Ansifera, Jaschhof, 2009

Jaschhof, Mathias, 2009, Ansifera, a new genus of Campylomyzini with remarkable antennal sensilla (Diptera: Cecidomyiidae: Lestremiinae), Beiträge Zur Entomologie = Contributions to Entomology 59 (2), pp. 513-526 : 514-516

Ansifera gen. n.

Type species: Ansifera japonica sp. n., by present designation.

Diagnosis:

Adults only. The translucent antennal sensilla in both sexes are typically looped, which is unknown in any other Campylomyzini and Lestremiinae , and are especially large and elaborate in the female ( Fig. 1 D-E). Some males have simply hair-shaped sensilla ( Fig. 3D ), like those in Neurolyga , or small, leaf-shaped sensilla ( Fig. 4A ), which are unknown from other Campylomyzini but found in many other Micromyidi. There is the propensity toward morphological regression throughout the genus. The combination of regressive characters, such as 3-segmented maxillary palpi, sparse setae on thorax and wings, short apicR1, and indistinct or missing costal break, is not met in any other Campylomyzini with fully developed wings. Male terminalia resemble those in some Neurolyga species ( Figs 1C , 2D ).

Description:

Small-sized, males maximally 1.5 mm long. Head capsule almost globular ( Fig. 2A ). Postocular bristles sparse or absent. Eye bridge usually slightly shorter laterally than dorsally, lateral ommatidia present. Male antenna with 12 flagellomeres, flagellomere nodes barrel-shaped, with crenulate whorls of sensory hairs, translucent sensilla on proximal 4-5 flagellomeres typically looped ( Fig. 1D ), otherwise simply hair-shaped ( Fig. 3D ) or leaf-shaped ( Fig. 4A ), lengths of flagellomere necks variable among species. Female antenna with 8 flagellomeres, apical flagellomeres constricted; flagellomere nodes barrel-shaped, entirely encircled by translucent sensilla, the latter filiform, forming an irregular network that arises from numerous pores and bears several long, one- or two-pointed processes; flagellomere necks long ( Fig. 1E ). Maxillary palpus 3-segmented, basal segment usually slightly swollen, with numerous hair-shaped translucent sensilla dorsomesally, apical segment longest of all, often asetose ( Fig. 1A ). Thorax small relative to head ( Fig. 2A ). Antepronotal lobe asetose. Scutum with sparse lateral and dorsocentral setae. Postphragma large. Wings ( Fig. 1B ) with regressive features, such as costal break indistinct or missing, apicR1 shorter than 3 times the length of Rs, M obsolete apically, CuA2 often very short, dorsal setae on veins sparse, ventral setae absent, alar setae comparatively sparse or absent. Dorsal setae on R1, R5, rm and CuA-stem, or variously reduced. Pattern of sensory buds: apicR1, 2-3; Rs, 1; R5, 1 basal (often situated on same level with Rs), 1-2 mesal/distal; buds often barely discernible due to small size. Scales on tibiae and tarsi sparse or absent. T5 very densely pubescent. Pretarsal claws crescentshaped, with fine teeth. Empodia narrow, slightly shorter than claws. Preabdomen weakly sclerotized, segment 1 asetose, anterior terga with lateral setae, posterior terga with lateral and dorsal setae and sclerotized anterior margins, sterna and pleural membranes 2-8 setose. Tergal plaques 0/2/2/2/1/1/1/0. Male terminalia ( Figs 1C , 2D ) small; tg9 subtrapezoid, only partly sclerotized, with membranous basal margin; gonocoxites short and wide, with ventral emargination of variable outline, dorsal transverse bridge often projecting beyond ventrobasal margin; antGA missing; gonostyli subcylindrical or tapered toward apex, often slightly flattened, without apical spine; ejaculatory apodeme usually longer than tegmen, with apical extension; tegmen membranous, subtriangular to subrectangular; apices of ejaculatory apodeme and tegmen usually closely linked with one another; ducts of accessory glands not discernible; st10 not traceable; cerci densely pubescent, asetose. Spermathecae 2, equal in size, comparatively small, strongly sclerotized, globular, with tiny plaques. Ovipositor short, unmodified, basi- and disticercus subequal in length.

Etymology: The name is Latin, meaning loop-bearer, which refers to the peculiar shape of the antennal sensilla. Gender is feminine.

