Milichiidae online

The ventral receptacle in the stem-species pattern of the Chloropidae family-group is non-chitinised and unchambered. The exact shape of the ventral receptacle in the stem-species pattern of the Chloropidae family-group is unknown, because it differs within the family-group as well as within the Acalyptratae.
In the Carnidae, at least two shapes of ventral receptacle are represented. In Meoneura the receptacle is globular and is separated from the vagina by means of a short, broad stem. In Hemeromyia the ventral receptacle does not have a stem and the lumen seems to be small. Since the shape of the ventral receptacle in the stem-species pattern of the Chloropidae family-group is unknown, the stem-species pattern of the Carnidae cannot be ascertained.
The ventral receptacle in the acartophthalmid Acartophthalmus nigrinus is elongate and ventrally curved, like a hook.
A pocket-like ventral receptacle is an apomorphy for the Milichiidae+Chloropidae (Sturtevant 1925-1926). Within the Chloropidae this shape of ventral receptacle is present in the Oscinellinae for example (Schwartz 1965). Within the Chloropinae there are species in which the wall near the opening of the receptacle bulges into the lumen of the receptacle, leaving space for sperm only near the outer wall. In these species sperm is stored in the enlarged basal part of the spermathecal ducts. I believe that a study of the female reproductive system would contribute valuable characters for the phylogeny of the Chloropidae.
Within the Milichiidae the ventral receptacle is pocket-like in all the species that have been studied. (ex Brake 2000)

The shape of the accessory glands in the stem-species pattern of the Chloropidae family-group is uncertain, because only a few glands have been described. The reason for this deficiency is that, because of their small size and soft structure, accessory glands are difficult to demonstrate in fresh material and nearly impossible to detect in dry or alcohol material.
The accessory glands of the Acartophthalmidae are unknown, and the accessory glands of the carnid Meoneura vagans have long ducts and are attached to the base of the ovaries.
In the chloropid subfamilies Oscinellinae and Chloropinae the accessory glands are long and with a short duct.
Within the Milichiidae the accessory glands of Leptometopa spp. and Madiza glabra have very short ducts, while the glands of Desmometopa sordida and Pholeomyia sp. 1, have long ducts. At the base of the gland there is a club-shaped widening in the duct, which is interpreted as a pump. Similar pumping organs have been described for other Acalyptratae (Klostermeyer & Anderson 1976, Solinas & Nuzzaci 1984, Kotrba 1993, Lachmann 1994). In Leptometopa spp. and Madiza glabra the gland is quite long. In Desmometopa sordida and Pholeomyia sp. 1 the gland is shorter and has a lumen. The distal end of the accessory gland is attached to the base of the ovaries. The shape of the accessory glands in the stem-species pattern of the Milichiidae cannot be ascertained, because the shape in the stem-species pattern of the other families of the Chloropidae family-group is also uncertain. (ex Brake 2000)

In the stem-species pattern of the Chloropidae family-group, as represented in the stem-species pattern of the Carnidae, there are sclerotised spermathecal capsules with spherical surrounding tissue. Sclerotised spermathecal capsules are considered plesiomorphic for the Chloropidae family-group because they are present in the stem-species pattern of the Acalyptratae.
Within the Carnidae, the stem-species pattern is represented in Neomeoneurites and Hemeromyia. However, in Meoneura, the capsules are reduced in size and can be found as small, sclerotised, pointed tips at the end of the distally slightly enlarged spermathecal ducts.
In Acartophthalmus nigrinus (Acartophthalmidae), the spermathecal capsules are completely reduced and the spermathecal ducts end with slight ramifications in the surrounding tissue.
In the Chloropidae, a spermathecal capsule is sometimes present and the shape of the spermathecae differs: the tissue surrounding the end of the spermathecal ducts is always spherical in the Siphonellopsinae and Oscinellinae that I studied, while it is spherical or unevenly shaped in the Chloropinae. In the Oscinellinae the tips of the spermathecal ducts are slightly enlarged and are connected to the mostly very small, lightly sclerotised spermathecal capsule via a short and slender duct. In the Siphonellopsinae, the tips of the spermathecal ducts are also slightly enlarged, but there is no capsule. In these cases the short and slender duct opens into a lumen surrounded by gland tissue. In the species of the subfamily Chloropinae that I examined, the spermathecal ducts end without an enlargement, but also with a short, slender duct which opens into a lumen within the surrounding gland tissue. A small spermathecal capsule, as is present in the Oscinellinae, probably represents the stem-species pattern of the Chloropidae because the presence of a capsule is the plesiomorphic character state for the Chloropidae family-group and for the Acalyptratae. As a result, the capsule must have been reduced several times within the Chloropidae. The short and slender duct at the end of the spermathecal duct is probably an apomorphy of the Chloropidae.
In the stem-species pattern of the Milichiidae, there is no sclerotised spermathecal capsule. The distal end of the spermathecal ducts projects slightly out of the coil and is surrounded by epithelial gland cells. There is only slight variation in the shape of the spermathecae within the Milichiidae: the spermathecae may be rather long or more spherical. In some species the distal end of the spermathecae is pointed. In Desmometopa the distal end of the ducts is slightly enlarged.
The shape of the spermathecae may be useful for phylogenetic studies. However, as yet not enough species have been studied, because unsclerotised spermathecae are very difficult to detect in preserved material.
Since spermathecal capsules are present in the stem-species pattern of the Chloropidae family-group and in the stem-species pattern of the Carnidae and Chloropidae, the capsule must have been reduced in the Acartophthalmidae, in the stem-species of the Milichiidae, and at least twice within the Chloropidae. A complete reduction of the spermathecal capsule also occurs convergently in several acalyptrate families, for example in the Ephydridae and Fergusoninidae. (ex Brake 2000)

