Characteristics
All species of Apiochaeta have three pairs of dorsocentral bristles, an oblique vein dm-cu, characteristic female genitalia and a pair of elongate spinulose lobes attached to the base of the distiphallus. Most species are also striking in appearance: two sister-species are characterized by a broad head, inset posterior fronto-orbital bristles and white shoulder patches; most other species are large, yellow, strongly striped and often with strongly-patterned wings (see figure to right).

Similar genera
Apiochaeta is an interesting genus morphologically, as it has some of the characters found in the northern hemisphere genus Clusia Haliday and some of the characters found in the distantly related genus Sobarocephala Czerny. Like the predominantly Holarctic Clusia, it has an inclinate anterior fronto-orbital bristle, a presutural intra-alar bristle, an M1+2 ratio (the length of the ultimate section of vein M divided by the penultimate) less than 2.5 (3.0 in A. bicolor (Schiner)), a fore femur with several outstanding bristles on the posterodorsal surface, three rows of ventral ctenidial bristles on the fore and mid male femora (one anterior, two posterior), a subnotal stripe, an elongate and medially bent distiphallus and a truncate notch on the posterior margin of the frons behind the ocelli.  On the other hand, it resembles the predominantly Neotropical Sobarocephala in having a dorsal preapical bristle on the mid tibia, a surstylus that is at least half as long as the epandrium and an enlarged ventrolateral lobe on the hypandrium.

Although morphologically most similar to Clusia, unpublished molecular evidence strongly supports placement of Apiochaeta in the Sobarocephalinae with Sobarocephala (Lonsdale et al., in manuscript). We follow this classification here. Apiochaeta is an interesting genus morphologically, as it shares characters found in either of the more northern genera Clusia Haliday and Sobarocephala Czerny. Like the predominantly Holarctic Clusia, it has an inclinate anterior fronto-orbital bristle, a presutural intra-alar bristle, an M1+2 ratio (the length of the ultimate section of vein M divided by the penultimate) less than 2.5 (3.0 in A. bicolor (Schiner)), a fore femur with several outstanding bristles on the posterodorsal surface, three rows of ventral ctenidial bristles on the fore and mid male femora (one anterior, two posterior), a subnotal stripe, an elongate and medially bent distiphallus and a truncate notch on the posterior margin of the frons behind the ocelli.  Conversely, like the predominantly Neotropical Sobarocephala, it has a dorsal preapical bristle on the mid tibia, a surstylus that is at least half as long as the epandrium and an enlarged ventrolateral lobe of the hypandrium.
 

Although morphologically most similar to Clusia, unpublished molecular evidence strongly supports placement of Apiochaeta in the Sobarocephalinae with Sobarocephala (Lonsdale & Marshall 2008c). We follow this classification here.

Distribution
Apiochaeta is restricted to Chile and western Argentina, primarily between 33° and 43° S, between Santiago and Isla de Chiloé. Only one species, A. vitticollis (seen above) occurs on the Juan Fernandez Islands. Most species are sympatric and multiple species are often taken by the same collectors at the same times and places. The only other Clusiidae in temperate South America are widespread neotropical species of the clusiodine genera Craspedochaeta Czerny, 1903 and Heteromeringia Czerny, 1903.

Relationships
Lonsdale & Marshall (2008c) divided the 16 species of Apiochaeta into two defined lineages. The first consists of one pair of sister-species that each have a similarly widened head, and the second consists of the remaining 14 species that have three subequal pairs of dorsocentral bristles, pale and striped bodies, and often very elaborately-patterned wings. Lonsdale & Marshall (2008c) included Alloclusia Hendel, 1917 as a junior synonym of Apiochaeta.

North American species: None.