Chromosome number in Dendroctonus micans and karyological divergence within the genus Dendroctonus (Coleoptera: Scolytidae)

2002 ◽  
Vol 134 (4) ◽  
pp. 503-510 ◽  
Author(s):  
Gerardo Zúñiga ◽  
Yolanda Salinas-Moreno ◽  
Jane L. Hayes ◽  
Jean Claude Grégoire ◽  
Ramón Cisneros

AbstractThe meiotic formula of the European spruce beetle, Dendroctonus micans (Kugelann), is 10 AA + Xyp in males and 10 AA + XX in females. This karyotype is different from the morphologically similar Dendroctonus punctatus LeConte (14 AA + Xyp), which is consistent with the taxonomic validity of both species. The chromosome number found in D. micans, added to karyological data from other species of the genus Dendroctonus Erichson, suggest that the karyological diversification within this genus may have occurred in two directions: one toward more southerly latitudes in North America and the other toward Europe and Asia.

Chromosoma ◽  
2021 ◽  
Vol 130 (1) ◽  
pp. 15-25
Author(s):  
Phuong T. N. Hoang ◽  
Jean-Marie Rouillard ◽  
Jiří Macas ◽  
Ivona Kubalová ◽  
Veit Schubert ◽  
...  

AbstractDuckweeds represent a small, free-floating aquatic family (Lemnaceae) of the monocot order Alismatales with the fastest growth rate among flowering plants. They comprise five genera (Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia) varying in genome size and chromosome number. Spirodela polyrhiza had the first sequenced duckweed genome. Cytogenetic maps are available for both species of the genus Spirodela (S. polyrhiza and S. intermedia). However, elucidation of chromosome homeology and evolutionary chromosome rearrangements by cross-FISH using Spirodela BAC probes to species of other duckweed genera has not been successful so far. We investigated the potential of chromosome-specific oligo-FISH probes to address these topics. We designed oligo-FISH probes specific for one S. intermedia and one S. polyrhiza chromosome (Fig. 1a). Our results show that these oligo-probes cross-hybridize with the homeologous regions of the other congeneric species, but are not suitable to uncover chromosomal homeology across duckweeds genera. This is most likely due to too low sequence similarity between the investigated genera and/or too low probe density on the target genomes. Finally, we suggest genus-specific design of oligo-probes to elucidate chromosome evolution across duckweed genera.


2021 ◽  
Author(s):  
Giuliano Cerasa ◽  
Gabriella Lo Verde

AbstractOzognathus cornutus (LeConte, 1859) (Coleoptera: Ptinidae: Ernobiinae), species native to North America, is a saproxylophagous species and is known to feed on decaying tissues within conspicuous galls and on vegetal decaying organic material such as dried fruits or small wood shavings and insect excrements in galleries made by other woodboring species. A few years after the first record in 2011, its naturalization in Italy is here reported. The insect was found as successor in galls of Psectrosema tamaricis (Diptera Cecidomyiidae), Plagiotrochus gallaeramulorum, Andricus multiplicatus and Synophrus politus (Hymenoptera Cynipidae). The galls seem to have played an important ecological role in speeding up the naturalization process. The lowest proportion of galls used by O. cornutus was recorded for P. tamaricis (23%), the only host belonging to Cecidomyiidae, while the percentages recorded for the other host species, all Cynipidae forming galls on oaks, were higher: 43.6%, 61.1% and 76.9% in A multiplicatus, S. politus and P. gallaeramulorum, respectively. Although O. cornutus is able to exploit other substrates like dried fruits and vegetables, for which it could represent a potential pest, it prefers to live as a successor in woody and conspicuous galls, which thus can represent a sort of natural barrier limiting the possible damages to other substrates.


1992 ◽  
Vol 6 ◽  
pp. 305-305
Author(s):  
Mahito Watabe

The late Miocene Chinese hipparions are morphologically diversified showing similarity to both western Old World's and North American forms. Two Chinese taxa that are phylogenetically related to western Old World's forms are Hipparion fossatum (= H. forstende) from Baode (Shanxi) and H. hippidiodus from Qingyang (Gansu) and Baode. The former is related to H. mediterraneum and the latter to H. urmiense - platygenys from the Turolian localities in the western Old World. H. fossatum and H. hippidiodus are associated with the “dorcadoides” (open-land) and “mixed” faunas in northern China. Hipparion fossatum that is characterized by POF located close to the orbit co-occurs with large and morphologically specialized form, H. dermatorhinum in Baode (Loc.30). H. hippidiodus with reduced POF is discovered with smaller H. coelophyes in Loc. 43, 44 (Baode) and Loc. 115 (Gansu).The hipparions associated with the “gaudryi” (forest) fauna are characterized by well defined and small POF located far from the orbit. Those forms are: H. platyodus from Loc. 70; H. ptychodus from Loc. 73; H. tylodus from Hsi-Liang in Yushe - Wuxiang basins; and H. sefvei from Loc. 12 at Xin-an in Henan province. H. coelophyes from Baode (Loc.43 & 44) and Qingyang (Loc. 115) also show similar facial morphology to the these forms, although it has small size and shallow POF. Those forms are similar in facial and dental morphology to Hipparion sensu stricto and some species of Cormohipparion in North America.The assemblages of Chinese hipparions are composed of two groups whose members are phylogenetically similar to the forms from both western part of Eurasia and North America. The “gaudryi” fauna is considered younger than the other two on the basis of faunal analyses. The similarity in hipparionine taxonomy between northern China and North America in the latest Miocene is an evidences for possible faunal interchange(s) occurred during that period, as suggested by taxonomic analyses on carnivores and proboscideans in eastern half of Eurasia and North America.


