Micro-Arthropods in the Surroundings of Nests of Messor arenarius Ants in the Negev Desert in Israel

The present research investigated a segment of the micro-arthropod populations residing within nests of Messor arenarius ants in the Negev Desert of Israel. The total frequencies of micro-arthropods in the chaff of those ants’ nests were found to be higher than in the surrounding soil of the same nests. Acari (mites) were observed to be more abundant during the spring season, whereas their presence decreased during the summer months. Springtails (Collembola) were found to follow the Acari pattern, commonly found within the nests of those ants during spring but were absent during summer. Psocoptera order inhabiting soil habitats were infrequently encountered during spring, but their prevalence increased significantly during summer, particularly within the chaff of the ants’ nests, suggesting that chaff is their primary food source in the Negev Desert. Our research suggests that shifts in seasonality have important consequences on the distribution of soil invertebrate communities with implications on nutrient cycling.

Taxonomic and community composition of epigeal arthropods in monoculture and mixed tree species plantations in a deciduous forest of Ghana

Tropical forests provide several ecosystem services and functions and support approximately two-thirds of the world’s biodiversity but are seriously threatened by deforestation.Approaches to counteract this menace have revolved around aff orestation with several or a single tree species.We thus investigated how plantation forests with either a single or several tree species infl uenced arthropod taxonomic and community composition using pitfall traps to sample selected groups of epigeal arthropods(Araneae,Coleoptera,Orthoptera and Hymenoptera)and with environmental variables assessed simultaneously.Our results revealed 54 taxonomic groups with signifi cantly higher taxonomic richness,activity density,and diversity in the mixed stands than in the monoculture stands.The significant differences in community composition were mainly driven by families including Lycosidae,Formicidae,Staphylinidae,Scotylidae,Hydrophilidae,Gryllidae and Scarabaeidae and were explained by distinct habitat characteristics(canopy openness,litter depth,deadwood volume,and tree height).While the diverse tree communities and heterogeneous vegetation structure off ered food and habitat resources for diverse arthropod groups,the allelopathic nature coupled with homogenous stand characteristics of the Tectona grandis stands in the monoculture suppressed the growth of understorey vegetation that could otherwise serve as food and habitat resources for arthropods,which might have led to limited activities and diversity of arthropods in the monoculture plantation stands.The fi ndings thus highlight the need to promote mixed tree plantations in degraded tropical areas,especially when restoring biodiversity is the prime management focus.

Study on the Comparison of Arthropod Communities in Three Kinds of Cruciferous Vegetable Fields at High Mountainous Area

[Objective]This research aimed to compare arthropod communities in different cruciferous vegetable fields at high mountainous area and provide guidance for pest control. [Method] The main arthropod species in 3 kinds of erueiferous vegetable fields at high mountainous area were investigated, the composition of arthropod community in different vegetable fields were analyzed. [Result] The main arthropod species in erueiferous vegetables fields at high mountainous area were similar, but had different quantity compositions. The richness was the highest in radish field. [Conclusion] Crop species had great influence on biological community; we should focus on the main pests in the process of pest control.

Community Structure and Seasonal Variation of Soil Arthropods in the Forest-Steppe Ecotone of the Mountainous Region in Northern Hebei,China

Soil fauna have been receiving more and more attention because they play an important role in nutrient cycling.However,there is a lack of information on soil arthropods in the forest-steppe ecotone in the mountainous region of northern Hebei,which makes it difficult to meet the need of protecting biodiversity in this area.Soil arthropod communities were investigated in the forest-steppe ecotone in northern Hebei province to provide basic information on changes in mountain soil fertility,which could promote the development of soil arthropod communities in mountain ecotones.From the preliminary identification,a total of 7994 individual soil arthropods were collected,which belonged to 25 groups,6 classes and 24 orders.Acarina,Hymenoptera and Collembola were the dominant groups in the ecotone.The number of Acarina was higher than Collembola,and this phenomenon was obviously different from other areas in the same climate zone.The increased abundance of rare groups in the Forest zone with the richer vegetation,higher arthropod abundance and more substantial litter depth,could be interpreted as a reaction to the suitable soil environment and food supply.And these rare groups were sensitive to environmental changes,which could be regarded as biotic indicators for evaluating soil quality.The analysis of community diversity showed that the abundance index (d),the Shannon-Wiener index (H'),the evenness index (J) and the density-group index (DG) were significantly higher in the forest zone,lower in the forest-steppe zone,and lowest in the meadow-steppe zone.Seasonal variations in community composition correlated with changes in average air temperature and precipitation in this ecotone.Groups and individuals of soil arthropod communities in the three zones were present in greater numbers in the middle of the rainy season than in the early or late periods of the rainy season as a whole.At the same time,seasonal changes in soil arthropod communities from different plots were also influenced by habitat condition.

