New records of the carabidicolous Laboulbeniales (Ascomycetes) of Japan (II)

Six carabidicolous species of Laboulbeniales are reported as new for the Japanese mycoflora. They areLaboulbenia finitima, L. separata, L. borneensis, L. manubriolata, Dimeromyces caribaeus, andDixomyces ornatus. In Japan, the former three species are parasitic onMochtherus luctuosus and the latter three species onPerigona nigriceps. Laboulbenia finitima occurs on the left legs (tarsi and tibiae);L. separata on the left elytral margin:L. borneensis on the pronotum;L. manubriolata on the pronotum and elytra;Dimeromyces caribaeus on the right inferior posterior surface of the prothorax (pronotal hypomeron); andDixomyces ornatus on the outer margin of the right elytron. Comments and photographs are given for each fungus.     

Field observations in the Oosterschelde (The Netherlands) onCoscinodiscus concinnus andCoscinodiscus granii (Bacillariophyceae) infected by the marine fungusLagenisma coscinodisci (Oomycetes)

During 1985–1990Coscinodiscus concinnus andCoscinodiscus granii from the Oosterschelde were infected by the marine fungusLagenisma coscinodisci, although not every year with the same intensity. Infected cells were only observed during the period July–October at water temperatures between 13.2 and 20.2°C. In 1986 and 1987 the course of the infection withL. coscinodisci inC. concinnus andC. granii, was recorded at three stations. The highest infection percentages varied between 22.2 and 58.3% inC. concinnus and between 7.1 and 41.9% inC. granii. It is concluded that the water temperature may play an important role in the appearance ofL. coscinodisci inC. concinnus andC. granii and that silicate limitation is of minor importance. Finally it is discussed that the infection was not of great importance for the phytoplankton community in the Oosterschelde.     

Allozyme variation in the diploid (A genome) populations ofScilla scilloides (Hyacinthaceae)

Allozyme variation at eleven loci encoding seven enzyme systems were examined in 20 populations of diploid (genome AA, 2n = 16)Scilla scilloides in China. In comparison with the average species of seed plants studied, populations of this species display a high amount of genetic variation (A = 2.0, P = 58.6%, H_o = 0.172, and H_e = 0.185). Allozyme variation pattern revealed predominant outcrossing within populations and considerable differentiation (F_ST = 0.314) among populations as well as between the subtropic and temperate regions. The wide distribution, long existence and outcrossing are presumably the main factors responsible for the high genetic diversity within populations. But the gravity dispersal of seeds and pollination by small insects set limits to the increase of genetic variation within populations and promote differentiation between populations and regions. In addition, allozyme variation does not distinguishS. scilloides var.albo-viridis and suggests that subtropic populations may be considered as a genetic entity.     

Allozyme diversity and the evolution ofCrepidiastrum (Compositae) on the Bonin (Ogasawara) Islands

The genusCrepidiastrum is distributed in East Asia and includes 7 species. In the Bonin Islands, three species ofCrepidiastrum occur, and all of them are endemic to the islands. For detecting the origin and speciation of these endemic species, electrophoretic studies have been done in three endemic species of the Bonin Islands as well as in the remaining four species ofCrepidiastrum, andYoungia denticulata which is considered to be closely related toCrepidiastrum. A total of 386 individuals were sampled from 14 populations. As a result, 17 loci of 10 enzyme systems were resolved and gene frequencies for each population were calculated. The genetic variability was low in island species, as reported in some oceanic island plants. Four groups were recognized in the dendrogram generated by the UPGMA method. The Bonin endemics were clustered together, suggesting a monophyletic origin.C. ameristophyllum andC. linguaefolium were found to be genetically very similar, and this may suggest recent and rapid speciation within the islands.     

Comparing the effects of the exotic cactus-feeding moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) and the native cactus-feeding moth, Melitara prodenialis (Walker) (Lepidoptera: Pyralidae) on two species of Florida Opuntia

This study examined the effects of the native cactus moth borer, Melitara prodenialis, and the invasive cactus moth borer, Cactoblastis cactorum, on two common cactus species, Opuntia stricta and O. humifusa at coastal and inland locations in central Florida. Opuntia stricta were present only at coastal sites and O. humifusa were present at coastal and inland sites. Throughout the duration of the study, coastal plants were subject to damage solely by C. cactorum and inland plants solely by M. prodenialis. Results showed marginally significantly higher numbers of eggsticks on O. stricta than O. humifusa and significantly higher numbers at coastal sites than at inland sites. There was also significantly higher moth damage on O. stricta than O. humifusa and at coastal sites than inland sites, but not significantly so. However, there was a higher level of plant mortality for O. humifusa than for O. stricta and a significantly higher level of cactus mortality at inland sites when compared to coastal sites. This increased mortality may be due to increased attack by true bugs, Chelinidea vittiger, and by Dactylopius sp., combined with attack by M. prodenialis. Inland plants also tended to be smaller than coastal plants and could be more susceptible to the combined effects of all insects. Further long-term research on coastal cactus survival when attacked and unattacked by Cactoblastis is necessary to fully determine the effects of this moth on Opuntia survival.     

