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SUMMARY. The drift of chironomid egg masses was investigated in the River Mole (Devon) and the River Wye (Powys) in 1981. Large numbers of egg masses were found in the drift just after dusk; on one occasion an estimated 50,000 egg masses passed a sampling point in 5 h. Oviposition of free-floating egg masses appeared to be initiated and synchronized by the onset of darkness. Egg masses of some Pentaneurini (Tanypodinae), Tanytarsini and Chironomini (Chironominae) were found in the drift and adhering to submerged stones. Flotation by means of a gas vacuole within the egg mass was observed in the Polypedilum ‘convictum’ group. The gas vacuole decreased in size over 8–11 h and the egg masses sank after 2–3h. Some chironomid egg masses are capable of drifting large distances after oviposition. The implications of sueh drift are briefly discussed in relation to the distribution of chironomid larvae.

Two new genera of Chironomini, Paraniloihauma gen.nov. and Neelamia gen.nov. are erected. Paranilothauma reissi spec. nov. is described from adult males and pupae; Neelamia fittkaui spec.nov. and Neelamia bergeri spec.nov. are described from adult males. All species were collected in the Amazon Valley of Brazil.

Nine rainpools in the savanna of northern Bolivia were examined using a random, semi‐quantitative sampling method. Both the macrophyte and insect assemblages showed that the longevity of a pool tended to be the dominant influence on the colonizing biota in the Tropics. Twenty‐four families of insects were recorded, including seven Heteroptera, five Odonata and five Diptera. The highly ephemeral (A‐)pools, which were dominated by beetles, differed from longer‐lived waters (B‐ and C‐pools). The composition of the insect assemblages in the B‐ and C‐pools formed a continuum, and the Chironomidae became more numerous and diverse with increasing water body longevity and habitat complexity. Out of the 20 recorded chironomid genera, three uncommon larval types are presented (Chironomini Gen X, "Tanytarsus”; (b), "Tanytarsus”; (dark L.o.). The study area is among the least researched in Bolivia, so many insects, and the chironomids in particular, are suspected as being newly discovered species.

SUMMARY. The chironomid fauna of a chalk stream in southern England is described from 1 year's catches of emerging adults and 2 year's quantitative samples of larvae on Common Clubrush, Schoertoplectus lacustris. The number of species in eaeh higher taxon as adult males and larvae on Schoenoplectus were: Tanypodinae, nine and three; Diamesinae, two for both; Orthoeladiinae, 26 for both; Chironomini. twelve and six; Tanytarsini, seven and five, respectively. A total of 66 species was recorded for both life stages. Adult Orthocladiinae were caught throughout the year. Tanytarsini were absent for a few weeks in winter, and Tanypodinae and Chironomini were caught for shorter periods in warmer months. Chironomids 93.5% of the total invertebrates on Schoenoplectus. Life histories are deseribed for seven speeies that formed 91% of the identified chironomids (32% of the total were unidentifiable first and second instar larvae). Four of these life histories appear for the first time. All seven species were multivoltine and had continuous recruitment for part of the year. The species diversity of larvae was mostly in the range 1.5–3.0 and it was determined more by equitability than by species richness. The numbers of chironomids through time were dependent on the weight of detritus on the leaves (r2= 0.69) and the availability of detritus therefore partly controlled their population size.

An emergence trap was operated for two years on a chalk stream in southern England. AH species of aquatic Diptera except Simuliidae and females of Chironomidae and Psychodidae were identified. Chironomidae formed 97% of the total Diptera and 81 species were recorded. Some of the nine species of Ceratopogonidae were occasionally numerous. No other family was important. Differences in the fauna between years were related to changes in the flow regime. Numbers of both species and individuals of Chironomini and Tanypodinae were notably higher in a severe drought than in more typical conditions. Many species had long flight times which in some cases may have been due to polyvoltinism. A comparison of temperatures in streams in which Chironomidae had been studied in southern England and Germany suggested that more generations could be completed in the more temperate English streams. Neozavreliafuldensis and Paratanytarsus lauterborni were new to Britain and a species of Palpomyia may be new to science.

Sixteen floating, box type emergence traps, each covering 0.1 m2, were placed along 150 m of a third-order stretch of the Bigoray River, a slow-flowing, vegetation-choked, brown-water muskeg stream. Effects of trap design, trap shading, length of sampling interval, and stream velocity on the number of midges caught was examined. Of the 112 species of Chironomidae caught, 32 species made up 90% of the catch and their emergence phenology is described in detail. There were more rare species than expected from Preston's lognormal distribution. Percentage of Bigoray species belonging to Tanypodinae, Orthocladiinae, Chironomini and Tanytarsini was 18%, 43%, 20%, and 19%, and was compared with 27 other studies on lotic chironomids. During the 140-day emergence period an average of 19.3 × 103 chironomids emerged per square meter of stream. Based on changes in male:female ratios throughout a species emergence period, it was postulated that 30% of the Bigoray chironomid species were univoltine, 50% were bivoltine, and 20% were trivoltine.

