Host Plant Specialization and Species Turnover of Caterpillars Among Hosts in the Brazilian Cerrado

Decrease in the species composition similarity of herbivore assemblages with increasing phylogenetic distance between host plants is a widespread pattern. Here we used data for caterpillars in the Brazilian Cerrado to investigate how the similarity in caterpillar species composition decreases as the taxonomic level and genetic distance (GD) of their host plants increases. In addition, we elucidate the plant taxonomic level that provides the greatest contribution to turnover in the caterpillar species composition among host taxa. Adult Lepidoptera were reared from caterpillars collected from 52 plants over 13 yr in the same area, with each host plant sampled for 1 yr. Most species were specialists, with 66 percent of genus specialists among the nonsingleton species. The similarity in caterpillar species composition across plant taxa decreased from host species to genera, and from host genera to orders. Above this level, the similarity was consistently low. The GD between plants explained 82 percent of the variation in the similarity of caterpillar species composition. The contribution of caterpillar species turnover among host orders from the same superorder and among host superorders from the same subclass explained 70 percent of the caterpillar species richness as a whole. Our results lend support to the view that most tropical caterpillars are host specialists. Our findings further indicate that the number of orders and superorders of plants provide the greatest contribution to the total caterpillar richness compared with all of the other host taxonomic levels combined. Abstract in Portuguese is available at http://www.blackwell‐synergy.com/loi/btp .     

No tree an island: the plant–caterpillar food web of a secondary rain forest in New Guinea

We characterized a plant–caterpillar food web from secondary vegetation in a New Guinean rain forest that included 63 plant species (87.5% of the total basal area), 546 Lepidoptera species and 1679 trophic links between them. The strongest 14 associations involved 50% of all individual caterpillars while some links were extremely rare. A caterpillar randomly picked from the vegetation will, with ≥ 50% probability, (1) feed on one to three host plants (of the 63 studied), (2) feed on < 20% of local plant biomass and (3) have ≥ 90% of population concentrated on a single host plant species. Generalist species were quantitatively unimportant. Caterpillar assemblages on locally monotypic plant genera were distinct, while sympatric congeneric hosts shared many caterpillar species. The partitioning of the plant–caterpillar food web thus depends on the composition of the vegetation. In secondary forest the predominant plant genera were locally monotypic and supported locally isolated caterpillar assemblages.     

Plant phylogeny drives arboreal caterpillar assemblages across the Holarctic

1. Assemblages of insect herbivores are structured by plant traits such as nutrient content, secondary metabolites, physical traits, and phenology. Many of these traits are phylogenetically conserved, implying a decrease in trait similarity with increasing phylogenetic distance of the host plant taxa. Thus, a metric of phylogenetic distances and relationships can be considered a proxy for phylogenetically conserved plant traits and used to predict variation in herbivorous insect assemblages among co‐occurring plant species.
2. Using a Holarctic dataset of exposed‐feeding and shelter‐building caterpillars, we aimed at showing how phylogenetic relationships among host plants explain compositional changes and characteristics of herbivore assemblages.
3. Our plant–caterpillar network data derived from plot‐based samplings at three different continents included >28,000 individual caterpillar–plant interactions. We tested whether increasing phylogenetic distance of the host plants leads to a decrease in caterpillar assemblage overlap. We further investigated to what degree phylogenetic isolation of a host tree species within the local community explains abundance, density, richness, and mean specialization of its associated caterpillar assemblage.
4. The overlap of caterpillar assemblages decreased with increasing phylogenetic distance among the host tree species. Phylogenetic isolation of a host plant within the local plant community was correlated with lower richness and mean specialization of the associated caterpillar assemblages. Phylogenetic isolation had no effect on caterpillar abundance or density. The effects of plant phylogeny were consistent across exposed‐feeding and shelter‐building caterpillars.
5. Our study reveals that distance metrics obtained from host plant phylogeny are useful predictors to explain compositional turnover among hosts and host‐specific variations in richness and mean specialization of associated insect herbivore assemblages in temperate broadleaf forests. As phylogenetic information of plant communities is becoming increasingly available, further large‐scale studies are needed to investigate to what degree plant phylogeny structures herbivore assemblages in other biomes and ecosystems.

