Spatial and temporal patterns of morel fruiting

The biotic and abiotic factors conditioning morel fruit body production are incompletely known. We examined spatial and temporal patterns of Morchella esculenta fruiting over five years in a wooded site in Missouri, USA. Fruiting onset was inversely correlated with spring air and soil temperatures, whereas abundance was positively correlated with rain events (>10 mm) during the 30 d preceding fruiting. The two years with the greatest fruiting had the shortest fruiting seasons (6–7 d). Fruiting season length was positively correlated with soil warming, suggesting that a narrow range of optimum soil temperatures favour the explosive production of fruit bodies. All woody stems of at least 1 cm diam were mapped and stem diameter and crown condition were noted. Morel fruit bodies were significantly closer to stems of Carya spp., Tilia americana and Ulmus americana than predicted by the frequencies of these woody species or their contribution to the total basal area on the site. Although intra-annual clustering of fruit bodies was often observed, inter-annual clustering was not. The spatial pattern of M. esculenta fruiting appears to be associated with vegetation pattern, whereas the onset and abundance of fruiting are determined by the interaction of spring temperatures with availability of supporting precipitation.     

Reduction of solar UV-B mediates changes in the Sphagnum capitulum microenvironment and the peatland microfungal community

The influence of near-ambient and reduced solar UV-B radiation on a peatland microfungal community was assessed by exposing experimental plots to UV-selective filtration. Replicate plots were covered with special plastic films to effect treatments of near-ambient and attenuated solar UV-B. The microfungal community from the top 1 cm of Sphagnum capitulum in a Tierra del Fuego peatland was censused throughout three growing seasons, between 1999 and 2002. Sphagnum capitula under near-ambient UV-B were more compressed and held more water than capitula under reduced UV-B. This water had a greater conductivity and was more acidic under near-ambient UV-B, as would be expected with increased leaching from the Sphagnum leaves. Nine regularly occurring hyphal fungi from the peatland were identified, at least to genus. Over three field seasons, no treatment effect on total fungal colony abundance was recorded, but individual species abundance was increased (Mortierella alpina), decreased (Penicillium frequentans), or was unaffected (P. thomii, Aureobasidium) by near-ambient UV-B. Species richness was also slightly lower under near-ambient UV-B. These treatment differences were smaller than seasonal or inter-annual fluctuations in abundance and species richness. In a growth chamber experiment, lamp UV-B treatments indicated that realistic fluxes of UV-B can inhibit fungal growth in some species. In addition to this direct UV-B effect, we suggest that changes in the peatland fungal community under near-ambient solar UV-B may also result from increased nutrient and moisture availability in the Sphagnum capitulum. The subtle nature of the responses of peatland fungi to solar UV-B suggests that most fungal species we encountered are well adapted to current solar UV-B fluxes in Tierra del Fuego.     

Interactions between fire,mycophagous mammals,and dispersal of ectromycorrhizal fungi in Eucalyptus forests

Several species of marsupials in Eucalyptus forests in Australia feed predominantly on the sporocarps of hypogeous fungi. This feeding is apparently beneficial to the fungi as it results in dispersal of spores. As these fungi are in almost all cases ectomycorrhiza-forming species, mycophagy by mammals may play an important role in the maintenance of mycorrhizal symbiosis in Eucalyptus forests. Fire is frequent and a dominant ecological factor in these forests, and this study tested the hypothesis that fire triggers both increased sporocarp production by some hypogeous ectomycorrhizal fungi associated with eucalypts, and increased mycophagy by mammals. Three experimental burns were set in E. tenuiramus forest in southeastern Tasmania. Digging activity (which reflects feeding on hypogeous fungi) by a mycophagous marsupial, the Tasmanian bettong Bettongia gaimardi, increased up to ten-fold after fire, with a peak about 1 month post-fire. This was associated with a similar pattern of increase in sporocarp production, which was due to species in the family Mesophelliaceae (especially Castoreum tasmanicum and Mesophellia spp.). This family appears to have radiated in association with eucalypts and has an exclusively Australasian distribution, unlike many of the other ectomycorrhizal fungi collected in this study which are cosmopolitan and have broad host ranges. No B. gaimardi were killed by fire, and there was no increase in mortality following fire. Population density increased after fire as a result of immigration of adult males. However, body condition and fecundity of individual B. gaimardi were maintained at pre-fire levels. This suggests that the availability of energy to B. gaimardi increased as a result of fire, and the fact that the contribution of fungus to the diet of B. gaimardi was high on burnt relative to control sites suggests further that this increase in energy availability was provided by hypogeous fungi. Effects of fire on hypogeous fungi and B. gaimardi were short-lived; all measured variables returned to control values about 4 months after fire. The capacity of B. gaimardi to survive fire and to harvest the increased sporocarp production triggered by fire provides a mechanism for the rapid dispersal of spores after fire. This should result in the establishment of ectomycorrhizae very early in post-fire succession. Because only some species of ectomycorrhizal fungi fruited in response to burning, fire probably has a strong influence on community structure among ectomycorrhizal fungi.     

