Ole A. Sæther

Underlying Synapomorphies and Anagenetic Analysis

Evaluations of holomorphological similarities are based on synapomorphies, symplesiomorphies, convergence, and parallelisms as results of parallel selection and of underlying synapomorphies respectively. Only synapomorphies and underlying synapomorphies can show genealogical relationships. Distinctions between parallel selections and underlying synapomorphies are of major phylogenetic importance, while distinctions between different evolutionary histories (eu‐parallelisms and pseudo‐parallelisms) are not. The circumstance when underlying synapomorphies are of special phylogenetic importance has been termed unique inside‐parallelism. Three such unique inside‐parallelisms are found in the female genitalia of the Chironomidae, where they are shown necessary for the understanding of subfamily relationships. — The first minimum criterion for recognizing synapomorphy (Schlee 1971) is corrected to: It should be present within the whole group or clearly secondarily reduced an apomorphic taxa. It should not be present in the same formation in any taxon outside the group which can be regarded as a possible sister group. — The anagenetic component of the evolutionary processes can, following a cladistic analysis, be calculated by means of the adjusted evolution index assigning the different recognizable steps of trends or morphocline number from 1 to 2 and calculating the arithmetic mean of all numbers. Examples from Chaoboridae and Chironomidae support the cladistic diagrams and point out that different stages belong to differing “grades”. Methods of numerical taxonomy may give a finer gradation of anagenetic levels.

THE INFLUENCE OF EUTROPHICATION ON DEEP LAKE BENTHIC INVERTEBRATE COMMUNITIES

ABSTRACT Some case histories of eutrophication in deep lakes are given. They include the lakes Vattern, Mlaren, Constance, Geneva, Maggiore, Mergazzo, Taho, The Great Lakes, and the Okanagan Lakes. Common for nearly all is that the first reaction to eutrophication consists in an increase in absolute and relative abundance of oligochaetes without any change in species composition. Also sphaeriids, large crustaceans and chironomids will increase in numbers. Secondly there is a shift in relative abundance of the common species. Only species of chironomids may possibly be eliminated from the profundal zone when a strongly oligotrophic lake change to a less strongly oligotrophic lake. The oligochaetes and sphaeriids show a broader trophic spectrum and although shifts in relative abundance are significant, the species composition first change when the mesotrophic stage is approached. More significant shifts in relative abundance and species composition take place in the littoral zone. Lists of characteristic chironomids in lakes of different trophic levels show that 15 subdivisions of communities can be delineated. There is a highly significant correlation between the 15 subdivisions and chlorophyll a/mean depth and between the subdivisions and total phosphorous/mean depth. These correlations show that while it is easy to change the benthic communities from ultraoligotrophic to moderately oligotrophic communities, it takes considerably higher shifts in primary production to change oligotrophic to mesotrophic, or mesotrophic to eutrophic benthic communities. The deeper a lake is the larger is the primary production increase needed in order to change the trophic level of the benthic communities, and the larger are the expected discrepancies between trophic evalustions based on epilimnetic algal biomass and those based on benthic invertebrate communities.

THE MYTH OF OBJECTIVITY—POST‐HENNIGIAN DEVIATIONS

Abstract— The punctuated equilibrium speciation mode is an implied consequence of the deviation rule and the differences between cladograms and phylogenetic trees implicitly were recognized by Hennig. Neocladism and transformed cladism, however, both are contradictory to the view of Hennig. Neither of them will be consistent when parallel changes exceed informative unparallel changes, which in the real world there are many indications to believe they do. In three tables cladogenetic trends used in erecting three schemes of argumentation, on the specific, generic, and subfamily levels respectively, are analyzed and divided into: “objective” synapomorphies not allowing for outside parallelism or secondary change, subjective synapomorphies, and underlying synapomorphies. Evaluations based on the strictest criteria for asserting synapomorphy are possible only when comparing higher taxa of subfamily level and up. On the generic level trends showing outside parallelism can be rejected if all other possibly synapomorphic trends are included. On the specific level it is necessary to take all kinds of synapomorphies into consideration, including those showing outside parallelism. There may often be a preponderance of trends caused by parallel selection in taxa with specialized sexual and/or feeding behaviors, as exemplified by some chironomid male imagines and larvae. It is necessary to have knowledge of the nature of the different possible natural processes and try to explain these before undertaking estimations of patterns of kinship. The persistent intuitive and subjective element in phylogenetics was stressed by Hennig. Objectivity is a myth.