     

Colonising aliens: caterpillars (Lepidoptera) feeding on Piper aduncum and P. umbellatum in rainforests of Papua New Guinea

Abstract.  1. Caterpillar assemblages feeding on two alien plants, Piper aduncum and P. umbellatum , were studied in lowland rainforest in Papua New Guinea and compared with assemblages from 69 species of native woody hosts, including congeneric P. macropiper .
2. Species richness of caterpillars feeding on P. aduncum (29 species per 1500 m² of foliage) and P. umbellatum (36 species) was higher than the median richness for the 69 native hosts (23 species).
3. The probability that a caterpillar species colonised alien Piper increased with its host range from 3% for the species feeding on a single plant family to 92% for the species with host range >10 plant families.
4. The assemblage on P. aduncum was dominated by a single species ( Herpetogramma sp. near licarsisalis , Crambidae), which represented 48% of individuals, and also had a high proportion (34%) of rare species, collected as single individuals. This community structure was indistinguishable from that of a typical native host. In contrast, the P. umbellatum assemblage was unusual as no species represented >10% of individuals.
5. The aggressive invasion by P. aduncum of early successional vegetation is not explained by a competitive advantage due to low herbivore load, as the abundance of caterpillars feeding on it was comparable to that of native pioneer plants.
6. The caterpillar assemblage on P. aduncum demonstrated that an assemblage indistinguishable from native assemblages in density, species richness, and dominance structure (but not in host specificity) can originate from the existing species pool in lowland rainforests on a recently established tree species in <50 years.     

Elevational contrast in predation and parasitism risk to caterpillars in a tropical rainforest

Invertebrate predators and parasitoids are among the most important natural enemies of insect herbivores. Yet, the strength of natural enemy pressure along an altitudinal gradient and interactions between the groups of natural enemies (such as predation on parasitized prey) are not well known. Various methods are used to reveal the mortality factors of herbivores. Predation pressure is usually assessed through exposure of artificial prey. However, this method cannot provide information about the attacks of parasitoids, or their eventual interactions with predators. Furthermore, artificial or dead prey might not attract predators because they do not show expected host behavior, and this method mostly cannot distinguish between predation and scavenging. For the first time in a tropical rainforest, we quantified elevational contrast in mortality factors using exposure of live caterpillars. We exposed a total of 800 live caterpillars of Talanga excelsalis moresbyensis Strand (Lepidoptera: Crambidae) on saplings of Ficus copiosa Steud. (Moraceae) at two elevations in primary tropical rain forest in Papua New Guinea (200 and 1 200 m a.s.l.). We exposed the caterpillars in two treatments: exposed to and protected from invertebrate predators and parasitoids. Disappearance of caterpillars was significantly higher in the exposed treatment. Furthermore, caterpillar disappearance was significantly higher in lowlands than in highlands (43 vs. 12%). We consider the vast majority of the disappearance to be due to predation, as migration of the caterpillars from the focal trees was not observed (except one caterpillar). This estimate of invertebrate predation rate corresponds with studies which used artificial caterpillar models. No significant difference in parasitism rate between the two elevations was observed (12 vs. 13%). The combination of the disappearance and parasitism rate patterns means that larval parasitoids face stronger pressure from invertebrate predators through higher predation of their hosts in the lowlands than in the highlands.     

