IsBombus inexspectatus (Tkalcu) a workerless obligate parasite? (Hym. Apidae)

Summary Bombus inexspectatus (Tkalc) is now known from 50 males, 36 females and two individuals which have been described as workers; the species has been found in the mountains of Austria, France, Italy, Spain and Switzerland at altitudes between 1,181 m. (N.W. Spain) and 2,100 m. (N.E. Italy). More than 10,000 bumblebees have been captured in localities whereB.inexspectatus is known to occur yet no further worker individuals have been discovered. The capture of some very undersized females in spring long before workers of any other species were flying puts the status of the two so-called workers in considerable doubt and examination of these two specimens points very strongly to their being females and not workers. The possibility that the femaleB. inexspectatus behaves like aPsithyrus and lives in the nest of another bee seems a not improbable explanation of the situation though proof may come only by chance discovery. Certain peculiarities of the female, notably absence of any indication, in pinned specimens, of either wax secretion or pollen collecting and at least the suggestion that the pollen collecting equipment may be degenerate if not entirely non-functional are added pointers to the necessity of a parasitic mode of living.Bombus ruderarius Müller is suggested as a likely host.

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Zusammenfassung Bombus inexspectatus (Tkalc), ist jetzt nach 50 Männchen, 36 Weibchen und 2 als Arbeiter beschriebenen Exemplaren bekannt; die Art ist in den Gebirgen Österreichs, Frankreichs, Italiens, Spaniens und der Schweiz in Höhen zwischen 1181 m. (N.W. Spanien) und 2100 m. (N.O. Italien) gefunden worden. Mehr als 10000 Hummeln sind an den Fundorten gefangen worden, wo das Vorkommen vonB. inexspectatus bekannt ist, doch hat man keine weiteren Arbeiter entdeckt. Das Sammeln einiger sehr kleinen Weibchen am Anfang des Frühlings — lange vor der Flugzeit der Arbeiter anderer Arten — lässt den Status der zwei Arbeiter bezweifeln, und eine Untersuchung zeigt, dass sie wahrscheinlich Weibchen und keine Arbeiter sind. Es ist durchaus möglich, dass das Weibchen vonB. inexspectatus sich wie einPsithyrus verhält und im Nest einer anderen Hummel lebt, doch vielleicht könnte eine zufällige Entdeckung diese Hypothese bestätigen. Gewisse Eigentümlichkeiten des Weibchens sind weitere Anzeiger der Notwendigkeit einer parasitischen Lebensweise: besonders die Abwesenheit jeder Andeutung entweder von Waschsabscheidung oder von Pollensammeln und die Möglichkeit, dass der Pollensammelapparat wenigstens degeneriert, wenn nicht ganz funktionlos geworden, ist.Bombus ruderarius Müller wird als wahrscheinlicher Wirt vorgeschlagen.

     

Oosterschelde estuary (S.W. Netherlands): a self-sustaining ecosystem?

The Oosterschelde estuary has a special position among the Dutch North Sea estuaries. With relatively unpolluted water and high transparency it combines high biotic diversity and high primary and secondary production. Before 1970 a major part of the water of the rivers Rhine and Meuse flowed into the Oosterschelde. The building of a permeable storm-surge barrier (1986) decreased the exchange between Oosterschelde and North Sea. The construction of two additional dams (1987) reduced the very limited fresh water discharge on the estuary even further. The total effect of these changes was a decrease of the nutrient levels in the water column.The estuary is used intensively for culture of mussels and fishery of cockles. Both zoobenthos groups use together up to 60% (in the western part) of the organic food available in the Oosterschelde estuary. The storm-surge barrier resulted in reduced current velocities and increased sedimentation, accompanied by higher transparency, hence accelerating primary production. This phenomenon is counteracted by the lowered nutrient concentrations throughout the year.In the seventies a preliminary carbon budget study indicated that a substantial import of organic carbon was required to sustain the ecosystem. Later studies did not confirm this hypothesis.In the present paper three different methods are presented to answer the question, if internal production suffices to sustain the foodweb. At first a steady state model is applied, secondly, calculations with actually measured process rates are carried out and, finally, a dynamic simulation model is used.The conclusion is drawn that, before the construction of the storm-surge barrier, primary production of organic matter by phytoplankton is much more important than import, although the latter can not be neglected as additional food source for mussels, cockles and zooplankton. The simulation model predicts that this conclusion will not have to be changed in the future. The Oosterschelde will remain largely a self-sustaining ecosystem.     