Usambaromyia nigrala gen. n., sp. n., and Usambaromyiinae, a new subfamily among the Chironomidae (Diptera)

The male and female imagines of Usambaromyia nigrala gen. n., sp. n. are described from the West Usambara Mountains in Tanzania. The species differs from other known chironomids by having nearly completely black wings in both sexes, tibial spurs with lateral denticles making them Tanypodinae—like, dense cluster of scalpellate sensilla chaetica on anepisternum I, male gonostylus without megaseta, laterosternite fused with tergite IX forming a single annulus and female genitalia apparently with only one seminal capsule and spermathecal duct, well developed gonocoxite IX and setae on segment X. A new subfamily, the Usambaromyiinae is erected based on U. nigrala and conceived as forming the plesiomorphic sister group of the Tanypodinae, the Podonomiinae and the Aphroteniinae combined. A subfamily diagnosis is given.

Buchonomyia burmanica sp. n. and Buchonomyiinae, a new subfamily among the Chironomidae (Diptera)

Male and female imagines of Buchonomyia burmanica sp.n. are described. While the male imago nearly exclusively shows plesiomorphous features, the female imago possesses three important underlying synapomorphies as unique inside‐parallelisms: the capacities for divisions of gonapophysis VIII and of tergite IX and for the development of an apodeme lobe. These and supporting evidence lead to the conclusion that Buchonomyia Fittkau deserves a new subfamily, the Buchonomyiinae, which forms the sister‐group of the monophyletic unit Chironominae‐t‐Orthocladiinae+Prodiamesinae+Diamesinae.

Metriocnemus van der Wulp: a new species and a revision of species described by Meigen, Zetterstedt, Stæger, Holmgren, Lundström and Strenzke (Diptera: Chironomidae)

The congenerity of Dolichopelma Lundstrom, 1915 and Chasmatocladius Kieffer, 1911 with Metriocnemus v.d. Wulp, 1874 is confirmed. Types from the Meigen Collection in Paris, the Holmgren Collection in Stockholm, the Zetterstedt Collection in Lund, the Staeger Collection in Copenhagen, and the Thienemann Collection in Munich have been examined. M. albolineatus (Meigen, 1818) is a senior synonym of M. atratulus (Zetterstedt, 1850) and probably of M. hirticollis (Staeger, 1839); M. obscuripes (Holmgren, 1869) a senior synonym of M. eurynotus (Holmgren, 1883), M. transgressus (Holmgren, 1883), M. ripicola (Holmgren, 1883), and M. hygropetricus Kieffer, 1912. M. brevinervis (Holmgren, 1869) is a senior synonym of Paraphaenocladius despectus (Kieffer, 1926). M. atratulus subsp. corticalis Strenzke, 1950a is raised to the species level. M. atriclava sensu Edwards 1929 is probably not identical to M. atriclava Kieffer, 1921. A diagnosis for the genus is given. M. brusti sp.n. is described as male imago, female and pupa, and a possible variety of M. obscuripes as female imago, pupa and larva. M. obscuripes and M. ursinus (Holmgren, 1869) are redescribed in all stages and both sexes; M. albolineatus and M. fuscipes (Meigen, 1818) as male imago, pupa and larva; M. hirticollis as female imago; M. corticalis as male imago and pupa; and M. longipennis (Holmgren, 1883) and M. atriclava sensu Edwards as male imago. The importance of including extensive morphometric descriptions when doing revisionary studies is shown.