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.     

云南松（Pinus yunnanensis）林外生菌根真菌的时空分布

2000年至2005年,调查了滇中及其附近云南松林下外生菌根真菌的生态分布,共采集、鉴定标本834号,计有27科39属211种（含变种、变型）。结果表明,红菇属（Russula）、牛肝菌属（Boletus）、乳菇属（Lactarius）、乳牛肝菌属（Suillus）、口蘑属（Tricholoma）、鸡油菌属（Cantharellus）和革菌属（Thelephora）等为云南松林下的主要外生菌根菌类群。它们的发生与分布受到气候（如：气温和降水）、植被（如：林龄、林地郁闭度和草本植被）、地形特征（如：海拔、坡向和坡度）、土壤条件（如：pH值、地表腐殖质和枯枝落叶层等）和人为干扰（比如：商业化采集、林木采伐、火烧和地表物清理）诸多因素的影响。总结为如下：(1）5a的调查结果显示,云南松外生菌根菌的分布表现出季节性变化的规律;其中以每年1、2、3月份的物种多样性为最低,雨季期间急剧增加,至中夏和秋末达到顶峰,种类最为繁多。(2）在海拔1500～2100 m,云南松外生菌根菌种类随着海拔的升高而逐渐增加,至顶峰后,又呈缓慢下降趋势。海拔因素不但对其物种多样性,而且对于类群的组成也具有重要的影响。特定的类群往往发生在特定海拔范围。(3）随着云南松林龄的增加,外生菌根菌呈现由少至多的演替过程。外生菌根菌多样性随云南松林生长而逐渐增加的演替方式,可能与宿主光合作用产物、根部分泌物和土壤条件的逐渐变化有关。(4）人类干扰是云南松外生菌根菌物种多样性和类群组成的主要负影响因子。大规模的商业化采集可破坏或枯竭地下菌丝体,打破各物种之间的竞争平衡,减少孢子释放影响资源再生能力,进而直接影响到子实体的产生。外生菌根菌物种多样性的减少趋势会随林木砍伐和火烧强度的增加而加剧。地表枯枝落叶层与杂草密度也会影响子实体的产生,其中枯枝落叶层的厚度与云南松外生菌根菌子实体的发生呈负相关性,而被紫茎泽兰覆盖的云南松林地内也很少会发现相应的子实体。     

Saproxylic moths reveal complex within-group and group-environment patterns

We investigated saproxylic moths of the family Tineidae, a neglected group inhabiting wood-decaying fungi and dead wood, within the Bia?owie?a Primeval Forest in Poland. Study data were obtained from the collection of 280 fruiting bodies of wood-decaying fungi and the subsequent rearing of adults. Spatial and statistical distribution of saproxylic moths, relationship among species and the influence of environment reflected by interaction with tree and fungal species together with tree and stand level characteristics were studied. Fifteen species and 533 individuals of saproxylic moths were reared. The fungal species, number of fruiting bodies and standing position of a tree influenced species richness. Moth abundance was influenced by fungal species, coniferous trees, increasing tree diameter, number of fruiting bodies and brown rot. Moth abundance was also enhanced by standing dead trees located in managed forests with higher canopy closure. Analyses indicate that several moth species favor a particular rot type and that some fungi host a richer fauna than others. Furthermore, our results indicate mutually independent fungal colonization events by saproxylic moth species, and thus a possible mechanism exists for competition avoidance with other saproxylic moths. Saproxylic moths revealed complex within-group patterns that responded differently to environmental variables. Thus, potential conservation of these organisms requires various approaches including ecosystem management, especially in the context of addressing their diverse habitat requirements.     

