scholarly journals The ‘twins’ and the ‘bachelor’, new potential synapomorphies inside the Cholevinae (Coleoptera: Leiodidae)

Author(s):  
Pedro Gnaspini ◽  
Eduardo C Gomyde ◽  
Caio Antunes-Carvalho

Abstract The fine morphology of the tarsus has recently been shown to provide phylogenetic signal at several supraspecific levels in leiodid beetles, as well as in other insects. We here include another system, namely, the spines at the apical margin of the tarsomeres and associated structures. The tribe Ptomaphagini, with a Holarctic-Neotropical-Oriental distribution, has been characterized by having a comb of equal, flat spines around the apex of the tibiae of all legs, with a row of spines extending along the outer edge of the protibia in some genera (which has also been reported in the Eucatopini). We here recognize (as a new synapomorphy for the tribe) that special, strong spines, forming a loose comb, also appear at the apex of the first three or four tarsomeres of the Ptomaphagini. Special features appear on the apical margin of the mesotarsomeres: a long and thin seta, here called the ‘bachelor’, appears between two spines at the external-lateral-ventral face of the first tarsomeres, whereas a group of two (three in some cases) special spines (with the apex bent, facing opposite to each other), here called the ‘twins’, appears on the opposite, internal-lateral-ventral face of the first three (or sometimes two) tarsomeres. We found the ‘twins’ were also present in the Anemadini: Eunemadina and Nemadina, and the Eucatopini; the ‘bachelor seta’ seems to also occur in the Anemadini: Nemadina.

1944 ◽  
Vol 35 (1) ◽  
pp. 43-48
Author(s):  
A. K. Marshall

♂♀. Derm black, with uniform dense grey scaling that has a coppery reflection.Head separated from rostrum by a narrow bisinuate stria; frons depressed below the level of the eyes and separated from them by a deep incision on each side, obliquely striolate and with a deep median sulcus; eyes moderately convex, extended sharply backwards for about one-third of their length, the orbit not projecting on the hind margin. Rostrum very slightly longer than its basal width, widest at base, gradually narrowing for two-thirds its length and thence more rapidly; dorsum broadly depressed, with longitudinally confluent punctures and a fine median carina. Antennae piceous; scape slightly exceeding hind margin of eye; funicle with joint 1 nearly twice as long as 2,3–7 subequal, about as long as broad and slightly widening distally. Prothorax nearly twice as broad as long, unusually flat, being only gently convex transversely, widest at the strongly arcuate base, the angles of which project laterally, with the sides almost straight and rapidly converging anteriorly, the apical margin being deeply sinuate on each side behind the eyes; dorsum flat longitudinally in the middle, densely squamose, each scale covering a minute granule. Elytra ovate, broader in ♀, widely sinuate at base, which is marginate, with the lateral angles projecting outwards and forwards, and the sides sinuate behind the angles; the dorsal outline moderately convex, sloping at the base; the shallow striae containing close deep punctures, which show through the scaling though partly covered and disappear behind, where the striae become deeper; intervals almost flat, with minute inconspicuous recumbent setae. Legs piceous, with dense concolorous scaling and their lower edges with a fringe of stiff erect setae; front tibiae compressed, with the outer edge carinate and the external apical angle produced laterally, the spines on the apical margin much reduced; hind tibiae with the inner face flattened and sinuate on the apical half, the corbels bare and ascending the dorsal edge more than usual, with the upper end angulate. Venter squamose laterally, but clothed elsewhere with dense stiff suberect setae.


Author(s):  
Pedro Gnaspini ◽  
Stewart Blaine Peck ◽  
Caio Antunes-Carvalho ◽  
Michel Perreau ◽  
Eduardo Coutinho Gomyde

Detailed studies of microstructure has recently been shown to provide phylogenetic signals at several supraspecific levels within leiodid coleopterans, as well as in other insects. The tribe Ptomaphagini (Leiodidae: Cholevinae), with a Holarctic-Neotropical-Oriental distribution, has been characterized, among other things, by having a comb of equal-sized, flat spines around the apex of the tibiae of all legs, with a row of spines extending along the outer edge of the protibiae in the subtribes Baryodirina and Ptomaphaginina (but not in Ptomaphagina). A pattern similar to the one in Ptomaphaginina also occurs in the Neotropical cholevine tribe Eucatopini, and this has been used to indicate a phylogenetic relationship between the two tribes (but recent phylogenetic studies have not supported such a close relationship). We here review and revise the presence and structure of periapical (here called an ‘apical crown’) and marginal (here called an ‘external comb’) combs of spines on tibiae in Ptomaphagini, using other cholevines (with and without apical tibial combs) for comparison. We find a phylogenetic signal in an apical crown of tibial spines not interrupted at the outer spur, which seems to be an additional synapomorphy of Ptomaphagini, differing from the pattern in Eucatopini and remaining cholevines with an apical comb of spines, in which the comb is interrupted. We highlight differences not previously noticed between the apical protibial armature of Ptomaphaginina and Eucatopini.


