or pubescent (hairy in some exotic species). Face of varying shape; concave (fig. 48), convex, arched (fig. 5), or vertical (fig. 7) below antennae, with (fig. 15) or without (fig. 52) a central tubercle or swelling; sometimes produced at oral margin (fig. 52); clothed with hairs or bare, and sometimes transversely wrinkled; oral margin horizontal, descending (fig. 63) or ascending (fig. 5); cheeks more or less well developed and usually clothed with hairs. The proboscis well developed, the labella larger or smaller; the palpi slender or stouter.

Thorax usually robust, sparsely or densely clothed with long or short hairs or with pile, or altogether bare; scutellum crescentic or quadrangular, sometimes tuberculate, clothed or bare. Legs well developed, slender or stout, the posterior femora sometimes thickened and with a swelling or a tooth-like process below toward apex or base; the tibiae and tarsi sometimes broadened and peculiarly developed; the legs sometimes clothed with longer or shorter hairs and less commonly with bristles which are most frequent on underside of the posterior femora, on the tarsi, and abdomen, particularly on the genital segments of the male; claws and pulvilli small or well developed, the empodium bristle-like or styliform.

The wings usually longer than the abdomen, in some cases shorter; incumbent when at rest or held slightly divergent just exposing the abdomen. The wings vary somewhat in outline, being apically pointed

Fig. 1.—Diagram of a syrphid wing, showing venation.

or blunt, while the anal angle is evenly rounded or strongly developed; the alula is usually short, but may be long and narrow, reaching almost to the posterior margin of the wing (fig. 2); the squamae and anti-squamae are well developed and fringed with hairs, those on the former being long and frequently branched, and on the latter short. In colour the wings are either clear or tinged over the whole or part of the membrane, the base and cell Sc being more deeply coloured. The venation (fig. 1), which is distinct and readily characterizes the family, presents some interesting peculiarities. The costa ends at its junction with vem R_{4 + 5} either at or before the apex of the wing; sometimes there is a supernumerary humeral vein present; in some cases Sc₂ is developed, uniting as a cross-vein, Sc₁ with R₁ near the apex of the former; vein R_{2 + 3} runs more or less straight, or is strongly curved upward and sometimes slightly backward at its apex to meet the costa or to unite with vein R₁, thus closing cell R₁; vein R_{4 + 5} is straight, slightly curved downward, or deeply looped into cell R₅, which is always closed apically either on, near, or considerably before the costa by the confluence of

R_{4 + 5} and M₁, the latter running almost parallel with the wing-margin; basally cell R₅ is closed by the cross-vein r-m, which is more or less oblique, longer or shorter, and situated before, near, at, or beyond the middle of cell 1st M₂. Intersecting the lower part of the cross-vein r-m and running through cell R to end in cell R₅ close to the vein M_{1 + 2} is a more or less developed—though sometimes absent—spurious vein characteristic of the family: this is the vena spuria. Basally the vena spuria may be evanescent, but otherwise arises from the origin of vein R_{2 + 3} usually in those forms where the cross-vein r-m lies before the middle of cell 1st M₂, or, where this cross-vein is beyond the middle of cell 1st M₂, the spurious vein originates from the vein M where the latter curves downward to meet vein Cu at the base of the wing. A little before r-m in cell R the vena spuria is swollen knob-like, from whence a vein-like stump may descend either to evanesce or unite with vein M, or a spurious cross-vein may connect the vena spuria above with the vein R_{4 + 5} near the origin of the latter, which is then somewhat angulated at this point. The vein M, just beneath the swelling of the vena spuria and behind the cell 1st M₂, is frequently sinuated; from the origin of this sinuation in some species (fig. 27) an indistinct vein arises perpendicularly into cell M and turns abruptly forward, crossing into cell 1st M₂. The veins M₁ and M₂ are united for the greater part of their length, branching near the wing-margin, the anterior branch, M₁, closing the cell R₅ as already noted; M₂ may either continue beyond the fork or be confluent with M₁, which in some cases is angulated, giving rise to a short stump into cell R₅ (fig. 22). Connecting the veins M and Cu₁+M₃ is the cross-vein m running more or less parallel with the wing-margin and meeting vein M either before the branching of M₁ in such forms where M₂ is continued toward the margin, or at the fork of M₁ where M₂ is confluent with M₁. As with vein M₂, the vein Cu₁+M₃ is either confluent with the cross-vein m or is continued beyond toward the margin; owing to the fusion of the veins Cu₁ and M₃, the cross-vein m-cu is eliminated. After the confluence of Cu₂ and 1st A, Cu₂ + 1st A either runs straight to the margin or is more or less prolonged and curved. In cell Cu₂ of most species is a distinctly developed vein arising at the origin of 1st A and, running close to vein Cu, ending beyond the middle of the cell. The basal “vein” of the alula is connected with the origin of Cu by a distinct cross-vein and the arculus between Cu and R, or M and R, is well developed.

