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.     

Alimentary canal formation in the stonefly,Kamimuria tibialis (pictet) (Plecoptera : Perlidae)

The alimentary canal formation in the stonefly, Kamimuria tibialis (Plecoptera : Perlidae) is described. The stomodaeum is formed as in other insect embryos. The proctodaeum is derived from the ectodermal fold an the caudal end of the embryo without the contribution of the amnion. The 3 Malpighian tubules develop from the blind end of the proctodaeum. The rectal pad is formed by the thickening of the dorsal wall of the proctodaeum. The midgut epithelium rudiment arises only from the blind end of the proctodaeum, i.e. it is completed by unipolar formation instead of bipolar. The yolk cells do not contribute to the formation of the midgut epithelium. The alimentary canal is transformed during the 1st nymphal instar and becomes functional in the next instar. The stomodaeum is differentiated into 3 parts: pharynx, oesophagus, and proventriculus. The midgut becomes shortened and its epithelium is well developed. Gastric caeca with tapering processes are formed.     

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).     

Agnetina den, a new species of perlid stonefly (Plecoptera: Perlidae) from Vietnam

A new species of perlid stonefly, Agnetina den, is described from Vietnam. Male adults of this species can be easily distinguished by their black body color pattern, submedian patches of sensilla basiconica on hemitergites 7–8, and clusters of long dense fine setae on the inner sides the abdominal tergites. Illustrations of habitat and diagnostic characters are presented.     

A test of crypsis and predator avoidance in the stonefly Paragnetina media (Plecoptera: Perlidae)

Few studies have considered whether cryptic coloration is protective. As a model predator/prey system, the visually foraging fish rainbow trout, Salmo gairdneri, and the stonefly nymph were used to examine cryptic coloration and anti-predator behaviour of prey. In both the laboratory and field, stonefly nymphs selected dark substrates on which they were inconspicuous and therefore less vulnerable to predation by trout. In the laboratory, substrate colour selection by nymphs ceased approximately 2 h after the lights were turned off but resumed within 1 h of lights being turned on. Stoneflies also selected dark patches, rather than light, on the surface of multi-coloured substrate. Colour selection behaviour was not different in the presence versus absence of trout. Stoneflies perceived colour through a combination of visual input from their compound eyes and oceli.     

New species and records of the stonefly genus Neoperla (Plecoptera,Perlidae) from Jinhuacha Nature Reserve,Guangxi of China

Two new Neoperla species (Neoperla mesospina, Neoperla latispina) are described from the adult male stage from the Jinhuacha Nature Reserve, Guangxi of China. The new species are compared with similar taxa. Taxonomic remarks are also provided for N. transversprojecta Du & Sivec and N. yao Stark. The latter species is newly recorded for Guangxi.     

External morphology and distribution of the antennal sensilla of the stonefly,Paragnetina media (Walker) (Plecoptera : Perlidae)

The distribution and external morphology of sensilla on the antennae of nymphal and adult stonefly, Paragnetina media (Plecoptera : Perlidae) were studied with light and scanning electron microscopy. A peculiar arrangement of 3 types of sensilla was observed on the antennae of the nymphs. Thick- and thin-walled sensilla basiconica and coniform sensillar complexes occur in a group, and 6 to 7 such groups are located around the distal margin on the segments in the mid-region of the flagellum. Campaniform sensilla are concentrated in a ring around a crown of thick- and thin-walled sensilla basiconica on the distal end of the pedicel. Two types of trichoid sensilla, long wavy, and stout straight, are present on the flagellum of the nymph. Adult stoneflies have an antennal surface profusely covered only with long and short trichoid sensilla; all other nymphal type sensilla are absent. The lack of nymphal type sensilla on their antennae may be related to the adult's brief, non-feeding terrestrial life.     

