tympanal organs at the forewings' base, enabling them to hear well. Some Chrysopa show evasive behavior when they hear a bat's ultrasound calls: when in flight, they close their wings (making their echolocational signature smaller) and drop down to the ground. Green lacewings also use substrate or body vibrations as a form of communication between themselves, especially during courtship. Species which are nearly identical morphologically may sometimes be separated more easily based on their mating signals. For example, the southern European Chrysoperla mediterranea looks almost identical to its northern relative C. carnea (Common Green Lacewing), but their courtship "songs" are very different; individuals of one species will not react to the other's vibrations. Adults are crepuscular or nocturnal. They feed on pollen, nectar and honeydew supplemented with mites, aphids and other small arthropods, and some, namely Chrysopa, are mainly predatory. Others feed almost exclusively on nectar and similar substances, and have symbiotic yeasts in their digestive tract to help break down the food into nutrients. Larvae have either a more slender "humpbacked" shape with a prominent