1979 ◽  
Vol 46 ◽  
pp. 77-88
Author(s):  
Edward L. Robinson

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.


Author(s):  
Venita F. Allison ◽  
J. E. Ubelaker ◽  
J. H. Martin

It has been suggested that parasitism results in a reduction of sensory structures which concomitantly reflects a reduction in the complexity of the nervous system. The present study tests this hypothesis by examining the fine morphology and the distribution of sensory receptors for two species of aspidogastrid trematodes by transmission and scanning electron microscopy. The species chosen are an ectoparasite, Cotylaspis insignis and an endoparasite, Aspidogaster conchicola.Aspidogaster conchicola and Cotylaspis insignis were obtained from natural infections of clams, Anodonta corpulenta and Proptera purpurata. The specimens were fixed for transmission electron microscopy in phosphate buffered paraformaldehyde followed by osmic acid in the same buffer, dehydrated in an ascending series of ethanol solutions and embedded in Epon 812.


2004 ◽  
Vol 171 (4S) ◽  
pp. 211-211
Author(s):  
Roger Paul ◽  
Mathias Hoppmann ◽  
Heiner van Randenborgh ◽  
Hubert Kübler ◽  
Michael Alschibaja ◽  
...  

2019 ◽  
Author(s):  
Marko J. Spasojevic ◽  
Sören Weber1

Stable carbon (C) and nitrogen (N) isotopes in plants are important indicators of plant water use efficiency and N acquisition strategies. While often regarded as being under environmental control, there is growing evidence that evolutionary history may also shape variation in stable isotope ratios (δ13C and δ15N) among plant species. Here we examined patterns of foliar δ13C and δ15N in alpine tundra for 59 species in 20 plant families. To assess the importance of environmental controls and evolutionary history, we examined if average δ13C and δ15N predictably differed among habitat types, if individual species exhibited intraspecific trait variation (ITV) in δ13C and δ15N, and if there were a significant phylogenetic signal in δ13C and δ15N. We found that variation among habitat types in both δ13C and δ15N mirrored well-known patterns of water and nitrogen limitation. Conversely, we also found that 40% of species exhibited no ITV in δ13C and 35% of species exhibited no ITV in δ15N, suggesting that some species are under stronger evolutionary control. However, we only found a modest signal of phylogenetic conservatism in δ13C and no phylogenetic signal in δ15N suggesting that shared ancestry is a weaker driver of tundra wide variation in stable isotopes. Together, our results suggest that both evolutionary history and local environmental conditions play a role in determining variation in δ13C and δ15N and that considering both factors can help with interpreting isotope patterns in nature and with predicting which species may be able to respond to rapidly changing environmental conditions.


Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 436
Author(s):  
Enrico Ruzzier ◽  
Marcin Kadej ◽  
Andrea Di Giulio ◽  
Andrea Battisti

Hastisetae are modified setae typical of Dermestidae Megatominae and are a primary defensive tool of both larvae and pupae against invertebrates and possibly vertebrates. Given their unique morphological features, hastisetae have recently been suggested as an additional character useful for larvae identification and possible source of information to clarify the systematics of Megatominae. Hastisetae are also recognized as important contaminants of stored products, work and living environment; in particular, the exposure to hastisetae seems to cause allergic reactions and the insurgence of skin rashes, asthma, conjunctivitis, and digestive system inflammation in humans. Starting from these basic concepts, the present paper provides a detailed description of the hastisetae of some Megatominae. Fine morphology of external and internal microstructures of the hastisetae is shown and compared at the genus level. The insertion on integument, the pedicel, the shaft, and the apical head are illustrated in detail, and the first observations of active defensive behavior based on hastisetae are recorded and presented. Possible implications to the systematics of skin beetles are proposed based on the results of the study.


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