Variable egg development of Dinocras spp. (Plecoptera, Perlidae) and the stonefly seed bank theory

1. Temperature dependence of egg development of Dinocras cephalotes (Curtis) (three German and one Norwegian population) and Slovenian D. megacephala (Klapálek) was studied under a constant 14 : 10 light : dark photoperiod and constant temperature ranges of 4–24 °C and 4–18 °C, respectively. D. cephalotes was also incubated under seasonal field conditions; natural daylength and fluctuating temperatures had no modifying effect. 2. Both species have very similar lower threshold temperatures (4 and 3.5 °C, respectively), thermal demand for development (c. 600 degree days) and high dependence of mean incubation period on temperature (exponents of regressions near 1.5). Present data on D. cephalotes agree with the literature on British and Norwegian material of the same species. 3. Development occurs only at cue temperatures above the lower threshold. Cue temperatures range from 6 °C (some D. megacephala) to 14 °C (some D. cephalotes) and vary strongly within and between egg masses of D. cephalotes. Variation is not random, but seems to be genetically determined. 4. The variable temperature response renders study of effects of particular experimental regimes, and comparisons between local populations, difficult. 5. A latitudinal gradient in cue temperatures for development from 6 °C at c. 46 °N to 12 or even 14 °C at c. 61 °N seems to reflect reduced diversity at high latitudes. 6. Average success of spontaneous hatching exceeded 90% between 12 and 20 °C, but declined towards higher and lower temperatures. 7. Unhatched eggs were not dead but in parapause; development at other, higher or lower, temperatures was induced. Spontaneous plus induced hatching success approached 90%. Developing eggs rarely died; most dead eggs were apparently unfertilized. 8. Dormant plecopteran eggs are proposed to form a seed bank in stream bed sediments. Highly successful development after up to 220 days of dormancy was ascertained in Dinocras, and survival for up to 3 years is reported for other Perloidea. 9. Only systellognathan egg morphology provides options for long dormancy; the other plecopteran superfamilies, notably Nemouroidea, follow different strategies.     

Descriptions of oriental Perlini (Plecoptera: Perlidae)

Three new species of Oriental Perlini are described and Agnetina aequalis (Banks) and A. quadrituberculata (Wu) are redescribed. Agnetina jarai sp. n. (Vietnam), Togoperla shan sp. n. (Thailand), and Tyloperla schmidi sp. n. (Assam), are described, compared with related congeners, and male holotypes are designated for each species.     

中国华襀属一新种记述（襀翅目：襀科）

记述中国襀科 Perlidae 华襀属 Chinoperla 1 新种:勐满华襀 Chinoperla mengmanensis sp. nov.。本新种与其他华襀属种类的区别在于:第9背板前缘中部骨片短小且强骨化,呈倒V形;半背片细长,紧挨第 9 背板中部骨片;阳茎部分骨化,阳茎囊未完全翻出,但是明显呈三叶,背外侧两叶完全覆盖小棘刺,中叶呈球形囊泡,无棘刺。模式标本保存于扬州大学昆虫标本室。     

Notes on Plecoptera (23). The Anchor of the Tetropina Egg (Plecoptera: Perlidae)

After a study of the type material of Baetis nexus Navás, 1918 and a comparison with Hungarian specimens of Baetis pentaphlebodes Ujhelyi, 1966 it is concluded that the two nominal species are synonyms and that B. nexus is the valid name.     

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.     

Molecular systematics and biogeography of the western Mediterranean stonefly genus Tyrrhenoleuctra (Insecta, Plecoptera)