Some streams near Dorset in south-central Ontario suffer from acid precipitation via run-off and seepage from thin soils with little buffering capacity. A spring-summer survey of eight headwater streams revealed some characteristics of their insect communities which could be correlated with pH. The streams could be divided into three groups according to pH and community structure. In the most acid group (annual pH range 4.3–4.8), Ephemeroptera were absent from two streams although mature Leptophlebia were collected just after spring thaw from the most acid one (pH 4.3–4.5). One of these three streams also lacked Plecoptera but the others had two or three genera, all shredders. The second group of three streams (pH 5.0–6.3), with one exception, did support Ephemeroptera (3–4 genera) and Plecoptera (1–4 genera), most of the latter being shredders. In all six of these acid streams, Trichoptera were more diverse and more dense than Ephemeroptera and Plecoptera; again, shredders were clearly dominant, especially the limnephilid caddisfly, Frenesia difficilis (Walker). These six streams also had similar chironomid communities (densities were an order of magnitude higher than other insects). Dominance by Chironomini and abundant Tanypodinae typified the most acid streams. In contrast, the two streams in the third group (pH 5.3–6.7) had richer and more balanced communities in general with relatively fewer shredders (no Frenesia), more collectors, and fewer Chironomini and Tanypodinae. As a field experiment showed that autumn-shed leaves decomposed more slowly in acid than in non-acid streams, summer-growing shredders may benefit from the pulse of acidity at snowmelt.

The sequence of qualitative and quantitative changes in the chironomid fauna of Laurel Creek Reservoir over the thirteen years of its existence are presented. There was a substantial decrease in the average numerical abundance Pram 1967 (6303m−2) to 1968 (3373m−2), and it has remained stable since (3166m−2 in 1975, 2856m−2 in 1980). There have been distinct changes in the faunal numerical abundance, although the genera have remained the same. In 1967, the Chironomini (Chironomus >Glyptotendipes) comprised 95% of the total throughout the year. In 1968, the Chironomini dominated (68%) the Tanytarsini increased (24%) and the Tanypodinae (6%) and Orthocladiinae (2%) remained low. In 1975, the Chironomini (Chironomus > Glyototendipep ≈ Cladopelma) (72%) and the Tanypodinae (Procladius) (21%) increased, the Tanytarsini decreased (5%) and the Orthocladiinae remained low (2%). By 1980, the Tanypodinae (Procladius) had become dominant (60%) while the Chironomini (Chironomus > Cladopelma > Glyptotendipes) ...

The tracheal systems of 142 chironomid larvae (42 species) were examined. These tracheal patterns showed considerable variation, both between subfamilies, and within a particular subfamily. The dorsal trunks, lateral trunks, dorsal anastomoses, and subcuticular tracheation were the major tracheal components examined in this study. Orthocladiinae, Diamesinae and Tanypodinae larvae exhibit the most extensive tracheal systems differing mainly in the placement of anastomoses. In some Podonominae species the tracheal system extends only to abdominal segment 8, where the trunks merge to form an open spiracle. Other podonomines, though not examined, are apneustic. The Chironominae tracheal system appears to extend the entire length of the larva, but only certain portions of it are filled with air. In Tanytarisini air is present in the thoracic tracheae and the terminal abdominal tracheae. In some Chironomini, air is present only in the thoracic tracheae, while other members of this tribe exhibit the 'Tanytarsini' pattern. The phylogeny of the Chironomidae, and the effects of environmental factors on the tracheal system are discussed.

Dead Man Lake (elevation 2,800 m) is one of several hundred shallow lakes on the flat, rolling crest of the Chuska Mountains. The lacustrine sediments consist of 7 to 10 m late—Pleistocene sandy silt or fine sand beneath only 0.1 to 0.3 m Holocene organic mud. Five faunal zones in the Pleistocene sediments contain distinctive assemblages of Cladocera and larval Chironomidae. The Chydoridae were the dominant Cladocera during Wisconsin glaciopluvial time, but only two or three species occurred in any of the zones. Tanytarsini and Procladius (Tanypodinae) were usually the dominant Chironomidae; populations of Orthocladiinae and Chironomini were smaller and chronologically discontinuous. The Pleistocene fauna is an impoverished as in other Pleistocene lake sediments and in modern arctic lakes. Therefore the faunal assemblages support the palynological evidence for alpine conditions on the crest of the Chuska Mountains during Wisconsin glaciopluvial time. The organic mud deposited since the end of the Pleistoc...

