Development and Reproduction of Ladybeetles (Coleoptera: Coccinellidae) on the Citrus Aphids Aphis spiraecola Patch and Toxoptera citricida (Kirkaldy) (Homoptera: Aphididae)

Seven species of Coccinellidae inhabiting citrus groves in Florida were evaluated for ability to develop and reproduce on the citrus aphids Toxoptera citricida (Kirkaldy) and Aphis spiraecola Patch. Choice tests performed with adults and larvae indicated that both aphid species were generally acceptable prey. Coccinella septempunctata L., Coleomegilla maculata fuscilabris (Mulsant), Coelophora inaequalis F., and Olla v-nigrum Mulsant were unable to complete development on either aphid. Hippodamia convergens Guerin larvae completed development on A. spiraecola with 68% survival; none survived on T. citricida. Only Cycloneda sanguinea (L.) and Harmonia axyridis Pallas completed development on both A. spiraecola (60 and 70% survival, respectively) and T. citricida (100 and 95% survival, respectively). Larval developmental time was shorter on T. citricida than on A. spiraecola, and resulting adults were heavier, differences being more pronounced in H. axyridis. Females of C. septempunctata, C. inaequalis, and O. v-nigrum produced viable eggs on T. citricida. O. v-nigrum did not produce eggs on A. spiraecola. Females of C. m. fuscilabris and H. axyridis produced no eggs on A. spiraecola and mostly infertile eggs on T. citricida. Female H. convergens laid twice as many eggs feeding on T. citricida as on A. spiraecola and egg viability was similar. C. sanguinea females laid similar numbers of eggs on both aphids, but eggs produced on A. spiraecola had higher fertility. Pollen added to the T. citricida diet temporarily improved the fertility of H. axyridis females, but not that of C. sanguinea females. C. sanguinea was judged the best candidate for augmentative biocontrol of T. citricida, the primary vector of citrus tristeza virus.     

A contribution to the rust flora (Uredinales) of southern Africa,with an emphasis on Namibia

Five new rust species are described and hitherto unknown spore states for the following seven species are reported: Puccinia desertorum on Evolvulus alsinoides, Uromyces comptus on Merremia bipinnatipartita, Puccinia halsei on Acacia hereroensis, Ravenelia transvaalensis on Acacia mellifera, Puccinia abutili on Abutilon angulatum, on Abutilon cf. austroafricanum, and on Abutilon cf. rehmannii, Puccinia lycii on Lycium sp. and Puccinia turgida on Lycium europaeum and on Lycium cf. oxycarpum. We also examined Uredo combreticola on Combretum cf. engleri, on Combretum hereroense, and on Combretum zeyheri, Puccinia afra on Lycium sp., and Uredopeltis cf. chevalieri on Grewia flavescens. All mentioned rust fungi are described in detail and are shown by line drawings. Selected species are illustrated with SEM-photographs. Part 220 in the series “Studies in Heterobasidiomycetes” from the Botanical Institute, University of Tübingen     

Food attraction and population growth of fungivorous nematodes with different fungi

Food attraction of the fungivorous nematodes Aphelenchus avenae and Aphelenchoides spp. to seven fungal species (Pyrenochaeta lycopersici, Botrytis cinerea, Rhizoctonia solani strains AG 3 and AG 2‐1, Verticillium dahliae, Pochonia bulbillosa, Mortierella hyalina and Trichoderma harzianum) was determined on agar plates by counting the number of test nematodes present on the mycelium of each fungus 24 h after inoculation. Population growth of A. avenae and Aphelenchoides spp. on five of the seven fungi included in the attraction test (P. lycopersici, R. solani strain AG 3, V. dahliae, P. bulbillosa and T. harzianum) was also determined on agar plates by counting nematode numbers every week during a 6‐week period. A. avenae and Aphelenchoides spp. were attracted to all the fungi tested. A. avenae was preferentially attracted to V. dahliae (P < 0.0001), and Aphelenchoides spp. did not show any preference except for low attraction to R. solani. A. avenae and Aphelenchoides spp. reproduced on all fungal species tested. After 6 weeks of incubation, the highest number of nematodes was found on P. lycopersici and P. bulbillosa, while the lowest number occurred on R. solani for A. avenae and on T. harzianum for Aphelenchoides spp. The suitability of a fungus as a host was not clearly related to the attraction to that fungus.     

