Molecular phylogeny of the fungus gnat tribe Exechiini (Mycetophilidae, Diptera)

The phylogenetic relationships within the fungus gnat tribe Exechiini have been left unattended for many years. Recent studies have not shed much light on the intergeneric relationship within the tribe. Here the first attempt to resolve the phylogeny of the tribe Exechiini using molecular markers is presented. The nuclear 18S and the mitochondrial 16S, and cytochrome oxidase subunit I (COI) genes were successfully sequenced for 20 species representing 15 Exechiini genera and five outgroup genera. Bayesian, maximum parsimony and maximum likelihood analyses revealed basically congruent tree topologies and the monophyly of Exechiini, including the genus Cordyla , is confirmed. The molecular data corroborate previous morphological studies in several aspects. Cordyla is found in a basal clade together with Brachypeza , Pseudorymosia and Stigmatomeria . The splitting of the genera Allodiopsis s.l. and Brevicornu s.l. as well as the sistergroup relationship of Exechia and Exechiopsis is also supported. The limited phylogenetic information provided by morphological characters is mirrored in the limited resolution of the molecular markers used in this study. Short internal and long-terminal branches obtained may indicate a rapid radiation of the Exechiini genera during a short evolutionary period.     

The sequoia-loving sprite,a new genus and species of fungus gnat (Diptera,Mycetophilidae) from California

California is one of the most biologically diverse regions of the world, yet the diversity of fungus gnats (Mycetophilidae) remains largely undocumented within the state. A modest survey of these flies has led to the discovery of a new genus and species of gnat that lives alongside one of the most iconic trees in the world, the giant sequoia (Sequoiadendron giganteum). Spritella sequoiaphilagen. et sp. n. is described and illustrated and its status among other mycetophilid genera is analyzed and discussed.     

Katatopygia gen. n., a monophyletic branch segregated from Boletina (Diptera, Mycetophilidae)

The genus Katatopygia gen. n. is proposed for the Boletina erythropyga/punctus-group that was first introduced by Garrett (1924, 1925) and currently comprises eight described species. Molecular studies have strongly indicated that this group forms a monophyletic sister-group to a clade consisting of all other Boletina, Coelosia and Gnoriste, and its monophyly is supported by morphological data as well. The new genus includes the following species: Katatopygia antoma (Garrett, 1924), comb. n., Katatopygia antica (Garrett, 1924), comb. n., Katatopygia erythropyga (Holmgren, 1883), comb. n.,Katatopygia hissarica (Zaitzev & Polevoi, 2002), comb. n., Katatopygia magna (Garrett, 1925), comb. n., Katatopygia laticauda (Saigusa, 1968), comb. n., Katatopygia neoerythropyga (Zaitzev & Polevoi, 2002), comb. n. andKatatopygia sahlbergi (Lundström, 1906), comb. n., all transferred from Boletina. Katatopygia sahlbergi is found to be a senior synonym of Boletina punctus Garrett, 1925, syn. n. A phylogeny based on morphological data and using parsimony analysis yielded four most parsimonious trees where the new genus is retrieved as monophyletic with high support. Katatopygia neoerythropyga is found to be the sister-taxon to all other species that form two clades, one with Katatopygia sahlbergi-like species and one with Katatopygia erythropyga-like species. A key to males of Katatopygia is provided.     

On the systematics of the fungus gnat subfamily Mycetophilinae (Diptera): a combined morphological and molecular approach

The phylogenetic relationships within the fungus gnat subfamily Mycetophilinae (Diptera) are addressed using a combined morphological and molecular approach. Twenty-four species, representing nine genera of the tribe Mycetophilini and 15 genera of the tribe Exechiini, were included in the study. Analyses include nucleotide sequences of mitochondrial (cytochrome oxidase I and 16S), and nuclear (18S and 28S rDNA) genes, in addition to 65 morphological characters. A combined parsimony analysis, including all characters, supports the monophyly of the subfamily Mycetophilinae and two of its tribes, Exechiini and Mycetophilini. There is also statistical support for a Mycetophila- group and a Phronia- group within the tribe Mycetophilini. The Phronia- group includes the genera Phronia , Macrobrachius and Trichonta . The Mycetophila- group includes the genera Mycetophila , Epicypta , Platurocypta , Sceptonia and Zygomyia . A Bayesian analysis based on the nucleotide sequences alone also support these clades within Mycetophilini except for the position of Dynatosoma which is recovered as the sister taxon to the Phronia- group. A somewhat different pattern, however, is observed for the tribe Exechiini – neither molecular data nor the combined data set support unambiguously any intergeneric relationships within Exechiini.     