According to the venation, the species discussed below form three groups. In the first (Plate XLVII, fig. 6) the costa ends with vein R_{4 + 5} at the apex of the wing, which is more or less blunt; the vein R_{4 + 5} is practically straight above cell R₅, and the veins Cu₁ + M₃ and M₂ are more or less developed beyond the cross-vein m and the vein M₁ respectively; also the cross-vein r-m is before the middle of cell 1st M₂ (Syrphinae). In the second group (figs. 3 and 4), the costa ends before the apex of the wing, which is more or less pointed; the vein R_{4 + 5} is gently curved into cell R₅, the veins Cu₁ + M₃ and M₂ are confluent with the cross-vein m and the vein M₁ respectively, and the cross-vein r-m is near or beyond the middle of cell 1st M₂ (Milesiinae). In the third group (fig. 1) the costa ends distinctly before the apex of the wing, which is pointed; the vein R_{4 + 5} is deeply curved into cell R₅; the veins Cu₁ + M₃ and M₂ as the second group; the cross-vein r-m beyond the middle of cell 1st M₂. A further reduction occurs in this group (Plate LI, fig. 3) in the closing of the cell R₁ of some species by the confluence of veins R₁ and R₂₊₃ (Eristalinae).

The abdomen is ovate (particularly in some females), elongate and narrow with parallel sides, or sides converging basally or along the middle, or rectangular; bare, or sparsely or densely clothed with hair, or sometimes with bristles to a certain extent. In the New Zealand species there are 4 visible segments in the male and 5 in the female; in the male segments 5–9 are curved to one side beneath the apex of the abdomen; in the female the apical segments are usually retracted within the 5th, but may be extruded to some considerable length.

The colours of the Syrphidae are frequently more intense in warmer parts of the Dominion and are usually conspicuous. Although a few are melanoid, many are brilliantly metallic, or black with yellow or white spots and stripes; there are also reflections of various hues caused by tomentum or the arrangement of the vestiture. On account of the structure, the flower-frequenting habit, and the mode of flight, many syrphids closely resemble certain Hymenoptera: the European narcissus-fly (Merodon equestris Fabr.), sometimes found in New Zealand, bears a strong resemblance to a bumble-bee, while the European drone-fly (Eristalis tenax Linn.), now well established in this country, is frequently mistaken for the honey-bee. The absence of indigenous Apidae may account for the absence among New Zealand syrphids of those densely-haired and bee-like species. It is also noteworthy that the native bees are all of the short-tongued group, and that there is an amount of resemblance between these insects and certain native syrphids: for example, Lepidomyia decessum Hutton is superficially similar to the native Halictus huttoni Cam.^*

In the following pages some thirty-three species are recorded, three of which are of European origin, one is found also in Australia, and the remainder are indigenous; of these, fourteen are new species. As in Part I, the terms pro-, epi-, meso-, meta-, and onycho-tarsus are used for the 1st to 5th tarsal joints respectively, as suggested by Williston. Unless otherwise stated, the term “front” refers to the front and vertex.

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