Breeding system, colony and population structure in the weaver ant Oecophylla smaragdina

Weaver ants ( Oecophylla smaragdina ) are dominant ants in open forests from India, Australia, China and Southeast Asia, whose leaf nests are held together with larval silk. The species, together with its sole congener O. longinoda , has been important in research on biological control, communication, territoriality and colony integration. Over most of the range, only one queen has been found per colony, but the occurrence of several queens per nest has been reported for the Australian Northern Territory. The number of males mating with each queen is little known. Here we report on the colony structure of O. smaragdina using published and new microsatellite markers. Worker genotype arrays reflect the occurrence of habitual polygyny (more than one queen per colony) in 18 colonies from Darwin, Northern Australia, with up to five queens inferred per colony. Monogyny (one queen per colony) with occasional polygyny was inferred for 14 colonies from Queensland, Australia, and 20 colonies from Java, Indonesia. Direct genotyping of the sperm carried by 77 Queensland queens and worker genotypic arrays of established colonies yielded similar results, indicating that less than half of the queens mate only once and some mate up to five times. Worker genotype arrays indicated that queens from Java and the Northern Territory also often mate with more than one male, but less often than those from Queensland. A strong isolation-by-distance effect was found for Queensland samples. The variation uncovered means that O. smaragdina is a more versatile study system than previously supposed.     

Microsatellite primers for Ficus racemosa and Ficus rubiginosa

We developed 11 polymorphic microsatellite loci each for the figs Ficus (Sycomorus) racemosa and Ficus (Urostigma) rubiginosa from AG‐ and TG‐enriched genomic libraries. These 22 loci were investigated for cross‐species amplification and polymorphism in 17–21 F. racemosa and 16–24 F. rubiginosa individuals from Townsville, Australia. Observed heterozygosities range from 0.12 to 0.90 in F. racemosa and from 0.25 to 1.0 in F. rubiginosa.     

Isolation and characterization of eight microsatellite loci in the mangrove mud‐nesting ant,Polyrhachis sokolova

We isolated and characterized eight anonymous microsatellite loci in the mangrove mud‐nesting ant, Polyrhachis sokolova. Three to 18 alleles were detected in 20 female workers collected from individual colonies at one location and observed heterozygosities ranged from 0.45 to 0.85. These microsatellite loci will be useful in studies on mating strategy, colony and population structure in P. sokolova.     

Metabolism of [14C]Indole-3-Acetic Acid by Coleoptiles of Zea mays L.

Reverse-phase high-performance liquid chromatography was usedto analyse [¹⁴C]-labelled metabolites of indole-3-acetic acid(IAA) in coleoptile segments of Zeo mays seedlings. After incubationfor 2 h in 10^–2 mol m^–3 [2-¹⁴C]IAA, methanolic extractsof coleoptiles contained between six and ten radioactive compounds,one of which co-chromatographed with IAA. The metabolic productsin coleoptile extracts appeared to be similar to those in rootextracts, with an oxindole-3-acetic-acid-like component as theprincipal metabolite, but the rate of metabolism was slowerin coleoptile than in root segments. Decarboxylation did notappear to play a major role in the metabolism of exogenous IAAduring the short incubation periods. Moreover, external IAAconcentration had little effect on the pattern of metabolism.Coleoptile segments were also supplied with [¹⁴C]IAA from agardonor blocks placed at the apical ends, and agar receiver blockswere placed at the basal ends. After incubation for 4 h, theidentity of the single radioactive compound in the receiverblocks was shown to be IAA by both reverse-phase high-performanceliquid chromatography and gas chromatography-mass spectrometrytechniques. Key words: Zea mays, Coleoptile, High-performance liquid chromatography, Indole-3-acetic acid     

Do feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) compete for nest sites?

Abstract Surveys of nesting sites of feral honey bees (Apis mellifera) and regent parrots (Polytelis anthopeplus) were made in the red gum/black box woodlands of Wyperfeld National Park, Victoria, Australia. Data on tree species and size, and number of hollows were collected from all trees within seven 500 × 100m plots. Nest site characteristics were quantified for both bees and parrots. We found 27 feral honey bee colonies, suggesting a density of 77.1 colonies per km². The average occupation rate for bees was 1.3% of trees and 0.7% of available hollows. The height, aspect and entrance characteristics of honey bee nests at Wyperfeld were not qualitatively different to those reported elsewhere. We found 15 pairs of nesting regent parrots. Nest sites chosen by these birds overlapped those chosen by honey bees, but 52% of bee nests were in cavities unsuitable for regent parrots. We suggest that honey bee population growth may be limited in the park by a lack of water.     

The Development of a High Performance Liquid Chromatograph with a Sensitive On-stream Radioactivity Monitor for the Analysis of 3H- and 14C-labelled Gibberellins

The development of a high performance liquid chromatograph forthe separation of gibberellins is described. The system combineshigh efficiency, peak capacity, and sample capacity with rapidspeed of analysis. In addition, the constructional details ofa sensitive on-stream radioactivity monitor are outlined. Theoverall versatility of the chromatograph is demonstrated bythe separation of a range of ³H- and ¹⁴C-labelled Gibberellinsand gibberellin precursors. The system also has considerablepotential for the analysis of abscisic acid and acidic and neutralindoles.     

