The adult flies of D. germana usually occur in the immediate neighborhood of running or stagnant water and may be swept from the rank vegetation in such places. The flies rest on the upper surface of the leaves of tall herbs and low shrubs. In eastern Kansas, the flies of D. winnemana, D. tigrina and D. minima often occur together. In June, D. winnemana appears on the wing and is found associated with Tipula morrisoni Alex., T. mingwe Alex., etc.; in July, D. minima appears, together with Tipula flavibasis Alex., T. unimaculata Lw., etc.; still later in July D. tigrina emerges and all three species fly together during August and into September when they fly with Tipula ultima Alex., T. unifasciata Lw., etc. It is curious that no other species of Limnobiinæ occur in the thamnophytic association frequented by Dicranoptycha. All three species of this genus as discussed above have habits that are generally similar to one another. They are usually found resting quietly on the upper surface of the leaves but fly readily and on slight disturbance. Pairs in copulation are often found resting, the bodies directed away from one another and the wings folded over the abdomen. While thus united they fly readily, sometimes the female taking the initiative, sometimes the rather smaller male. The eggs are deposited in the soft earth in these situations.
NATURAL AFFINITIES
In the Monographs (1869) Osten Sacken included the genus Dicranoptycha in his tribe (section) Limnobina anomala, or, as it subsequently became known, the Rhamphidini, and still later the Antochini. A recent survey of the immature stages of several Antochine genera has shown that the tribe is merely an artificial grouping based on superficial resemblance of the adult flies. This heterogeneous assemblage includes representatives of at least three other tribes, Dicranoptycha, together with Antocha, Elliptera, Rhamphidia, etc., showing an undeniable affinity with the Limnobiini, whereas Teucholabis, Elephantomyia, etc., show an equally clear relationship with the Eriopterini. Moreover a close phylogenetic relationship with the lowermost subtribes of the Hexatomini (Ularia, Epiphragmaria, etc.), is easily apparent.
Dicranoptycha shows the closest affinities with Antocha and Rhamphidia. The larvæ of these three genera, each of which typifies a division, show the following common characters:
Abdominal segments with basal transverse creeping welts or areas of microscopic points. The massive compact head-capsule with the præfrontal sclerite large, distinct, the externo-lateral plates large, mussel-shaped and very thin. The mentum is not completely divided medially. The maxillæ are large and of primitive structure, the cardines and stipites distinct, the two distal lobes large, subequal in size, covered with hairs and bearing sensory organs. Mandibles with one or more dorsal and two or more ventral teeth in addition to the apical point.
The differences between these allied divisions are best indicated by a key.
LARVAE
1. Spiracular disk with only the two long ventral lobes remaining; spiracles lacking or vestigial; abdominal segments with both dorsal and ventral welts; strictly aquatic.Antocharia.
Spiracular disk surrounded by four or five short lobes; spiracles large and functional; abdominal segments with ventral welts only (except the dorsum of segment eight); terrestrial or semiaquatic.
2. Body moderately elongated and covered with a long dark pubescence; spiracular disk squarely truncated, surrounded by five subequal stout lobes; mentum with five subequal teeth, the lateral one of either side not conspicuously reduced.Rhamphidaria.