Adult feeding habits of three Perloidea species (Plecoptera: Perlidae and Chloroperlidae)

The gut content composition of three species of the superfamily Perloidea, Marthamea selysii (Pictet, 1842), Dinocras cephalotes (Curtis, 1827), and Siphonoperla torrentium (Pictet, 1842), from northwestern Spain is analyzed and described. The quantity of food found in all adults of M. selysii and D. cephalotes was very low. Spores of fungi and pollen of angiosperms were the most abundant components in the diet of M. selysii. Pollen of angiosperms, followed by fungal spores, detritus, and animal matter were the most abundant components in the diet of both sexes of D. cephalotes. The adult diet of both sexes of S. torrentium consists mainly of pollen and agrees with data of the previous studies on this same species in other areas. Our results also show that the consumption of animal matter could be a way to get a nutritional complement and is more common than previously considered in adult stoneflies. The obtained data support the hypothesis that adult feeding is less important for large stoneflies (as M. selysii and D. cephalotes) than for other smaller Perloidea (as S. torrentium), but feeding habits in these large Plecoptera could not be as negligible as previously supposed.     

Prey switching in four species of carnivorous stoneflies

1. Previous studies compared the functional responses to their prey, and both intraspecific and interspecific interference, in mature larvae of Dinocras cephalotes, Perla bipunctata, Isoperla grammatica and Perlodes microcephalus. The present study examines switching by larvae of the same species presented with different proportions of two contrasting prey types; larvae of Baetis rhodani and Chironomus sp. In each experiment, 200 prey were arranged in nine different combinations of the two prey types (20 : 180, 40 : 160, 60 : 140, 80 : 120, 100 : 100, 120 : 80, 140 : 60, 160 : 40, 180 : 20). Prey were replaced as they were eaten. A model predicted the functional response in the absence of switching and provided a null hypothesis against which any tendency for switching could be tested. 2. No evidence for prey switching by Dinocras and Perla was obtained, both species showing a slight preference for Baetis over Chironomus. Prey switching occurred in Isoperla and Perlodes. As the relative abundance of one prey type increased in relation to the alternative, the proportion eaten of the former prey changed from less to more than expected from its availability, the relationship being described by an S‐shaped curve. Isoperla and Perlodes switched to a preference for Baetis when its percentage of the total available prey exceeded 57 and 42%, respectively. Equivalent values for Chironomus were 43 and 58% for Isoperla and Perlodes, respectively. Switching was strongest in Perlodes. 3. Non‐switching in Dinocras and Perla was related to their feeding strategy, both species being more successful when using a non‐selective ambush strategy at dusk and dawn rather than a search strategy during the night. Both Isoperla and Perlodes used a search strategy. The smaller Isoperla fed chiefly at dusk and dawn, and preferred Chironomus larvae, whereas most of the larger Perlodes fed continuously from dusk to dawn and preferred Baetis larvae.     

Nymphal feeding habits of Perla madritensis Rambur 1842 (Plecoptera: Perlidae)

The diet of Perla madritensis, endemic species of the northern half of the Iberian Peninsula, is described for the first time by means of a study carried out in north-western Spain. As other species of the genus Perla, this taxon behaves mainly as predator, with Chironomidae, followed by Baetidae, being the most abundant prey in its gut. Shifts in diet composition were detected in relation to size in this species, with smaller prey being replaced by larger ones such as Simuliidae and Leptophlebiidae when the nymphs become larger.     

Feeding of Perla grandis nymphs (Plecoptera: Perlidae) in an Apennine first order stream (Rio Berga,NW Italy)

Feeding habits of Perla grandis (Rambur) nymphs have been investigated in the Rio Berga, an Apenninic stream of Northwestern Italy. In this study, we analysed gut contents of 50 nymphs of this species, with the aim to investigate feeding preferences. Nymphs were collected from a single riffle, of which benthic coenosis was also determined. We detected a change in the diet during ontogenesis, with small instars feeding mainly on detritus and large instars strictly carnivorous. We also detected the existence of an evident trophic selection: diet was almost entirely dominated by Chironomidae, independently from their availability on the substratum. This finding is discussed on the basis of ecological and ethological considerations.     

