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1.
This paper presents an eco‐taxonomic study of the Neotropical representatives of the Thyreodon genus‐group (Hymenoptera: Ichneumonidae) present in Costa Rica, i.e. species of the genera Thyreodon and Rhynchophion. These ichneumonids are koinobiont endoparasitoids of the larvae of Sphingidae and Saturniidae. Intensive sampling in Costa Rica, conducted over 15 years, has revealed the presence of 23 species (12 of which are described here as new –Rhynchophion woodi, Thyreodon woodleyi, T. papei, T. whitfieldi, T. deansi, T. walkerae, T. sharkeyi, T. zitaniae, T. delvarei, T. schauffi, T. darlingi and T. carmeani), whereas earlier studies recognized only nine species in the same area. Several of the additional species we found are simply very scarce and thus unlikely to be encountered except by the type of intensive survey that, in the tropics, has only been conducted in Costa Rica. In some other cases, it has become apparent that more than one species has previously been confused under a single name. Thyreodon rufothorax Cameron is shown to be morphologically and biologically distinct from T. atriventris (Cresson), with which it has long been synonymized, and the relatively well‐known, chromatically distinctive species ‘T. laticinctus Cresson’ and ‘T. morosus Smith’ are both shown to be complexes of sibling species. Reared series have been essential in facilitating the separation of the species in these complexes. An illustrated key is provided to separate all taxa using simple morphological characters. Fourteen of the 23 species have been reared, and all have been found to be restricted to one or a few species of hosts, species of Thyreodon primarily on macroglossine Sphingidae (with one species on Saturniidae) and species of Rhynchophion on sphingine sphingids of the genus Manduca. No two species of these ichneumonids attack the same host caterpillar species, and not all species of macroglossines present in the study area are attacked by species in this genus‐group. Most species are apparently rather rare. Many have only been collected by rearing on a few occasions, other species have been collected at light (six in total) or in Malaise traps (ten in total), or by hand‐netting (20 in total), but no one method collected all of the species present in the principal study area, the Area Conservacion de Guanacaste. The two New World genera Rhynchophion and Thyreodon are found to be related to the Old World genera Dictyonotus and Euryophion, the former of which comprises species that are also sphingid parasitoids, whereas species of the latter attack the caterpillars of other large bombycoid moths, Saturniidae and Eupterotidae. A cladistic analysis shows that Thyreodon is the sister‐lineage to Dictyonotus, and Euryophion is the most basal lineage in the genus‐group. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141 , 297–351.  相似文献   

2.
The genus Isoetes L. in India is represented by 14species, of which eight species are recognized as being local endemics [confinedto one particular phyto-geographical division (PGD)] while the remaining sixoccur in more than one PGD and are described as endemic to a wider range. Thelocal endemic species are Isoetes dixitei,Isoetes panchganiensis and Isoetessahyadriensis in Western Ghats region; Isoetespantii, Isoetes bilaspurensis, Isoetesreticulata and Isoetes tuberculata inChotanagpur Malwa Vindhya Plateau and Isoetes debii innortheastern India. The wider endemic species are Isoetespanchananii, Isoetes sampathkumaranii,Isoetes rajasthanensis, Isoetesmahadevensis, Isoetes indica andIsoetes coromandelina. Our studies on the patterns ofendemism suggest that the radiation of quillworts advanced from dry lowlandareas to the rainy uplands and mountains. Isoetescoromandelina is the first Indian quillwort to colonize in lowlandsof the coastal zone (Coromandel), from where it spread to different parts of thesub-continent and gave rise to new species. Thus this species is a key Indianspecies which has played an important role in the radiation of quillwort in thecountry and appeared as the connecting link among the quillwort flora of variousPGDs. The centres of diversity for almost all the presently known Indianquillworts species are recognized.  相似文献   