Ectomycorrhizal fungi associated with ponderosa pine and Douglas-fir: a comparison of species richness in native western North American forests and Patagonian plantations from Argentina

The putative ectomycorrhizal fungal species registered from sporocarps associated with ponderosa pine and Douglas-fir forests in their natural range distribution (i.e., western Canada, USA, and Mexico) and from plantations in south Argentina and other parts of the world are listed. One hundred and fifty seven taxa are reported for native ponderosa pine forests and 514 taxa for native Douglas-fir forests based on available literature and databases. A small group of genera comprises a high proportion of the species richness for native Douglas-fir (i.e., Cortinarius, Inocybe, and Russula), whereas in native ponderosa pine, the species richness is more evenly distributed among several genera. The comparison between ectomycorrhizal species richness associated with both trees in native forests and in Patagonia (Argentina) shows far fewer species in the latter, with 18 taxa for the ponderosa pine and 15 for the Douglas-fir. Epigeous species richness is clearly dominant in native Douglas-fir, whereas a more balanced relation epigeous/hypogeous richness is observed for native ponderosa pine; a similar trend was observed for Patagonian plantations. Most fungi in Patagonian Douglas-fir plantations have not been recorded in plantations elsewhere, except Suillus lakei and Thelephora terrestris, and only 56% of the fungal taxa recorded in Douglas-fir plantations around the world are known from native forests, the other taxa being new associations for this host, suggesting that new tree + ectomycorrhizal fungal taxa associations are favored in artificial situations as plantations.     

Fruiting body and soil rDNA sampling detects complementary assemblage of Agaricomycotina (Basidiomycota, Fungi) in a hemlock-dominated forest plot in southern Ontario

This is the first study to assess the diversity and community structure of the Agaricomycotina in an ectotrophic forest using above-ground fruiting body surveys as well as soil rDNA sampling. We recovered 132 molecular operational taxonomic units, or 'species', from fruiting bodies and 66 from soil, with little overlap. Fruiting body sampling primarily recovered fungi from the Agaricales, Russulales, Boletales and Cantharellales. Many of these species are ectomycorrhizal and form large fruiting bodies. Soil rDNA sampling recovered fungi from these groups in addition to taxa overlooked during the fruiting body survey from the Atheliales, Trechisporales and Sebacinales. Species from these groups form inconspicuous, resupinate and corticioid fruiting bodies. Soil sampling also detected fungi from the Hysterangiales that form fruiting bodies underground. Generally, fruiting body and soil rDNA samples recover a largely different assemblage of fungi at the species level; however, both methods identify the same dominant fungi at the genus-order level and ectomycorrhizal fungi as the prevailing type. Richness, abundance, and phylogenetic diversity (PD) identify the Agaricales as the dominant fungal group above- and below-ground; however, we find that molecularly highly divergent lineages may account for a greater proportion of total diversity using the PD measure compared with richness and abundance. Unless an exhaustive inventory is required, the rapidity and versatility of DNA-based sampling may be sufficient for a first assessment of the dominant taxonomic and ecological groups of fungi in forest soil.     