New Bivalved Arthropods from the Cambrian(Series 3, Drumian Stage) of Western Hunan, South China

We report two new three-dimensionally phosphatized microfossils, Cambrolongispina reticulata gen. et sp. nov. and Cambrolongispina glabra gen. et sp. nov., from the middle Cambrian （Series 3, Drumian Stage） at Wangcun, Yongshun County, western Hunan, South China. They are bivalved arthropods, with thin, pliable, originally chitinous or chitin-calcareous shields （c. 350-517 I1 m long）. The shields are equipped with a pair of antero-dorsal spines. The spines are internally hollow, varying in length from 1/2 of to as long as the shield length in C. reticulata, and uniformly longer than the shield length in C. glabra. The spines of C. reticulata are ornamented with a longitudinal row of conical or blade-shaped denticles along the posterior edge. Cambrolongispina lacks marginal rims, valve lobation and sulci which are diagnostic of the Bradoriida sensu stricto. It also lacks a donblure/duplicature characteristic of phosphatocopids and some bradoriids. It could be related to the Monasteriidae （which may belong to Bradoriida sensu lato）, both characterized by a pair of antero-dorsal spines. Cambrolongispina may have been meiofaunai detritus feeders that lived on or within sediments. The antero-dorsal spines may have been sensory organs to detect nearby predators. The posterior denticles on these spines might have facilitated the sensory function of the spines.

A New Arthropod,Guangweicaris Luo,Fu et Hu gen. nov. from the Early Cambrian Guanshan Fauna,Kunming,China

The Guanshan Fauna is a soft-bodied fauna dominated by arthropods （including trilobites, trilobitoides, Tuzoia, Isoxys, and bradorids） in association with priapulids, brachiopods, anomalocaridids, vetulicoliids, sponges, chancellorids, and echinoderms. This paper reports and describes a new arthropod from the yellowish green mudstone at the lower part of the Wulongqing Formation, Canglangpuan Stage, Lower Cambrian in Kunming, Yunnan, China. The stratigraphic and geographic distribution, classification, fossil preservation, life style of this new arthropod and comparisons with other fossil arthropods are also discussed in details. The discovery and research of the non-mineralized arthropod, Guangweicaris Luo, Fu et Hu gen. nov. from the Guanshan Fauna adds new members to the taxonomic list and provides new information to the evolution of early arthropods. Furthermore, this study would shed new light into the ＂Cambrian Explosion＂ and the evolution of early life.

The effects of the identity of shrub species on the distribution and diversity of ground arthropods in a sandy desert ecosystem of northwestern China

Shrub is an important factor on structuring ground arthropod communities in desert ecosystems. In this study, in order to determine how shrubs and their species influence ground arthropod distribution patterns in a sandy desert scrubland dominated by two different shrub species, Calligonum mongolicum and Nitraria sphaerocarpa, the ground arthropods were sampled with pitfall traps during spring, summer and autumn. At the community level, total arthropod abundance was shown to be significantly higher under shrubs than in intershrub bare areas in spring; similar patterns occurred in terms of the richness of arthropod groups in the spring and over three seasons, suggesting season-specific shrub presence effects on arthropod activity. In addition, more arthropods were found under N. sphaerocarpa shrubs than under C. rnongolicum shrubs in autumn, suggesting season-specific effects of shrub species of arthropod activity, whereas more arthropods taxa were captured under C. mongoIicum than N. sphaerocarpa. At the trophic group level, the abundances of predator and herbivore arthropods were significantly greater under shrubs than in intershrub bare habitats, whereas herbivore arthropods were more abundant under N. sphaerocarpa than C. rnongolicum, and an opposite rule was detected for predator arthropods At the family level, the mean abundances of Carabidae, Curculionidae, Gnaphosidae and Lycosidae were significantly higher in the shrub microhabitats than in the intershrub bare habitat, there was no significant difference between habitats on the mean abundances of Formicidae and Tenebrionidae. The study results suggested that shrub presence and shrub species variation are important determinants of ground arthropod assemblages in this desert ecosystem, but the responses of ar- thropods differed among trophic and taxonomic groups.

