Survival of sub-zero temperatures by two South Georgian beetles (Coleoptera,Perimylopidae)

Summary The ability of adults and larvae of two species of perimylopid beetles (Hydromedion sparsutum, Perimylops antarcticus) to survive sub-zero temperatures was studied at Husvik, South Georgia in summer during October–December 1990. Experiments determined their survival at constant sub-zero temperatures, their lower lethal temperatures and individual supercooling points. The effects of cooling rates (0.015°, 0.5° and 2.0°C min^–1) and starvation on survival were also assessed. Mean supercooling points of field-collected individuals of both species were in the range -3.0° to -5.4°C with Perimylops having a deeper capacity (ca. 1.5°C) for supercooling relative to Hydromedion. The former species also survived freezing temperatures significantly better than the latter and its mean lower lethal temperature was 2.5°C lower. At a constant temperature of -8.5°C, the median survival times for Perimylops adults and larvae were 19 and 26 h respectively, whilst both stages of Hydromedion died within 3 h. The three cooling rates resulted in significantly different median survival temperatures for adult Hydromedion with 0.5°C min^–1 producing maximum survival. Prior starvation did not have a significant influence on the survival of either species at sub-zero temperatures although both adults survived less well. The results support field observations on the habitats and distribution of these insects, and suggest differing degrees of freezing tolerance.     

Body water content and desiccation resistance in some arthropods from subantarctic South Georgia

Summary The body water content and resistance to desiccation were studied in two perimylopid beetles, Perimylops antarcticus and Hydromedion sparsutum, a chironomid midge, Eretmoptera murphyi, and two spiders, Notiomaso australis and Perimaso grytvikensis from the subantarctic island of South Georgia. Comparisons were made between different species, different life stages and, where possible, between a high and a low altitude. Perimylops is abundant at higher elevations and in more exposed habitats (fellfields). This may be accounted for by its feeding behaviour, high body water content (relative to Hydromedion) and low rate of water loss under desiccating conditions, particularly in the larval stages. Hydromedion is more abundant at the lower collection site. It is a more robust beetle than Perimylops and its feeding preference is for plants such as grasses and Acaena. Nevertheless, at the upper site adult Hydromedion are able to withstand desiccation to an even greater degree than Perimylops. Water loss rates for both beetles are significantly higher than those reported for related beetles from arid and semi-arid regions. The ability to regulate water loss is not as apparent in the polar perimylopids Perimylops and Hydromedion as in related species from other xeric habitats. These two species, in fact, resemble more closely carabid beetles in xeric habitats in rates of water loss under controlled conditions. Increased temperatures elevate the rate of water loss significantly. South Georgia spiders have a similar rate of water loss to several species of spiders that have been studied in the temperate zone. Eretmoptera is restricted to moist conditions and cannot survive desiccating conditions even for brief periods. It has the highest body water content (78% of fresh weight) of all of the South Georgian arthropods studied. Among the spiders, sufficient information could be obtained only for Notiomaso. This species is much less resistant to desiccation than the perimylopid beetles, and it has a relatively high body water content. It is quite numerous in the lower, warmer habitats where its insect prey is more abundant and diverse.     

Respiratory metabolism in two species of carabid beetle from the sub-Antarctic island of South Georgia

The influence of feeding state on cold-adapted metabolism was investigated in the adults of two carabid beetles, Trechisibus antarcticus and Oopterus soledadinus (Coleoptera: Carabidae), which have been introduced to sub-Antarctic South Georgia. The metabolic rates in both fed and starved O. soledadinus and T. antarcticus were determined at eight temperatures ranging from 0 to 35°C, using a Servomex 570A oxygen analyser. There was no significant difference in the metabolic rates between the fed and starved animals of each species. In T. antarcticus this ranged from 0.28 to 3.84 ml O₂ g⁻¹ h⁻¹, and in O. soledadinus from 0.19 to 2.80 ml O₂ g⁻¹ h⁻¹ at 0 and 35°C, respectively. In each of the four experimental groups there was a strong positive correlation between metabolic rate and temperature, with the highest increase occurring between 0 and 5°C. In contrast, the metabolic rate was significantly negatively correlated with initial live weight of the beetles at most temperatures. The results are discussed comparatively with other species and against a background of the ecology of the two carabids at South Georgia. Received: 26 August 1996 / Accepted: 3 February 1997     

