Apiomorpha Rübsaamen 1894

Hodgson, Chris, 2020, A review of neococcid scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) based on the morphology of the adult males, Zootaxa 4765 (1), pp. 1-264 : 50-52

Apiomorpha Rübsaamen 1894

Brachyscelis Schrader 1863 , 2. Type species: Brachyscelis pileata Schrader by subsequent designation Lindinger 1937, 179. Junior homonym ( Rübsaamen 1894: 201).

Apiomorpha Rübsaamen 1894, 201 . Type species: Brachyscelis pileata Schrader by subsequent designation Lindinger1937, 179. Replacement name.

Introduction. Apiomorpha occurs exclusively in Australia, apart from Apiomorpha pedunculata Fuller (1896) which has also been recorded from Papua New Guinea ( Gullan 1984). The adult females induce some of the largest and most conspicuous scale-induced insect galls. The galls are sexually dimorphic and are found only on Australasian Eucalyptus species. This is the largest genus of strictly gallicolus coccoids ( Beardsley 1984). Adult females have been recorded as living for more than five years ( Cook & Gullan 2002). Females have three instars, males five ( Gullan 1984). The genus currently contains 45 species ( García Morales et al. 2019).

Molecular studies that have included Apiomorpha have all suggested a close relationship with the Acanthococcid clade rather than with the Gondwanan clade ( Cook & Gullan 2004; Kondo et al. 2016). On the other hand, Hodgson and Hardy (2013), based on the morphology of the adult males, found Apiomorpha to be closer to the Gondwanan clade although support for this was poor. The possession of round sensilla in a triangle on each trochanter does strongly suggest that this genus is close to the Acanthococcid clade (see key on p. 19). Adult male characters otherwise do seem to suggest that this genus falls somewhat in between the two clades. Differences from the acanthococcine group are: (i) hamulohalteres absent although alar lobes present; (ii) ocelli absent; (iii) simple eyes somewhat bulbous; (iv) capitate setae absent from all antennal segments (v) metaprecoxal ridge short or absent; (vi) abdomen often elongate, narrowing posteriorly to an elongate penial sheath and (vii) caudal extensions sometimes present.

The only previous description of an adult male in the genus Apiomorpha is that of Theron (1968), who described and illustrated that of A. spinifer Froggatt under the name A.?pharetreta (Schrader). Below the adult male of A. spinifer is redescribed and illustrated along with those of another four species. Based on adult male morphology, these five species fall into 2 distinct groups (see key below).

Generic diagnosis of Apiomorpha spp based on adult male morphology. Body often with a slightly attenuated abdomen; with few setae; loculate pores occasionally present (Group I). Head: simple pores absent on Group II but present on Group I; ocular sclerite with a few concentric striations or ridges between simple eyes laterally, each with numerous inner microridges; simple eyes quite large and somewhat bulbous; ocelli possibly absent; preocular ridges short; interocular ridge absent; genal setae present; postoccipital ridge well developed, with both anterior and posterior arms; head setae few; antennae 10 segmented; scape almost square, with pedicel extending more or less directly away from head; antennal segments with both hs and fs, both long; capitate setae absent on all antennal segments. Thorax: prosternum poorly developed; prescutum with or without prescutal setae; scutal setae rare or absent; scutellum with scutellar setae; basisternum without a median ridge; postmesospiracular setae absent; metasternum with few setae; metaprecoxal ridge absent; postmetaspiracular setae absent; loculate pores present associated with each spiracle in Group II, these absent in Group I; hamulohalteres absent; alar lobes present; alar setae absent; alar sensoria absent; trochanter with 3 round sensoria in a triangle on each side; tibia with 2 spurs only; tarsi 2 segmented; most leg segments with rather stout fs in Group II, but these only present on tibia and tarsus in Group I; claw digitules capitate; claws each with a small denticle. Abdomen: tergites and sternites showing some degree of sclerotisation; fs absent; glandular pouches present on segment VIII; segment VIII with a pair of distinct caudal extensions in Group II, absent in Group I; segment IX with short setae; anus distinct at posterior end of segment IX; style with a pair of long setae posteriorly; style much narrower than segment IX, becoming sharply pointed apically and at least twice as long as width at base; aedeagus quite stout.

Key to known adult males of Apiomorpha species

1. Caudal extensions present on abdominal segments, each extension at least a third as long as penial sheath. Fleshy setae present on almost all leg segments, including each coxa. Loculate pores present associated with at least each anterior spiracle (in addition to within glandular pouches) … Group I............................................................... 2

- Caudal extensions absent or, if considered present, very short. Fleshy setae only present on tibia and tarsal segments. Loculate pores entirely absent apart from within glandular pouches … Group II........................................... 3

2. Fleshy setae absent from each trochanter. Tarsal and claw digitules both long and capitate. Prescutal setae present............................................................................. A. munita tereticornuta Gullan ( Fig. 19 )

- Fleshy setae present on each trochanter. Tarsal and claw digitules both short and setose. Prescutal setae absent........................................................................................ A. ovicola (Schader) ( Fig. 20 )

3. Each abdominal tergite with 8 abdominal dorsal setae. Abdominal segment VIII with small bulges (caudal extensions?) on each lateral margin............................................................. A. rosaeformis (Froggatt) ( Fig. 22 )

- Each abdominal tergite with 4 abdominal dorsal setae. Abdominal segment VIII without small bulges (caudal extensions?) on each lateral margin.................................................................................... 4

4. Fleshy setae on tarsi almost as long as hs. Penial sheath 250–270 μm long. With 3 or 4 tegula setae.......................

.................................................................................. A. spinifer Froggatt (fig. 23) - Fleshy setae on tarsi much shorter than hs and quite stout. Penial sheath 215–230 μm long. With 6–11 tegula setae… A. pharetra-

ta (Schader) * ( Fig. 21 )

*The adult males of A. spinifer and A. pharetrata are almost identical and the value of the above differences is unknown.

Figures

FIGURE 19. Apiomorpha munita tereticornuta Gullan. Macropterous male. (Eriococcidae, Acanthococcid group). Where A=cranial apophysis, C=loculate pore, D=fleshy seta, E=hair-like seta, N=side view of simple eye, R=dermal reticulation on ocular sclerite and X=pores on head.

FIGURE 20. Apiomorpha ovicola (Froggatt). Macropterous male. (Eriococcidae,Acanthococcid group). WhereA=cranial apophysis, C=loculate pore, D=fleshy seta, E=hair-like seta, N=side view of simple eye and X=pores on head.

FIGURE 21. Apiomorpha pharetrata (Schrader). Macropterous male. (Eriococcidae, Acanthococcid group). Where A=cranial apophysis, D1=fleshy seta on antennae, D2=fleshy seta on tarsus, E=hair-like seta and R=dermal reticulation on ocular sclerite.

FIGURE 22. Apiomorpha rosaeformis (Froggatt). Macropterous male. (Eriococcidae,Acanthococcid group). Where D=fleshy seta and E == hair-like seta.