On the Lichen generaPlacocarpus andPlacidiopsis (Verrucariaceae)

Verrucaria schaereri (Fr.)Nyl. is accorded generic status asPlacocarpus Trev. emend.O. Breuss. The main differences between the two genera concern the thallus anatomy and the spores which are halonate inPlacocarpus. The following new combinations are proposed:Placocarpus schaereri (Fr.)O. Breuss andPlacidiopsis cinerascens (Nyl.)O. Breuss.     

Spore formation in the Actinoplanaceae (Actinomycetales)

Spore development in four genera, Actinoplanes, Dactylosporangium, Planomonospora, and Streptosporangium, was studied by transmission and scanning electron microscopy. Actinoplanes and Streptosporangium formed spores by fragmentation of a hypha within its expanded outer sheath, as do many other actinomycetes. Dactylosporangium and Planomonospora formed spores endogenously by development of wall material within the parent hypha. In this respect, they resembled the genera Actinobifida and Thermoactinomyces. The term sporangium has therefore been used to describe structures which are not homologous. It was suggested that the term should be confined to structures in which endogenous spore formation occurs.     

Diaspore diversity in the anemochorousGouanieae (Rhamnaceae)

Fruits and seeds of four anemochorous taxa ofRhamnaceae-Gouanieae were studied by SEM. Flight performance of diaspores of three genera was analyzed. Diverging postfloral morphogeneses lead to different fruit and diaspore types: (1) a solid schizocarp dehiscing into three 2-winged mericarps (Gouania, Crumenaria), (2) an inflated schizocarp dehiscing into three inflated mericarps (Reissekia), and (3) a hollow septicide capsule which releases three winged hemimericarps (Alvimiantha). The latter convey significantly heavier seeds thanGouania andReissekia at comparable fall rates. The generic status ofAlvimiantha is confirmed. The Neotropics are pointed out as being a site of strong adaptive radiation for the tribeGouanieae.     

Establishment and spread of two introduced parasitoids (Ichneumonidae) of the birch leafminer, Fenusa pusilla (Lepeletier) (Tenthredinidae)

Lathrolestes nigricollis(Thomson) and Grypocentrus albipes Ruthe,Palearctic specialist parasitoids of thebirch-leafmining sawfly Fenusa pusilla(Lepeletier), were imported from central Europe andreleased at three locations in Edmonton, Alberta,Canada during 1994–1996. Parasitoids becameestablished at two locations, L. nigricollis atboth and G. albipes at one, and were recoveredfor 3–5 years after release. Lathrolestesnigricollis has dispersed throughout most ofEdmonton, and at least 13 km from release sites, butG. albipes has been recovered only 400–500 mfrom one release site. Five years after introductionat one site, percent parasitism by L.nigricollis was 78% and 84% for the first andsecond generations, respectively, and about 48% ofparasitoid eggs were encapsulated.     

Serial reconstruction and behaviour during cytokinesis of the chondriome ofProrocentrum minimum (Pavillard) Schiller (Pyrrhophyta)

Summary Serial reconstruction of the chondriome of vegetative cells ofProrocentrum minimum (Pavillard) Schiller has revealed a major reticulated mitochondrion and several small satellite mitochondria. During cytokinesis the major portion of the chondriome splits passively with the cell. The significance of this structure and division mechanism is discussed.     

Sublethal effects of Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes) on the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) under laboratory conditions

Sublethal effects were evaluated in subsequent generations of whiteflies Bemisia tabaci (Gennadius) arising from parental generations exposed in the four nymphal stages to the fungus Beauveria bassiana (Balsamo) Vuillemin. Examples of such effects include impaired fertility, production of malformations or external variations, and reduced survival of later generations. Malformations of the head, legs, wings or abdomen were not observed in adults derived from treated nymphs, nor were negative effects observed in the fecundity and fertility of the descendants of the whiteflies treated with the fungus. However, moulting problems were observed in insects descended from B. bassiana-treated whiteflies. This is the first time that such effects have been reported, with almost 30% of imagos resulting from treated nymphs unable to detach completely from the exuvia. A gradual reduction in mortality rates between subsequent generations was observed. The importance of these results is discussed in the light of findings from other studies into the effects of entomopathogenic fungi on pest insects.     