Feeding in the two phytophagous beetles Hydromedion sparsutum and Perimylops antarcticus from South Georgia

Summary The consumption of fresh plant materials by adults and larvae of Hydromedion sparsutum and Perimylops antarcticus (Col., Perimylopidae) was estimated from the production of faecal pellets and amount of excreted plant remnants as dry weight. Adults and larvae of Hydromedion consumed large quantities of grasses, including the alien Poa annua, but smaller amounts of the indigenous great burnet, Acaena magellanica. Both stages of Perimylops consumed much smaller quantities of grasses and Acaena. Different species of mosses were eaten in both species, and appeared to be a major source of food for Perimylops in addition to microphytes on rocks. The consumption of mosses and microphytes reflects the adaptation of Perimylops to living in habitats at higher altitudes (e.g. above 200 m), where other plants are scarce.     

Respiratory Metabolism of sub-Antarctic insects from different habitats on Marion Island

Oxygen uptake of the foliage-dwelling larvae ofEmbryonopsis halticella Eaton (Lepidoptera: Yponomeutidae) and adults ofEctemnorhinus marioni Jeannel (Coleoptera: Curculionidae), the litter-dwelling larvae ofPringleophaga marioni (Lepidoptera: Tineidae) and the wrack-dwellingParactora dreuxi Séguy (Diptera: Helcomyzidae) was examined over the range of temperatures experienced by these insects in their microhabitats. With the exception of the kelp fly,P. dreuxi, Q₁₀s and activation energies were generally lower than those found in temperate and Arctic insects, but were similar to values found in beetles from sub-Antarctic South Georgia Island. Q₁₀ and activation energy of each species reflected the temperature regime found in its microhabitat. Activation energies of the Marion Island species were intermediate between those found in temperate and polar arthropods, but towards the polar end of the range. The hypothesis that insects are capable of showing respiratory adaptation to temperature is supported.     

Ice nucleation studies of two beetles from sub-antarctic South Georgia

Summary Supercooling points of adults and larvae of the coleopterans Hydromedion sparsutum and Perimylops antarcticus at South Georgia ranged from -3.0 to -5.4°C with Perimylops freezing at c.1.6°C lower than Hydromedion. Intact excised guts from adults of both species froze c. 1°C lower than the adult insects. Ice nucleating activity of homogenized faeces from larvae and adults of both species and excised guts were compared with three potential food plants using an ice nucleation spectrometer. Mean supercooling points of the insect materials at four concentrations in distilled water (range from 0.01 to 10 g 1^–1) were significantly different (P<0.01) within species, and within life stages between species. Differences in the supercooling points of suspensions of Polytrichum alpinum (moss) and Usnea fasciata (lichen) were not significant. In general, differences between supercooling points were greater at the higher concentrations. Histograms of the supercooling points showed unimodal distributions particularly at high concentrations and greater dispersion with increased dilution. Spectra showing the concentration of active ice nucleators over the temperature range 0 to -20°C were developed. These showed that nucleation occurred as high as -2°C in faecal material and all insect samples nucleated above -3°C, whereas the plant materials nucleated between -4 and -5°C. The calculated number of ice nucleators for each material in suspension revealed low values (5.3 to 5.8 × 10³) for the plants, but a greater abundance (1.3 × 10⁵ to 1.3 × 10⁶) in the insect samples. It is concluded that c.1000 active nucleators g^–1 are required for ice nucleation to occur in these suspensions. Ice nucleator activity of a suspension of Hydromedion faeces was much reduced by heating to 75°C, suggesting a proteinaceous structure. These results are discussed in relation to ice nucleation in other insects, and it is concluded that bacteria may be responsible for the high nucleation temperatures, and hence poor supercooling, in these South Georgia insects. An empirical model is developed for ice nucleation spectra based on these data.     

