Crane Fly Identification Keys
Tipulidae is the largest family in the Diptera. According to the classification concept of Charles P. Alexander (as used here), the family Tipulidae includes three subfamilies: Tipulinae, Cylindrotominae, and Limoniinae. Some crane fly specialists recognize four families (Tipulidae, Limoniidae, Cylindrotomidae and Pediciidae) following the classification in the Catalogue of the Craneflies of the World (Oosterbroek 2005).
In North America, most large crane flies belong to the subfamily Tipulinae. These are characterized by having the terminal segment of the maxillary palps slender and longer than the penultimate segment, and the antennae are normally 13-segmented. In the Limoniinae and Cylindrotominae the terminal segment of the maxillary palps is as short as the others, and the antennae usually have 14 to 16 segments.
Crane fly identification has traditionally been based on the comparisons of differences in various morphological characteristics among groups, the presence or absence of certain structures, the relative body size, and especially the variation of the genitalia. Images for diagnostic characters are provided whenever available.
Viewers are advised that the follow identification key is based mainly on characteristics observed on dry mounted crane fly specimens, thus the description of the characters may differ from specimens preserved in liquid. This simplified preliminary key is modified from Alexander (1942; 1967), Alexander and Byers (1981), Byers (1961), and Young (1978). The species included in this key are not exclusive to Pennsylvania. Many have a geographical distribution through out eastern North America.
KEYS TO ADULT CRANE FLIES OF PENNSYLVANIA[* eastern North American species not recorded in Pennsylvania]
- 1A. Wings with a single anal vein (A1) reaching the wing margin 2
- 1B. Wings with two anal veins (A1, A2) reaching the wing margin 5
- 2A(1). Wings with 5 branches of radius vein. [Family Tanyderidae (Primitive crane flies)] Protoplasa fitchii
- 2B(1). Wings with 4 branches of radius vein. [Family Ptychopteridae (Phantom crane flies)] 3
- 3A(2). Antennae with 16 segments; wings with cell M1; legs not patterned with black and white Ptychoptera quadrifasciata
- 3B(2). Antennae with 20 or more segments; wings with cell M1 lacking; legs banded with black and white 4
- 4A(3). Basitarsi of all legs dilated Bittacomorpha clavipes
- 4B(3). Basitarsi not dilated Bittacomorphella jonesi
- 5A(1). Three ocelli present; wings with second anal vein (A2) short and strongly curved at apex and bent suddenly towards the wing margins. Family Trichoceridae (Winter crane flies) Trichocera garretti