Studies in the embryology ofHeliantheae (Compositae)

The embryology ofLagascea mollis, Zinnia angustifolia andGalinsoga parviflora has been studied. The anther archesporium is hypodermal and consists of a single row of 6–8 cells, there are two layers below the epidermis of the anther and a periplasmodial tapetum. Ripe pollen grains are tricolpate and 3-celled. The ovary contains a single ovule, but in a few cases ofGalinsoga parviflora two ovules have been found. The female archesporium is unicellular, but sometimes more than one archesporial cell occurs inLagascea mollis andZinnia angustifolia. The embryo sac development is of the Polygonum type, the synergids are hooked, antipodal cells show great variation. The endosperm development is cellular inGalinsoga parviflora and peripheral layer persists in the mature seed. The embryo development conforms to the Senecio variation of the Asterad type. The pericarp structure and cmbryological features support the disputed systematic position ofLagascea withinHeliantheae. Part of a Ph.D. thesis, accepted at Andhra University.     

Lepidocoleus cf.ulrichi (Machaeridia) from the Trenton Group (Ordovician) of Ontario (Canada)

A specimen of the machaeridianLepidocoleus cf.ulrichi described herein focuses attention on taxonomical difficulties with extremely dorso-ventrally elongated sclerites found in some lepidocoleid taxa.Lepidocoleus ulrichi Withers, 1926 andLepidocoleus sigmoideus Withers, 1926 exhibit very similar appearances and prove indistinguishable based onWithers 1926 criteria. The key to separating taxa as similar as these may instead lie in the most juvenile stages of growth.     

Karyotaxonomic analysis of the genusBunium (Umbelliferae)

Chromosome numbers are reported for 23 species of the genusBunium, distributed mainly in Middle Asia and Transcaucausia. The great diversity of basic chromosome numbers is unusual for a genus ofUmbelliferae: x = 11, 10, 9, 8, 7, and 6. This series obviously has to be interpreted as descending dysploidy. Infraspecific aneuploidy was found in three species, but there are no B-chromosomes or polyploidy. The karyotypes of 18 species are described, using two morphometric chromosome parameters, centromere position and relative length (Table 2), and illustrated (Figs. 2–4). Species vary greatly in their karyotype asymmetry (20.4–45.9%). Chromosome numbers and structures appear to be useful in the karyotaxonomical and biogeographical analysis of the genus.     

Additions to the genusXenidiocercus (coelomycetes) from Ghana

Two new species of the coelomycete genusXenidiocercus are described and illustrated,X. macrospora on leaves ofMacaranga rowlandii andX. pyriformis on leaves ofM. huraefolia. They differ from the type species in having wider and ellipsoidal or pyriform conidia. A key to species ofXenidiocercus andIdiocercus is provided.     

Sedum surculosum andS. jaccardianum (Crassulaceae) share a unique 70 bp deletion in the chloroplast DNA trnL (UAA)-trnF (GAA) intergenic spacer

TrnL (UAA)-trnF (GAA) chloroplast DNA spacer sequences of three species ofMonanthes, Sedum surculosum (=Monanthes atlanticum) andS. jaccardianum were compared.S. surculosum, the systematic position of which has been disputed ever since its discovery, shares a phylogenetically highly significant 70 bp deletion withS. jaccardianum. In addition to this large deletion the two Moroccan species ofS. ser.Monanthoidea differ in three more indels as well as in four nucleotide substitutions from the species ofMonanthes. These data render strong support for the monophyly ofS. ser.Monanthoidea andMonanthes. Spacer length in seven species and one subspecies ofMonanthes is relatively uniform.     

On the taxonomic position ofSilene thebana (Caryophyllaceae)

Silene thebana Orph. exBoiss. is transferred as a subspecies toS. fabaria (L.)Sm., resulting in the new combinationS. fabaria (L.)Sm. subsp.thebana (Orph. exBoiss.)Melzh. The chromosome count of 2n = 24 is recorded for the first time for this taxon.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday, 16th October 1986.     

Relationships between the ant Brachymyrmex obscurior (Hymenoptera, Formicidae) and Acacia pennatula (Fabaceae)

Summary. In central Mexico, the ant Brachymyrmex obscurior Forel feeds on nectar produced by extrafloral nectaries of Acacia pennatula (Schlecht. & Cham.) Benth. However, no studies have determined whether the ants visitation is related to plant nectar availability and whether ants protect A. pennatula from herbivory. The objectives of this 2-yr study (2000–2001) were to assess whether seasonal changes in ant visitation coincide with extrafloral nectar productivity in A. pennatula and to determine whether ants protect the plant. At the end of the dry season (April–June) B. obscurior was the only ant species on A. pennatula and extrafloral nectar production is limited to this period. Exclusion experiments, performed at the end of the dry season showed that A. pennatula did not receive a protective benefit when visited by ants. Branches with ants and branches where ants are excluded had similar numbers of the nonmyrmecophile leafhopper Sibovia sp. which was the only herbivore observed under natural conditions.Received 24 March 2004; revised 4 September 2004; accepted 8 September 2004.