Fire and habitat management for a mycophagous marsupial,the Tasmanian bettong Bettongia gaimardi

Abstract The Tasmanian bettong, Bettongia gaimardi, is a mycophagous marsupial that occurs in fire-prone dry sclerophyll forests. Previous studies have demonstrated that some of the hypogeous fungi on which it feeds become abundant soon after fire, and have suggested that it might depend on regular burning of its habitat. The longer-term effects of burning on B. gaimardi and its food supply were evaluated by comparing six sites, matched for soil, vegetation and climate, in southeastern Tasmania that had been left unburnt for periods ranging from 1 to 50 years. At each site, the density of B. gaimardi diggings was measured and sporocarps of hypogeous fungi were surveyed. Abundance of hypogeous sporo-carps was low at sites 2 years or less post-fire, but was high at sites 4 years and more post-fire. Species richness was similarly low at recently burnt sites, an effect that was due to the absence of many shallow-fruiting taxa. All species (with one exception) present at recently burnt sites were also present in long-unburnt sites. Densities of B. gaimardi diggings were highest at a very recently burnt (<1 year) site and at a site left unburnt for 10 years. These trends suggest that a high frequency of burning may be unfavourable to B. gaimardi in the forest type investigated in this study.     

一株产虫草素的冬虫夏草内生真菌 Bionectria ochroleuca OS17

虫草素是一种核苷类似物,具有多种药理作用。利用虫草素产生菌发酵的方式获得虫草素,可能是产生虫草素的一种新方法。为筛选能产虫草素的内生真菌,从中国传统的中药冬虫夏草子实体中共分离得到42株真菌,经PDB液体培养后,采用高效液相色谱（HPLC）鉴定其代谢产物。结果表明：菌株OS17的代谢产物中含有虫草素,且虫草素产量为40.16 mg/L。基于形态学特征和ITS序列分析,菌株OS17被鉴定为淡色生赤壳菌(Bionectria ochroleuca)。这是首次从冬虫夏草中分离得到能产虫草素的生赤壳属,表明了内生真菌具有产生多种生物活性物质的潜力。     

Combining high-throughput sequencing with fruit body surveys reveals contrasting life-history strategies in fungi

Before the recent revolution in molecular biology, field studies on fungal communities were mostly confined to fruit bodies, whereas mycelial interactions were studied in the laboratory. Here we combine high-throughput sequencing with a fruit body inventory to study simultaneously mycelial and fruit body occurrences in a community of fungi inhabiting dead wood of Norway spruce. We studied mycelial occurrence by extracting DNA from wood samples followed by 454-sequencing of the ITS1 and ITS2 regions and an automated procedure for species identification. In total, we detected 198 species as mycelia and 137 species as fruit bodies. The correlation between mycelial and fruit body occurrences was high for the majority of the species, suggesting that high-throughput sequencing can successfully characterize the dominating fungal communities, despite possible biases related to sampling, PCR, sequencing and molecular identification. We used the fruit body and molecular data to test hypothesized links between life history and population dynamic parameters. We show that the species that have on average a high mycelial abundance also have a high fruiting rate and produce large fruit bodies, leading to a positive feedback loop in their population dynamics. Earlier studies have shown that species with specialized resource requirements are rarely seen fruiting, for which reason they are often classified as red-listed. We show with the help of high-throughput sequencing that some of these species are more abundant as mycelium in wood than what could be expected from their occurrence as fruit bodies.     

Observations on post-fire black morel ascocarp development in an Israeli burnt forest site and their preferred micro-sites

Morchella species ascocarps (morels) are sought-after edible mushrooms that exhibit pyrophilous behavior, proliferating in fire-affected soils of certain types of forests. The factors governing fruiting in this habitat are poorly understood. An observational approach was used to determine the spatial distribution on preferred micro-sites of black morel fruiting in a forest after a summer fire, subjected to different post-fire forestry management activities. Clearing the burnt tree stumps from the site, compaction of the burnt soil by heavy machinery (bulldozers) and covering the soil with chopped wood created preferred micro-sites for black morel fruiting. Fewer fruit bodies developed on untouched burnt soil, and almost none on non-burnt soil at the same site. These observations enhance understanding the ecological principles underlying the distribution and abundance of morel ascocarp development in natural habitats; such an understanding could contribute to conservation and management of morel fruiting in the wild.     

