The skippers are a worldwide family of about 3500 species that appear to be "sister" to the rest of the "true butterflies". The clubs on the tips of the antennae are usually hooked. Our California skippers fall into two or three subfamilies: the spread-wing skippers (Pyrginae), the folded-wing skippers (Hesperiinae), and the Heteropterinae.
The spread-winged skippers are generally dark brown and hold both sets of their wings open when landed. They use a wide variety of hostplants, including oaks, Ceanothus, legumes, mallows, and even saltbush. California genera include Pyrgus, Heliopetes, Erynnis, Thorybes, Epargyreus, and Pholisora.
The folded-wing skippers have a characteristic posture when they land: the forewings are held at a 45o angle to the rest of the body while the hindwing is held open and flat. This gives them a "fighter-jet" like appearance. They are largely orange and tawny, and many have whitish chevrons on the ventral hindwing, although some genera are dark brown. All members of this group feed on grasses or grassy-like plants (like sedges and rushes) as caterpillars, and as a result, they are often called the grass skippers. California genera include Hesperia, Ochlodes, Polites, Poanes, Hylephila, Lerodea, Amblyscirtes, and Atalopedes.
A third subfamily, the Heteropterinae, is weakly differentiated from the other skipper subfamilies, but the lone California representative is distinctive: Carterocephalus palaemon.
With about 6000 species worldwide, the morphological diversity within the brushfoots is immense. There have been decades of debates about how to classify the group and what traits are important and useful. For our purposes, the uniting characteristic of the brushfoots is the reduction of the front pair of legs into small, brush-like appendages that serve no real function, rather like the human appendix or tailbone. As a result, while they still have 3 pairs of legs (an insect characteristic), only two of those leg pairs are actually functional. Brushfoots are some of our largest and recognizable butterflies, including the monarch (Danaus plexippus), painted lady (Vanessa cardui), California tortoiseshell (Nymphalis californica), and mourning cloak (Nymphalis antiopa).
The Gossamer-wings are a very diverse and complex family with at least 4750 species worldwide. In California, they can be grouped into the coppers (subfamily Lycaeninae), the blues (subfamily Polyommatinae), and the hairstreaks (subfamily Theclinae). Many species have mutualistic relationships with ants (myrmecophily) where the caterpillar excretes complex carbohydrates through specialized glands for the ants (similar to aphids). In return, the ants defend the caterpillar from predators and parasitoids. While this relationship is usually facultative, the mutualism turns into trickery in some Lycaenid species and the butterfly caterpillars switch from being herbivores to become obligate predators on ant larvae inside the ant mound. As long as the caterpillar continues to produces sugary rewards for the ants, the ants are willing to accept, or are oblivious to, the carnage around them. Other Lycaenid caterpillars are predators on aphids being tended by ants.
This family contains the largest and some of the most recognizable of all California butterflies. There are about 600 species worldwide. The swallowtails (subfamily Papilioninae) usually have at least one set of long tails on the hindwings and have stripes of black and yellow or white. Our genera are Battus and Papilio. The parnassians (subfamily Parnassiinae), also sometimes called Apollos, lack tails and are ghostly transluscent white or yellow-white with black and red spots: not your typical swallowtail. Our two Parnassius species are the only California representatives of this relatively small group.
Pierids are rather conspicuous white, yellow, or orange butterflies, with around 1000 species worldwide. They primarily feed on plants in the legume and crucifer families, although some odd groups, like our Neophasia menapia, feed on conifers. Some Pierids, especially Colias sulphurs and Pieris whites, have taught us much about species recognition (based on ultraviolet reflectance patterns) and seasonally-induced polymorphism and phenotypic plasticity.
The Metal-marks are a dramatically colored and patterned, and consist of at least 1250 species. Most of these small butterflies are Neotropical in distribution, and only one species ranges into central California. Like the Gossamer-wings, many metal-marks are myrmecophilous.