Ground-active arthropod responses to rainfall-induced dune microhabitats in a desertified steppe ecosystem,China

Different microhabitats along dune slope were found to affect the distribution of plant performances and soil properties in desertified ecosystems. However, the ground-active arthropod responses to rainfall-induced dune microhabitats were largely unknown in desertified regions. At dune top, midslope and bottom, ground-active arthropods were sampled by the method of pitfall traps in addition to the herbaceous and soil measurements during spring, summer and autumn from 2012 to 2013. Ground-active arthropod had a strong dynamics in time, seasonally and yearly in responses to rainfall-induced dune microhabitats and the variations were significant higher than those of soil and herbaceous properties. The abundance distribution of dominant taxa （i.e. Melolonthidae, Carabidae, Glaphyridae, Tenebrionidae and Formicidae families） among dune microhabitats was similar between seasons within the same year, whereas they differed markedly between two sampling years with varying rainfall patterns. A significant （P〈0.05） difference in total abundance, taxa richness and Shannon index among dune microhabitats was found only in certain season time, particularly in 2013; however, no significant （P〉0.05） differences were found among dune microhabitats when averaged on three sampling seasons within the year of either 2012 or 2013. In all, the taxonomical structure differed considerably from the community structure in ground-active arthropod response to rainfall-induced dune microhabitats. The spatial distribution of taxonomical groups among dune microhabitats was significantly affected by inter-annual rainfall changes, whereas that of community structure was affected by both intra- and inter-annual rainfall changes in desertified ecosystems.

Distribution of arthropods in rice grains in Malaysia

Objective:To determine distribution of arthropods in rice grains obtained from different sources.Methods: Rice samples were randomly collected from public in urban areas,farmers in rice field areas,aborigines in undeveloped areas and retailers in commercial premises.Random samples of rice were taken out from each sample for isolation of arthropods using a modified Berlese Tullgren Funnel Method.Mites were mounted prior to identification; weevils were directly identified.Results:Samples of rice from retailers in commercial premises had the highest infestation by arthropods followed by samples from urbanites,aborigines and rice farmers.Two species of weevils,Sitophilus oryzae(S.oryzae) and Sitophilus granarius(S.granarius),were found.Samples from commercial premises had the least percentage of weevils compared to those collected from domestic premises. Depending on the source of samples,densities of S.granarius and S.oryzae ranges from 11-103 weevils/ kg and 7- 80 weevils/kg,respectively.Important species of mites in stored rice identified were mainly members of the families Cheyletidae,Echimyopodidae,Pyroglyphidae,Saproglyphidae and Tenuipalpidae.Among the species of mites identified were Austroglycyphagus malaysiensis,Cheyletus fortis,Cheyletus malaccensis,Dermatophagoides pteronyssinus,Grammolichus malukuensis and Suidasia pontifica.Average density of most of the mites was less than 40 mites/kg of rice grains.In this study,the highest number of mites in rice samples was recovered from commercial premises,followed by samples from urbanites.Samples from farmers and aborigines contained lesser mites.Conclusion:This study demonstrated the presence of 3 allergenic mite species in rice, i.e A.malaysiensis,D.pteronyssinus and S.pontifica.Weevils,S.oryzae and S.granarius that are known to be allergenic,were also found.

Effects of transgenic poplar clone 741 with insect resistance on structure and diversity of arthropod community

Arthropod community structure and diversity were investigated in transgenic insect-resistant hybrid poplar 741 field trial plots, which had five isogenic clones with two genes （Bt. toxin [Cry IAc] and arrowhead proteinase inhibitor [API]） in comparison to control plots. Transgenic poplar clones were investigated according to their insect resistance （high and medium resistant clones）, being systematically probed into varying levels with feeding tests before. Investigations were carded out during three years （2002, 2003 and 2005）. The results indicated that among the basal species, transgenic plants in general had lower amounts of phytophagous insects, and an increased quantity of neutral arthropods such as saprophytic and strolling species. Among the top and intermediate species in transgenic variants, the quantity of predatory natural enemies was increased, while the amount of parasitoid ones was slightly reduced. The arthropod community characteristic indices were analyzed from different aspects in the three variants. It was discovered that, not only the characteristic indices of the whole arthropod community, but also the characteristic indices of the sub-communities （such as natural enemy, pest and neutral arthropods） and the functional groups categorized by their feeding patterns, showed a higher diversity and evenness and a lower dominancy concentration indices in the high-resistant and medium-resistant plots compared with the control. Transgenic poplar 741 showed improved ecological effects both in partial and total aspects. It could be concluded that composition and structure of the arthropod community in plots with transgenic insect-resistant poplar were turned to be more reasonable and itsdiversity and stability was enhanced.