3.
Aim The plant genus Bursera, with 104 species of trees and shrubs, has been used as a model for biogeographical analyses because of its high species richness and large number of endemic species. The biogeographical patterns of Bursera and their implications for its phylogenetic classification are reviewed in order that some hypotheses on the historical biogeography of tropical Mexico can be proposed. Location Bursera is found in the south‐western USA, most of Mexico, mainly below 1700 m elevation in tropical forests, with some species in xeric shrublands, diversifying along the Pacific slope, Central America, and north‐western South America. A few species occur on the Galapagos and Revillagigedo archipelagos, some of which are endemics, whereas in the Antilles species are distributed extensively, with several endemics in the Bahamas, Cuba, Jamaica, and Hispaniola. Methods Data from specimens in herbaria and the literature were used to construct a matrix of 104 species in 160 areas. Distributional patterns of the species of Bursera were inferred applying track analysis, parsimony analysis of endemicity (PAE), and Brooks parsimony analysis (BPA). Results Track analysis revealed four individual tracks: (1) a circum‐Caribbean track, comprising species of the Bursera simaruba species group; (2) an Antillean track, including species that have been transferred to Commiphora based on their pollen traits; (3) a Mexican Pacific track, including species of the B. fragilis, B. microphylla, and B. fagaroides species groups, called ‘cuajiotes’; and (4) a Neotropical Pacific track, including the two species groups assigned to section Bullockia, in which the individual track of the Bursera copallifera species group is nested within the track of the B. glabrifolia species group. The four tracks overlap in a node in the Mexican Pacific slope, where they are highly diversified. PAE allowed us to identify 22 areas of endemism: 12 in Mexico (11 along the Mexican Pacific slope), six in the Antilles, two in Central America, one in South America, and one in the Galapagos. The general area cladogram obtained by BPA has two main clades: one includes the greater Antilles; and the other, 12 Mexican areas of endemism. Main conclusions Bursera fragilis, B. microphylla, and B. fagaroides species groups can be treated together as a new section within Bursera, sect. Quaxiotea, because they are segregated from the other groups of sect. Bursera based on morphological, anatomical, molecular and geographical evidence.  相似文献   

4.
The Hawaiian Drosophilidae possess spectacular diversity in male foreleg modifications, many of which are unknown in other Diptera. The greatest diversity in foreleg morphology is in the antopocerus, modified tarsus, and ciliated tarsus clade (AMC Clade), a group of 95 species. The modified tarsus flies are divided into the bristle, ciliated, split, and spoon tarsus subgroups. The bristle tarsus species feature one or two rows of thickened setae on the basitarsus. The split tarsus species are characterized by only having four tarsal segments, in contrast to five tarsomeres in the remainder of Diptera. Based on comparisons of the apparent ground state of ventral setal rows across the Hawaiian Drosophila, we suggest that it is the second tarsal segment which has been lost. The spoon tarsus species are characterized by having the second tarsomere modified into a setae‐filled, concave‐shaped spoon. The ciliated tarsus species, all of which possess one or more elongate setae on the tarsus of males, are probably not monophyletic with respect to the bristle tarsus subgroup. The antopocerus flies are characterized by a long basitarsus, with extensive setation on the tibia and basitarsus of some species. The use of these foreleg modifications in courtship behavior has been previously described and it is suggested that they represent the results of sexual selection. The current work expands on previous morphological analyses, presenting a level of detail not previously possible without SEM images. The new characters revealed will figure prominently in future cladistic studies. J. Morphol. 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

5.
Loss of rainforest because of agricultural and urban development may impact the abundance and diversity of species that are rainforest natives. Tropical fruit flies are one group of such organisms indigenous to rainforests. In southeast Queensland, a region subject to rapid urbanization, we assessed the impact of habitat disturbance on the distribution and abundance of native fruit flies. Data on four species (Bactrocera tryoni, Bactrocera neohumeralis, Bactrocera chorista, and Dacus aequalis) were gathered and analyzed over 6 months in three habitat types: suburbia, open sclerophyll forest, and rainforest. We also analyzed the data at a combined "dacine fruit fly" level incorporating all fruit fly species trapped over the period of study (as might occur in a biodiversity assessment): these included the four species already named and Bactrocera melas, Bactrocera bryoniae, Bactrocera newmani, and Dacus absonifacies. Analysis at the species level showed that the polyphagous pest species responded differently to the monophagous species. Bactrocera tryoni, which has more exotic than native hosts, was positively affected by transformation of natural habitat into suburbia whereas B. neohumeralis, which has nearly identical numbers of native and exotic hosts, was found equally across habitat types. Bactrocera chorista and Dacus aequalis, each monophagous on a species-specific rainforest host plant, were most abundant in rainforest. The analysis based on the combined data suggests that replacing rainforest with suburbia has a neutral, or even positive, effect on the abundance of fruit flies as a whole. At the species level, however, it can be seen that this is an erroneous conclusion biased by the abundance of a single pest species. Our discussion raises the issue of analyses at supraspecific levels in biodiversity and impact assessment studies. Received: March 6, 2000 / Accepted: June 19, 2000  相似文献   

6.
Ophion Fabricius is a diverse genus of nocturnal ichneumonid wasps (Insecta: Hymenoptera) that is particularly species‐rich in temperate areas, yet has received little taxonomic attention in the Holarctic region, where most species occur. While there have been some attempts to divide Ophion into monophyletic species groups, the vast majority of species have been lumped into a single, paraphyletic group, the O. luteus species group, which is defined only by the lack of characters specific to the other groups. The challenging morphology of this large catch‐all group has limited attempts to subdivide it, and no phylogenetic hypothesis has been proposed for the genus as a whole. In this study, we use DNA sequence data [28S ribosomal RNA (28S), cytochrome oxidase 1 (COI) and internal transcribed spacer 2 (ITS2)] to present the first molecular phylogeny of Ophion. We also describe the secondary structure of ITS2 for the first time in Ichneumonidae, and explore its implications for phylogeny estimation. We define 13 species groups, nine of which were previously considered part of the O. luteus species group s.l. The included species groups are the O. minutus, O. areolaris, O. scutellaris, O. flavidus, O. parvulus, O. slossonae, O. nigrovarius, O. pteridis, O. luteus s.s., and O. obscuratus species groups, along with three groups lacking described species (Species group 1, New Zealand group, Madagascar group). This study provides a framework for future studies of this diverse and morphologically challenging genus.  相似文献   

