Slow continuous wing-moult of Zebra Finches Poephila guttata from southeast Australia

Moult of the remiges was studied over eight years in a population of Zebra Finches from southeast Australia. In first-year birds the first primary was lost at mean age of 80 days in both sexes; moult took 204 days to complete in males and 223 in females. Birds hatched in autumn postponed the start of their primary moult until spring. Primaries were replaced slowly in a rigid, non-overlapping, ascending order from #1 to #9 but the secondaries did not display a rigid sequence.
Adult Zebra Finches moulted remiges throughout the year. Primary moult was initiated in any month. Primary moult had a mean duration of 229 days for males and 240 days for females. Primaries moulted in continuous waves: the interval between successive moults in males was –16 days and +6 days in females. Limited food, low temperatures and breeding slowed, but did not stop, wing-moult. Birds caring for eggs and young actively replaced remiges.
The pattern of wing-moult displayed here by Zebra Finches is exceptional for passerines and may be related to the opportunistic breeding strategy necessary in an arid, unpredictable environment. Its presence in the Victorian birds may be non-adaptive.     

AN EMPIRICAL COMPARISON OF NUMERICAL WAGNER COMPUTER PROGRAMS

Abstract— The performance of four computer programs that calculate Wagner trees (WAGNER 78, WAGPROC, PHYLIP, and PHYSYS) was compared for twenty-five data sets. Eight combinations of algorithms and options were tried, including different methods of adding taxa, optimizing stem states, obtaining multiple trees, and branch swapping. Using the criterion of finding a minimum length tree, PHYSYS with the WAG.S option performed best, providing the shortest tree for twenty-four of the twenty-five data sets. WAGPROC with the GLOB option found sixteen minima for eighteen data sets, exceeding run time on the remaining seven. All other algorithm/options were less successful in providing minimum trees. In comparing the options we found that minimum homoplasy is not completely reliable in optimizing trees and that the brute force algorithm is helpful but not required for finding minimum trees. The advancement index criterion for adding taxa to a tree is more effective than adding taxa in their data file sequence. The success of the PHYSYS WAG.S option and the WAGPROC GLOB demonstrate that both multiple trees and branch swapping are necessary to produce a minimum length tree.     

The cytotoxic and photodynamic inactivation of micro-organisms by Rose Bengal

Rose Bengal was cytotoxic to the following bacteria at the concentrations given in parentheses (highest concentrations of dye in mol/1 at which growth occurred on nutrient medium): Brochothrix thermosphacta and Deinococcus radiodurans (1 times 10^-6 or less); Streptococcus, Micrococcus, Staphylococcus, Bacillus, Arthrobacter and Kurthia spp. (1 times 10^-5–1 x 10^-4), and Pseudomonas spp. and Enterobacteriaceae (5 times 10^-3–1 x 10^-2 or greater). These organisms were killed rapidly when suspended in illuminated (170 μE/m²/s) solutions of Rose Bengal (1 times 10^-4 mol/1) providing oxygen was present. Singlet oxygen was identified as the lethal agent, because the rate of killing was increased by dissolving the dye in deuterium oxide while the organisms were protected against photoinactivation by L-histidine or crocetin. Yeasts from chilled foods were killed in illuminated solutions of Rose Bengal but a light intensity of 315 μE/m²/s was needed for a death rate comparable with that of bacteria. The yeasts present in a range of chilled meat and dairy products failed to form colonies on Rose Bengal (5 times 10^-5 mol/1) media exposed continuously to modest illumination (55–80 μE/m²/s).     

Effects of fungicide spray regimes on incidence of dicarboximide resistance in grey mould (Botrytis cinerea) on strawberry plants