New Laboulbeniales (Ascomycota) parasitic on Staphylinidae from Ecuador

Nine new species of Laboulbeniales parasitic on Staphylinidae from Ecuador are described and illustrated. These are: Corethromyces palumboi, parasitic on Sepedophilus sp. (Tachyporinae); Diandromyces onorei, parasitic on Hypotelus sp. (Piestinae); Dimeromyces osellae, parasitic on Plesiomalota cotopaxiensis Pace (Aleocharinae); Dimorphomyces carolinae, parasitic on Parosus sp. (Oxytelinae); Kleidiomyces ambiguus, parasitic on Anotylus sp. (Oxytelinae); Mimeomyces gregarius, parasitic on Philonthus sp. (Staphylininae); Monoicomyces trogacti, parasitic on Trogactus sp. (Oxytelinae); Scaphidiomyces pusillus, parasitic on Baeocera sp. (Scaphidiinae); and Teratomyces heterothopsis, parasitic on Heterothops sp. (Staphylininae).     

Addition and re-examination of Japanese species belonging to the genus <Emphasis Type="Italic">Cercospora</Emphasis> and allied genera. X: newly recorded species from Japan (5)

Cercospora yakushimensis is proposed as a new combination, Pseudocercospora yakushimensis comb. nov., and the morphology of the species is characterized from herbarium specimens, including the type. Six additional species belonging to the genus Cercospora and its allied genera are newly added to the Japanese mycoflora, namely, Cercospora dioscoreae-pyrifoliae on Dioscorea tokoro, Pseudocercospora catalpigena on Catalpa ovata, Pseudocercospora coriariae on Coriaria japonica, Pseudocercospora lythri on two species of Lythrum, Pseudocercospora pteroceltidis on Celtis boninensis, and Passalora puncta on Foeniculum vulgare.     

Addition and reexamination of Japanese species belonging to the genus <Emphasis Type="Italic">Cercospora</Emphasis> and allied genera. VIII. Newly recorded species from Japan (3)

Four species belonging to the genus Cercospora and allied genera were newly added to the Japanese mycoflora. They are Cercospora plantaginis on Plantago asiatica, Pseudocercospora asystasiae on Asystasia gengetica, P. cassiae-fistulae on Cassia fistula, and Pseudocercosporella ranunculacearum on Clematis grata var. ryukyuensis.     

Bionomics of aphids reared on cereals and some Gramineae

In controlled temperature, light and relative humidity, Metopolophium dirhodum and Sitobion avenae multiplied more on young Proctor barley than on Blenda oats, and less on Cappelle wheat. Rhopalosiphum padi increased in number fastest on barley and slowest on oats. More survived, and generation lengths seemed shorter, on barley for M. dirhodum and S. avenae and on wheat for R. padi. Tests with young cereals outdoors generally agreed with those in controlled conditions. On mature plants, there were more M. dirhodum on barley, more R. padi on wheat and more S. avenae on oats than on the other cereals. Given a free choice in large cages outdoors, most aphids were found on barley. When allowed to choose between grasses, more M. dirhodum were on Dactylis glomerata, Poa pratensis and Festuca pratensis, more R. padi on Lolium perenne and F. pratensis, and more S. avenae on D. glomerata and L. perenne. Most aphids of all species combined were on F. pratensis, Lolium and Phleum, and fewest on Festuca rubra and Holcus mollis.     

Bambusicolous fungi in Japan (1): four <Emphasis Type="Italic">Phaeosphaeria</Emphasis> species

Four Phaeosphaeria species on bamboos are reported. Leptosphaeria lelebae on culms of Bambusa multiplex is synonymized with P. oryzae. A Phaeosphaeria sp. on leaves of Sasa kurilensis is noted to have some similarities to Leptosphaeria sasae. Cultural characteristics of P. brevispora collected from culms of Sasa sp. are first recorded. Phaeosphaeria bambusae on leaves of Pleioblastus simoni is redescribed. In addition, the history of taxonomic studies on bambusicolous fungi in Japan is briefly reviewed.     

