Food preference, growth and maturation of Nemurella pictetii (Plecoptera: Nemouridae)

1. The stonefly Nemurella pictetii has a highly variable life cycle and is semi‐ and uni‐, but also plurivoltine in different geographical areas. 2. The influence of the type of food on growth and maturation of larvae was studied in laboratory experiments. Food preference was also assessed. 3. Larvae of N. pictetii are strongly opportunistic feeders utilising a broad range of food sources. However, biofilm was preferred over detritus (conditioned leaves), green algae and animal food. The highly mobile larvae quickly found the preferred food. Larvae fed on biofilm grew and developed significantly faster than larvae fed on conditioned leaves. 4. Larval growth and maturation in experiments as well as in the field differed with available food qualities. Phases of faster growth and maturation corresponded well with maximum availability of biofilm in the field. This contributes to the interpretations of differences in life cycles in the field.     

新疆倍叉(虫责)属一新种记述(襀翅目:叉(虫责)科)

本文记述了采自新疆喀纳斯的倍叉[虫责]属Amphinemura 1新种：环齿倍叉[虫责]Amphinemura tricintusidens Wang＆Zhu,sp．nov。根据肛侧突中叶端部有3或4个环绕的小齿和肛上突背骨片端部形成的圆形腔可将该新种与其它种类相区别。正模♂,新疆喀纳斯,2005-Ⅷ—01,朱江艳等采。副模1♂,采集资料同正模。新种的模式标本保存在扬州大学昆虫标本馆。     

Two new species of the stonefly genus Amphinemura (Insecta,Plecoptera, Nemouridae) from China

Two new species of the genus Amphinemura Ris from China are described and illustrated, i.e. A. annulata Du & Ji, sp. n. from Zhejiang, Shanxi, Shaanxi and Guizhou Province, and A. lingulata Du & Wang, sp. n. from Shaanxi and Sichuan Province. A. annulata is similar to A. tricintusidens Wang & Zhu in having an apical cavity of the epiproct, but the epiproct ventral sclerite and the median paraproct lobe of the two species are different. A. lingulata is related to A. didyma Zhu & Yang in having the similar epiproct, but they differ mostly in paraproct median and outer lobes.     

The Group of Amphinemura flavostigma (Plecoptera,Nemouridae)

Three closely related species from Japan are treated and defined as composing the Amphinemura flavostigma group (Okamoto, 1922). One species, A. nikkoensis, is described as new to science. Two already known species, A. flavostigma and A. monotuberculata (Kawai, 1956), are redescribed, while the female of the latter is described for the first time. Another species, A. tetraspinosa Kawai, 1960, is regarded as a subjective synonym of Nemoura flavostigma Okamoto, 1922.     

Notes on the genus Agnetina (= Phasganophora) (Plecoptera: Perlidae)

Genus Agnetina Klapálek, 1907 is removed from synonymy with Dinocras Klapálek, 1907 and synonymy between Agnetina and Phasganophora Klapálek, 1914 is established. A list of presently recognised nominal species of Agnetina is provided. For all west palaearctic species, i.e., A. elegantula (Klapálek), A. senilis Klapálek, A. werneri (Kempny), comb, n., lectotypes are designated. Distinctive characters of these three species are described, external male genitalia and eggs are illustrated. Asian A. brevipennis (Navás), comb, n., is briefly compared. A. dubia nom. n. is proposed to replace A. brevipennis Klapálek, 1921 (not Navás, 1912), a doubtful Asian species. A. pedata (Koponen, 1949) and A. undaata (Klapálek, 1921) are considered possible synonyms of A. senilis. which is for the first time recorded from Central Asia (Baikal area).     