Heterodera longicolla,n. sp. (Nematoda: Heteroderidae) from Buffalo-grass (Buchlo? dactyloides) in Kansas

Heterodera longicolla n. sp., a member of the H. goettingiana group, is described and illustrated from roots of buffalo-grass, Buchloë dactyloides (Nutt.) Engelm., in Manhattan, Kansas. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau & Cobb, 1962, but differs particularly in having a shorter stylet in larvae, males and females; in possessing only three annules on the head of larvae and males; in having a shorter tail in larvae; and by the presence on cysts of a small anus without a circum-anal pattern.     

Are the differences between Stw 431 (Australopithecus africanus) and A.L. 288-1 (A. afarensis) significant?

Recent studies of early hominin body proportions paint a complex evolutionary picture, with multiple instances of reversal in body shape. These interpretations rest heavily upon the inferred limb joint proportions of Australopithecus africanus. For example, the partial skeleton Stw 431 has been suggested to show ape-like joint proportions compared to the A. afarensis specimen A.L. 288-1. This suggests an evolutionary reversal in the more recent A. africanus. However, no study has examined the probability of sampling the differences between Stw 431 and A.L. 288-1 from a single extant hominoid species. The present study compares elbow/hip and elbow/lumbosacral joint size ratios between Stw 431 and A.L. 288-1 using exact randomization, based on chimpanzee and human models of variation. Results indicate that differences in elbow/hip proportions between Stw 431 and A.L. 288-1 can be sampled from a single species. In contrast, differences in elbow/lumbosacral proportions between Stw 431 and A.L. 288-1 show a significantly low probability of being sampled from a single species. Thus, Stw 431 and A.L. 288-1 are not significantly different from each with regard to limb joint proportions, but Stw 431 has a significantly smaller lumbosacral joint. This pattern does not conform to previous interpretations of limb proportions in A. africanus. Low statistical power in the present study may account for the discrepancy. Further research is needed to illuminate the functional implications of variation in relative lumbosacral joint size in early hominins.     

The phylogeny ofPapaver s. l. (Papaveraceae): Polyphyly or monophyly?

An RFLP analysis of the chloroplast genetrnK of 32 species of the generaPapaver, Roemeria, Stylomecon, andMeconopsis leads to the following conclusions: (1) AsianMeconopsis consists of two distinct clades and is paraphyletic in relation toPapaver, Roemeria, Stylomecon, and the W EuropeanMeconopsis cambrica. (2) Sister group relationships ofRoemeria toPapaver sect.Argemonidium and ofStylomecon toPapaver californicum are well-supported. (3)Meconopsis cambrica is nested withinPapaver (incl.Roemeria andStylomecon). The consideration of morphology, geographical distribution and ecology leads to the conclusion thatM. cambrica is best regarded as a member ofMeconopsis, and thatPapaver arose polyphyletically from within a paraphyleticMeconopsis in response to Tertiary climatic aridification. — The removal ofM. cambrica from the taxon matrix is discussed. It is concluded that this experiment illuminates the importance of critical taxon sampling, and shows that at least potentially the assessment of taxa as mono-, para-, or polyphyletic may characterize their present status only and need not reflect their phylogenetic history.     

Is Phillyrea angustifolia L. (Oleaceae) an androdioecious species?

LEPART, J. & DOMMEE B., 1992. Is Phillyrea angustifolia L. (Oleaceae) an androdioecious species? Observations during two or three years on three natural populations of Phillyrea angustifolia growing in contrasting environments in southern France show that two distinct phenotypes occur in approximately equal proportions: hermaphrodites, which produce pollen and seeds, and males, which produce pollen only. The populations studied are thus morphologically androdioecious. Biometric investigation of the two morphs shows that they are clearly distinguished by (1) the shape of the stigma and (2) the ovary which is well developed in hermaphrodites and aborted in males. Neither size of anthers and corolla, nor pollen germination, differ between the two sexes. In the Camargue, where P. angustifolia is presently an invader, controlled crosses between hermaphrodites (selfing and inter-individual) are partially successful. In contrast, such crosses are sterile in the well-established population of the La Gardiole. Hence the Camargue population appears to be functionally androdioecious and La Gardiole functionally dioecious. This breeding system is particularly puzzling, since the occurrence of anemogamy and possible selfing do not fit classical explanations of androdioecy. The ability of hermaphrodites to be functionally male and female could be particularly adaptive in founding populations. Since functional hermaphroditism occurs in expanding populations of the Camargue population, we consider that the androdioecy of P. angustifolia could be a kind of leaky dioecism.     

