TACHINIDAE OF AUSTRALIA 19 



Tachinidae but has taxonomic importance as a taxonomic feature in a few 

 forms in which it bears long dense hair (e.g. Microtropesa and Paratropeza). 



pollinose. With a covering of pollinosity (q.v.). 



pollinosity. A nap-like covering to any part of the body formed by closely 

 aggregated ultramicroscopic pubescence. 



The extent, density and colour of pollinosity can provide taxonomic characters 

 and are largely responsible for the general appearance of many Tachinidae. 

 Banded or spotted patterns are typically produced either by islands of dense 

 pollinosity surrounded by less pollinose areas, or alternatively by non-pollinose 

 islands in areas that are mainly thickly coated with pollinosity (e.g. the 

 conspicuous spot patterns of Amphibolia) . When pollinosity is not evident 

 at normal magnifications of the entomological microscope (up to X 100 or x 150) 

 or is very inconspicuous on any area then the area is said to be 'non-pollinose'. 

 When the cuticle is dark, non-pollinose areas are typically metallic and the extent 

 of metallic colour can be important taxonomically (e.g. in Rutiliini). 



postabdomen. The part of the abdomen including the terminalia lying beyond 

 segment 5 (the last segment normally readily visible). 



In many forms much of the postabdomen is concealed and tergite 5 forms 

 the end of the immediately visible abdomen. In some forms the postabdomen 

 is more conspicuously developed than normal and may be distinctly recurved 

 under the main part of the abdomen (preabdomen) (e.g. Cylindromyiini) and 

 may bear elaborate modifications associated with oviposition (e.g. various 

 forcipate processes in female Phasiinae). 



postalar calli. The paired convexities forming the posterolateral corners of the 

 thoracic dorsum (Text-figs 4 & 7). 



postalar setae. The strong horizontal setae standing on the postalar calli 

 (Text-fig. 4). 



In nearly all Tachinidae there are two strong postalar setae, but in all 

 Rutiliini there are three or more (sometimes as many as six or seven) strong 

 postalars, the distinction between three, and four or more, being very important 

 in taxonomy of the group. Outside of Rutiliini the development of a strong 

 third postalar seta is rare (but occurs, e.g., in some Microtropesa). Rarely only 

 a single strong postalar seta is developed (e.g. in some Phasiini). 



postalar wall. The vertical declivity forming the outer surface of the postalar 

 callus (Text-fig. 7). 



This area is of taxonomic value in the Rutiliini where the postalar wall bears 

 a dense tuft of hair in Formosia and Fortnodexia Crosskey that is absent in 

 other genera. These genera appear to be the only forms represented in the 

 Tachinidae with such hair (in all others the postalar wall is bare or at most has 

 only one or two hairs on its extreme upper part immediately below the rounded 

 haired outer lip of the callus). 



postbucca. A vaguely defined area between the gena and the occiput forming 

 the posteroventral corner of the head (postgena) (Text-fig. 1). 



posteroventral declivity of the thorax. That part of the thorax laying between 

 the base of the abdomen and the insertions of the hind coxae (Text-fig. 7). 



