Characteristics
Species of Hendelia Czerny usually range from 3.0-5.3 mm (rarely less than 3.5 mm) in length, but several tropical Old World species are 2.3-2.5 mm and are among the smallest clusiids. Like members of its sister-genus Clusiodes, Hendelia species have reduced anterior and posterior fronto-orbitals, interfrontal bristles, well developed medial genal bristles, swollen spermathecal ducts, a large subapical disc on the ventral receptacle, a longitudinal desclerotization on the female seventh sternite, a crested fin-like phallapodeme, a distiphallus that is rod-like basally with a membranous distal section and an elongate pregonite that is perpendicular to the long axis of the hypandrium (Lonsdale & Marshall, 2007b).

Hendelia is defined on the basis of male genitalic characters (perianal area longer than wide; surstylus usually small, lobate and perpendicular to the long axis of the epandrium; ejaculatory apodeme widest apically), but is nonetheless easily recognized and distinguished  from the similar Clusiodes by diagnostic ancestral states: the arista is variably plumose or laterally compressed (never pubescent); the male fore and mid femora have one anterior and one posterior row of ventral ctenidial bristles (never two posterior rows); and the scutum never has white lateral stripes (Lonsdale & Marshall, 2007b). Furthermore, strongly modified heads are characteristic of many species in the genus (see below) and have likely developed independently numerous times.

Distribution & Relationships
Hendelia
, with 44 described species (Lonsdale & Marshall, 2007c), has a mostly pantropical and south-temperate distribution in contrast with it sister genus, the north temperate Clusiodes.  The type species of Hendelia (H. beckeri Czerny) is an exception to this distributional pattern because it is widespread in the Palaearctic.  Hendelia beckeri is also an unusual species morphologically. The sexes are highly dissimilar (they were previously classified as different species) and look very different from other Hendelia. This has caused much confusion in clusiid classification over the past 40 years and led to a proliferation of unnecessary genus-level names, which have only recently been straightened out. Lonsdale & Marshall (2007b) redefined Hendelia, expanding the generic concept to include 33 of the species previously treated as Clusiodes (almost all the tropical and south temperate species previously treated as Clusiodes), Prohendelia Frey, Xenoclusia Frey and several other genus-level names.

Biology
Caloren & Marshall (1998) recently described the behaviour, biology and faunistics of the New World Clusiodes and Hendelia, and Roháček (1995) provided information about H. beckeri in the Czech and Slovak Republics. Adults of Clusiodes and Hendelia usually occur on hardwood, but several Clusiodes have been collected from softwood trees such as pine, hemlock and fir (Caloren & Marshall, 1998; Roháček, 1995; Withers, 1985). Species of both genera have been reared from puparia collected in numerous species of rotting deciduous tree trunks including alder, aspen, ash, beech, birch, elm, hornbeam, maple, poplar, tulip trees (Withers, 1985; Greve & Midtgaard, 1986; Roháček, 1995; Caloren & Marshall, 1998) and linden (D. Gavryushin, pers. comm.). Adults are often seen on bare patches of wood, and many species of Clusiodes and Hendelia are attracted to small dung baits.

A number of Hendelia species have strikingly modified heads that are presumably associated with male agonistic behaviour. Examples include the pale excavated face and flattened arista seen in H. beckeri males, the elongate antennae of H. extensicornis Frey, the strongly widened head and corkscrewed vibrissae of several Australian species, and the elongate genal processes of the neotropical H. mirabilis (Frey) and H. kinetrolikros (Caloren & Marshall) (Caloren & Marshall, 1998; Marshall, 2000; McAlpine, 1976). Several of these species have been observed while engaged in male agonistic behavior at lek sites, usually on exposed tree trunks. Tuomikoski (1936) observed the pre-mating behaviour of H. beckeri, where males held their fore legs and "shivered" the fore tarsi, using them as feeler-like organs when approaching females.

North American species: None.