On the visibility of radiation at the human fovea

1. Seeing-frequency functions (ψ[S]) determined uniocularly for small (1.6'), brief images at the thoroughly dark-adapted human central fovea take the form of log-Gaussian integrals, for intensity or for exposure-time as the independent variable. They cannot be of Poisson type, since mean (τ') and standard deviation (σ) are quite independently modifiable. 2. The properties of τ', the abscissa of inflection in the log-Gaussian integrals, and of σ, are discussed in relation to customary determinations of spectral visibilities; agreements and certain necessary divergences are considered. 3. The values of σ_{logΔIlogΔI0}, are distributed periodically, with 5 maxima in the range λ383 to λ712. Outside the fovea this is not the case. These maxima, and the intervening minima, are definitely correlated with "irregularities" in the values of τ' as function of λ, with data on color threshold intensities, with data on "saturation," and quite specifically with minima and maxima in the data of λ discrimination. They are unmistakably of analytical significance. 4. The interpretation of these properties is taken to require (consistent with the indications of other evidence) that under specified conditions the magnitude of σ is a measure of the "size" of the population of excitable elements of neural effect, in the range of 0 to 100 per cent response-frequency as a function of wave number. This means that under the procedure used there is detectable the spectral distribution of local, specific, photosensitization. The σ's refer to a property of the excitation process which is not affected by the action of irrelevant absorbers. 5. A preliminary test of this has been made by the use of mixed "monochromatic" lights. The total energy is empirically the significant quantity, although the separate effects of λ's are sharply exhibited. 6. The λ distribution of photosensitization indices, σ_{logΔIlogΔI0}, is necessarily taken to have the nature of "action spectra." Careful search discloses, surprisingly enough, precise and apparently unique correspondence with the maxima and minima (and details of shape) required for the participation of: cytochrome-c reductase; the reduced forms of cytochromes-a and -c; and the often overlooked ferric-prophyrin bands of oxidized cytochrome-c. 7. For the central fovea, in which blood vessels are absent, and in which resistance to anoxia is at a maximum, the presence of an enzyme system of the sort here indicated is entirely reasonable. It is pointed out that a number of specific experiments can be based upon the general finding, whatever the causal mechanism for the sensitized λ regions may in the end prove to be. The data cannot be reconciled to the demands of existing color primary theories, although apparently quite accurately consistent with varied observational data.     

Effects of AMO-1618 on Growth, Morphology, and Gibberellin Content of Phaseolus Cocineus Seedlings

A study was made of the effects of AMO-1618 on the endogenousgibberellin (GA) levels and stem, leaf, and root growth of Phaseoluscoccineus seedlings. The data establishes that some of the effectsof AMO-1618 on the growth of Phaseolus seedlings are mediatedby factors other than an inhibition of GA biosynthesis.     

Effect of changes in nitrogen nutrition on the polyamine content of Alnus glutinosa

Abstract. The principal polyamines in Alnus glutinosa roots, nodules and root pressure sap, putrescine, spermidine and spermine, were quantified by reversed-phase, high-performance liquid chromatography with fluorescence detection following precolumn derivatization with 9-fluorenylmethyl chloroformate and 1-ada-mantanamine. Putrescine was the major component of all tissues and sap. It comprised 70% or more of the polyamine pool except in roots of KNO₃-fed plants, in which similar amounts of putrescine and spermidine were present at levels five-fold lower than plants fed (NH₄)₂SO₄. Polyamine levels in nodules were 50% greater than in roots. The polyamine content of roots and nodules was not altered significantly when the nitrogen nutrition was changed from sole reliance on nitrogen fixation to partial or complete utilization of (NH₄)₂SO₄. However, the polyamine content of root pressure sap from nodulated plants increased almost four-fold when they were fed with increasing concentrations of NH₄NO₃, although the total polyamine content remained low (5mmol m⁻³ sap). The polyamine content of the Alnus root system changed with plant age. In particular, the spermidine content of both roots and nodules was higher in 10- as compared to 16-week-old plants.     

Effects of light on the catabolism of [2-14C]-3-indole acetic acid in protoplasts, a chloroplast-rich fraction, and a crude cytoplasmic preparation from barley (Hordeum vulgare L)

Abstract. Combined gas chromatography-mass spectrometry has been used to identify 3-indole acetic acid in an extract from protoplasts of barley. In addition, a study has been made of the effect of light on the rate of catabolism of [2-¹⁴C]-3-indole acetic acid by protoplasts, a chloroplast-rich fraction and a crude cytoplasmic preparation from barley leaves. While light enhanced the rate of catabolism of [2-¹⁴C]-3-indok acetic acid by protoplasts and, to a lesser degree, by the chloroplast-rich fraction, it did not affect the catabolic activity of the crude, cytoplasmic fraction. These findings, when considered along with the data of Sandberg, Jensen & Crozier (1983), imply that the rate of turnover of 3-indole acetic acid, in both protoplasts and chloroplasts, is more rapid in light than it is in darkness.