1987 ◽  
Vol 58 (4) ◽  
pp. 119-124 ◽  
Author(s):  
Gail M. Atkinson ◽  
David M. Boore

Abstract A stochastic model of ground motion has been used as a basis for comparison of data and theoretically-predicted relations between mN (commonly denoted by mbLg) and moment magnitude for eastern North America (ENA) earthquakes. mN magnitudes are recomputed for several historical ENA earthquakes, to ensure consistency of definition and provide a meaningful data set. We show that by itself the magnitude relation cannot be used as a discriminant between two specific spectral scaling relations, one with constant stress and the other with stress increasing with seismic moment, that have been proposed for ENA earthquakes.


Phytotaxa ◽  
2016 ◽  
Vol 257 (3) ◽  
pp. 280 ◽  
Author(s):  
Hao Zhou ◽  
Si-rong Yi ◽  
Qi Gao ◽  
Jie Huang ◽  
Yu-jing Wei

Aspidistra revoluta (Asparagaceae) is described and illustrated as a new species from limestone areas in southern Chongqing Municipality, China. The new species can be distinguished from the other Aspidistra species by its unique umbrella-like pistil with large revolute stigma lobes that bent downwards and touch the base of the perigone. A detailed morphological comparison among A. revoluta, A. nanchuanensis and A. carnosa is provided. The pollen grains of A. revoluta are subspherical and inaperturate, with verrucous exine. The chromosome number is 2n = 38, and the karyotype is formulated as 2n = 22m + 6sm + 10st. The average length of chromosome complement is 4.50 μm, and the karyotype asymmetry indexes A1 and A2 are respectively 0.37±0.03 and 0.49±0.01.


1980 ◽  
Vol 112 (S112) ◽  
pp. 1-92 ◽  
Author(s):  
D.D. Munroe ◽  
Ray F. Smith

AbstractThe systematics of Acalymma sensu stricto of North America including Mexico are revised. Acalymma sensu stricto is defined and distinguished from the other species groups of Acalymma. Sixteen species are discussed including four new species: A. blomorum, A. palomarense, A. invenustum, and A. luridifrons all from Mexico. Three new subspecies of A. blandulum (LeConte) are described: blandulum (LeConte) new status, nigriventre, and yucatanense. Acalymma coruscum costaricense Bechyné is placed as a synonym of A. innubum (Fabricius). Keys are presented to all species and subspecies. Habitus and male genitalia drawings are given for all species and distribution maps are given where appropriate.


1987 ◽  
Vol 119 (1) ◽  
pp. 103-103
Author(s):  
S. Koponen ◽  
M.S. Wasbauer

Anoplius tenuicornis (Tournier) is a holarctic species with a broad distribution both in Europe (Wolf 1967) and North America (Wasbauer and Kimsey 1985). Despite the widespread occurrence of the species, individuals are not frequently encountered, so it is not surprising that biological information on it has not been available for North America and very little for Europe. Richards and Hamm (1939) gave two fragmentary reports of some significance on A. tenuicornis in England, reported as A. piliventris (Morawitz). In one case, cocoons of the wasp were found in dead thistle stems. In the other, an old burrow of Ectemnius continuus (Fabricius) (Sphecidae) (reported as Solenius) in rotten wood contained a series of wasp cocoons and fragments of clubionid spiders, the presumed prey.


Episteme ◽  
2021 ◽  
pp. 1-13
Author(s):  
Barry Allen

Abstract Indigenous cultures of North America confronted a problem of knowledge different from that of canonical European philosophy. The European problem is to identify and overcome obstacles to the perfection of knowledge as science, while the Indigenous problem is to conserve a legacy of practice fused with a territory. Complicating the difference is that one of these traditions violently colonized the other, and with colonization the Indigenous problem changes. The old problem of inter-generational stability cannot be separated from the post-colonial problem of sovereignty in the land where the knowledge makes sense. I differentiate the question of the value of knowledge (Part 1), and its content (Part 2). The qualities these epistemologies favor define what I call ceremonial knowledge, that is, knowledge that sustains a ceremonial community. The question of content considers the interdisciplinary research of Indigenous and Traditional Ecological Knowledge, as well as the issue of epistemic decolonization.


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