?Kenyaichthyidae fam. nov. and ?Kenyaichthys gen. nov. – First Record of a Fossil Aplocheiloid Killifish (Teleostei,Cyprinodontiformes)

The extant Cyprinodontiformes (killifishes) with their two suborders Cyprinodontoidei and Aplocheiloidei represent a diverse and well-studied group of fishes. However, their fossil record is comparatively sparse and has so far yielded members of the Cyprinodontoidei only. Here we report on cyprinodontiform fossils from the upper Miocene Lukeino Formation in the Tugen Hills of the Central Rift Valley of Kenya, which represent the first fossil record of an aplocheiloid killifish. A total of 169 specimens - mostly extraordinarily well preserved - and a sample of ten extant cyprinodontiform species were studied on the basis of morphometrics, meristics and osteology. A phylogenetic analysis using PAUP was also conducted for the fossils. Both the osteological data and the phylogenetic analysis provide strong evidence for the assignment of the fossils to the Aplocheiloidei, and justify the definition of the new family †Kenyaichthyidae, the new genus †Kenyaichthys and the new species †K. kipkechi sp. nov. The phylogenetic analysis unexpectedly places †Kenyaichthys gen. nov. in a sister relationship to the Rivulidae (a purely Neotropical group), a probable explanation might be lack of available synapomorphies for the Rivulidae, Nothobranchiidae and Aplocheilidae. The specimens of †K. kipkechi sp. nov. show several polymorphic characters and large overlap in meristic traits, which justifies their interpretation as a species flock in statu nascendi. Patterns of variation in neural and haemal spine dimensions in the caudal vertebrae of †Kenyaichthys gen. nov. and the extant species studied indicate that some previously suggested synapomorphies of the Cyprinodontoidei and Aplocheiloidei need to be revised.     

Are Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. migratory relicts?

It remains unclear why there are only two vascular plant species in Antarctica, Deschampsia antarctica Desv. (Poaceae) and Colobanthus quitensis (Kunth) Bartl. (Caryophyllaceae). Despite progressing climate warming, there is also just one alien plant species found in the region, introduced by humans and spreading mainly in disturbed habitats. In the present article we try to interpret the data concerning the history of the biota and glaciations of the continent, proceeding from the assumption that both plants migrated to Antarctica during the Oligocene-Pliocene, when it was less isolated and the climate was more favorable for their naturalization. Genetic evidence was also taken into consideration. Our data allow suggesting secondary dispersal in the region, due to transfer by birds with regard of climate changes. With this in mind, we believe that D. antarctica and C. quitensis are migratory relicts.     

Cordaites schatzlarensis sp. nov. and Samaropsis newberryi (Andrews) Seward from the Westphalian (Carboniferous) of the ?aclé? area (Czech Republic)

The monotonous cordaitalean leaves are usually difficult to determine as leaf shape and venation can be similar in many species. Therefore cuticular analysis is an important method for distinguishing cordaitalean leaves. Pennsylvanian Cordaites schatzlarensis nov. sp. comes from the ?aclé? locality in the Intrasudetic Basin, Czech Republic. It has been found in mudstone accompanying the upper coal seams No. 9 and 10 of the Jan Šverma Coals, Lampertice Member, ?aclé? Formation and are late Duckmantian in age. The leaves of Cordaites schatzlarensis are lanceolate, amphistomatic. Stomata of the adaxial epidermis are scarce, isolated, or in very short stomatal rows. In contrast, the density of stomata on the abaxial cuticle is high and stomata are arranged into single or double stomatal rows. The cuticles of C. schatzlarensis are comparable with the Chinese Upper Permian C. baodeensis Ge. Leaves can be narrow, comparable to French Bolsovian Dorycordaites zeilleri Ledran, or relatively wide. Accompanying big seeds more than 5 cm in diameter are attributed to Samaropsis newberryi (Andrews) Seward. The pith casts Artisia Sternberg were found in sandy channel fill deposits.     