Pollination by fungus gnats (Diptera: Mycetophilidae) and self-recognition sites in Tolmiea menziesii (Saxifragaceae)

Coleeae (Bignoniaceae) are a tribe almost entirely restricted to Madagascar. Coleeae have previously been placed in neotropical Crescentieae due to species with indehiscent fruits, a character otherwise unusual in Bignoniaceae. A phylogeny based on three chloroplast regions (ndhF, trnT-L spacer, trnL-F spacer) identifies a monophyletic Coleeae that is endemic to Madagascar and surrounding islands of the Indian Ocean (Seychelles, Comores and Mascarenes). African Kigelia is not a member of Coleeae, rather it is more closely related to a subset of African and Southeast Asian species of Tecomeae. The molecular phylogeny indicates that indehiscent fruit have arisen repeatedly in Bignoniaceae: in Coleeae, Kigelia and Crescentieae. The characteristic fleshy fruits of species of Coleeae likely arose autochthonously in Madagascar. Within Coleeae Colea and Ophiocolea are sisters, Phyllarthron is sister to Colea + Ophiocolea, and Rhodocolea is sister to the rest of the tribe.     

Quantitative sampling method for fungus gnat (Diptera: Sciaridae) eggs in soilless growing media

A simple method is described for separating fungus gnat eggs from soilless growing media. The flotation/extraction method primarily involves the use of a MgSO4 solution (density 1.065 g cm(-3)) and a series of sieving procedures. Bradysia sp. nr. coprophila Lintner eggs were collected in an isolation chamber containing adult fungus gnats. Three soilless growing media were used: Metro-Mix 560 with Scott's Coir, Sunshine LC1 Mix, and Universal SB 300 Mix. Each growing medium was inoculated with 100 fungus gnat eggs. Growing medium samples were processed using separatory funnels and a MgSO4 solution. Eggs were washed through a 250-microm sieve and collected on a 53-microm sieve, and then the eggs were rinsed into glass petri dishes. The sieving process separated fungus gnat eggs from the larger growing medium particulates (perlite, bark, and peat), providing a sample consisting of water, eggs, and fine growing medium particulates (peat). Using a vortex for 60 s increased the number of fungus gnat eggs recovered (37.4 +/- 3.7-67.1 +/- 1.9 [mean +/- SEM]) for all three growing media. The mean number of fungus gnat eggs recovered from the three soilless growing media was significantly different, with the growing medium containing coir (Metro-Mix 560) having the highest recovery rate of 61.0 +/- 2.1. For all three growing media, there was > 50% recovery of fungus gnat eggs. In addition to fungus gnat eggs, this method also may prove useful for quantitative recovery of shore fly (Scatella sp.) eggs and the eggs of other arthropods from soilless growing media.     

Field and laboratory observations on the substrates of the mushroom fungus gnat Lycoriella auripila (Diptera: Sciaridae)

The movements of Psila rosae larvae were studied under field and laboratory conditions. In the field, larvae moved up to 60 cm along and between carrot rows, although more larvae moved during the first generation than the second. Sudden increases in soil moisture, and not its prevailing level, stimulated the larvae to move from carrots into the soil surrounding the roots. Up to 50% of the larvae that left their mines in carrots following a sudden increase in soil moisture did not return to the same mine. Evacuation of mines by larvae appears to be a reflex response to the flooding of their mine and might be connected with the production of toxic conditions within the mine following flooding.     

Towards a phylogeny and definition of species at the molecular level within the genus Mycobacterium

16S rRNA sequences from Mycobacterium tuberculosis, M. avium, M. gastri, M. kansasii, M. marinum, M. chelonae, M. smegmatis, M. terrae, M. gordonae, M. scrofulaceum, M. szulgai, M. intracellulare, M. nonchromogenicum, M. xenopi, M. malmoense, M. simiae, M. flavescens, M. fortuitum, and M. paratuberculosis were determined and compared. The sequence data were used to infer a phylogenetic tree, which provided the basis for a systematic phylogenetic analysis of the genus Mycobacterium. The groups of slow- and fast-growing mycobacteria could be differentiated as distinct entities. We found that M. simiae occupies phylogenetically an intermediate position between these two groups. The phylogenetic relatedness within the slow-growing species did not reflect the Runyon classification of photochromogenic, scotchromogenic, and nonchromogenic mycobacteria. In general, the phylogenetic units identified by using rRNA sequences confirmed the validity of phenotypically defined species; an exception was M. gastri, which was indistinguishable from M. kansasii when this kind of analysis was used.     