Inter- and intra-specific differences in the number of larval instars in British populations of 24 species of stoneflies (Plecoptera)

1. Ontogenetic changes during the life cycle of aquatic insects are important not only in life‐history studies but also in evaluating food‐web structure. They require information on the growth and number of larval instars but such information is lacking for many species, including Plecoptera. Therefore, the chief objectives of the present study were to determine inter‐ and intra‐specific differences in the number of larval instars in British populations of 24 species of stoneflies, to test Dyar’s hypothesis that growth followed a geometric progression, and to synthesise this information with previously published values for four British species. 2. Larvae were reared at constant temperatures in the laboratory from eggs from 63 populations (one to six populations per species). First instars from each population were divided into three batches and each batch was reared at one of three constant temperatures. For each species, the rearing temperature and source population had no significant effect on the mean size of each larval instar. 3. The relationship between the geometric mean length of each instar and instar number was well described by an exponential equation (P < 0.001, r² > 0.9 for all species), thus supporting Dyar’s hypothesis. Only one species, Brachyptera risi, had the same number of instars for males and females (12–13). For the other 15 herbivorous species and the four smaller carnivorous ones, the number of instars was higher for females than males (range 11–16 for males, 12–17 for females). The larger size of the females was due to their additional instars, not a sex difference in growth rates. In contrast, there was a clear growth separation of the sexes after the 9th or 10th instar for the four largest carnivores. The number of larval instars was highest for these four species (range 16–19 for males, 18–23 for females), and females were much larger than males. 4. A multiple regression equation with data from the present and previous studies (n = 27) showed that variability in the mean length of the first instar and the maximum number of larval instars for each species accounted for 88% and 91% of the variability in the mean length of the final instar for males and females, respectively. 5. Values for Plecoptera in other countries were in general agreement with those in the present study, especially in the same families. Two old, but widely quoted, high values are doubtful. The present study and four previous ones provide a sound basis for ontogenetic studies on 28 species of Plecoptera and their role in aquatic ecosystems.     

Introgression and species demarcation in western European Leuctra fusca (Linnaeus, 1758) and L. digitata Kempny, 1899 (Plecoptera: Leuctridae)

The compilation of a DNA barcoding library of Norwegian stonefly (Plecoptera) species revealed that Leuctra fusca (Linnaeus, 1758 Linnaeus, C. (1758), Systema naturae Per Regna Tria Naturae: Secundum Classes, Ordines, Genera, Species, Cum Characteribus, Differentiis, Synonymis, Locis. Stockholm: Laurentius Salvius. [Google Scholar]) and Leuctra digitata Kempny, 1899 (Leuctridae) share haplotypes in northernmost Scandinavia. Phylogenetic analyses of the mitochondrial (mt) DNA barcode marker COI and the nuclear marker 28S show that the shared haplotypes must result from the introgression of a L. fusca mitochondrion into a L. digitata population on at least two occasions. Although mt introgression is widespread in animals, this represents the first documented case in Plecoptera. This study also included specimens of L. cf. fusca from the Sierra Nevada massif in Spain, a population previously known as L. carpentieri Despax, 1945. Their mt haplotypes are ca. 13% different from other European L. fusca. However, their 28S alleles are compatible with their morphological identification as L. fusca. In view of the possibility of mt introgression, the taxonomic status of this population remains undecided.     

First fossil record of Brachyptera (Plecoptera: Taeniopterygidae) in Eocene Baltic amber

The extant taeniopterygid genus Brachyptera Newport, 1848 is reported from the Eocene Baltic amber for the first time. A new species, Brachyptera dewalti n. sp. (Plecoptera: Taeniopterygidae), is described and illustrated based on a well-preserved female in the amber, distinguished by the presence of three well-developed ocelli, the dark color of antennae, maxillary palps, head, prothorax, and abdominal segments, the CuA vein of forewing with three branches, the nearly rhombus, dark brown postgenital plate, and the four-segmented cerci. It is the fourth taeniopterygid species known from the Baltic amber.     