Bioefficacy of Blumea mollis (D. Don) Merr. and Hygrophila schulii (Buch.-Ham.) (Syn. H. auriculata) against Helicoverpa armigera (Hübner)

Indiscriminate use of synthetic pesticides to control the pests causes negative effects on non-target organisms. Some of the chemicals under B and C categories are carcinogenic to humans. The present study was aimed to assess the antifeedant, larvicidal and pupicidal activities of Hygrophila schulii (syn. H. auriculata) and Blumea mollis against Helicoverpa armigera. Maximum antifeedant activity of 70.01% was observed in ethyl acetate extract of H. schulii at 5.0% concentration with LC₅₀ value of 2.0%. B. mollis ethyl acetate extract at 5.0% concentration showed antifeedant activity of 35.40% with LC₅₀ value of 8.38%. The data for antifeedant activity showed homogeneity of variances in Levene Statistics and normality in Shapiro–Wilk test. Ethyl acetate extract of H. schulii at 5.0% concentration showed 68.66% larvicidal activity with LC₅₀ value of 2.97%. It also showed 73.33% pupicidal activity and was statistically significant from other treatments. No pupicidal activity was observed in ethyl acetate extract of B. mollis. All concentrations of ethyl acetate extract of H. schulii showed promising biological activities which differed statistically from other treatments. Ethyl acetate extract of H. schulii could be used to develop new botanical formulations to manage agricultural pests.     

Can Yeast (S. cerevisiae) Metabolic Volatiles Provide Polymorphic Signaling?

Chemical signaling between organisms is a ubiquitous and evolutionarily dynamic process that helps to ensure mate recognition, location of nutrients, avoidance of toxins, and social cooperation. Evolutionary changes in chemical communication systems progress through natural variation within the organism generating the signal as well as the responding individuals. A promising yet poorly understood system with which to probe the importance of this variation exists between D. melanogaster and S. cerevisiae. D. melanogaster relies on yeast for nutrients, while also serving as a vector for yeast cell dispersal. Both are outstanding genetic and genomic models, with Drosophila also serving as a preeminent model for sensory neurobiology. To help develop these two genetic models as an ecological model, we have tested if - and to what extent - S. cerevisiae is capable of producing polymorphic signaling through variation in metabolic volatiles. We have carried out a chemical phenotyping experiment for 14 diverse accessions within a common garden random block design. Leveraging genomic sequences for 11 of the accessions, we ensured a genetically broad sample and tested for phylogenetic signal arising from phenotypic dataset. Our results demonstrate that significant quantitative differences for volatile blends do exist among S. cerevisiae accessions. Of particular ecological relevance, the compounds driving the blend differences (acetoin, 2-phenyl ethanol and 3-methyl-1-butanol) are known ligands for D. melanogasters chemosensory receptors, and are related to sensory behaviors. Though unable to correlate the genetic and volatile measurements, our data point clear ways forward for behavioral assays aimed at understanding the implications of this variation.     

B.B.Brodie(1907～1989)

B.B.Brodie博土,一个先驱药理学家和美国国家科学院院士,1989年2月28日逝世。生前是美国国立卫生研究院心脏研究所化学药理实验室的创始人和第一任主任。     

邓叔群(S.C.Teng)先生生平

1902年12月12日出生于福建省福州市。 1915年考入北京清华学堂。 1923年赴美国康奈尔大学留学取得农学士、森林学硕士学位。 1925—1928年攻读康奈尔大学植物病理学博士并被授予全美国最高科学学会 PHI-KAPPA-PHI和SIGMA-XI两枚金钥匙证章并成为其荣誉会员。 1928年回国,任岭南大学、金陵大学和中央大学一级教授。 1932—1941年历任中国科学社生物研究所、中央自然历史博物馆、中华教育文化基金董事会和中央研究院动植物研究所研究员、中央研究院林业实验研究所副所长。 1941—1946年任甘肃省水利林牧公司林业部经理。 1948年当选…     

Corbicula (Bivalvia: Sphaeriacea) vs. Indigenous Mussels (Bivalvia: Unionacea) in U.S. Rivers: A Hard Case for Interspecific Competition?

At a time when populations of indigenous river mussels havebeen dwindling and/or disappearing, the introduced Asian clam,Corbicula, has spread through many U.S. rivers from Californiato Florida. In the Arkansas River Navigation System, a heavilymanaged waterway, Corbicula presently has a different "competitive"presence than it does in the relatively unmanaged Buffalo Riverin Arkansas. Comparative studies of both Corbicula and indigenousbivalved mollusks reveal biological bases for the contrastingkinds of benthic faunal change. There are ecologically relevant,distinctive differences between the two kinds of animals: inmantle/shell and mantle/gill apparatus, in the reproductivecomplex and neuroanatomy, and in spawning and locomotor behaviors.It is argued that the conservative molluscan characteristicsof Corbicula enable it to function in an exclusive, "contradictory"role with indigenous bivalves in a heavily managed waterway,and in a "contrary" competitive role elsewhere. Rationale ispresented for incorporating organismic evaluation into studiesof competition between distantly related taxa.     

Bergh?nfling(Carduelis f. flavirostris) mit r?tlichen Brustfedern

Ohne Zusammenfassung