A molecular phylogeny for the frog genus Limnodynastes (Anura: myobatrachidae)

Members of the genus Limnodynastes are a prominent and widespread feature of the Australian frog fauna. Yet despite their potential to be informative about biogeographic history and mechanisms of speciation, the relationships among these taxa are not well known. We investigated phylogenetic relationships within the genus Limnodynastes via sequencing of mitochondrial (mt)DNA from current members of the genus Limnodynastes and the monotypic genus Megistolotis. a 450-bp fragment of the 16S rRNA gene and a 370-bp fragment of the protein-coding gene ND4 were used to infer a molecular phylogeny. We revise traditional species groupings and now recognize four species groups within Limnodynastes: the L. ornatus group (L. ornatus and L. spenceri), the L. peronii group (L. peronii, L. tasmaniensis, L. fletcheri, the L. depressus), the L. salmini group (L. salmini, L. convexiusculus, and L. lignarius), and the L. dorsalis group (L. dorsalis, L. terraereginae, L. dumerilii and L. interioris). The L. ornatus species group forms a highly distinctive clade that is a sister group to the other Limnodynastes groups. Pending broader phylogenetic studies it could be removed from the genus Limnodynastes. Our results concur with previous suggestions that Megistolotis lignarius is nested within Limnodynastes, and we therefore reclassify this species as Limnodynastes lignarius. Furthermore, specimens identified as L. depressus form a mtDNA lineage distinct from other species in the genus, confirming the validity of the species. Specimens of species from the L. dorsalis group (L. dorsalis, L. dumerilii, L. interioris, and L. terraereginae) are closely related such that L. dumerilii is paraphyletic with two other species. Finally, our study provides broad support for previous phylogenies based on microcomplement fixation.     

Molecular phylogeny and host use evolution of the genus Exorista Meigen (Diptera: Tachinidae)

Members of the genus Exorista are parasitoids of a diverse array of insect hosts in the orders, Lepidoptera, Hymenoptera, Mantodea and Orthoptera. Phylogenetic relationships among subgenera and species of Exorista were inferred using four nuclear (Tpi, white, 18S and 28S) and four mitochondrial DNA (16S, 12S, ND5 and CO1) genes in maximum parsimony (MP), maximum likelihood (ML) and Bayesian Markov chain Monte Carlo (MCMC) analyses. Separate trees based on different sets of genes (mt DNA, nuclear, ribosomal, etc.) were compared and found to be nearly concordant. According to the molecular tree generated from the concatenated sequence data, the genus Exorista is paraphyletic. The phylogenetic analyses indicate the existence of two major clades of Exorista, including two genera Parasetigena and Phorocera. Morphological traits supporting clades indicated by molecular analyses within this genus are evaluated. Evolutionary patterns of the host use and host shifts are examined by optimizing host information using maximum likelihood on the molecular phylogeny. The ancestral host group of the tribe Exoristini (excluding Ctenophorinia and Phorinia) appears to be the order Lepidoptera, although hosts of some species are unknown. A major host shift to the Hymenoptera occurred in the clade of subgenus Adenia, and the ancestral state of subgenus Spixomyia is equivocal because there is little information available on the hosts in members of a subclade of this group (subclade A: Exorista hyalipennis group).     

A molecular phylogeny of warbling-finches (Poospiza): paraphyly in a neotropical Emberizid genus

We investigated the phylogenetic relationships of 12 species within a single genus of neotropical passerine (Poospiza) using 849 bp (283 codons) of the cytochrome b mitochondrial gene. We further explored evolutionary affinities of these taxa using sequence from an additional 47 thraupine (tanagers) and 7 emberizine (sparrows and buntings) genera, members of the predominantly New World family Emberizidae. Poospiza have traditionally been considered part of the emberizine radiation. However, our analyses suggest that members of this genus are more closely related to some thraupine lineages than they are to the other neotropical emberizine genera included in our study (Atlapetes, Embernagra, Melopyrrha, Phrygilus, Saltatricula, Tiaris). Although member taxa are closely related, the genus Poospiza appears to be paraphyletic with representatives of 6 thraupine genera (Cnemoscopus, Cypsnagra, Hemispingus, Nephelornis, Pyrrhocoma, Thylpopsis) interspersed among four well-supported Poospiza clades. The majority of species within this Poospiza-thraupine clade have geographic ranges that are exclusive to, or partially overlap with, the Andes Mountains. It is probable that these mountains have played an important role in driving cladogenesis within this group. Sequence divergence (transversions only; mean 4.7+/-1.3%) within the clade suggests that much of this diversification occurred within the late Miocene and Pliocene, a period coincident with major orogenic activity in central-western South America.     