Caterpillar assemblages on Chusquea bamboos in southern Ecuador: abundance,guild structure,and the influence of host plant quality

1. Information on the guild structure of foliage‐associated tropical insects is scarce, especially as caterpillars are mostly considered only as herbivores feeding on living leaves. However, many caterpillar species display alternative trophic associations, feeding on dead or withered leaves or epiphylls (‘non‐herbivores’). 2. To determine the contribution of these non‐herbivores, caterpillar communities associated with Chusquea Kunth (Poaceae) in the Andes of southern Ecuador were investigated. Caterpillars were collected at two elevation levels (montane rainforest ～2000 m and elfin forest at ～3000 m a.s.l.) and assigned to three feeding guilds (strict herbivores, non‐herbivores, and switchers) based on feeding trials. Foliage quality and leaf area were recorded to test for their influence on guild composition and caterpillar density. 3. Three hundred and eighty‐nine individuals belonging to 175 Lepidoptera species associated with Chusquea bamboos were found. The species richness of caterpillars was similarly high at both elevation levels but varied between feeding guilds. Approximately half (46.5%) displayed an alternative feeding association, i.e. were non‐herbivores (31.1%) or switchers (15.4%). 4. Caterpillar density was nearly two‐fold higher in the elfin forest, but only strict herbivores and switchers increased significantly with elevation. Leaf area positively influenced the density of strict herbivores and switchers; foliage quality only affected strict herbivores. The density of non‐herbivores did not differ significantly between the forest types and was not related to leaf area or foliage quality. 5. The present study underpins that non‐herbivores make up a considerable fraction of caterpillar communities in tropical mountain ecosystems and demonstrates that elevation, foliage quality and available plant biomass further shape feeding guild composition.     

An alien in an archipelago: Spathodea campanulata and the geographic variability of its moth (Lepidoptera) communities in the New Guinea and Bismarck Islands

Aim This analysis of moth (Lepidoptera) communities colonizing an alien tree invading secondary rain forest vegetation in Melanesia examines the predictability of insect herbivorous communities across distances of tens to thousands of km and the effect of dispersal barriers on community composition in the tropics. Location Six secondary rain forest sites were studied within four equidistant yet distinct geographic areas of the New Guinea mainland and the Bismarck Archipelago, including two watershed areas (Madang and Sepik) on mainland New Guinea and the adjacent large island of New Britain and small island of Unea. Methods The analysis is based on feeding records obtained by quantitative sampling and rearing of caterpillars from the alien host Spathodea campanulata (Bignoniaceae). It examines the variation in Lepidoptera community composition at six study sites distributed on three adjacent islands ranging in size from 30 to 865,000 km². Results Spathodea campanulata was colonized by 54 folivorous species of Lepidoptera. Most of them were generalists, feeding on > 1 native plant family. However, the three most abundant species representing 83% of all individuals (Acherontia lachesis, Hyblaea puera complex and Psilogramma menephron) were relatively host specific, feeding predominantly on a single native family that is not the Bignoniaceae. Most of the 23 species analysed in detail had a wide geographic distribution, including 13 species spanning the entire 1000‐km study transect. While the Lepidoptera in two New Guinea areas 280 km apart were similar to each other, there was a discontinuity in species composition between New Guinea and the smaller islands. However, no negative effect of small islands on species richness was detected. Main conclusions Spathodea campanulata was rapidly colonized by folivorous Lepidoptera communities with species richness and dominance structure indistinguishable from the assemblages feeding on native hosts, despite its phylogenetic isolation from the native vegetation. Although most species were generalists, the highest population densities were reached by relatively specialized species, similar to the communities on native hosts. The species turnover across distances from 10 to 1000 km was relatively low as most of the species had wide geographic ranges.     

Predictably simple: assemblages of caterpillars (Lepidoptera) feeding on rainforest trees in Papua New Guinea

Predictability in the composition of tropical assemblages of insect herbivores was studied using a sample of 35,952 caterpillars (Lepidoptera) from 534 species, feeding on 69 woody species from 45 genera and 23 families in a lowland rainforest in Papua New Guinea. Caterpillar assemblages were strongly dominated by a single species (median 48% of individuals and 49% of biomass). They were spatially and temporally constant (median normalized expected species shared (NESS) similarity between assemblages from the same host was greater than or equal to 0.85 for three sites 8-17 km apart as well as for three four-month periods of the year). Further, the median presence of species was 11 months per year. Assemblages on hosts from different families and genera were virtually disjunct (NESS similarity less than 0.05) as the caterpillars were mostly specialized to a single plant family (77% of species) and, within families, to a single genus (66% of species), while capable of feeding on multiple congeneric hosts (89% of species). The dominance of caterpillar assemblages by a small number of specialized species, which also exhibited low spatial and temporal variability, permitted robust and reliable estimates of assemblage composition and between-assemblage similarity from small samples, typically less than 300 individuals per host plant. By contrast, even considerably larger samples were insufficient for estimates of species richness. A sample of 300 individuals was typically obtained from 1,050 m(2) of foliage sampled during 596 tree inspections (i.e. a particular tree sampled at a particular time) in the course of 19 sampling days (median values from 69 assemblages). These results demonstrate that, contrary to some previous suggestions, insect herbivore assemblages in tropical rainforests have a predictable structure and, as such, are amenable to study.     