Seasonal Variation in the Diets of Bluefish, Pomatomus saltatrix (Pomatomidae) and Striped Weakfish, Cynoscion guatucupa (Sciaenidae) in Southern Brazil: Implications of Food Partitioning

The stomach contents of 516 Pomatomus saltatrix and 506 Cynoscion guatucupa from southern Brazil were examined. Both species preyed primarily upon teleosts and crustaceans and occasionally squid. Seasonal variation in the diet was related to prey availability in the area, confirming the opportunistic feeding behaviour of both species. During the summer, P. saltatrix preyed upon four prey species (Loligo sanpaulensis, Artemesia longinaris, Mullus argentinae and Paralonchurus brasiliensis), whereas in the autumn and winter Engraulis anchoita was the predominant prey. C. guatucupa similarly preyed upon A. longinaris and P. brasiliensis during the summer, with juvenile C. guatucupa and E. anchoita also consumed. The latter species was an important dietary constituent during other seasons, as were A. longinaris (autumn), Umbrina canosai (winter), Trachurus latami and euphausids (spring). Although P. saltatrix had a broader diet than C. guatucupa during the summer, the latter species had a broader diet overall. Diet breadths were lower from autumn to spring, due to the predominance of E. anchoita in the diet of both species. This restricted diet resulted in significant intra- and inter-specific diet overlap during the winter but, because of the seasonal abundance of E. anchoita, the high levels of diet overlap do not necessarily indicate competition.     

Distribution Patterns,Species Assemblages and Habitat Selection of the Stoneflies (Plecoptera) from Two Mediterranean River Basins in Southern Spain

The stonefly distribution and its relationship with habitat changes, based on stream physico chemical features, were investigated in two Mediterranean river basins (Guadaira and Guadalete, S Spain). Plecopteran nymph distribution varied along an elevation gradient. Both stonefly species richness and species diversity increased with altitude. Stoneflies were able to tolerate a wide range of environmental conditions but were absent from low altitude sites, temporary streams with high salinity values and high water temperature. A total of 13 stonefly species were found in the study area, from which Tyrrhenoleuctra minuta (Klapálek ) and Protonemura sp. were dominant. The most widespread species were Nemoura lacustris and Capnioneura mitis. Three distinct species assemblages were observed according to their distribution patterns, but with similar environmental preferences. Capnioneura petitpierreae and T. minuta showed preferences to low altitude sites, whereas C. mitis and N. lacustris were found throughout all sites. T. minuta and N. lacustris inhabited permanent and temporary sites, while the same species and C. mitis also were found in semipermanent streams. Temporally, most stoneflies were caught during winter (85.9%), especially at the low altitude sites.     

贵州钩(虫责)属一新种记述((襀)翅目:(虫责)科)

记述采自贵州宽阔水保护区的钩(虫责)属l新种:巨刺钩(虫责)Kamimuria grandispinata Du ＆Sun,sp.nov.,该新种的阳茎特征与长刺钩虫责K.longispina Wu相似,但长刺钩(虫责)阳茎囊背面近端部有1膜质突起,上面生有粒状微刺,而新种阳茎囊背面近端部是1个近似三角形的刺斑,无突起...     

First record of male drumming call of the genus Capnioneura Ris, 1905 (Plecoptera,Capniidae)

The male call of Capnioneura mitis, produced by drumming, is recorded and analyzed for the first time. It also represents the first known signal for the genus. It consists of a highly variable number of beats (2–32) with inter‐beat duration approximately constant along the call, but inter‐beat duration is temperature dependent. Thus, at 13°C the mean inter‐beat duration is 1.397 s (SD = 0.050) while at 21°C it is 1.139 s (SD = 0.093). The call pattern exhibited by this species, as those of the majority of previously studied Capniidae species, can be catalogued as an ancestral or near‐ancestral percussive monophasic signal.     