Biology of the Eucalyptus leaf beetle Paropsisterna selmani (Chrysomelidae: Paropsini): a new pest of Eucalyptus species (Myrtaceae) in Ireland

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Genome size increase in the phytophagous ladybird beetle Henosepilachna vigintioctomaculata species complex (Coleoptera: Coccinellidae)

This study reports genome size (C‐value) estimates for seven species of ladybird beetles (Coleoptera: Coccinellidae) in Japan using flow cytometry. The results demonstrated genome sizes of 1.0–1.4 Gb in four closely related phytophagous ladybird beetles belonging to the Henosepilachna vigintioctomaculata species complex. These values were approximately two times larger than that of a congeneric phytophagous ladybird beetle H. vigintioctopunctata (0.66 Gb), and of two very distantly related common carnivorous ladybird beetles, Harmonia axyridis (0.46 Gb) and Coccinella septempunctata (0.42 Gb). These lines of evidence suggest that rapid and large genome size increase occurred just after the branching of the common ancestor of the H. vigintioctomaculata species complex from other ladybird species.     

The dietary relationships of Tribolium castaneum (Herbst) with microfungi

The ecology of Tribolium castaneum (Herbst) outside of grain storage facilities is poorly known. However, high densities of T. castaneum adults are known to infest stored cotton seeds (Gossypium hirsutum (L.)) in Queensland, Australia, despite the absence of stored food products in the immediate vicinity. Previous studies suggest that the beetles are attracted to the fungal colonies growing on the residual fibres that remain on the cotton seeds after ginning, but the specifics of this remain unclear, even as to the species of fungi involved. In the current study, 14 fungal species were isolated from stored cotton seeds collected from four sites in Queensland. The feeding preferences of the adult beetles and the developmental success of the larvae were recorded for each fungal species. Gut analyses of T. castaneum adults, after exposure in no-choice feeding tests, showed that the beetles will feed on any one of the 14 fungal species when exposed (over 14 days) to cotton seeds that had been inoculated with one particular fungal species. The developmental success of the larvae varied depending on the fungal species, with most fungal species supporting only low levels of successful development (<30%). Tests with each fungal species and the volatiles they release revealed that neither adult nor larval survival was significantly affected by the presence of any particular fungal isolate. These results indicate that T. castaneum will feed on a variety of fungal species but that none of the tested fungal species on its own provides a good larval diet for T. castaneum.     

Evidence of temperature‐independent metabolic rates in diurnal Namib Desert tenebrionid beetles

To investigate whether the sensitivity to environmental temperature varies between nocturnal and diurnal species of tenebrionid beetle, the metabolic rates of three diurnal species (Onymacris plana Peringuey, Onymacris rugatipennis Haag and Physadesmia globosa Haag) and three nocturnal species (Epiphysa arenicola Penrith, Gonopus sp. and Stips sp.) of beetles from the Namib Desert are measured over a range of temperatures (15–40 °C) that are experienced by these beetles in their natural habitat. The diurnal species O. plana, O. rugatipennis and P. globosa exhibit temperature‐independent metabolic rates (mean Q₁₀ = 1.2) within temperature ranges that are ecologically relevant for diurnal desert beetles (30–40 °C). Onymacris plana, in particular, has a 20–40 °C rate–temperature slope (0.007 log₁₀ mL O₂ h^?1 g^?1 °C^?1; Q₁₀ = 1.1) that is less than half that of the other five beetle species (0.022–0.063 log₁₀ mL O₂ h^?1 g^?1 °C^?1; Q₁₀ ranges from 1.3–1.9), suggesting that O. plana is more metabolically independent of temperature than the other nocturnal and diurnal tenebrionids being investigated. Animals with metabolic rates that are decoupled from body temperature (or ambient temperature) may have an ecological advantage that allows them to exploit thermal and spatial niches during extreme temperature conditions.     

REPRODUCTIVE ISOLATION BY HOST SPECIFICITY IN A PAIR OF PHYTOPHAGOUS LADYBIRD BEETLES

Crossing experiments and food-choice tests show that two sympatric species of phytophagous ladybird beetles, Epilachna niponica and E. yasutomii, are reproductively isolated by host-plant specificity. Adult beetles selected their natural hosts when given choices, though some accepted the host of the other species when no choice was offered. In each species, survival of larvae to the second instar was significantly higher on their own host plant. No evidence for sexual isolation, gametic isolation, hybrid inviability, or reduced hybrid fertility was detected. Reproductive isolation by host specificity is an important prerequisite for certain models of sympatric speciation. Although the present example supports the plausibility of such models, an allopatric origin of host-plant specificity cannot be discounted.     