Diet and trophic structure in assemblages of montane frugivorous phyllostomid bats

Neotropical frugivorous bats display a trophic structure composed of bat species with dietary preferences of core plant taxa (Artibeus-Ficus  +  Cecropia, Carollia-Piper, Sturnira- Solanum  +  Piper). This structure is hypothesized to be an ancestral trait, suggesting that similar diets would be observed throughout a species' range. However, most evidence comes from lowlands where data from montane habitats are scarce. In high mountain environments both diversity of bats and plants decreases with altitude; such decline in plant diversity produces less plants to feed from, which should ultimately affect the trophic structure of frugivorous bats in mountain environments. Here, we present a comprehensive review of the diet of frugivorous bats in Neotropical montane environments and evaluate their trophic structure in middle and higher elevations by combining a literature database with field data. We use the concept of modularity to test whether frugivorous montane bats have dietary preferences on core plant taxa. Our database revealed 47 species of montane bats feeding on 211 plant species. We find that the networks are modular, reflecting the trophic structure previously reported. We also found that in highlands the tribe Ectophyllini are Cecropia  +  Cavendishia-specialists rather than Ficus-specialists, and we describe new interactions reflecting 14 species of plants, including three botanical families previously not reported to be consumed by bats.     

Effects of predation risk and plant resistance on Manduca sexta caterpillar feeding behaviour and physiology

相似文献   

Community structure of arboreal caterpillars within and among four tree species of the eastern deciduous forest

Abstract.  1. A seasonally replicated experimental design was used to address the question of how differences within and among host tree species affect arboreal caterpillar communities.
2. Seasonal variation influenced caterpillar community composition most significantly, and the similarity among caterpillar assemblages did not necessarily follow the pattern of phylogenetic relatedness among host trees.
3. Species richness and abundance of caterpillars were higher on oaks and maples than on American beech. Diversity partitioning models revealed that β diversity was only occasionally greater or less than expected by chance alone.
4. When β diversity was significant, values tended to be greater than expected by chance among replicate trees within each species and lower than expected by chance among the four tree species.
5. Differences among trees appeared important for determining patterns of species presence/absence for rare species and influencing patterns of species dominance within caterpillar assemblages. Differences among tree species had a significant effect on overall lepidopteran community composition and mean species diversity (i.e. α diversity).
6. Because β diversity of caterpillars among host trees was lower than expected by chance, host specificity within the Lepidoptera may be less prevalent than thought previously.     

Behavioural ecology of defence in a risky environment: caterpillars versus ants in a Neotropical savanna

1. Predatory ants may reduce infestation by herbivorous insects, and slow‐moving Lepidopteran larvae are often vulnerable on foliage. We investigate whether caterpillars with morphological or behavioural defences have decreased risk of falling prey to ants, and if defence traits mediate host plant use in ant‐rich cerrado savanna. 2. Caterpillars were surveyed in four cerrado localities in southeast Brazil (70–460 km apart). The efficacy of caterpillar defensive traits against predation by two common ant species (Camponotus crassus, C. renggeri) was assessed through experimental trials using caterpillars of different species and captive ant colonies. 3. Although ant presence can reduce caterpillar infestation, the ants' predatory effects depend on caterpillar defence traits. Shelter construction and morphological defences can prevent ant attacks (primary defence), but once exposed or discovered by ants, caterpillars rely on their size and/or behaviour to survive (secondary defence). 4. Defence efficiency depends on ant identity: C. renggeri was more aggressive and lethal to caterpillars than C. crassus. Caterpillars without morphological defences or inside open shelters were found on plants with decreased ant numbers. No unsheltered caterpillar was found on plants with extrafloral nectaries (EFNs). Caterpillars using EFN‐bearing plants lived in closed shelters or presented morphological defences (hairs, spines), and were less frequently attacked by ants during trials. 5. The efficiency of defences against ants is thus crucial for caterpillar survival and determines host plant use by lepidopterans in cerrado. Our study highlights the effect of EFN‐mediated ant‐plant interactions on host plant use by insect herbivores, emphasizing the importance of a tritrophic viewpoint in risky environments.     