Life histories of Nemouridae and Leuctridae in Southern Ontario (Plecoptera)

The life-histories of seven species of Nemouridae and two of Leuctridae have been investigated in Southern Ontario. Eleven sampling stations were chosen to illustrate the range of temperature conditions found in local streams.The Nemouridae and Leuctridae make up most of the stonefly fauna of the upstream cooler stations, but their numerical importance decreases considerably downstream.There is a definite seasonal succession of the species: Soyedina aallicularia, Prostoia completa and Shipsa rotunda appear in late spring, Nemoura trispinosa, Amphinemura delosa} and A. nigritta in early summer, Leuctra tenuis in midsummer and A. linda in late summer. L. ferruginea emerges throughout most of the summer, at least in the headwater streams.All the species are univoltine, except L. ferruginea which is usually semivoltine. Most Nemouridae, A. spp., P. completa and S. rotunda undergo a long embryonic diapause, whereas N. trispinosa and S. vallicularia develop directly. The nymphal development of N. trispinosa was compared in three streams; although the general pattern is similar, the growth is much more synchronized in the warmest station. There appears to be 16 nymphal instars in this species. L. ferruginea was common in seven stations; in the coolest, the life-cycle lasts two years, but in the warmest, many specimens succeed in completing their cycle in one year.

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Résumé Les cycles vitaux de sept espèces de Nemouridae et deux espèces de Leuctridae ont été étudiés dans onze ruisseaux du Sud de l'Ontario; ces stations d'échantillonnage représentent la gamme des températures des ruisseaux de cette région.Les Nemouridae et les Leuctridae constituent la majeure partie de la faune des Plécoptères dans les stations froides de l'amont. Cependant, leur importance décroît de façon significative dans les stations plus en aval.On reconnaît une succession bien définie des espèces durant l'année: Soyedina aallicularia, Prostoia completa et Shipsa rotunda apparaissent à la fin du printemps, Nemoura trispinosa, Amphinemura delosa et A. nigritta au début de l'été, Leuctra tenuis au milieu de l'ete et A. linda à la fin de l'été. L. ferruginea emerge pendant presque toute la saison chaude, du moins dans les stations de l'amont.Toutes ces espèces sont univoltines, sauf L. ferruginea qui est ordinairement semivoltine. La plupart des Nemouridae, soient A. spp., P. completa et S. rotunda doivent compléter une longue diapause embryonnaire, alors que N. trispinosa et S. vallicularia se développent directement. On a comparé la vie larvaire de N. trispinosa dans trois ruisseaux: bien que l'essentiel de la biologie soit semblable dans les trois cas, on remarque un plus grand synchronisme de la croissance dans la station la plus en aval. Il semble y avoir 16 stades larvaires chez cette espèce. L. ferruginea était abondante dans sept stations; dans la plus froide, le cycle vital dure deux ans, alors que dans la plus chaude, plusieurs specimens arrivent a boucler leur cycle en un an.

     

Global diversity of stoneflies (Plecoptera; Insecta) in freshwater

Plecoptera, or stoneflies, is a small order of hemimetabolous insects: according to our data, more than 3,497 species have been described so far in the world. The total number of species has enormously increased in the last 30 years (2,000 species estimated in 1976) and, if the trend continues, then it will nearly double in the near future. The order is divided into the suborders Arctoperlaria and Antarctoperlaria, and includes 16 families: 12 arctoperlarian and 4 antarctoperlarian. The Arctoperlaria account for a total number of 3,179 species, and Antarctoperlaria, only 318 species. The total number of genera is 286. We give in this article the estimated number of species for each family. The fauna and diversity of stonefly in North America (650 species reported) and Europe (426 species) are best known. Nevertheless, in the last 25 years, a mean of 2.6 Plecoptera species per year were described in Europe. Stonefly-faunas of Australia (191 species, Tasmania included) and New Zealand (104 species) are relatively well-known, while our knowledge of the Plecoptera of Central and South America (95 and 378 species respectively) is poor and still not representative of the real diversity. Africa has a reduced stonefly fauna (126 species). Asian stonefly diversity (approximately 1,527 species) is much greater than that of Europe or North America despite the fact that, except for Japan and Asiatic Russia that have been well studied, our knowledge of the remaining Asiatic areas is extremely poor. Even though our data indicate the Holarctic Region as the diversity hot-spot for the order, the analysis of the specific diversity divided by family suggests also an important role of tropical stoneflies. Guest editors: E.V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

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.     