A molecular phylogeny of the genus Ichthyocotylurus (Digenea, Strigeidae)

Three nucleotide data sets, two nuclear (ribosomal internal transcribed spacer regions 1 and 2, ITS1 and ITS2) and one mitochondrial (cytochrome c oxidase subunit 1, CO1), were analysed using distance matrix and maximum likelihood methods to determine the inter-relationships amongst the four species attributed to the genus Ichthyocotylurus Odening, 1969. Sequence data obtained from all gene loci investigated supported the position of Ichthyocotylurus variegatus as a species discrete from Ichthyocotylurus platycephalus. Phylogenetic analyses yielded congruent trees, with I. variegatus isolates comprising a common clade to which I. platycephalus constitutes a sister taxon. Ichthyocotylurus erraticus and Ichthyocotylurus pileatus were found to demonstrate a similarly close inter-specific relationship. The greatest intra-generic divergence occurred in the CO1 region (16% variability), with resultant disparities in three to eight encoded amino acids. PCR amplification yielded multiple ITS1 products for all Ichthyocotylurus spp. Analyses of equivalent-sized amplicons showed 5.4% intra-generic variation and several point mutations between I. variegatus isolates from different geographical localities and from different piscine hosts. The ITS2 locus was extremely conserved, with less than 1% variation between species. No intra-specific variation was recorded for any CO1 or ITS2 sequences.     

The molecular phylogeny of Alpinia (Zingiberaceae): a complex and polyphyletic genus of gingers

Alpinia is the largest, most widespread, and most taxonomically complex genus in the Zingiberaceae with 230 species occurring throughout tropical and subtropical Asia. Species of Alpinia often predominate in the understory of forests, while others are important ornamentals and medicinals. Investigations of the evolutionary relationships of a subset of species of Alpinia using DNA sequence-based methods specifically test the monophyly of the genus and the validity of the previous classifications. Seventy-two species of Alpinia, 27 non-Alpinia species in the subfamily Alpinioideae, eight species in the subfamily Zingiberoideae, one species in the subfamily Tamijioideae, and three species in the outgroup genus Siphonochilus (Siphonochiloideae) were sequenced for the plastid matK region and the nuclear internal transcribed spacer (ITS) loci. Parsimony analyses of both individual and combined data sets identified six polyphyletic clades containing species of Alpinia distributed across the tribe Alpinieae. These results were supported by a Bayesian analysis of the combined data set. Except in a few specific cases, these monophyletic groupings of species do not correspond with either Schumann's (1904) or Smith's (1990) classification of the genus. Here we build on previous molecular analyses of the Alpinioideae and propose the next steps necessary to recognize new generic boundaries in the Alpinieae.     

Taxonomy and preliminary phylogeny of the parasitic genus Apocephalus, subgenus Mesophora (Diptera: Phoridae)

Abstract. The species of Apocephalus , subgenus Mesophora , are revised and twenty-eight species are recognized, including the following twenty-two new to science: from the Nearctic Region A. brunnipes, A. gemursus, A. pristinus, A. setialvus and A. unitarsus , and from the Neotropical Region A. absentis, A. adustus, A. anfractus, A. angustistylus, A. bisetus, A. brevicercus, A. curtus, A. gracilis, A. hansoni, A. leptotarsus, A. longistylus, A. micrepelis, A. moraviensis, A. prolatus, A. trisetus, A. tritarsus and A. truncaticercus. Additionally, three species known only from female specimens are described but not formally named. A lectotype is designated for A. mortifer Borgmeier, and immature stages of A. borealis, A. antennatus and A. mortifer are described. Unlike larvae of other Apocephalus species, all of which are parasites of ants (Hymenoptera: Formicidae), those of Mesophora species are parasites of various other hosts.     