Cascading effects of host size and host plant species on parasitoid resource allocation

1. The bottom‐up factors that determine parasitoid host use are an important area of research in insect ecology. Host size is likely to be a primary cue for foraging parasitoids due to its potential influence on offspring development time, the risk of multiparasitism, and host immunocompetence. Host size is mediated in part by host‐plant traits that influence herbivore growth and potentially affect a herbivore's quality as a host for parasitoids. 2. Here, we tested how caterpillar host size and host plant species influence adult fly parasitoid size and whether host size influences wasp parasitoid sex allocation. We measured the hind tibia lengths and determined the sex of wasp and fly parasitoids reared from 11 common host species of polyphagous caterpillars (Limacodidae) that were in turn reared on foliage of seven different host plant species. 3. We also tested how host caterpillar species, host caterpillar size, and host and parasitoid phenology affect how the parasitoid community partitions host resources. We found evidence that parasitoids primarily partition their shared hosts based on size, but not by host species or phenology. One index of specialisation (d′) supports our observation that these parasitoids are quite generalised within the Limacodidae. In general, wasps were reared from caterpillars collected in early instars, while flies were reared from caterpillars collected in late instars. Furthermore, for at least one species of solitary wasp, host size influenced sex allocation of offspring by ovipositing females. 4. Host‐plant quality indirectly affected the size attained by a tachinid fly parasitoid through its direct effects on the size and performance of the caterpillar host. The host plants that resulted in the highest caterpillar host performance in the absence of enemies also yielded the largest parasitoid flies, which suggests that host plant quality can cascade up to influence the third trophic level.     

Distribution and Flowering Ecology of Bromeliads along Two Climatically Contrasting Elevational Transects in the Bolivian Andes1

We compared the diversity, taxonomic composition, and pollination syndromes of bromeliad assemblages and the diversity and abundance of hummingbirds along two climatically contrasting elevational gradients in Bolivia. Elevational patterns of bromeliad species richness differed noticeably between transects. Along the continuously wet Carrasco transect, species richness peaked at mid‐elevations, whereas at Masicurí most species were found in the hot, semiarid lowlands. Bromeliad assemblages were dominated by large epiphytic tank bromeliads at Carrasco and by small epiphytic, atmospheric tillandsias at Masicurí. In contrast to the epiphytic taxa, terrestrial bromeliads showed similar distributions across both transects. At Carrasco, hummingbird‐pollination was the most common pollination mode, whereas at Masicurí most species were entomophilous. The proportion of ornithophilous species increased with elevation on both transects, whereas entomophily showed the opposite pattern. At Carrasco, the percentage of ornithophilous bromeliad species was significantly correlated with hummingbird abundance but not with hummingbird species richness. Bat‐pollination was linked to humid, tropical conditions in accordance with the high species richness of bats in tropical lowlands. At Carrasco, mixed hummingbird/bat‐pollination was found especially at mid‐elevations, i.e., on the transition between preferential bat‐pollination in the lowlands and preferential hummingbird‐pollination in the highlands. In conclusion, both richness patterns and pollination syndromes of bromeliad assemblages varied in distinct and readily interpretable ways in relation to environmental humidity and temperature, and bromeliad pollination syndromes appear to follow the elevational gradients exhibited by their pollinators.     