Because the discussion in Cumming, Sinclair & Wood is convincing and the descriptions and illustrations are readily comprehensible, I will follow the revised epandrial hypothesis on this website even though it has been criticised by some authors (Griffiths 1996, Zatwarnicki 1996).

According to Cumming, Sinclair & Wood (1995), the male genitalia in Schizophora consist of the dorsal saddle-shaped epandrium, which evolved from T9, and the ventral hypandrium, which evolved from a fusion of S9 and the gonocoxites. The tips of the U-shaped hypandrium articulate with the epandrium. Inside the epandrium this articulation is connected with the cerci and the surstyli via the subepandrial sclerite. The surstyli themselves articulate with the ventral side of the epandrium. The subepandrial sclerite evolved from a sclerotisation of the ventral membrane of the dorsal part of segment 9. The paired cerci belong to the 11th segment; between them lies the anus. The surstyli are secondary appendages of the epandrium. They hold the female ovipositor at copulation.
Inside the epandrium the base of the phallus, which is inserted into the female vagina at copulation, lies at rest. The phallus consists of the aedeagus fused with the parameres and is divided into basi- and distiphallus. At its base the phallus articulates with the rod-like phallapodeme, which is thought to have originated from a longitudinal invagination of the inner wall of the hypandrium. Laterally the basiphallus is encircled by the postgonites. Anterior to the postgonites are the pregonites, which are connected with the hypandrium anteriorly. Both postgonites and pregonites probably evolved from gonopods, but pregonites were newly formed within the Schizophora. The phallus is moved by the muscles of the phallapodeme; post- and pregonites prevent a lateral movement. From the phallus the ejaculatory duct leads to the sperm pump with the ejaculatory apodeme, which are situated shortly anterior to the epandrium inside the abdomen. The ejaculatory apodeme was originally a part of the aedeagus. The sperm pump consists of a membraneous sac, which is squeezed in order to press sperm into the female vagina. (ex Brake 2000)

The mouthparts of most higher Diptera consist of a tube-like sucking apparatus, the proboscis. The main parts of the proboscis are the basal fulcrum, and the labium with the distal labella. The proboscis is connected to the head capsule by the clypeal membrane. The fulcrum is surrounded by this membrane. Anterolaterally at the distal end of the fulcrum are the maxillae. Cardo, stipes, and lacinia are fused to each other, but the cardo and stipes are enclosed within the clypeal membrane, while the lacinia is external. The stipes bears the maxillary palpus at its proximal tip and in most acalyptrate flies there is a ventral appendage at the middle of the stipes (Frey 1921).
The labium consists of the proximal prementum and the distal labella. The prementum forms a trough on the ventral side, in which the hypopharynx and labrum are situated. At its distal end it bears the paired labella. The inner surface of the labella is furnished with small sclerotised grooves, reminiscent of tracheae, which are called pseudotracheae. The pseudotracheae radiate from the terminus of the food canal and are used to distribute saliva and to suck up liquids. They are braced by a series of sclerotised rings, the tips of which can be of different shapes. Zaitsev (1982) distinguished two basic types of pseudotracheal ring tips: the dentate type (rounded or flattened tips) and the spinose type (elongated and pointed tips). Intermediate shapes of the ring tips are possible (Elzinga & Broce 1986).
Because the proboscis is short and not geniculate in most Schizophora and in the Acartophthalmidae, I think that this is also the shape of the proboscis in the stem-species pattern of the Chloropidae family-group. The proboscis of the Carnidae is apomorphically highly specialised: the prementum is strongly sclerotised and bulbous, and the labella are very short and inconspicuous.
An apomorphy for the Milichiidae+Chloropidae is a slightly elongated and geniculate proboscis, which means that the labella are folded back. I have not included this character in the cladistic analysis, because it is very difficult to decide whether a proboscis is slightly elongated or not elongated, and if it is only slightly elongated, whether it is geniculate or not. The geniculation is only easy to see in long probosces. In species with a strongly elongated proboscis, the labium with the labella and sometimes the fulcrum is elongated, but never the stipes (from Brake 2000)