Evolutionary history of Stratiomyidae (Insecta: Diptera): the molecular phylogeny of a diverse family of flies

Stratiomyidae is a cosmopolitan family of Brachycera (Diptera) that contains over 2800 species. This study focused on the relationships of members of the subfamily Clitellariinae, which has had a complicated taxonomic history. To investigate the monophyly of the Clitellariinae, the relationships of its genera, and the ages of Stratiomyidae lineages, representatives for all 12 subfamilies of Stratiomyidae, totaling 68 taxa, were included in a phylogenetic reconstruction. A Xylomyidae representative, Solva sp., was used as an outgroup. Sequences of EF-1alpha and 28S rRNA genes were analyzed under maximum parsimony with bootstrapping, and Bayesian methods to recover the best estimate of phylogeny. A chronogram with estimated dates for all nodes in the phylogeny was generated with the program, r8s, and divergence dates and confidence intervals were further explored with the program, multidivtime. All subfamilies of Stratiomyidae with more than one representative were found to be monophyletic, except for Stratiomyinae and Clitellariinae. Clitellariinae were distributed among five separate clades in the phylogeny, and Raphiocerinae were nested within Stratiomyinae. Dating analysis suggested an early Cretaceous origin for the common ancestor of extant Stratiomyidae, and a radiation of several major Stratiomyidae lineages in the Late Cretaceous.     

Molecular phylogeny of black fungus gnats (Diptera: Sciaroidea: Sciaridae) and the evolution of larval habitats

The phylogeny of the family Sciaridae is reconstructed, based on maximum likelihood, maximum parsimony, and Bayesian analyses of 4809 bp from two mitochondrial (COI and 16S) and two nuclear (18S and 28S) genes for 100 taxa including the outgroup taxa. According to the present phylogenetic analyses, Sciaridae comprise three subfamilies and two genus groups: Sciarinae, Chaetosciara group, Cratyninae, and Pseudolycoriella group + Megalosphyinae. Our molecular results are largely congruent with one of the former hypotheses based on morphological data with respect to the monophyly of genera and subfamilies (Sciarinae, Megalosphyinae, and part of postulated “new subfamily”); however, the subfamily Cratyninae is shown to be polyphyletic, and the genera Bradysia, Corynoptera, Leptosciarella, Lycoriella, and Phytosciara are also recognized as non-monophyletic groups. While the ancestral larval habitat state of the family Sciaridae, based on Bayesian inference, is dead plant material (plant litter + rotten wood), the common ancestors of Phytosciara and Bradysia are inferred to living plants habitat. Therefore, shifts in larval habitats from dead plant material to living plants may have occurred within the Sciaridae at least once. Based on the results, we discuss phylogenetic relationships within the family, and present an evolutionary scenario of development of larval habitats.     

A molecular phylogeny of the hawkmoth genus Hyles (Lepidoptera: Sphingidae, Macroglossinae)

The hawkmoth genus Hyles is one of 15 genera in the subtribe Choerocampina of the subfamily Macroglossinae. Due to a remarkable uniformity, morphological characters usually used to identify and classify Lepidoptera at the species level cannot be used in this genus. Instead, we used DNA sequences comprising about 2300 bp derived from the mitochondrial genes COX I, COX II, and tRNA-leucine to elucidate the phylogeny of Hyles. The results corroborate the monophyly of Hyles but conflict with previous internal classifications of the genus based on morphology. Hyles seems to have evolved in the Neotropics during the Oligocene/Eocene epochs and the molecular data (which evolved clock-like) confirm the hypothesis that it is a very young genus that radiated on a global scale rather quickly. We hypothesize its sister group to be one of the genera Deilephila, Theretra or Xylophanes. The Nearctic may have been colonized rapidly by Hyles once the land bridge formed during the Pliocene, since within this same Epoch, the invasion of the Palaearctic appears to have proceeded from the East, via the Bering route. The colonization of Australia appears to have occurred rather early in Hyles radiation, although the route is not clear. We propose that the radiation of the Hyles euphorbiae-complex s. str. (HEC) occurred as recently as the Pliocene/Pleistocene boundary and that its roots can still be reconstructed in Asia. Hyles dahlii is closely related to the HEC, but a sister group relationship to the HEC s. str. cannot be corroborated unequivocally. HEC population ranges appear to have tracked climate oscillations during the Pleistocene Ice Ages, resulting in hybridization around the Mediterranean Sea as they repeatedly intermingled. Comparison of the phylogeny with food plant affiliations leads us to hypothesize that Euphorbia monophagy evolved at least two times independently within Hyles.     