In tunnel experiments, the efficacy of dicarboximide sprays in controlling grey mould of strawberries was greatly decreased by the presence of dicarboximide-resistant forms of Botrytis cinerea. The use of dichlofluanid, as a tank-mix or in an alternating programme, with a dicarboximide fungicide, procymidone, helped to maintain the efficacy of disease control but failed to prevent an increase in the proportion of dicarboximide-resistant forms of the pathogen. Alternative ‘partner’ fungicides (thiram, chlorothalonil) delayed build-up of resistance to dicarboximides. Build-up of resistance was absent or relatively small in unsprayed plots. Application of dichlofluanid alone was always associated with a substantial increase in dicarboximide resistance, although less than in procymidone-treated plots. Monitoring dicarboximide resistance in the tunnels during the winter, when no further sprays were applied, revealed a gradual decline in the proportion of dicarboximide-resistant forms in all previously treated plots. In laboratory studies on inoculated leaf debris, dichlofluanid treatment induced the build-up of dicarboximide-resistant forms of B. cinerea. Leaf-disc tests revealed cross-resistance of dicarboximide-resistant isolates towards dichlofluanid but not towards thiram or chlorothalonil. Dichlofluanid is widely used for control of B. cinerea and the implications of these results for the practical management of dicarboximide resistance in this pathogen are discussed.     

An outline of a revised classification of Saxifraga L.

GORNALL, R. J., 1987. An outline of a revised classification of Saxifraga. A revised classification of Saxifraga is presented in which 15 sections, 19 subsections and 34 series are recognized. A total of 394 names are accounted for, including the following new taxa, combinations and names: series Hirculoideae (Engler & Irmscher) Gornall, stat. nov.; series Lychnitidae (Engler & Irmscher) Gornall, stat. nov.; series Nulanles (Engler & Irmscher) Gornall, stat. nov.; series Cinctae (H. Sm.) Gornall, stat. nov.; series Gemmiparae (Engler & Irmscher) Gornall, stat. nov.; series Spinulosae (C. B. Clarke) Gornall, stat. nov.; subsection Rosulares Gornall, nom. nov.; subsection Serpyllifoliae Gornall, subscct. nov.; subsection Hemisphaericae (Engler & Irmscher) Gornall, stat. nov.; section Merkianae (Engler & Irmscher) Gornall, stat. nov.; subsection Stellares (Engler & Irmscher) Gornall, stat. nov.; series Birostres Gornall, ser. nov.; series Melanocentrae (Engler & Irmscher) Gornall, stat. nov.; series Astasianlhes (Sternberg) Gornall, stat. nov.; subsection Micranthes (Haworth) Gornall, stat. nov.; series Aulaxis (Haworth) Gornall, stat. nov.; series Dermasea (Haworth) Gornall, stat. nov.; series Micranthes (Haworth) Gornall, stat. nov.; scries Aretioideae (Engler & Irmscher) Gornall, stat. nov.; series Juniperifoliae (Engler & Irmscher) Gornall, stat. nov.; series Lilacinae Gornall, ser. nov.; series Marginatae (Engler & Irmscher) Gornall, stat. nov.; series Squarrosae (Engler & Irmscher) Gornall, stat. nov.; series Rigidae (Engler & Irmscher) Gornall, stat. nov.; subsection Engleria (Siindermann) Gornall, stat. nov; series Subsessiliflorae Gornall, ser. nov.; series Oppositiofoliae (Hayek) Gornall, stat. nov.; series Tetrameridium (Engler) Gornall, stat. nov.; subsection Mutatae (Engler & Irmscher) Gornall, stat. nov.; subsection Florulentae (Engler & Irmscher) Gornall, stat. nov.; section Odontophyllae Gornall, sect, nov.; series Biternatae (Engler & Irmscher) Gornall, stat. nov.; subsection Triplinervium (Gaudin) Gornall, stat. nov.; series Arachnoideae (Engler & Irmscher) Gornall, stat. nov.; subsection Tridactylites (Haworth) Gornall, stat. nov.     

Novobiocin-Induced Ultrastructural Changes and Antagonism of DNA Synthesis in Trypanosoma cruzi Amastigotes Growing in Cell-Free Medium