Additional references and information on most of the topics covered here may be found in this excellent book. Even with this restriction a high degree of selection is necessary and most of the papers on genetics, physiology, pro­ ductivity and biomass, and fish food are not considered. Many of the papers cited have been chosen because they are most likely to be useful for fur­ ther reference. CLASSIFICATION It seems necessary to comment briefly on the reasons for the confusion which exists in the classification of the Chironomidae. Part of the confusion arises from the dual use of two family names. The name Tendipes Meigen 1800 was used rather than Chironomus Meigen 1803 by many taxonomists as the type genus of the family. A recent ruling of the International Com­ mission on Zoological Nomenclature has suppressed the Meigen 1800 names in favor of his 1803 names (se e Fittkau 39). As a result, the name Ten­ dipes was suppressed in favor of Chironomus, and similarly Pelopia was suppressed in favor of Tanypus. This action means that the correct name of the family is Chironomidae not Tendipedidae. Furthermore, it also estab­ lishes that the subfamily names Chironominae and Tanypodinae are correct. Although not covered by a ruling it is generally accepted that Orthocladii­ nae be used in place of Hydrobaeninae. Tanytarsus has been used as a ge­ nus in the tribe Chironomini, but another ruling (Bull. Zool. Nom. 18, Opin­ ion 616) established it as a genus in the tribe Tanytarsini. The classification of holometabolous insects presents special difficulties because the characteristics of all the life stages must be considered. Differ­ ent ecological requirements of each stage often result in greater diversity, both ecological and morphological, in one stage than in another. The adults of the Chironomidae are usually more uniform in stru cture than are the immature stages, especially the larvae. The adult stage is somewhat ephem

The composition and succession of the subfossil chironomid fauna has been studied in a sediment core from Lake Taylor. The sediments of the core are all within the Nothofagus phase of the last 3000 years within the Aranuian. In the older sediments of the core the chironomid fauna was dominated by Tanytarsini and Orthocladiinae whereas Chironomini dominated in the more recent sediments. The species diversity is very high compared with the results of other studies of the recent chironomid fauna of lakes in the South Island. The most abundant head capsules belong to the taxa Chironomus zealandicus, Tanytarsus vespertinus, Corynocera sp., and Eukiefferiella sp. Several additional taxa which have not yet been described also occurred in large numbers. It is not possible to correlate any definite changes in the composition of the subfossil chironomid fauna with a change in climatic conditions or the trophic status of the lake.

Drift nets were placed in the stream for 24 hour periods twice each month. Pupal exuviae and larvae were examined. Results of 6 months of sampling are given. Five major taxa of Chironomidae were found: Chironomini (dominant), Orthocladiinae, Tanytarsini, Tanypodinae, and Diamesinae. Forty-two genera were identified. Future work is outlined.

A comparison of the chironomid fauna of the western Palaearctic and the Aethiopian faunal region demonstrates: Africa contains a relatively low number of species. The majority of genera belongs to phylogentic more recent groups. Phylogenetic old taxa are limited in their distribution to the regions of Southern Africa with temperate climatic conditions. Diamesinae are almost missing in Africa. Orthocladiinae are highly represented belonging to the same genera as in the Palaearctic. There is a high number of African endemie genera of Chironomini; Pseudochironomini, abundant in the Neotropic, are missing.

Aspects of physicochemical limnology and the zooplankton, littoral invertebrates and fish of dune lakes on Fraser Island are described and compared. The comparisons highlight differences between perched, humic lakes and the non-humic Lake Wabby, a water-table window with some morphometric and biological features typical of dune barrage lakes. Lake Wabby has been partially infilled by a mobile sand dune moving mainly in a north-westerly direction across the northern end of the lake. The maximum rate of dune advance estimated from aerial photos was 5.03 m year-1, between 1948 and 1958. Sand infilling between 1975 and 1984 altered the morphometry and substrate characteristics of the lake's eastern region and reduced maximum depth from 13.0 to 11.5 m and volume by 43%. The number of benthic invertebrates was reduced from 14 taxa in 1975 to six taxa in 1984; there was also a significant decrease in abundance of benthic Chironomini during this period (ANOVA, P < 0.05). In both years, an undescribed species of Conochironomus was the most abundant benthic invertebrate in Lake Wabby (250-700 individuals m-2). A new genus of Chironomini (near Paralauter borniella) was discovered. Lake Wabby supported 11 species of fish in 1975 and 1984, but the perched lakes had only one or two species. The five most abundant species in Lake Wabby in 1975 showed evidence of partitioning of food resources, of which the main components were benthic invertebrates and filamentous algae. Allochthonous food resources were not important in fish diets. The possible long-term effects of sand infilling on food resources, fish diets and the composition of the zooplankton in Lake Wabby are discussed.