贵州新虫责属二新种记述1(襀翅目:虫责科:虫责亚科)

记述采自中国贵州的新虫责属 2新种 ,即双瘤新虫责 Neoperla bituberculata,sp.nov.和曲囊新虫责 N eoperla flexiscrotata,sp.nov.。模式标本存扬州大学植物保护系昆虫标本室 ( YU)     

A new species of Pseudoloris (Omomyidae,Primates) from the middle Eocene of Sant Jaume de Frontanyà (Eastern Pyrenees,Spain)

In this article we describe a new species of Pseudoloris (Omomyidae, Primates) from the Robiacian (middle Eocene) locality of Sant Jaume de Frontanyà (Eastern Pyrenees, Spain). Pseudoloris pyrenaicus is characterized by its medium size, thickened paracristid, absence of a distinct paraconid, and well‐developed buccal cingulid in the lower molars, large hypoconulid in the M₃, paraconule and hypocone reduced in the M¹ and M² and absent in the M³. The material from Sant Jaume de Frontanyà constitutes the most abundant sample of the genus Pseudoloris found until now in the Iberian Peninsula. Almost all the dental elements have been recovered, including those teeth hardly known for other species of the genus, such as lower and upper incisors. The new species shows intermediate features between Pseudoloris isabenae from Capella and Pseudoloris parvulus, present in different Spanish and French sites. Therefore, we consider that Pseudoloris pyrenaicus is an intermediate form between these two species. Am J Phys Anthropol 143:92–99, 2010. © 2010 Wiley‐Liss, Inc.     

Two new species in the subfamily Perlinae (Plecoptera,Perlidae) from China

Two species in the genera Neoperla and Kamimuria (Plecoptera: Perlidae) from China are described as new: Kamimuria guangxiasp. n., and Neoperla mesostylasp. n. The new species are compared to similar taxa.     

A new species of Anthemis L. (Asteraceae) from Central Spain

CARRETERO, J. L., 1992. A new species of Anthemis L. (Asteraceae) from Central Spain. A new species of Anthemis is described from the eastern Toledo Mountains. The morphological relationships to other taxa, as well as the chorology and ecology of the new species are presented.     

New Species of Macrogynoplax Enderlein 1909 from North Brazil (Plecoptera,Perlidae, Acroneuriinae)

Three new species of Macrogynoplax Enderlein 1909, M. delicata, M. pulchra and M. poranga are described. They were collected in Manaus, Amazon State.     

Comparative Study of the Nymphal Biology of Two Coexisting Species of Mayflies (Insecta: Ephemeroptera) in a Mediterranean Stream in Southern Europe

We study the life history, nymphal feeding and secondary production of two leptophlebiid mayfly species (Habrophlebia eldae and Paraleptophlebia submarginata). They cohabit in a Mediterranean stream and present a very high niche overlap in terms of trophic resources. The life cycle was estimated using size‐frequency analysis of samples taken throughout a year. Both species have a similar but displaced period of the nymphal development. Secondary production was calculated by means of the size‐frequency method. Annual secondary production of P. submarginata is much higher than that of H. eldae (1.95 g DW m^–2 year^–1 vs. 0.17 g DW m^–2 year^–1), and presents a quite similar annual P/B ratio, but slightly higher in ^{P. submarginata} (6.97 in ^{P. submarginata} and 9.21 in ^{H. eldae}). The study of the gut contents revealed that they are mainly detritivores but, when larger they feed also on CPOM from leaves fallen in the stream. They present an almost total niche overlap in terms of food acquisition. However the previously mentioned shift in trophic resources utilization with size makes it possible that, because no similar size classes of each species are present at the same time, niche segregation exists between the two species. Though further studies are needed to confirm it, this could be the consequence of previous episodes of competition between them. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

中国瘤属一新种记述 (襀翅目:科)

记述采自中国陕西佛龙的瘤属Tyloperla 1新种:双凹瘤Tyloperla bihypodroma Du, sp. nov.,该种与尖突瘤Tyloperla attenuata 很相近,但前者第8背板近后缘形成1个隆起脊、其中部有1凹陷,后者则在背板中部形成1近圆形的隆起、其上的锥状感觉器比前者多;前者第9背板中央微凹、其前缘骨化明显、极小的锥状感觉器稀少,后者中部有1丛明显的锥状感觉器;前者翅透明,后者翅微烟褐色。新种的模式标本保存在扬州大学昆虫标本馆。     

Differences in Species Composition and Feeding Ecology of Catostomid Fishes in Two Distinct Segments of the Missouri River, North Dakota, U.S.A.

