Heteromyza rotundicornis (Zetterstedt, 1846)

Rotheray, Graham E., 2012, Morphology of the puparium and breeding sites of eight species of Heleomyzidae (Diptera), Journal of Natural History 46 (33 - 34), pp. 2075-2102 : 2091

Heteromyza rotundicornis

Puparium. Length 5–6 mm (n = 2), length of second abdominal segment 0.5 mm, red-brown in ground colour; dorsal transverse striae strongly developed ( Figure 1A ); locomotory spicules numerous and variable in size with middle rows consisting mostly of small spicules about the size of those in the extreme anterior and posterior rows, largest spicules confined to an interrupted band just in front of the extreme posterior rows of which the latter are numerous ( Figure 7C ); anterior spiracles ( Figure 3F ) transverse rosette in shape with 10-11 respiratory bulbs; projections bearing posterior spiracular plate taller than basally wide ( Figure 2 ) and plates separated by more than twice the width of a spiracular plate; spiracular plate ( Figure 4F ), with indented rim and a projection between spiracular slits 1 and 2 bearing a tuft of peristigmatical setae; posterior spiracular slits long, longer than the diameter of the ecdysial scar; head skeleton ( Figure 10E,F ), length 1.1 mm; mandible with a pin-hole window; intermediate sclerite club-shaped with ventral bridge towards anterior end ( Figure 10F ); epipharyngeal plate lightly sclerotized.

Material examined. Scotland, Midlothian, Edinburgh, Blackford, NT 2571, two puparia ex garden compost (decaying plant material), collected as larvae 22 April 2011, K.P. Bland, det D. Horsfield .

Additional rearing records. Basden reared 87 specimens from three nests of three bird and mammal hosts: Berkshire, Farnham Royal , 62 specimens ex nest of a blue tit, Parus caeruleus , 26 cm deep in a hollow of an elm stump, nest collected 18 June 1931 , adults emerged 7–15 July 1931; Buckinghamshire, nr Marlow , five specimens ex nest of a coal tit, Periparus ater , in a tunnel 15 cm deep in a bank of a hedge, nest collected 5 June 1932 , adults emerged 4 July 1932; Buckinghamshire, Temple , 20 specimens ex nest of a water vole, Arvicola terrestris , nest 0.9 m along a burrow made in a bank of a stream, nest collected 7 May 1932 , adults emerged 1–13 June 1932.

Taxonomic notes

The puparia of these three heteromyzine species are very similar and distinguished from other species studied here by the club-shaped intermediate sclerite, transverse rosette-shaped anterior spiracles (except H. borealis ), indented posterior spiracular plate (except H. borealis ) with a projection between spiracular slits 1 and 2 and locomotory spicules of variable sizes. The puparium of Het. rotundicornis is easily separated from those of T. flavipes and T. tarsalis by the greater length of the projections supporting the posterior spiracular plate, longer than basal width. In T. flavipes and T. tarsalis these projections are shorter than their basal width. The puparia of T. flavipes and T. tarsalis are very similar but can be separated by the locomotory spicules of which the middle rows are larger than the extreme anterior and posterior rows in T. flavipes but are of a similar size in T. tarsalis .

Figures

Figure 1. Heleomyzidae, whole puparia, lateral view, anterior end to the left, dorsal margin uppermost, (A) Heteromyza rotundicornis, length 5 mm, (B) Heleomyza borealis, length 6 mm, (C) Suillia variegata, length 4 mm.

Figure 2. Heteromyza rotundicornis, anal segment, dorsal view, width at base 1.1 mm.

Figure 3. Heleomyzidae, anterior spiracles, lateral view, scale bar 0.1 mm, fan shape: (A) Eccoptomera microps, (B) Scoliocentra brachypterna; transverse rosette shape: (C) Heleomyza borealis, (D) Tephrochlamys flavipes, (E) Tephrochlamys tarsalis, (F) Heteromyza rotundicornis; rosette shape: (G) Suillia variegata, (H) Suillia laevifrons, and (I) Suillia ustulata.

Figure 4. Heleomyzinae and Heteromyzinae, posterior spiracles, apical view, scale bar 0.1 mm, Heleomyzinae: (A) Eccoptomera microps, (B) Scoliocentra brachypterna, (C) Heleomyza borealis; Heteromyzinae: (D) Tephrochlamys flavipes, (E) Tephrochlamys tarsalis, (F) Heteromyza rotundicornis.

Figure 7. Heteromyzinae, locomotory spicules, across mid-ventral zone of the posterior margin of the second and the anterior half of the third abdominal segment, uppermost vertical line indicates the mid-ventral point, horizontal line indicates approximate segment boundary, (A) Tephrochlamys flavipes, (B) Tephrochlamys tarsalis, (C) Heteromyza rotundicornis.

Figure 10. Heteromyzinae, head skeletons, left hand figures, whole structure, lateral view, mandible to the right, right hand figures, dorsal view of intermediate sclerite and mandible in that order, scale bar 0.25 mm, (A, B) Tephrochlamys flavipes, (C, D) Tephrochlamys tarsalis, (E, F) Heteromyza rotundicornis.