Bittacus londti Midgley, 2023

Midgley, John M. & Bellingan, Terence A., 2023, Notes on the Bittacus (Mecoptera, Bittacidae) of Mozambique, with the description of a new species, African Invertebrates 64 (2), pp. 95-107 : 95

Bittacus londti Midgley sp. nov.

Figs 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10

Material examined.

Holotype (Figs 2 - 5 , 9 , 10 ) Mozambique • 1 ♂; Sofala Province, Gorongosa National Park, Palm forest site 1, 18°59.518'S, 34°19.153'E; 40 m a.s.l.; 10-20 Mar. 2017; S. van Noort & M. Buffington leg.; Malaise trap; Closed Palm Forest ; Site code: GOR17-PALM1-M05; SAM-MEC-A000068.

Paratype (Figs 6 - 8 ) Mozambique • 1 ♀; Sofala Province, Gorongosa National Park, Palm forest site 1, 18°59.518'S, 34°19.153'E; 40 m a.s.l.; 10-20 Mar. 2017; S. van Noort & M. Buffington leg.; Malaise trap; Closed Palm Forest ; Site code: GOR17-PALM1-M05; SAM-MEC-A000069 .

Diagnosis.

Bittacus londti sp. nov. can be distinguished from other Afrotropical Bittacus (except Bittacus bullatus Londt, 1972b) by the bulla on the hind femur of males. The following characters permit differentiation from B. bullatus : B. londti has the femoral expansion situated more distally; a shorter pterostigma and smaller body size. Additionally, in the lateral view, B. bullatus has a pointed epandrium with a basodorsal projection ( Londt 1972b fig. 23) while B. londti has a blunt epandrium without a basodorsal projection (Fig. 9 ). In the dorsal view, the epandrium is wide apically in B. bullatus ( Londt 1972b fig. 24) and narrow in B. londti (Fig. 10 ). In the keys provided in Londt (1972b; 1978), this species keys as Bittacus kunenensis Wood 1933, but can be distinguished by the femoral bulla in the male.

Description.

Measurements: Wing lengths: fore = 12.6 - 13.2 mm; hind = 11.5-11.8 mm.

Head (Figs 2 - 4 , 6 - 8 ). Head light brown, except ocellar triangle dark brown to black; with yellowish pubescence, which is longer on the bottom half of the head and shorter above. Three distinct ocelli, lateral ocelli slightly larger (diameter approx. 1.15 times) than median. Antennae long, filiform, light brown with slightly darker pubescence. At least 15 flagellomeres in male (antennae broken), 18 in female.

Thorax (Figs 2 - 4 , 6 - 8 ). Light brown on tergum, pale on pleuron and sternum, with yellowish pubescence. Antepronotum with one or two brown setae on lateral margins, postpronotum with yellow pubescence, but no setae. Mesonotum and metanotum with scutellum slightly paler, with scattered black setae. With ten small light brown setae and one large darker seta on basalare.

Legs (Figs 2 - 4 , 6 - 8 ). Coxae pale, trochanters pale with dark margin to sulcus; with yellowish pubescence on both coxae and trochanters. Femur and tibia set with sparse short black setae. Femora pale, with dark apical tips. Fore- and mid- femur long, thin; hind femur in male with medial bulla with 16 to 18 short black setae. Tibia pale with dark apical tips, approx. as long as femora, with two long apical spurs; spurs about two thirds the length of the basitarsus in forelegs, about 3/4 the length of basitarsus in mid legs, one slightly shorter and one slightly longer than basitarsus in hind leg. Tarsi pale brown; male with fore- and mid- tarsi approx. the length of tibiae, hind tarsus slightly shorter length of hind tibia; female with all tarsi approx. the length of tibiae. Male tarsomere ratios: fore tarsus 5.1:2.0:1.4:1.1:1.0; mid tarsus 5.5:2.5:1.7:1.3:1.0; hind tarsus 1.9:1.1:1.0:1.6:1.6; female tarsomere ratios: fore tarsus 4.9:2.1:1.3:1.1:1.0 mid tarsus 4.6:2.1:1.3:1.0:1.0 hind tarsus 3.8:1.3:1.0:1.7:1.7