The life history of the diving beetle, Lancetes angusticollis (Curtis) (Coleoptera: Dytiscidae), on sub-Antarctic South Georgia

Two populations of the world's most southerly diving beetle (Lancetes angusticollis) were studied on sub-Antarctic South Georgia between November 1995 and April 1996. Parallel observations were made on laboratory cultures of each life stage. All juvenile stages of L. angusticollis are voracious predators, preying mainly on the herbivorous copepod Boeckella poppei. Adult beetles additionally predate benthic ostracods. Laboratory predation rates and field population densities found in this study suggest that L. angusticollis has a more significant impact on its prey than recognised in recent studies of South Georgian lakes. Spring field samples contained only a few individuals of larval instar IV and adults. Young larvae were present from December onwards, with a rapid progression through juvenile instars during the summer months. Fourth instar larvae left the water for pupation between mid-December and at least mid-February. Combining these observations with known developmental threshold temperatures for each life stage implies that L. angusticollis has a complex biennial (minimum) life-cycle, with overwintering possible in three life stages [aquatic larvae, terrestrial pupae (not proven) and aquatic adults]. L. angusticollis may be a suitable indicator species in the context of climate warming studies: a small (1°C) rise in mean environmental temperatures, comparable to that already observed at several sub-Antarctic and maritime Antarctic localities, would allow completion of an annual (univoltine) life-cycle, with concomitant rapid population increase, and serious implications for trophic interactions in these simple lake ecosystems. Received: 24 November 1997 / Accepted: 12 April 1998     

Biology and distribution of the littoral rove beetle Psamathobledius punctatissimus (Le Conte) (Coleoptera: Staphylinidae)

The intertidal macrofauna on a small sheltered marine beach at Pawley's Island, South Carolina, was dominated by insects, primarily Psamathobledius punctatissimus, a small beetle which attained densities of up to 2 260 adults m⁻². Both adult and larval beetles remained buried in the sand when covered by the tide, then emerged to form mole-like surface trails and feed upon diatoms when exposed. Eggs and young larvae were maintained within special maternal burrows, while larger larvae and non-breeding adults occupied their own individual burrows. Both adults and larvae became comatose when in direct contact with water, but recovered after as long as six hours submergence. In the field, burrows retained air during tidal coverage, allowing the beetles to avoid direct contact with sea water. Seaward extension of the population is probably limited by time available for feeding, while longshore distribution is restricted by sand texture and diatom concentration, or by sediment mobility in more exposed locations. Although very locally distributed, P. punctatissimus has achieved considerable success in a habitat poorly exploited by competitors of either marine or terrestrial origin. Contribution No. 434 of the Belle W. Baruch Institute for Marine Biology and Coastal Research Contribution No. 434 of the Belle W. Baruch Institute for Marine Biology and Coastal Research     

Morphology and biology of the flower‐visiting water scavenger beetle genus Rygmodus (Coleoptera: Hydrophilidae)

Hydrophilidae (water scavenger beetles) is well known as an aquatic beetle family; however, it contains ca. 1,000 secondarily terrestrial species derived from aquatic ancestors. The New Zealand endemic genus Rygmodus White is a member of the hydrophilid subfamily Cylominae, which is the early‐diverging taxon of the largest terrestrial lineage (Cylominae + Sphaeridiinae) within the Hydrophilidae. In this paper we report that Rygmodus beetles are pollen‐feeding flower visitors as adults, but aquatic predators as larvae. Based on analyses of gut contents and a summary of collecting records reported on museum specimen labels, adult Rygmodus beetles are generalists feeding on pollen of at least 13 plant families. Rygmodus adult mouthparts differ from those of other (saprophagous) hydrophilid beetles in having the simple scoop‐like apex and mola with roughly denticulate surface, resembling the morphology found in pollen‐feeding staphylinid beetles. Larvae were found along the sides of streams, under stones and in algal mats and water‐soaked moss; one collected larval specimen was identified using DNA barcoding of two molecular markers, mitochondrial cytochrome oxidase 1 (cox1) and nuclear histone 3 (H3). Larvae of two species, Rygmodus modestus and Rygmodus sp., are described in detail and illustrated; they closely resemble ambush‐type predatory larvae of the hydrophilid tribe Hydrophilini in the head morphology. Rygmodus is the only known hydrophilid beetle with adults and larvae inhabiting different environments.     