Egg-laying preference of female fungus gnat Bradysia sp. nr. coprophila (Diptera: Sciaridae) on three different soilless substrates

Fungus gnats, Bradysia spp., are major insect pests in greenhouses. Adult female fungus gnats prefer to lay eggs in growing medium that is microbially active or that contains high amounts of peat moss or hardwood bark. However, egg-laying preference has not been demonstrated quantitatively. This study was designed to determine whether fungus gnat Bradysia sp. nr. coprophila females prefer any of the three soilless growing media provided. The three soilless growing media tested were Metro-Mix 560 with Scott's Coir, Sunshine LC1 Mix, and Universal SB 300 Mix. Initially, the egg-laying potential of the fungus gnat species used in this study was assessed by dissecting mated females after 24, 48, and 72 h. For the egg-laying preference experiment, adults that emerged from pupae were aspirated into a plastic vial, sexed, and then allowed to mate for 24 h. Individual mated females were released into an experimental chamber (15 by 15 by 5-cm plastic container) consisting of four 6-cm petri dishes, three of which contained soilless growing media and one with filter paper (control). In total, there were 50 experimental chambers, with each chamber representing a replication. Females remained in the experimental chambers for 48 h after which the growing media were processed using a flotation/extraction method. The number of eggs laid by female fungus gnats ranged from 21 to 217 with most eggs recovered after 48 h (141.0 +/- 9.3). There were no significant differences among the three soilless growing media in terms of number of eggs laid, although all three growing media were significantly different from the filter paper with higher numbers of eggs laid in the soilless growing media than the filter paper. Despite no significant difference among the growing media in the number of eggs laid, fungus gnat females tended to lay eggs more often, based on the number of petri dishes in which at least one egg was laid, in Metro-Mix 560 (86%) than Sunshine LC1 (66%), Universal SB 300 (52%), or filter paper (18%). Based on the results of this study, female fungus gnats may not prefer a specific growing medium for oviposition. However, fungus gnat females may rely on other factors not tested in this study such as moisture content and volatiles emitted from growing media in their decision where to lay eggs.     

A phylogeny of robber flies (Diptera: Asilidae) at the subfamilial level: molecular evidence

We present the first formal analysis of phylogenetic relationships among the Asilidae, based on four genes: 16S rDNA, 18S rDNA, 28S rDNA, and cytochrome oxidase II. Twenty-six ingroup taxa representing 11 of the 12 described subfamilies were selected to produce a phylogenetic estimate of asilid subfamilial relationships via optimization alignment, parsimony, and maximum likelihood techniques. Phylogenetic analyses support the monophyly of Asilidae with Leptogastrinae as the most basal robber fly lineage. Apocleinae+(Asilinae+Ommatiinae) is supported as monophyletic. The laphriinae-group (Laphriinae+Laphystiinae) and the dasypogoninae-group (Dasypogoninae+Stenopogoninae+Stichopogoninae+ Trigonomiminae) are paraphyletic. These results suggest that current subfamilial classification only partially reflects robber fly phylogeny, indicating the need for further phylogenetic investigation of this group.     

A study of fungus flies (Dipteral Mycetophilidae) in beech woodland

Abstract. 1. A study was made of larval and adult Mycetophilidae in coppiced beech woodland in southern England. Adult mycetophilids were trapped throughout 1968 using sticky traps at ground level. Larvae inhabiting terrestrial fungi were collected from all sporophores from a defined area of the woodland floor between August and October 1968.
2. Larval mycetophilids were extracted from only 12.6% of all sporophores collected and from fifteen of thirty-eight species of fungi present. Some species of fungi were never inhabited by larval mycetophilids while others appeared to be highly attractive to them. Since it was not possible to identify the larvae beyond the level of tribe it was impossible to ascertain host preferences for different species. Peak numbers of larvae occurred at the beginning of September and the beginning of October.
3. Adult mycetophilids had two peaks of activity, the first in March and April when the dominant species were Boletina gripha and Phronia basalis and the second in autumn when species of the genus Mycetophila were dominant. Phronia basalis is a species whose larvae inhabit dead wood and the abundance of this species (40% of all adults) probably reflects the amount of rotting wood in this type of habitat. The autumn peak of adult activity was due to species known to inhabit agaric sporophores and came about 1 month after the peak of larval numbers in fungi.
4. The adult fauna was rich with 107 species representing about a quarter of the known British fauna. However, only twelve species were trapped in sufficient numbers to allow deductions concerning seasonal activity.
5. The results were discussed with respect to the problems of assessing populations of insects inhabiting fungal sporophores and to the previous work on this neglected group.