New species of Ichthyocladius Fittkau, a Member of the Corynoneura-Group (Diptera: Chironomidae: Orthocladiinae), with a Review of the Genus

Emended diagnoses of all stages of the genus Ichthyocladius Fittkau are given. The genus appears to be a basal member of the Corynoneura group showing affinities also to the Eukiefferiella group. A number of features apparently are the result of the phoretic life on catfishes. Ichthyocladius kronichticola sp. n. and I. lilianae sp. n. are described and figured in all stages. Additional pupae from the Amazonas in Brazil and from the Parque Nacional Iguazú in Argentina are also described and figured. Keys to pupae and larvae of the genus are given.

Orthocladiinae (Diptera: Chironomidae) from SE U.S.A., with descriptions of Plhudsonia, Unniella and Platysmittia n. genera and Atelopodella n.subgen

3 new genera and 1 new subgenus are described: Plhudsonia n.gen. apparently related to Austrobrillia Freeman; Georthocladius Strenzke subgen. Atelopodella n.subgen.; Unniella n.gen. near Mesosmittia Brundin, but with genitalia resembling the Parakiefferiella group; and Platysmittia n.gen. related to Mesosmittia Brundin and Unniella n.gen. The genera Antillocladius Sasther, Lipurometriocnemus Saether, Stilocladius Rossaro and Bryophaenocladius Thienemann are emended. A key to male imagines of Antillocladius is given. 10 new species are described: Plhudsonia partita, Antillocladius arcuatus, Antillocladius pluspilalus, Lipurometriocnemus vixlobatus, Psilometriocnemus cristatus, Atelopodella curticornus, Compterosmittia clavigera, Stilocladius clinopecten, Bryophaenocladius psilacrus, Unniella multivirga, and Platysmittia fimbriata. The description of Georthocladius (Atelopodella) curticornus is based on female, pupa and larva, while that of Psilometriocnemus cristatus and Stilocladius clinopecten includes male, female, pupa and larva; of Plhudsonia partita male and pupa, and the remaining ones are based on male imagines only. The South Carolina population of Diplocladius cultriger is compared with other Nearctic material and a male from Finse, Norway, and the possibility of non-conspecificity pointed out. Two unassociated pupae are described, one belonging to a genus near Brillia Kieffer, and one to a genus near Psilometriocnemus Saether. One peculiar, unassociated larva is described apparently related to Acamptocladius Brundin. The orthoclad fauna treated show strong evidence of an ancestral generalized track between the southeastern states and the Antilles as well as evidence of common Gondwanean origin with some related genera from the subantarctic islands of New Zealand.

Revision of the orthoclad genus Propsilocerus Kieffer (= Tokunagayusurika Sasa) (Diptera: Chironomidae)

Generic diagnoses to all stages of the genus Propsilocerus Kieffer, 1923 (= Tokunagayusurika Sasa, 1978, syn. n.) are given. Parsimony analyses of the primitive orthoclads show that either the more plesiomorphic genera of Orthocladiinae form a monophyletic group or Propsilocerus may be more closely related to less plesiomorphic groups. Chasmatonotus Loew forms its likely sister group. The genus is monophyletic in all cladograms. A synapomorphic diagram for Propsilocerus shows P. sinicus sp. n. forming the sister species of the other four species. Keys are given to all stages. Propsilocerus sinicus is described from male and female imagines and as pupa; P. akamusi (Tokunaga) is redescribed in all stages and in all larval instars; P. taihuensis (Wen, Zhou & Rong) comb. n. as male and female; P. paradoxus (Lundstrom) as male, female and pupa; and P. lacustris Kieffer is described in all stages.

Friederia, a new Afrotropical tanytarsine genus (Diptera: Chironomidae)

Generic diagnosis to the male imago of the new genus Friederia is given. Friederia villosa sp. n. from the rain forest of Western Ghana is described as male imago. Parsimony analyses of the subtribe Zavreliina of the tribe Tanytarsini of the subfamily Chironominae show that Friederia forms the sister genus of the unambiguously monophyletic Stempellinella Brundin with Zavrelia Kieffer as the sister group of the two combined, Neostempellina Reiss as the sister group of all three, and otherwise confirm previous phylogenetic analyses.