7.
Brazil has one of the greatest bird diversities in the world, with around 1,800 species. However, many species are now threatened by illegal capture and trade that is largely driven by the culture of keeping wild birds as pets. This study documents the nature and purpose of bird capture and trade in the semi-arid Caatinga biome in northeastern Brazil, which has around 510 bird species and a population of around 25 million people. Data were obtained through observation in the homes of bird keepers and at open air markets, as well as through semi-structured and open-ended interviews and informal conversations with 52 wild bird keepers. We recorded 38 species of birds kept as pets in this study. The family with the largest number of species recorded was the Emberizidae (29%), followed by the Columbidae (16%) and the Psittacidae (16%). The most frequently kept species were: Paroaria dominicana, Aratinga cactorum, Icterus jamacaii, Sporophila albogularis, Turdus rufiventris and Cyanocompsa brissonii, which are all native to this region. Among the recorded species, only Pintassilgo (Carduelis yarrellii) is listed as an endangered species in Brazil. Of the people interviewed, 32% observed a reduction in abundance, or disappearance, of several bird species in the region. The need for measures aimed at the sustainability of wild avifauna use is therefore evident. These include law enforcement, commercial breeding and environmental education, of which the last is considered the most likely to be effective.  相似文献   

8.
Invasive alien weeds pose a serious threat to the biodiversity of natural ecosystems and a significant constraint to agricultural production worldwide. The use of co-evolved natural enemies, a strategy referred to as classical biological control (CBC), has proven to be a potentially efficacious, cost-effective, and safe option for the management of alien weeds. An analysis of CBC of invasive weeds in Latin America is presented, which shows that only 5% of the worldwide releases of agents, overwhelmingly arthropod, have been in this region. Fungal pathogens are increasingly being considered in CBC programmes, and there are now 11 examples of Latin American fungi having been released as biocontrol agents in other regions of the world. In contrast, only three weed pathogens have been deliberately released in the region. Possible reasons for the paucity of CBC programmes in Latin America are presented, despite the presence of a significant number of alien weed species (60 are listed). An analysis of these weeds reveals that many of them could be amenable to control using natural enemies, including nine weed species for which CBC programmes have been successfully implemented elsewhere in the world. In addition, for many of these 60 species, a co-evolved and damaging mycobiota has already been recorded. The prospects for management of invasive alien weeds in Latin America, using co-evolved fungal pathogens, are assessed with particular reference to selected species from the genera Ambrosia, Broussonetia, Calotropis, Commelina, Cyperus, Dichrostachys, Echinochloa, Pittosporum, Rottboellia, Rubus, Sonchus and Ulex. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

9.
10.
164 taxa were identified in the net zooplankton of the pelagial of L. Peipsi-Pihkva in 1909–1987, including 3 species of protozoans, 74 species of rotifers, 58 species of cladocerans, 28 species of copepods and 1 mollusc. One rotifer species, Ploesoma peipsiense Mäemets et Kutikova, has been described as new for science here. The zooplankton of L. Peipsi-Pihkva is remarkably rich in species including rarities in Estonia: Limnosida frontosa, Drepanothrix dentata, Bythotrephes longimanus, B. cederstroemi etc. Due to its large surface area, L. Peipsi-Pihkva provides a large scale of biotopes of a diverse trophic state and humic content, which support species with different ecological requirements. Most of the aquatory of the lake has lately been mesotrophic, favouring the coexistence of indicators of oligo- and mesotrophic state and species preferring a higher trophic state. The occurrece of 10 species of the genus Bosmina including B. berolinensis, B. gibbera, B. lilljeborgi, B. thersites and B. crassicornis, sparse in Estonian lakes, is the most noteworthy feature of the zooplankton of L. Peipsi-Pihkva. The coexistence of B. coregoni and B. berolinensis, B. gibbera, B. lilljeborgi etc. which were earlier regarded as subspecies of B. c. coregoni proves that they are different species producing usually no hybrids. The species composition was subjected to certain changes during the years under consideration. Larvae of Dreissena were first found in zooplankton in 1962. The oligo-mesotrophic indicator Holopedium gibberum occurred in the lake in 1909–1964, but was lacking in later samples.  相似文献   

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