Host plan preferences of Oscinella spp. (Diptera: Chloropidae) in the laboratory

The oviposition preferences of Oscinella frit, O. vastator, O. nitidissima, O. albiseta andO. nigerrima for differenct Gramineae were investigated in the laboratory. O. frit, laid most eggs on oats, Lolium multiflorum and Festuca rubra, relatively few eggs were laid on barley and virtually none on Dactylis glomerata None of the other Osinella species oviposted on cereals. Of the other species, O. vastator appeared to be the most polyphagous and the preferred hosts were L. multiflorum, Lolium perenne and Festuca pratensis; few eggs were laid on either F. rubra, Agrostis tenuis or Poa pratensis. The host ranges of the remaining species were much more limited. Although a few eggs were laid by O. nitidissima on Lolium, the preferred host was A. tenuis. Oscinella albiseta oviposited only on D. glomerata whilst nearly all the eggs laid by O. nigerrima were deposited on shoots of Arrhenatherum elatius. The distribution of eggs by O. frit on L. multiflorum and A. tenuis was different from that on oats; on grasses most eggs were laid inside withered leaf sheaths whereas on oats most were deposited inside the coleoptile. The oviposition sites of O. nitidissima, O. nigerrima and O. albiseta on their respective host grasses were similar to those of O. frit on grasses. O. frit laid most eggs on grasses which were at the five-leaf stage and tailoring.     

<Emphasis Type="Italic">Puccinia calystegiae-soldanellae</Emphasis>, a new rust species on <Emphasis Type="Italic">Calystegia soldanella</Emphasis> from Japan

A rust species on Calystegia soldanella in Japan has been treated as Puccinia convolvuli to date. However, morphological characteristics of specimens on C. soldanella collected from Japan are significantly different from those of specimens on other Calystegia and Convolvulus species from different areas of the world. It is proved by inoculation experiment that the rust on C. soldanella is specific to C. soldanella. Based on these results, Puccinia rust on C. soldanella from Japan is described as a new species, Puccinia calystegiae-soldanellae.     

Substrate type and microbial interactions as factors affecting ascocarp formation by mangrove fungi

The growth and ascocarp formation of Aigialus parvus, Lignincola laevis and Verruculina enalia in single and mixed cultures on wood of Avicennia alba, Bruguiera cylindrica and Rhizophora apiculata was studied. In pure cultures, these fungi grew well on all three species of wood. Except for Aigialus parvus on B. cylindrica, all three fungi also formed abundant ascocarps. The time needed for ascocarp formation after inoculation ranged from six to eight weeks for L. laevis on all wood species, and for V. enalia on Avicennia alba; to ten weeks for V. enalia on B. cylindrica and R. apiculata; and 12 weeks for Aigialus parvus on Avicennia alba and R. apiculata.Mixed cultures involving two or three of the test fungi delayed the onset of sporulation and affected the abundance of ascocarps formed. Sporulation by Aigialus parvus on Avicennia alba and R. apiculata was markedly reduced by L. laevis alone or in combination with V. enalia. Likewise, sporulation by L. laevis was suppressed by Aigialus parvus and/or V. enalia. In contrast, the presence of L. laevis enhanced ascocarp formation by V. enalia on all types of wood. These observations suggest the presence of interference competition among the test fungi.     

Life history of the predatory mite <Emphasis Type="Italic">Phytoseiulus fragariae</Emphasis> on <Emphasis Type="Italic">Tetranychus evansi</Emphasis> and <Emphasis Type="Italic">Tetranychus urticae</Emphasis> (Acari: Phytoseiidae,Tetranychidae) at five temperatures

