Fauna And Distribution Of Tenebrionid Beetles Inalxa Plateau (Coleoptera: Tenebrionoidea)

This dissertation is focus on the taxonomy and fauna study of the Tenebrionidae (Coleoptera) in theAlxa Plateau, based on a lot of named specimens, also refer to the origin, distribution pattern, including therelationship with the adjacent areas, and the following results are obtained:I. There are5subfamilies,23tribes,52genera and206species (subspecies) are recorded in the AlxaPlateau, based on the accurate results of identifying tenebrionid specimens preserved in the Museum ofHebei University, as a result, one species Cheirodes (Pseudanemia) scalarithoracus Ren, Ning et Jia,2011has been described from the Alxa Plateau,4pupae (Melanesthes (Melanesthes) jintaiensis Ren, M.(Opatronesthes) rugipennis Reitter, Eumylada potanini (Reitter), Penthicus (Myladion) nojonicus (Kaszab))are newly described. The diagnoses and the keys of subfamily, tribe along with genus are presented. Thecitations of genera and species with information of examined materials are given.II. In this region,186tenebrionid species are Central Asian components of Palearctic realm (90.3%),most of them have narrow distribution; the highest percentage of composition of subfamily are Pimeliinaeand Tenebrioninae (total:175species,84.9%), the most diverse of composition of tribe is Tentyriini (54species,26.1%), next is Opatrini (48species,23.2%); Blaps is the most abundant in composition of genera(23species,11.1%); the genus Jintaium is the only endemic genus;41species are the endemic species inthe Alxa Plateau (20.0%).III. The relationship of distributing type of tenebrionid beetles in the Alxa Plateau with theZoogeographical region of Chinaa. In the distributing type, tenebrionid beetles of the Alxa Plateau can be classified into16types, ofwhich tenebrionid beetles of the Alxa Plateau is closest to the distributing type of Mongo-Xingjiang Region(39genera,75%;130species,63.1%), the next is the distributing type of the Alxa (41species,19.9%), thedistributing type of North China Region and Mongo-Xingjiang Region (17genera,32.7%;30species,14.6%), and the distributing type of Qinhai-Xizang region and Mongo-Xingjiang Region (8genera,15.4%;19species9.2%), the rest of the distributing type possess a small proportion.b. The data shows that tenebrionid beetles of the Alxa Plateau have the highest similarity withMongo-Xingjiang Region (52genera,100%;206species,100%), next is North China Region (29genera,55.8%;56species,27.2%), Qinhai-Xizang region (15genera,28.8%;34species,16.5%), Central ChinaRegion (9genera,17.3%;15species,7.3%), Southwest Region (8genera,15.4%;15species,7.3%),Northeast Region (9genera,17.3%;13species,6.3%) and South China Region (6genera,11.5%;10species,4.9%). IV. The relationship of Tenebrionid beetles of the Alxa Plateau with adjacent and related areasa. Mongolia is an important part of Mongolian Plateau, the darkling beetles currently includes6subfamilies,25tribes,58genera and223species, there are common composition with the Alxa Plateau inthe tribe, genus and species, they accounted for60.9%,51.9%and37.4%separately of the Alxa Plateau,the data shows that tenebrionid beetles of the Alxa Plateau are very similar to Mongolia.b. The Alxa Plateau is an important part of Inner Mongolia Plateau. The darkling beetles currentlyincludes7subfamilies,26tribes,62genera and209species, the common composition accounted for78.3%,73.1%and61.2%separately of the Alxa Plateau, the data shows that there is a high level of similaritybetween them.c. Ningxia Plain is the transition zone between the Alxa Plateau and Loess Plateau, also, it is theboundary between desert and semidesert, helan mountain is the mark. The darkling beetles currentlyincludes140species, of which116species (56.3%) are same to the Alxa Plateau, it shows that theirrelationship is very close.V. The result of using Grid-Cluster analysis shows that the richness of tenebrionid species decreasewith increasing latitude but it increase with increasing longitude. Alxa Plateau could be divided into5endemic area using Grid-Cluster analysis i.e. Xiqilian-e’jina subregion, Helishan-longshoushan subregion,A’zuoqi desert subregion of west of helanshan, Helanshan-xiangshan subregion, Southern subregion ofwuqiaoling.Research result of vertical distribution patterns shows that Tentyriini (40%) is predominant in loweraltitude (<1000m); with the elevation increasing, Opatrini (25.8%) and Blaptini (25%) become thedominant group; number of darkling beetles decrease in the high altitude (>3000m), but some endemicspecies occurred, eg. B.(B.) nanshanica Semenov et Bogatchev and B.(B.) caraboides Allard etc.VI. Referring to the geologic formation and the biogeographical history of Alxa Plateau, the originand adoption type of the darkling beetles of the Alxa Plateau are analyzed and discussed. The preliminaryresults show that it maybe originate from Cretaceous transgression and regressions, Central Asian is theorigin and dispersal center of Eurasian tenebrionid beetles, and eastward expansion to the Alxa Plateau, theexisting distribution pattern is gradually taking shape. The Alxa Plateau currently has common species(24.1%) to Central Asian.The darkling beetles has a special ability to adapt the Alxa Plateau as following:a. Physiological adaptation. The adult gain the water through using the sub-elytralcavity;b. Morphology adaptation. Tenebrionid beetles of the Alxa Plateau have somany special characteristics in order to adapt to the desert and semidesert;c. Biological adaptation. In order to avoid the heat of desert, most tenebrionid beetles are nocturnal,they often live in the cave of mammal and make good use of micro habitat; larvae often feed humus, andhave semisocial behavior.