suspended material (seston), including living organisms and both organic and inorganic detritus. Filter-feeding insects constitute important pathways for energy flow and are very important in the productivity of aquatic environments. Yet, some of these animals epitomize the complex relation­ ship between man and insects since biting adults of certain groups are among man's oldest adversaries. The major objectives of this article are to review the means by which filter-feeding insects obtain their food and to assess the role of these animals in aquatic ecosystems. Filter-feeding strate­ gies by other invertebrates in both marine and freshwater habitats have been partially reviewed elsewhere (82, 100, 101).

Filter-feeding ecology of aquatic insects

Thirty‐four genera belonging to the Gondwanian subfamily Atalophlebiinae are known from the Neotropics. Development of the lower Central American isthmus was marked only by dispersal of Gondwanian Atalophlebiinae from South America into Central America. No member of the Laurasian subfamily, the Leptophlebiinae, has dispersed from North America into Central or South America. The Antilles were colonized entirely by Atalophlebiinae from South and Central America. Genera of Neotropical Atalophlebiinae are placed into one of two faunal components: either the Patagonian Shield, South Andean, Cold‐Adapted Genera; or the Guiana & Brazilian Shields, Warm‐Adapted Genera. The 10 Patagonian Shield Genera are primarily associated with cold‐water streams of southern South America. Secondary diversification has occurred in the southern coastal mountains of Brazil, and at high elevations in the central and northern Andes. Phylogenetically, Patagonian Shield Genera are related to diverse genera on several Gondwanian conti...

Biogeographic classification of the Neotropical Leptophlebiidae (Ephemeroptera) based upon geological centers of ancestral origin and ecology

Abstract Leptophlebiidae is among the largest and most diverse groups of extant mayflies (Ephemeroptera), but little is known of family‐level phylogenetic relationships. Using two nuclear genes (the D2 + D3 region of 28S ribosomal DNA and histone H3) and maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI), we inferred the evolutionary relationships of 69 leptophlebiids sampled from six continents and representing 30 genera plus 11 taxa of uncertain taxonomic rank from Madagascar and Papua New Guinea. Although we did not recover monophyly of the Leptophlebiidae, monophyly of two of the three leptophlebiid subfamilies, Habrophlebiinae and Leptophlebiinae, was recovered with moderate to strong support in most analyses. The Atalophlebiinae was rendered paraphyletic as a result of the inclusion of members of Ephemerellidae or the Leptophlebiinae clade. For the species‐rich Atalophlebiinae, four groups of taxa were recovered with moderate to strong branch support: (i) an endemic Malagasy clade, (ii) a Paleoaustral group, a pan‐continental cluster with members drawn from across the southern hemisphere, (iii) a group, uniting fauna from North America, southeast Asia and Madagascar, which we call the Choroterpes group and (iv) a group uniting three New World genera, Thraulodes, Farrodes and Traverella. Knowledge of the phylogenetic relationships of the leptophlebiids will aid in future studies of morphological evolution and biogeographical patterns in this highly diverse and speciose family of mayflies.

Phylogenetic relationships of leptophlebiid mayflies as inferred by histone H3 and 28S ribosomal DNA

The leptophlebiid mayfly fauna of New Zealand at present consists of three named genera, of which two are clearly polyphyletic. Analysis of these elements and addition of undescribed genera indicate the presence of at least 14 genera. The genera can be divided into five lineages which exhibit varying degrees of radiation within New Zealand and which show evolutionary progression in a number of character states. Four genera appear to be most closely related to genera in New Caledonia, two to generic groups in Chile, and the remainder to other genera in New Zealand, except for one genus for which the nearest known relatives are in New Guinea.

Phylogenetic Relationships of the Leptophlebiidae of New Zealand (Ephemeroptera)

Atalophlebioides Phillips is redescribed as a monotypic genus endemic to New Zealand All life stages of A cromwelli (Phillips) are described, and a lectotype is designated The relationships of the genus and the ecology of A cromwelli are discussed

G.Jr Edmunds

Papers

Revision of the generic classification of the Eastern Hemisphere Leptophlebiidae (Ephemeroptera)