Ansifera , a new genus of Campylomyzini with remarkable antennal sensilla

The genus Ansifera gen. n. is established for one species, A. japonica sp. n., from and four species, A. asetosa sp. n., A. gombakensis sp. n., A. longipalpus sp. n. and A. malayensis sp. n., from West Malaysia. Adult morphological characters indicate Ansifera belongs to the Campylomyzini and is allied to Neurolyga . The presence of looped translucent sensilla on the male and female antennae is considered an underlying synapomorphy of Ansifera . The looped sensilla of the female are complex circumfila, which are typical of Porricondylinae and Cecidomyiinae, yet the two morphotypes are only superficially similar and certainly result from a parallel development. und Cecidomyiinae charakteris-tisch sind, doch beruhen die beiden Morphotypen mit Sicherheit auf Parallelentwicklung. 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.


Introduction
The antennal sensilla of adult gall midges (Cecidomyiidae) are more diverse than those of any other dipteran family. Thin-walled, translucent sensilla in particular occur in a wide variety of different morphotypes. The most elaborate type, circumfila, are restricted to Porricondylinae and Cecidomyiinae (GAGNÉ 1981: Figs 56-64), while the more primitive cecidomyiids, classified in the subfamily Lestremiinae, have various other, simpler types (JASCHHOF & JASCHHOF 2009: Fig. 11). The structure of circumfila and other translucent sensilla in Cecidomyiinae suggests they are olfactory receptors with differing roles in males and females (SLIFER & SEKHON 1971, SOLINAS & NUZZACI 1987, CROOK & MORDUE 1999, ZHANG & YANG 2008. The structure of Lestremiinae antennal sensilla has not yet been studied in similar detail, but there is no reason to doubt that their translucent sensilla are also chemoreceptors. Form, number and position of translucent sensilla usually differ in the two sexes of one and the same species as well as between different species, a fact that is used in identification and classification. It is worth noting that various morphotypes may occur within one and the same monophyletic group, even small genera. One such genus is Ansifera, a new genus of campylomyzine Lestremiinae that is here erected for five new species from Japan and Malaysia. Ansifera, the "loop-bearers", are peculiar for their looped antennal sensilla. Those of the female are especially elaborate and no less complex than circumfila, but the two morphotypes certainly result from a parallel development. In this paper the looped sensilla, which are a novel morphotype and not found in other Lestremiinae, are documented and the new taxa are described.

Material and methods
Most specimens were collected during an entomological expedition of the Swedish Museum of Natural History, Stockholm (NHRS), to the Malay Peninsula in 1997. A few other specimens result from the collectings, mainly by the author, for a survey of Lestremiinae diversity in Japan during the years 1998-2000(cf. JASCHHOF 2000. Holotypes of the new species are deposited either with the JASCHHOF collection in the Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany (SDEI) or in the NHRS. Paratypes and other vouchers are shared between SDEI and NHRS. Specimens were mounted on microscope slides following the procedure of JASCHHOF & JASCHHOF (2009), which is also the reference for the morphological terminology used here. The name Lestremiinae is used in the traditional sense, denoting a subfamily of the Cecidomyiidae, besides Catotrichinae, Porricondylinae and Cecidomyiinae.

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. 1D-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).

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.

Diagnosis:
Males are characterized by the very long flagellomere necks (Fig. 1D), the thin ejaculatory apodeme that lacks a sclerotized apical extension (Fig. 1C), and the acuminate tegmen (Fig. 1C). The female, which is the only known example of a female Ansifera, has complex antennal sensilla of an unmistakable outline (Fig. 1E).

Distribution and phenology:
Two specimens, apparently a pair, were Malaise trapped in a deciduous forest on Hokkaido, Japan. No further specimens, either of this or any other Ansifera species, were found in the 340 insect samples studied from all over Japan (cf. JASCHHOF 2000).

Etymology:
The name is derived from Japan, where japonica is the only Ansifera species known.

Diagnosis:
Males are characterized by the following features in combination: the antennal translucent sensilla are looped (Fig. 2C), the eye bridge is throughout of equal length ( Fig. 2A), the ventral emargination of the gonocoxites is shallow (Fig. 2D), and the gonostyli are comparatively slender (Fig. 2D).

Distribution and phenology:
Specimens come from two primary rainforests in the Selangor and Pahang Provinces, West Malaysia. The collecting sites are located at altitudes of 250 and 1000 m above sea level. Specimens were collected over rotten wood or elsewhere in the forest interior and along forest edges.

Etymology:
The name refers to Malaysia, where all the known specimens were collected.

Diagnosis:
Males are characterized by the combination of the following character states: the antennal translucent sensilla are simply hair-shaped (Fig. 3D), the flagellomere necks are very short (Fig. 3D), the basal palpus segment is clearly swollen (Fig. 3C), the gonostyli are comparatively short (Fig. 3A), and the large ejaculatory apodeme has a sclerotized, funnel-shaped apical extension (Fig. 3A).

Distribution and phenology:
All specimens known of R. gombakensis are from the type locality, a lowland rainforest in the Selangor Province, West Malaysia. Specimens captured by aspirator were observed swarming over moist, rotten wood, others were taken by sweepnet and Malaise trap elsewhere in the forest.

Etymology:
The species name is derived from the type locality, Ulu Gombak.   Ansifera asetosa sp. n.

Diagnosis:
This is the only species of Ansifera in which the translucent sensilla on the male antennae are leafshaped (Fig. 4A), the wing membrane is devoid of setae, and CuA2 is practically absent.

Distribution and phenology:
Ansifera asetosa is only known from the type locality, which is identical to that of the previous species. One of the two specimens was captured over moist, rotten wood, the other specimen was caught elsewhere in forest.

Etymology:
The name is Latin, meaning asetose, referring to the bare wing membrane characteristic of this species.

Diagnosis:
In this species regressive morphological characters are least obvious. There is a distinct row of postocular bristles, and both wing veins and setae are well developed. The apical segments of the maxillary palpi are longer than in any other species of Ansifera (Fig. 5C). The pretarsal claws have one relatively strong tooth that points inwards, apart from the ordinary line of fine teeth also present in the congeneric species. The gonostyli are strongly tapered, resulting in an almost subtriangular outline (Fig. 5B), but a variety exists with subcylindrical gonostyli (Fig. 5A).

Variation:
Eighteen male specimens, which were collected together with the types, differ from typical R. longipalpus by their subcylindrical gonostyli with broadly rounded apices (Fig. 5A). Apparently this difference in shape is real, not just the result of different inclination or angle. Even so, I doubt that distinct specific status for these specimens is warranted, as all other characters fit the description as given above. Six males collected in a lowland rainforest in the Selangor Province might belong to a species distinct from R. longipalpus. In these specimens, the gonocoxites have a deeper ventral emargination and a reinforced ventrobasal margin, and the ejaculatory apodeme is longer and has a more strongly sclerotized apical extension. There are other specimens, from the Malay Peninsula (Pahang and Selangor Provinces, West Malaysia) and Borneo (Sabah), which deviate slightly from R. longipalpus in one or more characters, indicating the presence of further, closely similar species. More and better conditioned specimens are needed to identify discriminatory characters and to determine possible infraspecific variation.

Distribution and phenology:
This species is known from three sites in the Genting Highlands, Pahang Province, West Malaysia. Specimens were captured in primary rainforests at altitudes between 1000 and 1750 m.