In 1997 and 1998, we sampled the Missouri River, North Dakota to determine if anthropogenic disturbances had influenced catostomid species composition and feeding ecology. We compared two distinct river segments, the Missouri River between the mouth of the Yellowstone River and Lake Sakakawea (the Yellowstone–Sakakawea segment (YSS)), a moderately altered segment and the Missouri River between Garrison Dam and Lake Oahe (the Garrison–Oahe segment (GOS)), a highly altered segment. The segments exhibited greatly different sucker communities. Bigmouth buffalo, Ictiobus cyprinellus, smallmouth buffalo, Ictiobus bubalus, and river carpsucker, Carpiodes carpio, represented 94% of the sucker catch in the YSS, whereas in the GOS, white sucker, Catostomus commersoni, and longnose sucker, Catostomus catostomus, constituted 98% of the sucker catch. In the YSS, high zooplankton densities led to greater sucker zooplanktivory and food niche overlap than in the GOS. Intense anthropogenic disturbances to the GOS are associated with the differences in sucker species composition, prey density and composition, and sucker feeding ecology between the two segments.     

Perlesta ephelida, a new Nearctic stonefly species (Plecoptera, Perlidae)

A new Nearctic species of Perlidae (Insecta, Plecoptera), Perlesta ephelidasp. n., is described from the male, female, and egg stages. This species has been previously reported as, or confused with, Perlesta shubuta Stark from several central and eastern U.S. states. Perlesta ephelida is distinctive from Perlesta shubuta and other regional Nearctic congeners mainly according to male genitalic and egg characteristics. Perlesta ephelida is a widely-distributed eastern Nearctic species, whereas Perlesta shubuta appears to be restricted to a narrow latitudinal belt in the Gulf Coast region from Louisiana east conservatively to the Florida panhandle. The egg of Perlesta shubuta is depicted with scanning electron microscopy for the first time.     

中国瘤(虫责)属一新种记述(襀翅目:(虫责)科)

记述采自中国陕西佛龙的瘤(虫责)属Tyloperla 1新种:双凹瘤(虫责)Tyloperla bihypodroma Du, sp. nov.,该种与尖突瘤(虫责)Tyloperla attenuata很相近,但前者第8背板近后缘形成1个隆起脊、其中部有1凹陷,后者则在背板中部形成1近圆形的隆起、其上的锥状感觉器比前者多;前者第9背板中央微凹、其前缘骨化明显、极小的锥状感觉器稀少,后者中部有1丛明显的锥状感觉器;前者翅透明,后者翅微烟褐色.新种的模式标本保存在扬州大学昆虫标本馆.     

Trophic and Spatial Niches of two Large-sized Species of Leptodactylus (Anura) in Southeastern Brazil

Leptodactylus ocellatus (LO) and L. labyrinthicus (LL) are known to prey on other frogs. Here we compare their food habits based on the analysis of stomach contents and their spatial distribution when in sympatry. LO was found most frequently near stream banks, and LL on the margins of lakes and ponds. LO was found within 10 m of permanent water bodies; LL frequently used ponds far from lakes and rivers. Coleoptera, Formicidae, and Isoptera comprised 52% of the prey types identified in the LO sample, whereas Coleoptera and insect larvae represented 58% of the prey items of LL. Frogs were not frequent in the diet of either species but, in volume, represented the second most important category for LO and the first for LL. LO showed a larger trophic niche breadth than LL. The trophic niche overlap between the two species was 68.3% for percentage of prey items. The present work confirms the relative importance of frogs in the diet of both species. The greater capacity of LL in moving far away from permanent water bodies may generate better opportunities for prey selection and a narrower trophic niche breadth. The large range of prey used by these two species indicates they are generalist/opportunistic feeders.