Tetranychus evansi Baker and Pritchard and Tetranychus urticae Koch (Acari: Tetranychidae) are important pests of Solanaceae in many countries. Several studies have demonstrated that T. urticae is an acceptable prey to many predatory mites, although the suitability of this prey depends on the host plant. T. evansi, has been shown to be an unfavorable prey to most predatory mites that have been tested against it. The predator Phytoseiulus fragariae Denmark and Schicha (Acari: Phytoseiidae) has been found in association with the two species in Brazil. The objective of this work was to compare biological parameters of P. fragariae on T. evansi and on T. urticae as prey. The study was conducted under laboratory conditions at 10, 15, 20, 25 and 30°C. At all temperatures, survivorship was lower on T. evansi than on T. urticae. No predator reached adulthood at 10°C on the former species; even on the latter species, only about 36% of the predators reached adulthood at 10°C. For both prey, in general, duration of each life stage was shorter, total fecundity was lower and intrinsic rate of population increase (r _m ) was higher with increasing temperatures. The slower rate of development of P. fragariae on T. evansi resulted in a slightly higher thermal requirement (103.9 degree-days) on that prey than on T. urticae (97.1 degree-days). The values of net reproduction rate (R ₀), intrinsic rate of increase (r _m ) and finite rate of increase (λ) were significantly higher on T. urticae, indicating faster population increase of the predator on this prey species. The highest value of r _m of the predator was 0.154 and 0.337 female per female per day on T. evansi and on T. urticae, respectively. The results suggested that P. fragariae cannot be considered a good predator of T. evansi.     

<Emphasis Type="Italic">n</Emphasis>-Alkane assimilation and <Emphasis Type="Italic">tert</Emphasis>-butyl alcohol (TBA) oxidation capacity in <Emphasis Type="Italic">Mycobacterium austroafricanum</Emphasis> strains

Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C₂ to C₁₆). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C₁ to C₁₆) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during MTBE metabolism.     

Biological species ofArmillaria and their mycoparasitic associations withRhodophyllus abortivus in Hokkaido

Specimens of basidiomes and/or rhizomorphs ofArmillaria mellea complex and basidiomes ofRhodophyllus abortivus, developing on the same decaying stumps or stems of forest trees, were collected in three forests in Hokkaido. Normal basidiomes ofR. abortivus were found near to, but free from, the rhizomorphs and/or basidiomes ofArmillaria, while abnormal basidiomes, as carpophoroid forms, were developed on the rhizomorphs ofArmillaria. Of three mycoparasiticArmillaria isolates found withR. abortivus, one was identified asA. gallica and two asA. jezoensis. The isolates ofR. abortivus showed excellent mycelial growth and rhizomorph formation on PDA. However, on MDA, RMDA and BMDA, they showed poor aerial mycelia growth and no rhizomorphs. In the contrapositional cultures, the growth ofA. gallica was completely inhibited byR. abortivus on PDA but only slightly inhibited on MDA and RMDA. On the other hand, mutual inhibition at a distance was observed on BMDA. The mycelial growth and rhizomorph formation inA. jezoensis were severely inhibited by the colony ofR. abortivus on PDA, but only slightly inhibited on MDA. On RMDA and BMDA, the colonies of twoArmillaria species andR. abortivus showed mutual inhibition at a distance and apparent rhizomorph formation by bothArmillaria species.     

Addition and re-examination of Japanese species belonging to the genus <Emphasis Type="Italic">Cercospora </Emphasis>and allied genera. V. Collections from the Nansei Islands (2)

 Five species collected in the Nansei Islands are discussed. Of these, one species found on Gardenia jasminoides is described as a new species, Cercosporidium okinawaense Kobayashi et Nishijima. Asperisporium caricae on Carica papaya, Pseudocercospora melastomobia on Melastoma candidum, and P. neoliquidambaris Nakashima et Kobayashi, nom. nov. on Liquidambar formosana are newly added to the Japanese mycoflora. Cercospora violamaculans on Rhaphiolepis umbellata is transferred to the genus Pseudocercospora as Pseudocercospora violamaculans (Fukui) Kobayashi et Nakashima, comb. nov., with some additional notes. Received: October 26, 2001 / Accepted: March 13, 2002     

Rust fungi in the subantarctic islands of New Zealand

Twenty-four species of rust fungi known from Auckland Islands and Campbell Island are listed, together with details of their host plants. Several species are recorded for the first time in these subantarctic islands. Four species are newly described and illustrated, viz., Milesia polystichi-vestiti on Polystichum vestitum (Dryopteridaceae), Petersonia dracophylli on Dracophyllum longifolium (Epacridaceae), Puccinia austrina on Isolepis habra (Cyperaceae), and Puccinia chathamica on Carex trifida (Cyperaceae). Uredo inflatus is transferred to Uromyces (as Uromyces inflatus comb. nov.) following recognition of the spores on Anisotome latifolia (Apiaceae) as teliospores.     