Lepidopteran caterpillar fauna of cerrado host plants

The cerrado biome is rich in caterpillar species although the general biology and ecology of most tropical species remains unknown. Three host plant genera (Byrsonima, Erythroxylum and Qualea) were examined for caterpillars in four cerrado sensu stricto areas near Brasi´lia (DF, Brazil), from 1991 to 1995. Altogether, more than 16000 host plants were sampled and less than 20% of them possessed caterpillars. All the caterpillars found were reared under laboratory conditions. We successfully reared 137 species of 24 lepidopteran families. The average number of caterpillar species per host species was 28.3. The faunal similarity among plant genera, as well as among study sites, was low, and not related to the distances between them. The low proportion of host plants with caterpillars and the high incidence of rare species appears to be a general pattern for the cerrado. A large proportion (74%) of the caterpillar species occurred on only one host plant family. The most frequent species were either specialists (restricted to one host plant genus) or generalists. We provide a brief outline of some taxonomic problems, some observations on general biology, and temporal and local patterns of some specific caterpillars species. The methodology used, which included weekly data collection, in restricted study areas of the same habitat, with the same sampling method for recording the caterpillar species on the same host plant species, can be used as a tool to explore biodiversity and to discuss some aspects of the conservation of cerrado insects.     

Does a polyphagous caterpillar have the same gut microbiota when feeding on different species of food plants?

We used classical culture techniques to explore gut bacteria and changes associated with dietary change in the highly polyphagous, tropical caterpillar Automeris zugana (Saturniidae). Fifty-five third instar wild-caught sibs feeding on Annona purpurea (Annonaceae) in the Area de Conservación Guanacaste (ACG) in northwestern Costa Rica were divided into eight groups. Each of seven groups was reared to the ultimate instar on another species of food plant normally used by A. zugana. Some pupae were also analyzed for the presence of bacteria. Aerobic bacterial cultures were obtained from all 33 caterpillar guts and the eight pupae inventoried. There was no clear pattern in species composition of cultivated bacteria among the eight diets, and each caterpillar on a given food plant carried only a small fraction of the total set of species isolated from the set of caterpillars feeding on that food plant. Taken as a whole, the larvae and pupae contained 22 species of cultivable bacteria in 12 genera. Enterobacter, present in 81.8% of the samples, was the genus most frequently isolated from the caterpillars, followed by Micrococcus and Bacillus. Bacillus thuringiensis was isolated from 30.3% of the dissected caterpillars, but found in caterpillars feeding on only half of the species of food plants.     

Preference and performance of Lepidoptera varies with tree age in juniper woodlands

1. As trees age, they undergo significant physiological and morphological changes. Nevertheless, tree ontogeny and its impacts on herbivores are often overlooked as determinants of plant–herbivore population dynamics and the strength of plant–herbivore interactions. 2. Juniperus (Cupressaceae) is a dominant, long‐lived conifer that serves as the sole host to a specialised assemblage of caterpillars. Over the past 150 years, several juniper species in western North America have expanded their geographic occupancy at local and regional scales, which has resulted in an increase in the number of immature trees on the landscape. Using assays in the laboratory, the effects of tree ontogeny on caterpillar performance and oviposition preference for two juniper specialist caterpillars, Callophrys gryneus (Lycaenidae) and Glena quinquelinearia (Geometridae), were examined. The study considered whether responses to tree ontogeny were consistent across caterpillar species and juniper host species. 3. Tree age was found to be a reliable predictor of caterpillar performance, with caterpillars developing more quickly and growing larger when fed foliage from young trees. Differences in the phytochemical diversity between foliage from trees of different ages might help to explain observed differences in caterpillar performance. Interestingly, the specialist butterfly, C. gryneus, displayed an oviposition preference for foliage from old‐growth Juniperus osteosperma trees, despite the fact that larvae of this species performed poorly on older trees. 4. It is concluded that young juniper trees are an important resource for the specialised Lepidopteran community and that tree ontogeny is an important component of intraspecific variation, which contributes to the structure of plant–herbivore communities.     