Coping with an antagonist: the impact of a phytopathogenic fungus on the development and behaviour of two species of alpine leaf beetle

Herbivorous insects and phytopathogenic fungi often share their host plants. This creates a network of direct and indirect interactions, with far‐reaching consequences for the ecology and evolution of all three parties. In the Alps, the leaf beetles Oreina elongata and Oreina cacaliae (Coleoptera: Chrysomelidae), and the rust fungus Uromyces cacaliae (Uredinales: Pucciniaceae) are found on the same host plant, Adenostyles alliariae (Asterales: Asteraceae). We compare the impact of rust infection on these two closely‐related beetle species, one of which, O. cacaliae, is a specialist on A. alliariae, while the other, O. elongata, moves repeatedly between Adenostyles and an alternative host, Cirsium spinosissimum. Larval performance, feeding preference, oviposition choice and dispersal behaviour were studied in field and laboratory experiments. When reared on rust‐infected leaves, larvae of both beetle species had lower growth rates, lower maximum weights and longer development times. Larvae and adults discriminated among diets in feeding trials, showing a preference for discs cut from healthy leaves over those bearing a patch of sporulating rust, those from elsewhere on an infected leaf, and those from an upper leaf on an infected plant. Females of the two species differed in behaviour: in O. cacaliae they favoured healthy leaves for larviposition, while in O. elongata they showed no significant preference during oviposition. In the field, larvae and adults of both species dispersed more rapidly when placed on infected host plants. The results demonstrate that rust infection reduces the quality of the plant as a host for both Oreina species, and they combine the ability to detect systemic infection with the evolution of evasive behaviours. For these beetles, competition with a rust clearly increases the difficulty of survival in the harsh conditions of alpine environments, and may have a profound impact on the evolution of their life history traits and host plant use.     

Thermal sensitivity of oxygen uptake of Diptera from sub-Antarctic South Georgia and Marion Island

 Oxygen uptake of Paractora dreuxi (apterous) from Marion Island, which lies to the north of the Antarctic Polar Front, was compared to that of P. trichosterna (macropterous) and Antrops truncipennis (apterous) from South Georgia, which lies within the Antarctic Polar Front, over the range of temperatures experienced by these insects in their microhabitats. No differences in the slopes of log metabolic rate on temperature were found between the larvae of the two Paractora species, but the slope of the regression of log metabolic rate on temperature was steeper in the adults of P. trichosterna than in those of P. dreuxi. Therefore, metabolic cold adaptation was not found in P. trichosterna compared to P. dreuxi. However, some evidence for temperature compensation in A. truncipennis was found, although this could not be considered an adaptation. The difference in the thermal sensitivity of metabolic rate of the adults of the Paractora species is ascribed to differences in their life history strategies. Paractora trichosterna is a winged species in which retention of a thermal sensitivity similar to that of its larvae may facilitate resource location and so enhance fitness. On the other hand, the loss of flight in P. dreuxi may have allowed a reduction in thermal sensitivity that could mean a reduction in respiratory water loss at higher temperatures. Received: 12 December 1995/Accepted: 13 March 1996     

Theoretical habitat templets, species traits, and species richness: aquatic Coleoptera in the Upper Rhône River and its floodplain

• 1 To test predictions of the river habitat templet and the patch dynamics concept, trends in species traits and species richness of aquatic beetles were related to the spatial-temporal variability of eighteen habitat types in the alluvial floodplain of the French Upper Rhône River. One hundred and twenty species of beetles were used in this analysis.
• 2 The basic information was obtained either from the literature (for most of the species traits) or from observations made at approximately 500 sampling sites in the Brégnier-Cordon and Jons sections over the past 19 years (for habitat utilization). This information was structured by a fuzzy coding technique and examined by ordination analyses.
• 3 Analyses of the relationships among nineteen species traits revealed a clear distinction according to traits such as body form (for adults), functional feeding type and food (adults and larvae), attachment to the substrate and dissemination potential (adults and larvae), and patterns of aquatic and/or terrestrial life of adults and larvae. Species traits such as number of descendants per reproductive cycle, and number of reproductive cycles per year or per individual showed less contrast, because these traits are rather homogeneous in aquatic beetles.
• 4 Analyses of the habitat utilization by the aquatic beetles revealed a vertical gradient that separates interstitial from superficial habitats, and a transverse gradient for the superficial habitats, which extends from the main channel towards permanent oxbow lakes and temporary waters.
• 5 The significant relationship betweeen species traits and habitat utilization demonstrates that most beetle species use a particular set of habitat types with a particular set of species trait modalities.
• 6 Species traits of aquatic beetles are homogeneous but evidently very successful and are adapted to many potential conditions of spatial–temporal variability. Because of this homogeneity, observations on aquatic beetles do not support trends of traits in the framework of spatial–temporal variability predicted from the river habitat templet.
• 7 The observed species richness of aquatic beetles is low in habitat types with a low spatial–temporal variability, increases as spatial variability increases, and tends to be highest at intermediate temporal variability. This pattern matches predictions of the patch dynamics concept.