The antimicrobial agent novobiocin, an inhibitor of the bacterial enzyme topoisomerase II (DNA gyrase), is known to antagonize Trypanosoma cruzi amastigotes growing in cell-free medium. To determine sites of antagonism of novobiocin, the effects of drug on parasite ultrastructure and incorporation of radiolabeled precursors of DNA, RNA and protein into macromolecules were determined. The predominant ultrastructural abnormality seen after exposure to 0.40 mM novobiocin for 24 h was the presence of electron-dense clumps in the mitochondrion-kinetoplast organelle in 95 of 257 (37%) of cells, in comparison to no clumps seen in 110 drug-free cells. In addition, in the nucleus, the karyosome was less distinct than in control cells and appeared to merge with the chromatin. In the radiolabcling studies, incorporation of thymidine was inhibited in a dose-dependent fashion by novobiocin (0.16–0.80 mM) in a range of drug concentrations that also inhibited parasite growth. For 0.16 and 0.24 mM novobiocin, incorporation of thymidine was inhibited up to 65% relative to drug-free control cells while uptake of uridine and leucine was unaltered. We interpret these ultrastructure and precursor-incorporation studies as suggesting that (i) the mitochondrion-kinetoplast and possibly the nucleus are sites of novobiocin antagonism of T. cruzi amastigotes and (ii) that novobiocin appears to antagonize DNA synthesis within these organisms. Whether the drug target is topoisomerase II, however, is as yet unknown.     

Sexual dimorphism in snake tail length: sexual selection,natural selection,or morphological constraint?

Male snakes typically have longer tails relative to body length than females, but the extent of this dimorphism varies among species. Three hypotheses have been suggested to explain tail dimorphism. The Morphological Constraint Hypothesis proposes that males have relatively longer tails to accommodate hemipenes and retractor muscles. The Female Reproductive Output Hypothesis proposes that females have relatively shorter tails as a secondary result of natural selection for increased reproductive capacity. The Male Mating Ability Hypothesis proposes that sexual selection favours relatively longer tails in males during courtship. These hypotheses make different predictions about the relationships among tail length, body size, male reproductive morphology, female reproductive output, mode of reproduction, and male mating behaviour among and within taxa. Predictions were tested using published data for 56 genera in the family Colubridae and original data for the water snake, Nerodia sipedon. Tail length dimorphism was more male-biased in tam having relatively short tails (r=–0.52, P < 0.001), hemipenes and retractor muscles occupied a greater proportion of the tail in taxa having relatively short tails (r=– 0.71, P < 0.00l and r=– 0.66, P = 0.001, respectively), and tail length dimorphism was more male-biased in taxa in which body size dimorphism was more female-biased (r=– 0.60, P < 0.001). These results support both the Morphological Constraint Hypotheses and the Female Reproductive Output Hypothesis. However, tests of other predictions, including those regarding patterns within N. sipedon , failed to support any of the three hypotheses. Comparisons among taxa suggest several species in which further tests of these hypotheses would be especially appropriate.     

Euphorine phylogeny: the evolution of diversity in host-utilization by parasitoid wasps (Hymenoptera: Braconidae)

ABSTRACT.

• 1 New data on the phylogeny of the braconid subfamily Euphorinae supports the hypothesis that parasitism of adult insects by Euphorinae originated during parasitism of Chrysomelidae, a group whose larvae are ecologically coincident with adults.
• 2 Evolution of the habit of attacking the adult stage opened a new adaptive zone; subsequently the Euphorinae have diversified on to a phylogenetically greater variety of hosts than any other braconid subfamily.
• 3 Parasitism of eumastacid grasshoppers evolved from beetle parasitism in the tribe Perilitini.
• 4 The tribe Euphorini shows the greatest diversity of hosts utilized. Most attack Heteroptera; however, Chrysopopthorus diversified on to adult Chrysopidae, Euphoriella on to Psocoptera, and Cryptoxilos on to Scolytidae.
• 5 Parasitism of bark beetles (Scolytidae) has evolved independently in three genera: Cosmophorus, Cryptoxilos and Ropalophorus. This is the most specialized form of beetle parasitism by euphorines, since it involves direct parasitism of concealed hosts.
• 6 Parasitism of adult hymenopterans by the tribe Syntretini may be related to attacking hosts while they are foraging at flowers.
• 7 The pattern of diversification in the Euphorinae indicates several adaptive radiations within host orders, as well as a history of major host-shifts between phylogenetically distantly-related host groups: Coleoptera to Orthoptera; Coleoptera to Hymenoptera; Coleoptera to Heteroptera; Heteroptera to Neuroptera, Psocoptera, and back to Coleoptera. Both the‘host taxonomy’and‘host habitat’hypotheses of host-shifting are supported. Host-shifts have involved hosts occurring in the same micro-habitat and usually having similar feeding habits. This is consistent with current theory of host-location by means of host-produced kairomones and visual cues.