Traditional Regulation of Edible Caterpillar Exploitation in the Kopa Area of Mpika District in Northern Zambia

The Traditional Ecological Knowledge (TEK) of the Bisa people of northern Zambia on species, life cycles and host plants of the caterpillars they exploit for food and for household income generation, and the traditional control of caterpillar harvesting, were investigated through a household survey. The accessed indigenous knowledge on caterpillar biology was validated through a forest survey, caterpillar collections and identifications. Eight species of caterpillars were harvested from the surrounding miombo woodlands. Their life systems and host plants were well understood by members of local communities and this knoweldge was communicated amongst them orally. Popular commercial species were Gynanisa maya Strand and Gonimbrasia zambesina Walker. Over 20 miombo tree species hosted the two species but the mean numbers of the caterpillars on Julbernadia paniculata Troupin were significantly larger than those on other host plants (p < 0.05), indicating that J. paniculata was probably the main host plant of the two species. Traditional regulation of caterpillar harvesting involved: (i) monitoring for edible caterpillar development and abundance and for changes in caterpillar habitats, (ii) protection of host plants and moth eggs against late bush fires, through use of traditional fire technology, and (iii) temporal restriction of edible caterpillar harvesting. The possibility of the Zambian Government promoting caterpillar harvesting as an economic incentive to the Bisa people to conserve both this renewable edible caterpillar natural resource and their environment is discussed.     

Patterns of host utilisation by herbivore assemblages of the genus Caloptilia (Lepidoptera; Gracillariidae) on congeneric maple tree (Acer) species

1. The pattern of host utilisation by congeneric Caloptilia caterpillars on 14 different species of Acer (maple) was investigated in temperate mixed forests of central Japan. A multi‐filtering model of host plant utilisation was proposed to address how phylogenetically related herbivore assemblages are constructed on phylogenetically related host plant species. 2. Two hypotheses were examined. The first questioned whether a negative relationship exists between the phylogenetic distance of plants from the most suitable host species and the abundance of herbivorous insects on the host. Regarding the second, it was investigated whether the assemblage dissimilarity of herbivorous insects among host plant species increases with increasing distance of plant phylogeny and traits. 3. Mantel and partial Mantel tests were used to measure the relationship between assemblage dissimilarity of Caloptilia species and the distance of plant phylogeny and leaf traits. 4. Both hypotheses were confirmed, clearly suggesting that the utilisation and suitability of hosts for Caloptilia caterpillars were strongly influenced by phylogenetic relatedness and leaf trait similarity among Acer species. This implies that phylogenetic distance is an integrated measure of phenotypic and ecological attributes of congeneric Acer species that can be used to explain specialisation and constraints of host utilisation of congeneric herbivore species even on a short evolutionary timescale.     

Highlighting declines of cold‐demanding plant species in lowlands under climate warming

High rates of species extinction have been predicted for the next century as a consequence of climate change. Although species range shifts have been widely reported, evidence of changes in species frequency linked to recent climate change is scarce. Moreover, studies have mainly focused on mountainous ecosystems and species. There is thus a clear lack of understanding of the recent changes in species frequencies linked to climate change across their whole range. Using a large forest vegetation‐plot database, we investigated changes in cold and warm‐demanding forest plant species frequencies between the periods 1914–1987 and 1997–2013 in French lowlands and highlands. Changes in frequencies were assessed for 185 lowland (warm‐demanding), 135 sub‐montane (intermediate) and 104 montane (cold‐demanding) forest plant species. Observed changes were compared to predicted changes derived from species distribution model predictions. The frequency of montane and sub‐montane species strongly declined, whereas the frequency of lowland species remained steady in lowland areas. In highlands, the frequency of lowland, sub‐montane and montane species increased, remained steady and decreased, respectively. Predicted and observed trends of changes in the frequency of forest plant species were in agreement. These results clearly show that cold‐demanding species are currently declining in lowlands that correspond to their warm range margins, whereas warm‐demanding species are expanding in highlands that correspond to their cold range margins. These trends can be seen as early signs of future regional extinction and reshuffling of the spatial presence of species due to climate warming.