Post-fire, seasonal and annual dynamics of the ectomycorrhizal community in a Quercus ilex L. forest over a 3-year period

Two study plots, burned and control, were established in autumn 1998 in a Quercus ilex forest located in northern Spain, part of which had been affected by a low intensity fire in 1994. Soil samples for ectomycorrhizae (ECM) were taken over a 3-year period in each study plot in spring, summer, autumn and winter. ECM morphotypes were identified and the relative abundance of each morphotype in each soil sample calculated, along with species richness, Shannon diversity index and percentage of mycorrhization in each soil sample. The relative abundance of certain ECM morphotypes differed between burned and control plots, and the percentage of mycorrhizal tips was significantly lower in the burned than in the control plot. Nevertheless, there were no significant differences in the diversity, species richness or species composition of the ECM community in the burned and control plots. The dominant ECM morphotypes in both stands were Cenococcum geophilum and several thelephoroid fungi. Sphaerosporella brunnea and Pisolithus tinctorius thrived especially in the burned plot, whereas three ectomycorrhizal morphotypes assigned to the genus Hebeloma were especially abundant in the control plot. There was no significant variation in the relative abundance of the ECM morphotypes between seasons, but ECM community species richness was highest in autumn and lowest in summer. The percentage of mycorrhizal tips reached a maximum in winter, with its minimum in autumn. Collection of samples over the 3-year period also enabled us to detect a significant increase in percentage of ECM colonisation in the burned stand over time.     

人工疏蕾对杏鲍菇产量及品质的影响

【背景】工厂化栽培中,杏鲍菇是不定点出菇,通常采用人工疏蕾的方法来实现对子实体数目的控制,但目前关于人工疏蕾保留子实体的数目无具体的研究。【目的】通过人工疏蕾的方式,研究保留不同子实体数目对杏鲍菇产量及品质的影响。【方法】对各处理组进行基质利用情况测定,对采收后各组子实体进行产量、形态指标及质构特性的测定。【结果】保留3—4个子实体的基质利用率较高,在生产实际中对成本的浪费较少;保留不同子实体数目对子实体形态指标、单菇重量及单包产量都有显著影响,保留1个子实体时,单菇重量最大但单包产量最低,保留4个子实体时,单包产量较高且子实体形态一致;从质构特性来看,保留子实体数目为4个时,杏鲍菇子实体品质最好、口感最佳。【结论】在杏鲍菇工厂化生产的人工疏蕾环节,保留子实体数目为3—4个时可以减少对成本的浪费,获得产量较高、品质较好的产品。     

Allocasuarina tree hosts determine the spatial distribution of hypogeous fungal sporocarps in three tropical Australian sclerophyll forests

Across three tropical Australian sclerophyll forest types, site-specific environmental variables could explain the distribution of both quantity (abundance and biomass) and richness (genus and species) of hypogeous fungi sporocarps. Quantity was significantly higher in the Allocasuarina forest sites that had high soil nitrogen but low phosphorous. Three genera of hypogeous fungi were found exclusively in Allocasuarina forest sites including Gummiglobus, Labyrinthomyces and Octaviania, as were some species of Castoreum, Chondrogaster, Endogone, Hysterangium and Russula. However, the forest types did not all group according to site-scale variables and subsequently the taxonomic assemblages were not significantly different between the three forest types. At site scale, significant negative relationships were found between phosphorous concentration and the quantity of hypogeous fungi sporocarps. Using a multivariate information theoretic approach, there were other more plausible models to explain the patterns of sporocarp richness. Both the mean number of fungal genera and species increased with the number of Allocasuarina stems, at the same time decreasing with the number of Eucalyptus stems. The optimal conditions for promoting hypogeous fungi sporocarp quantity and sporocarp richness appear to be related to the presence and abundance of Allocasuarina (Casuarinaceae) host trees. Allocasuarina tree species may have a higher host receptivity for ectomycorrhizal hypogeous fungi species that provide an important food resource for Australian mycophagous animals.     

Partial restoration of fungal and plant species diversity by removal of litter and humus layers in stands of Scots pine in the Netherlands

A field experiment was set up in five mature Scots pine (Pinus sylvestris) stands in the Netherlands in order to study the effects of removal of litter and humus on ectomycorrhizal fungi and vegetation of higher plants, bryophytes, and lichens. Lime was also applied as a countermeasure to the removal of surplus cations. Application of lime did not have significant effects on mycorrhizal fungi. Removal of ectorganic material increased species richness of ectomycorrhizal fungi. The number of fruit bodies was also higher in the sod-cut plots, but the difference compared with the controls was not significant in all years. A major effect of removal of the ectorganic layer was a reversion of ectomycorrhizal succession to earlier stages. Liming increased the number and cover of ruderal, nitrophilous plant species. Sod-cutting caused a reversion of the green vegetation to earlier successional stages.     