The stonefly genus Tyrrhenoleuctra includes species living in western Mediterranean temporary freshwater streams, sometimes also at sea level, a very unusual habitat for most Plecoptera. Traditional morphological approaches proved unsuccessful in drawing both taxonomic and phylogenetic patterns, thus hampering discussion of biogeographical patterns for this interesting group. We aimed at: (a) assessing the taxonomic status of populations of Tyrrhenoleuctra covering the geographic range of the genus; (b) studying the phylogenetic relationships among the recognized species; and (c) describing biogeographic patterns. We used phylogenetic analyses to infer the phylogenetic history of this group of stoneflies based on a combined data set of 1666 bp including fragments of the 12S ribosomal (12S) and cytochrome oxidase I (CO‐I) mtDNA genes, with maximum likelihood and Bayesian methods. Two main clades have been identified: a Sardo‐Corsican one, including Tyrrhenoleuctra zavattarii, and an Ibero‐Maghrebian one including four lineages of unkown taxonomic rank from the Balearic Islands (Maiorca), from northern Africa (Ceuta) and southernmost Spain (Algeciras), and a complex preliminarily referred herein to T. minuta (Klapálek, 1901), which includes two lineages, one from Cordoba, and one from Sierra de Grazalema (El Cerro) and Portugal (Tellhares) respectively. Dating the nodes by fixing the split of the Ibero‐Maghrebian clade from the Sardo‐Corsican one at 29 million years ago (Mya), yielded dates referring to the major geological events in the Mediterranean basin. Estimated molecular evolutionary rates ranged from 0.02–0.09% per million years (my) in the T. zavattarii lineages, to 0.2–0.7% per MY in the Ibero‐Maghrebian clade. The phylogenetic pattern emerged from the present study is congruent with the known paleo‐history of the western Mediterranean basin, with the divergence of the two main Tyrrhenoleuctra lineages corresponding to the split of the Sardo‐Corsican microplate from the Iberian block. Vicariance events have characterized the history of this stonefly group along its entire biogeographical history. Surprisingly low evolutionary rates, previously supposed by Fochetti (1991, 1994) and Fochetti et al. (2004) based on nuclear markers (allozymes), have been herein found also in mitochondrial markers.     

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。     

Molecular systematics,evolution and zoogeography of the stonefly genus Siphonoperla (Insecta: Plecoptera,Chloroperlidae)

The stonefly genus Siphonoperla Zwick, 1967 (Chloroperlidae) ranges from the Atlas Mountains of North Africa, throughout Europe and east to the Lesser Caucasus Mountains in Armenia. Systematic relationships within the genus are unknown. We provide the first molecular phylogenetic reconstruction of the genus, based on sequence variation of 1348 bp of the mitochondrial cytochrome c oxidase subunit I gene and relate this phylogeny to a few key morphological features as well as zoogeographical perspectives. A total of 15 taxa (32 individuals), including four outgroup species (Chloroperla Newman, 1836 and Xanthoperla Zwick, 1967 ) were screened. Monophyly of Siphonoperla, as well as each purported taxon was supported, with net pairwise distances ranging from 0.7% to 13.7%. Within‐taxon variability ranged from 0% to 6.2%, whereby the upper value relates to Siphonoperla torrentium Pictet, 1841 represented in our sample by three allopatric subspecific taxa. These taxa, displayed as a polytomy with an estimated time to the most recent common ancestor of about 5.4 Myr, are also shown to have distinct genitalia. These data could be used to support a species‐level distinction for the three subspecific taxa. Siphonoperla ranged from 13% (Xanthoperla) to 16.2% (Chloroperla) divergent from the outgroup genera. The recently described Siphonoperla ottomoogi, Graf, 2008 from Austria is not closely related to the sympatric Siphonoperla montana Pictet, 1841 and is a minimum of 7.8% divergent from congenerics, supporting its status as a micro‐endemic relict surviving on the edge of Alpine glaciation throughout the Pleistocene. Overall, the genus shows the highest levels of diversification in the Mediterranean and Southeast regions whereby at least some of the species found in Central Europe today may have persisted there in peri‐glacial refugia throughout the Pleistocene.     

A wingless alpine stonefly from New Zealand,and further information on genus Holcoperla (Plecoptera: Gripopterygidae)

Abstract

Holcoperla magna n.sp. is described and figured from material collected on Headlong Peak, Mt Aspiring National Park. New information is given on H. angularis (Wisely) and H. jacksoni McLellan, and the 3 species are compared. Larvae designated as type specimens of H. angularis are shown to be Apteryoperla monticola Wisely.     

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.