Classification and phylogeny:

The absence of a sensory bud on r-m and the structure of the male terminalia, with simple, spineless gonostyli and long, apically enlarged ejaculatory apodeme, are the main arguments to classify Ansifera with the Campylomyzini (cf. JASCHHOF & JASCHHOF 2009). Male genitalic characters suggest a closer affinity of Ansifera to the genus Neurolyga RONDANI, 1840 . The looped antennal sensilla, present in three of the five species, are unique and considered an underlying synapomorphy of Ansifera . A whole set of characters reflect the trends toward miniaturization and morphological regression, which are observable in all but one of the species included. The same phenomena are known from two other Campylomyzini , Micropteromyia ghilarovi MAMAEV, 1960 and Neurolyga degenerans (MAMAEV & MOHRIG, 1975) , which however lack looped sensilla and differ in several other character states (cf. JASCHHOF 1998). The genus Ansifera includes five species, all new to science: A. japonica , A. malayensis , A. gombakensis , A. asetosa , and A. longipalpus . Apparently there is a complex of sibling species around A. longipalpus , which needs further study (see below).

Distribution and phenology:

To my present knowledge, the distributional range of Ansifera comprises Japan, the Malay Peninsula and Borneo. Most specimens by far, and four of the five species known, were found in the Malay Peninsula. Considering the lack of data on the occurrence of Lestremiinae in most of the region in question, one may assume the centre of the recent distribution of Ansifera lies in the Malay Subregion of the Oriental Region. Ansiferas are forest-dwellers, which cope with environ- ments as different as cool-temperate deciduous forest and both mountain and lowland tropical rainforest. On several occasions adult Ansifera were observed flying over moist, strongly rotten wood, which presumably is the substrate where larvae live. The east Palaearctic/Malay distribution pattern, as exhibited by Ansifera , is shared by other lestremiine species groups and genera, such as Pseudoperomyia JASCHHOF & HIPPA, 1999 .

Species identification:

Characters to discriminate among Ansifera males lie mainly in the structure of the antennae, maxillary palpi, wings and terminalia. Genitalic characters include the outline of gonocoxites, gonostyli and tegmen, which are structures that may be easily distorted in specimens mounted on slides. Ansifera longipalpus appears to be the most common member of a species complex and further study is needed to assess the extent of individual variation in A. longipalpus and to determine the discriminatory characters that separate possible sibling species (see below). As only one Ansifera female is known so far, the possibility to identify species using female characters remains unexplored for the time being. One may anticipate the discovery of many more species of Ansifera , which should be borne in mind when using the key given below.

Key to species (males)

1 Antennal translucent sensilla always hair-shaped ( Fig. 3D ) ................. gombakensis sp. n.

- Antennal translucent sensilla at least partly looped ( Figs 1D , 5D ) or leaf-shaped ( Fig. 4A ) ......................................................................................................................B

2 Postfrons setose. Postocular bristles 5-7. Apical segment of maxillary palpus 3 times as long as the preceding segment or longer ( Fig. 5C ) ....................................... longipalpus sp. n.

- Postfrons asetose or with maximally 1 seta. No more than 2 postocular bristles. Apical segment of maxillary palpus 2 times as long as the preceding segment or shorter ........ 3

3 Antennal translucent sensilla leaf-shaped ( Fig. 4A ). Wing membrane asetose .................. ................................................................................................................... asetosa sp. n.

- Antennal translucent sensilla looped. Wing membrane setose ......................................D

4 Neck of fourth antennal flagellomere much longer than node ( Fig. 1D ). Ejaculatory apodeme thin, without sclerotized apical extension ( Fig. 1C ) ......................... japonica sp. n.

- Neck of fourth antennal flagellomere slightly longer than node (Fig.BC). Ejaculatory apodeme thicker, with sclerotized, funnel-shaped apical extension ( Fig. 2D ) ................... .............................................................................................................. malayensis sp. n.

Figures

Fig. 1: Ansifera japonica sp. n. - A: male maxillary palpus, lateral view; - B: male wing, dorsal view - C: male terminalia, ventral view; - D: male fourth antennal flagellomere, lateral view; - E: female fourth antennal flagellomere, lateral view. Length of scale bar = 0.05 mm (for A, C-E) and 0.5 mm (for B).

Fig. 3: Ansifera gombakensis sp. n., male. - A: terminalia, ventral view; - B: ditto, ejaculatory apodeme and aedeagus expanded; - C: maxillary palpus, lateral view; - D: fourth antennal flagellomere, lateral view. Length of scale bar = 0.05 mm.

Fig. 4: Ansifera asetosa sp. n., male. - A: fourth antennal flagellomere, lateral view;

Fig. 2: Ansifera malayensis sp. n., male. - A: head and thorax, lateral view; - B: maxillary palpus, lateral view; - C: fourth antennal flagellomere, lateral view; - D: terminalia, ventral view. Length of scale bar = 0.05 mm (for B-D) and 0.1 mm (for A).

Fig. 5: Ansifera longipalpus sp. n., male. - A: gonostylus, ventral view; - B: terminalia, ventral view; - C: maxillary palpus, lateral view; - D: fourth antennal flagellomere, lateral. Length of scale bar = 0.025 mm (for A) and 0.05 mm (for B-D).