Wings (Figs 2 - 8 ). Narrow with apex rounded. Membrane pale brownish, pterostigma brown, 2.2 to 2.9 times longer than wide; thyridia present. Forewing: one subcostal crossvein; humeral crossvein present; Sc ending beyond first fork of Rs; Rs1+ 2 forking before end of pterostigma; Rs3+ 4 forking at level of mid distance between apex of Sc and pterostigma; one pterostigmal crossvein; M origin basal to Rs origin; M and Rs first forks at same level; Cu1 ending beyond apex of Sc; A1 ending level with origin of Rs. Hind wing similar to forewing, except Rs1+ 2 not forked in one wing on male, when present forking level with end of pterostigma; A1 ending beyond origin of Rs. In female, Rs3+ 4 forking closer to pterostigma than apex of Sc.

Abdomen (Figs 2 - 4 , 6 - 8 ). Bearing yellowish pubescence. Pale brown, segments 1-3 with thin, dark apices.

Male terminalia (Figs 9 , 10 ). pale brown, matching the abdomen, with yellowish pubescence. Epandrium in dorsal view: outer margins subparallel, inner margins evenly curved; internal margin with short brown setae on apical half; In lateral view: ending level with end of basystilus; base and apex subequal in height, narrowed medially; dorsal corner of apical margin right angled, ventral corner rounded; in posterior view dorsal and ventral corners pointed internally, ventral point slightly larger, internal margin crescent shaped. Cercus approx. as long as sternite IX, light brown, with yellowish setae. Basystilus with yellowish pubescence, dorsal margin straight, ventral margin convex in lateral view. Gonostylus short, dark brown. Penisfilum broad at base, abruptly narrowed medially, tapering towards apex, curving backwards but not forming a complete coil.

Female terminalia. Cercus short, dark brown apically, with light brown setae. Subanal plate and tergite IX light-brown, with light-brown setae. Cercus, subanal plate extended beyond tergite IX. Gonocoxosternite light-brown, with light-brown setae which are darker near the posterior margin; fused ventrally.

Etymology.

The species is named in honour of Dr Jason Londt, who has described over 25% of the Afrotropical Bittacidae , more than any other author.

Comments.

The specimens were found in malaise trap samples and were mounted from ethanol. The wings are folded and legs could not be arranged neatly. The malaise trap was in a closed palm forest (Fig. 11 ).

Figures

Figure 2. Dorsal view of holotype male Bittacus londti sp. nov. (SAM-MEC A 000068).

Figure 3. Frontal view of holotype male Bittacus londti sp. nov. (SAM-MEC A 000068).

Figure 4. Lateral view of holotype male Bittacus londti sp. nov. (SAM-MEC A 000068).

Figure 5. Wing venation of holotype male Bittacus londti sp. nov. A forewing, drawn from composite of left and right wing B left hindwing, digitally flipped. (SAM-MEC A 000068).

Figure 6. Dorsal view of paratype female Bittacus londti sp. nov. (SAM-MEC A 000067).

Figure 7. Frontal view of paratype female Bittacus londti sp. nov. (SAM-MEC A 000067).

Figure 8. Lateral view of paratype female Bittacus londti sp. nov. (SAM-MEC A 000067).

Figure 9. Dorsal view of the genitalia of holotype male Bittacus londti sp. nov. (SAM-MEC A 000068).

Figure 10. Lateral view of the genitalia of holotype male Bittacus londti sp. nov. (SAM-MEC A 000068).

Figure 11. In situ photograph of the malaise trap at the collection site and habitat of Bittacus londti. Photograph © Simon van Noort (Iziko Museums of South Africa).