The occurrence of arthropods in processed rice products in Malaysia

Objective:To determine distribution of arthropods in processed rice products such as rice flour and rice cereal-based infant food.Methods:Random samples of rice flour and rice cereal-based infant food purchased from commercial outlets were examined for the presence of arthropods using a modified Berlese Tullgren Funnel Method.Mites were mounted prior to identification and weevils were directly identified.Results:For non-expired products, infestation was found in 6.7%of rice flour and none was found in rice cereal-based infant food samples.The arthropods found in the flour samples were Cheyletus spp.,Suidasia pontifica(S. pontifica),Tarsonemus spp.,Tyrophagus putrescentiae(T.putrescentiae),Sitophilus granarius(S. granarius) and Sitophilus oryzae(S.oryzae).Others which cannot be identified were Oribatid and Prostigmatid mites.The most common mites in rice flour were Tarsonemus spp.(69.1%),followed by S.pontifica(18.2%).For expired products,only one sample of rice cereal-based infant food was infested and the infestation was by mites of the family Tydeidae.Conclusions:This study demonstrates the presence of 4 allergenic species of S.pontifica,T.putrescentiae,S.granarius and S.oryzae in rice flour.These arthropods can contribute to the incidence of anaphylaxis upon consumption by atopic individuals.There was no infestation of arthropods in rice cereal-based infant food surveyed except for an expired product in a moderate rusty tin container.

Contrasting arthropod communities associated with dwarf mistletoes Arceuthobium globosum and A. vaginatum and their host Pinus hartwegii

Arthropod communities and epiphytic plants associated with tree canopies have been widely studied and have revealed a great diversity of organisms; however,the community hosted by parasitic plants,such as dwarf mistletoes,remains poorly known.In the coniferous forests of North America,dwarf mistletoe infection（Arceuthobium spp.） significantly damages the health of the forest,causing large financial losses for the forest industry,but it also positively affects diversity,especially of mammals and birds.This study examined the attributes of the arthropod communities associated with two species of dwarf mistletoe [Arceuthobium globosum Hawksw.＆ Wiens and A.vaginatum（Humb.＆ Bonpl.ex Willd.） J.Presl] and their host Pinus hartwegii Lindl.In 2010,in five sites located in Zoquiapan（Central Mexico）,we collected plant tissue from the three species bimonthly.Arthropods were separated from the plant tissue and identified to the finest level possible.We collected 32,059 individuals,for which51 morphospecies were identified,belonging to 15 taxonomic orders; the most abundant orders for the three plants were Prostigmata,Thysanoptera and Homoptera.The community associated with P.hartwegii had the highest value of diversity（H＇= 1.47; A.globosum,H＇= 0.64; A.vaginatum,H＇= 0.68） and species richness（S = 40; A.globosum,S = 30; A.vaginatum,S = 35）; while abundance was significantly higher for the mistletoes（A.globosum,n = 407 individuals/sample; A.vaginatum,n = 536 individuals/sample; P.hartwegii,n = 134 individuals/sample）.Species richness,abundance and diversity were significantly different for the three studied plants,as well for sampling month and the interaction of these two factors（except for diversity）.The results suggest that the canopy of P.hartwegii is an important element in the ecosystem,providing a mosaic of resources and conditions to the associated fauna.We also propose that mistletoes are key species within the forest canopy,as they greatly influence the establishment of diverse organisms,particularly arthropods.