     

How predacious are predators? A study on Ocypus similis,a rove beetle of cereal fields

It is attempted determine the diet breadth and to quantify the predator pressure by Ocypus similis (F.) (Coleoptera: Staphylinidae), a dominant species of the rove beetle fauna in a winter wheat field. Laboratory and field experiments were conducted to determine the range of prey taxa and the consumption of a whole predator generation (including larvae) during its activity in the field. In laboratory experiments, adults and larvae of O. similis fed on a variety of prey except spiders and larvae of soldier beetles (Cantharidae), but they preferred millipedes as food (Diplopoda: Julidae, Polydesmidae). This preference could also be observed in the field. Although the predator population reached its maximum density in April, highest predator pressure occurred in June because of high consumption rates during the second larval stage. Adult beetles and the individuals of the second larval stage contributed both about 1/3 to total population consumption. Predation by adult beetles was mainly restricted to early spring and summer while larval consumption was highest from April to July. The staphylinids reduced the population density of diplopods by 7–35%. Because millipedes are an important part of the decomposer community, predator activity may lead to a decrease of decomposition rates.     

The Restoration of Phytophagous Beetles in Species‐Rich Chalk Grasslands

This study focuses on the restoration of chalk grasslands over a 6‐year period and tests the efficacy of two management practices, hay spreading and soil disturbance, in promoting this process for phytophagous beetles. Restoration success for the beetles, measured as similarity to target species–rich chalk grassland, was not found to be influenced by either management practice. In contrast, restoration success for the plants did increase in response to hay spreading management. Although the presence of suitable host plants was considered to dictate the earliest point at which phytophagous beetles could successfully colonized, few beetle species colonized as soon as their host plants became established. Morphological characteristics and feeding habits of 27 phytophagous beetle species were therefore tested to identify factors that limited their colonization and persistence. The lag time between host plant establishment and colonization was greatest for flightless beetles. Beetles with foliage‐feeding larvae both colonized at slower rates than seed‐, stem‐, or root‐feeding species and persisted within the swards for shorter periods. Although the use of hay spreading may benefit plant communities during chalk grassland restoration, it did not directly benefit phytophagous beetles. Without techniques for overcoming colonization limitation for invertebrate taxa, short‐term success of restoration may be limited to the plants only.     

青藏高原高寒草甸门源草原毛虫取食偏好及其与植物C、N含量的关系

草食性昆虫对不同植物物种的取食存在偏好,这种取食偏好可能受其自身对蛋白质和碳水化合物的需求及二者平衡的调节。以青藏高原高寒矮嵩草草甸31种常见植物及门源草原毛虫为对象,通过饲喂实验,研究了草食性昆虫对不同物种和不同功能群植物的取食偏好,及其与植物叶片C、N含量和C∶N之间的关系。在31种植物中,门源草原毛虫对19种植物进行了取食,尤其对矮嵩草、红棕薹草、藏异燕麦和垂穗披碱草四种植物表现出强烈的取食偏好,而对另外12种植物未进行任何取食。在物种水平上,门源草原毛虫取食量与植物叶片N含量呈显著负相关,与叶片C∶N呈正相关。从功能群水平上看,门源草原毛虫对莎草类的取食偏好最大,而对豆科植物取食偏好最低;相应地,莎草类植物叶片N含量最低、C∶N最高,而豆科植物叶片N含量最高、C∶N最低。因此,即使在土壤有效氮匮乏、植物生长受氮素限制的高寒草甸生态系统,植物体内N含量的增加也可能不利于草食性昆虫的取食。门源草原毛虫对优势植物矮嵩草和垂穗披碱草的取食对高寒矮嵩草草甸物种共存和生物多样性维持可能具有重要的作用。