Biological performance of Myzus persicae and Macrosiphum euphorbiae (Homoptera: Aphididae) on seven wild Solanum species

Resistance level of seven accessions of wild Solanum species (Solanaceae) to Myzus persicae and Macrosiphum euphorbiae (Homoptera: Aphididae) was evaluated by measuring survival and fecundity during sleeve cage experiments and population growth on whole plants in a controlled environment. The survival was lowest on the Solanum circaeifolium spp. capsicibaccatum, Solanum pinnatisectum and Solanum trifidum accessions for M. persicae and on the S. circaeifolium spp. capsicibaccatum, Solanum okadae and S. trifidum, accessions with M. euphorbiae. Plant species significantly influenced the fecundity of both aphid species. Aphid population growth on whole plants was negatively affected by the age of the plant, but generally followed the levels of net reproductive rate on different plant species observed during the sleeve cage experiment. The population of M. persicae varied among the seven wild potato accessions with the lowest growth rates on S. circaeifolium spp. capsicibaccatum, Solanum polyadenium, Solanum tarijense and S. trifidum. The number of M. euphorbiae also varied among accessions but the smallest population was collected from S. polyadenium. The results can be used to identify sources of resistance to aphids within those accessions already known to be resistant to the Colorado potato beetle. This study highlights the difficulties involved in developing a high-throughput screening test for aphid resistance compatible with a potato breeding programme.     

Population growth of Asplanchna sieboldi fed two Brachionus spp. (Rotifera) raised on green alga and baker's yeast

We conducted population growth experiments of A. sieboldi using Brachionus calyciflorus and Brachionus patulus as prey. The prey rotifers were mass cultured separately on Chlorella vulgaris, Saccharomyces cerevisiae or on their mixture. Data on population growth of A. sieboldi showed prey type and food density-related differences. At any given prey concentration, both B. calyciflorus and B. patulus raised on a mixture of alga and yeast, resulted in higher abundance of the predator than those raised solely on alga or yeast. The rate of population increase per day (r) of A. sieboldi increased with increasing prey density for both prey species. However, predators grown on B. patulus showed higher r values compared to those grown on B. calyciflorus.     

Oviposition preference and larval performance of the sweet potato butterfly Acraea acerata on Ipomoea species in Ethiopia

• 1 The sweet potato butterfly Acraea acerata is an indigenous species in Ethiopia that has become a major pest on the introduced sweet potato Ipomoea batatas. To assess the role of wild Ethiopian Ipomoea species as host plants, the presence of larvae on wild ipomoeas was studied, and female oviposition choice and larval performance were tested on five wild ipomoeas, as well as on sweet potato.
• 2 In laboratory tests, oviposition and larval development were successful on two wild ipomoeas (Ipomoea tenuirostris and Ipomoea cairica) but no oviposition occurred on the remaining three species. Of the latter, larvae did not feed on Ipomoea hochstetteri and Ipomoea indica, and survival rates were extremely low on Ipomoea purpurea.
• 3 Sweet potato was a better host plant than I. tenuirostris and I. cairica in terms of oviposition preference, larval survival and pupal size; pupae were larger, resulting in more fecund female butterflies.
• 4 In the wild butterfly populations were abundant on I. tenuirostris but absent on I. cairica. Females also tended to prefer I. tenuirostris to I. cairica in oviposition choice experiments. However, no significant differences in performance were found between larvae raised on I. tenuirostris and I. cairica in the laboratory.
• 5 Wild populations of A. acerata also existed on Ipomoea obscura, a plant not investigated in the present study.
• 6 The abundance of A. acerata on wild ipomoeas is too low to likely affect butterfly population densities on sweet potato. However, wild populations may act as reservoirs subsequent to butterfly population bottlenecks on sweet potato.