Diversity and dominant species of arthropods in different forests of Aershan,Inner Mongolia

Taking different forests in Aershan of Inner Mongolia as sample plots, diversity and dominant species of arthropods were studied. The results show that two classes, 17 orders, 68 families, 130 species and 3742 individuals were identified and 92.31% of total species appeared in natural forests, and 75.38% of total species appeared in plantations. The orders of Lepidoptera, Coleoptera, Diptera and Hymenoptera covered most of the collected arthropods. In different forest types, diversity indices is natural mixed forests （Betula platyphylla x Larix gmelinii）〉 natural pure B. platyphylla forests〉natural pure L. gmelinii forests〉plantations with pesticide treatment〉plantations without pesticide treatment. In natural forests, more than 70% of the arthropod families, species and individuals were distributed in shrub and herb layer, while in plantations 75% of the arthropod families, 78% of species and 80% of individuals were also distributed in shrub and herb layer. Lepidoptera, including Loxostege sticticalis （Linnaeus）, Chilo suppressalis （Walker） and Lymantria dispar （Linnaeus）, had the highest dominant degree.

Canopy arthropods community within and among oak species in central Mexico

Quercus rugosa and Q.laurina are species that presents a wide geographical distribution range in temperate forests of Mexico. Oak canopies contain a considerable portion of arthropod diversity and the arthropods fauna fulfill a wide variety of ecological roles. We examined the effect of oak species and seasonal changes on some community structure parameters (diversity,composition,similarity,biomass,rare species,and density of arthropod fauna) of canopy arthropods. In total,40 oak canopies were fogged during rainy and dry season. A total of 614 identified arthropod morphospecies were recognized belonging to 22 orders associated with tree canopies. A separation of host tree species during both seasons,suggesting a different community structure on host plants species was demonstrated by the principal component analyses (PCA),therefore,differences between oak species results in phenotypes that structure the composition of the arthropod community. Q.laurina registered the highest densities,diversity index and number of rare species in comparison with Q.rugosa. While arthropod biomass showed an inverse pattern. Trees more close to one another (spatial distance) register a more similar canopy arthropod fauna. This study suggests that the trees of Q.laurina could act as a center of biodiversity by the accumulation of arthropod fauna with a considerable number of rare species,which presents wide ecological roles or is involved in critical processes that maintain forest ecosystems.

Soil Arthropod Abundance and Diversity Following Land Application of Swine Slurry

Soil arthropods play an important role in nutrient cycling and maintenance of soil structure, and their abundance and diversity provide an indication of the biological quality of soil. Land application of livestock manure provides crop nutrients and may also impact the soil arthropod community. This study was conducted to quantify soil arthropod abundance and diversity for a period of one year following swine manure application via broadcast or injection. Arthropods were extracted from plot soil samples using Berlese funnels, identified and counted, and the QBS index (Qualità Biologica del Suolo) was calculated for each soil sample. Collembola (Hypogastruridae and Isotomidae) populations were greater (p p in the injection treatment compared to the broadcast and control treatments. Acari populations and the QBS index were not significantly impacted by manure application.

Impact assessment of genetically modified herbicide-tolerant cotton on arthropod communities

Background:Cotton(Gossypium spp.)is one of the most important economic crops worldwide,and its production plays an important role in the economy of many countries.Genetically modified herbicide-tolerant(GMHT)crops,which were developed to minimize the losses caused by weeds,have gradually become the most widely adopted genetically modified crops in the world due to their economic and environmental benefits.However,the potential ecological and environmental risks of GMHT crops have attracted extensive attention and controversy.Arthropod communities form a promine nt part of the biodiversity of agroecosystems and are important indicators of environmental health.Elucidating the effects of GMHT crops on the diversity of arthropod communities is necessary to ensure the safety of GMHT crops.Result:In this 2-year study,we investigated the potential impact of GMHT crops on arthropod communities.The GMHT cotton variety GGK2 with glyphosate tolerance and its near-isogenic non-GMHT variety K312 were used for the experimental groups.The Shannon diversity index(H),Simpson diversity index(D),Pielou evenness index(J),and principal co-ordinates analysis(PCoA)of the Bray-Curtis distance were used to evaluate the population dynamics and biodiversity of arthropods in cotton fields.No significant differences were found between GGK2 and K312 in their total abundance of arthropod communities,and biodiversity indexes on most sampling dates.The arthropod composition in the GGK2 and K312 plots was similar.Sampling elates had a significant effect on biodiversity indexes,whereas no clear tendencies related to cotton variety or cotton variety x sampling elates interaction were recorded.In addition,PCoA revealed high similarity between the arthropod communities in the plots of the GMHT cotton variety GGK2 and its near-isogenic variety K312.Conclusion:There was no obvious difference in abundance,diversity indexes of arthropod communities between GMHT cotto n variety GGK2 and its near-isogenic variety K312 under the small-scale plan ting regime.