Ammonia fungi of iriomote Island in the southern Ryukyus,Japan and a new ammonia fungus,Hebeloma luchuense

Species composition and fruiting season of ammonia fungi were investigated in Iriomote Island of the southern Ryukyus, Okinawa Prefecture, Japan.Castanopsis andPinus forests were surveyed and 10 species of ammonia fungi were collected, including one new agaric species,Hebeloma luchuense sp. nov. This new fungus is characterized by having a rooting, squamulose-scaly stipe and cortinate veil and forms ectomycorrhizae withCastanopsis cuspidata var.sieboldii. Although the general mushroom season in theCastanopsis forest in Iriomote island was very short and restricted to summer, ammonia fungi were observed to fruit throughout the year in urea-treated plots.     

After the gold rush,or before the flood? Evolutionary morphology of mushroom-forming fungi (Agaricomycetes) in the early 21st century

Mushroom-forming fungi (Agaricomycetes, approx. syn.: Homobasidiomycetes) produce a diverse array of fruiting bodies, ranging from simple crust-like forms to complex, developmentally integrated forms, such as stinkhorns and veiled agarics. The 19th century Friesian system divided the mushroom-forming fungi according to macromorphology. The Friesian taxonomy has long been regarded as artificial, but it continues to influence the language of mycology and perceptions of fungal diversity. Throughout the 20th century, the phylogenetic significance of anatomical features was elucidated, and classifications that departed strongly from the Friesian system were proposed. However, the anatomical studies left many questions and controversies unresolved, due in part to the paucity of characters, as well as the general absence of explicit phylogenetic analyses. Problems in fruiting body evolution were among the first to be addressed when molecular characters became readily accessible in the late 1980s. Today, GenBank contains about 108,000 nucleotide sequences of ‘homobasidiomycetes’, filed under 7300 unique names. Analyses of these data are providing an increasingly detailed and robust view of the phylogeny and the distribution of different fruiting body forms across the 14 major clades that make up the agaricomycetes. However, it would be wrong to suggest that all the important questions about fruiting body evolution have been resolved. Recent studies focusing on resupinate forms suggest that there may still be undetected major clades of agaricomycetes, which could have a significant impact on our estimates of the ancestral forms in this morphologically diverse group. Modern approaches, including comparative phylogenetic analyses and developmental studies, have the potential to yield novel insights into both the macroevolutionary processes and cellular mechanisms of fungal morphological evolution.     

Food web structure of the fungivorous insect community on bracket fungi in a Bornean tropical rain forest

1. If fungivorous insect diversity is maintained by host specialisation on particular fungi, it should be higher in the tropics than in temperate or boreal regions owing to high macrofungus species diversity. 2. To reveal the community and food web structure of fungivorous insects on bracket fungi, fungivorous insects were collected from 427 fruiting bodies belonging to 22 genera throughout the development and deterioration process in a 3‐ha plot of lowland dipterocarp tropical rain forest on Borneo Island. 3. Eight hundred and twenty‐nine individuals of 82 coleopteran species in 13 families from 111 fruiting bodies of 15 fungal genera were collected. Tenebrionidae and Staphylinidae were most common. Fifty‐three and 19 insect species were observed on Ganoderma and Phellinus, respectively. The numbers of insect species and individuals on a particular fungal genus were positively correlated with the abundance of that fungal genus. 4. Quantitative food web analysis revealed a high degree of specialisation at the whole‐community level. At least 65% of insect individuals were observed on Ganoderma at every stage of development and deterioration. Diverse insects coexist on one dominant fungal genus, Ganoderma, in contrast to our hypothesis. 5. The high abundance of Ganoderma fruiting bodies, which lack obvious defences against insect feeding, probably influences the bracket fungus–insect food web in this tropical rainforest.