Leuctra dylani sp. n. (Plecoptera: Leuctridae) from Italy

Leuctra dylani sp. n. from Trentino-Alto Adige, Italy, is described and illustrated.     

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。     

中国钮虫责属种类记述(襀翅目:鰿科:钮虫责亚科)

记述中国钮虫责属 Acroneuria Pictet昆虫 4种 ,其中包括 2新种 :莫氏钮虫责Acroneuria morsei,sp.nov.和多锥钮虫责 Acroneuria multiconata,sp.nov.。模式标本存扬州大学植物保护系昆虫标本室 ( YU)和西北农林科技大学昆虫博物馆 ( NW-STUAF)。     

科昆虫地理分布研究初探

本文就科昆虫的起源,各亚科、族及属的分布特点进行了分析和总结;并根据各属的世界分布情况,将其分为８种类型。文中还就中国科昆虫的地理分布及特点作了初步的探讨,结果表明：在我国已知的２亚科４族２０个属中,东洋区分布的有１０个属,其中有３个属仅分布于我国;古北区分布的有１个属;东洋－古北区分布的有３个属;东洋－新北区分布的有１个属;东洋－古北－新北区分布的有４个属;东洋－古北－新北－非洲区分布的有１个属。此外,科昆虫在中国的一个主要分布特点就是多数种类集中分布于华中区、华南区和西南区;而华中区则很可能是科种类的分化中心,并以此为中心向其他区扩散。     

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...     

The temperature dependence of embryonic and larval development in Protonemura intricata (Plecoptera: Nemouridae)

SUMMARY. 1. Egg development and larval growth of Protonemura intricata (Ris, 1902) (Plecoptera: Nemouridae) were studied in the laboratory and in the Breitenbach, a small stream-in Germany (F.R.G.). 2. The mean number of eggs in batches collected from the field was 627 (S=314). 3. Mean batching success in the laboratory was 60–100% at 2–18°C. Cumulative hatch in individual batches could be described by asymmetrically sigmoid curves. The length of the hatching period was positively correlated with the length of the incubation period. 4. The incubation period of I', intricata normally consists of an initial dormancy followed by subsequent development. The length of embryonic development (Y. days) is strongly inversely temperature (T, °C) dependent and can be described by the equation: 5. The length of dormancy is dependent on oviposition dale, and is shorter the later that the eggs are laid. It also depends on temperature during incubation and is increased by rising temperatures. As a consequence, larvae hatch more or less synchronously in the field during autumn. Total incubation period, i.e. dormancy and actual development, exhibits a complex dependence on both incubation temperature and oviposition date. Under constant laboratory temperatures, a late sharp fall in temperature can terminate dormancy earlier. 6. Photoperiod probably induces dormancy and may already act on the last larval instars of the parent generation. The dormancy of P. intricata is classified as an oligopause (Müller. 1970, 1976). 7. In the laboratory. P. intricata larvae from early batches with long dormancy grew faster than larvae from late batches with direct development. Final size was the same in both cases. This acted against the population synchrony induced through egg dormancy. Benthos samples suggest the same in the field. 8. Avoidance of the suboptimal summer conditions in streams by the cold stenothermous P. intricata is suggested to partly explain the success of the species, which contributes more to total emergence biomass than do other Plecoptera in the Breitenbach.     

A new species report of Caroperla Kohno, 1946 (Plecoptera: Perlidae) from China

A brief taxonomic synopsis of the genus Caroperla Kohno, 1946 is presented and its further generic delimitation is defined along with a new species, C. siveci sp. n. from the Wuyishan Mountain of Fujian, China. It represents the first report of the genus from China and the third species of the genus. The morphological comparison of the new species with the two other known species is given.