Community Composition and Structure of Soil Macro-Arthropods Under Agricultural Land Uses in the Black Soil Region of Jilin Province, China

Soil macro-arthropods in the black soil region in Jilin Province of China were investigated with the emphasis laid on the species richness and abundance in relation to the types of land-use, i.e., farm yard, farm land and Three-North Forest Shelter Belt. Soil macro-arthropods were hand-sorted in the field. A total of 2 357 soil macro-arthropod individuals was captured and fell into 70 families. The results suggested that type of land use affected the species richness and abundance of soil macro-arthropods. Agricultural practices had a strong impact on the soil macro-arthropods community, the conventional cultivations changed the vertical structure of macro-arthropods in the soil profile, and improved the richness and abundance of macro-arthropods in the lower soil layers especially in July. The results also showed that different groups of soil macro-arthropods had various responses to land use changes.

Creek Proximity and Flora Effects on Arthropod Populations in Riparian Buffers in Washington State, USA

Due to federal, state, and local regulations pertaining to clean water and salmon recovery, stream health and water quality are major concerns in the Pacific Northwest of the United States. An integral component of most riparian rehabilitation efforts is the effective establishment of preferred vegetation. We conducted arthropod surveys in representative disturbed and rehabilitated riparian buffers directly adjacent to apple orchards and grape vineyards in the Lower Yakima Valley near Prosser, Benton County, Washington State USA. Objectives of the study were to determine whether densities of select predatory and pest taxa changed with distance from the waterway and to test whether densities differed among disturbed, rehabilitated, or pristine riparian buffers. The studies suggest that populations of some beneficial arthropods, including spiders and ground beetles, were higher in the presence of exotic flowering plant species. In the riparian environments surveyed, more native woody plant species were found adjacent to the waterway, and this apparent stability appears to have had a positive effect on beneficial arthropods. Concurrently, data indicated that some exotic, flowering species of plants may be preferred over native plant species as hosts to certain arthropod pests. These plants tend to persist in degraded riparian buffers and at the interface of riparian habitats and cultivated areas, whereas native plant species are predominant in pristine or properly maintained and rehabilitated buffers.

Differences in arthropod communities between island and inland Masson pine forests infested by pine wilt disease in Zhejiang Province

The invasion of Bursaphelenchus xylophilus （pine wood nematode, PWN） carried by Monochamus alternatus predominately attacks Masson pine （Pinus massoniana） forests and causes great economic losses in China. In this study, we assessed whether the effect of the invasion of PWN is different between island and inland forests. Arthropods were sampled in Fuyang （inland） and Zhoushan （island） counties in Zhejiang Province with sweep netting and light traps at four plots. During two field periods （May to June 2004 and September to October 2005） a total of 21,916 insects, representing 384 species belonging to 99 families and 15 orders, were collected in the sample plots from the island, whereas, from the inland forest a total of 29,262 insects, representing 308 species belonging to 96 families and 13 orders, were found. A hierarchical cluster analysis （HCA） and one-way ANOVA, based on the composition of different arthropod guilds, were performed. The results showed that there was no significant difference in the composition of arthropod communities at the family level between inland and island. But these two habitats had a significant effect on the composition of species, individuals, sub-communities and energy class levels. Statistically, the composition of the two orders, Lepidoptera and Diptera, in the two habitats were significantly different.

Waptia-like Euarthropods from Burgess - Shale - type Biotas in the Early Cambrian of Eastern Yunnan, China

Waptia-like euarthropods existed for rather a long time in the Early Cambrian of eastern Yunnan;well preserved representatives come mainly from three Burgess Shale-type biotas:Chengjiang,Xiaoshiba and Guanshan.Here,we introduce a newly-discovered bivalved euarthropod from the Guanshan biota,the specific identity of which cannot be confirmed due to the absence of soft parts and poor preservation of the specimen,but its general morphology allows it be attributed to Waptia.Two representatives from the Chengjiang and Xiaoshiba biotas are also reconsidered:the preservation mode and length of specimens of Clypecaris pteroidea are variable;Clypecaris serrate has limbs beneath the carapace,which can number up to at least 4 pairs.The fossil sections bearing Waptia-like euarthropods occur over a wide area around Dianchi Lake.