Darting and marking techniques for an arboreal forest monkey,Cercopithecus ascanius

Techniques are described for capturing and marking redtail monkeys (Cercopithecus ascanius). An air-powered darting rifle and syringe darts loaded with a Ketamine-Rompun mixture were used for capture. Ketamine was used for maintaining anesthesia. Monkeys were darted 48 times and captured 27 times. In 24 of the 27 captures, the monkeys were released unharmed. Adult males were marked with radiotransmitters attached to collars of nylon webbing. Females received nylon webbing collars with colorcoded plastic washers for identification.     

Coordinate induction of electrophoretic variants of juvenile hormone esterase

Major and minor electrophoretic variants of juvenile hormone esterase (JHE) were found in the hemolymph of last instar larvae of Trichoplusia ni, both before and after metamorphic commitment. The average ratios of activity of the two major forms were similar during both last stadium peaks in activity. Immunological analysis showed that the hemolymph concentration of JHE during this stadium paralleled the level of enzymatic activity, and no putative higher molecular weight, inactive forms were detected. Immunological analysis provided the first evidence of relatedness of major and minor forms. After hormonal stimulation, the concentration of the two major forms increased concomitantly and by a similar proportion, suggesting that charge variation, at least for these two major forms, is not a point of hormonal or developmental regulation of JHE.     

Cell wall residues in yeast protoplast preparations

Protoplast preparations made from Saccharomyces cerevisiae by prolonged treatment with snail digestive juice contained fibrils and chitinous bud-scar residues from the original cell wall.     

Actinomycin synthesis in Streptomyces antibioticus. Purification and properties of a 3-hydroxyanthranilate 4-methyltransferase

A methyltransferase, which utilizes 3-hydroxyanthranilic acid (HAA) as a substrate, has been purified to near homogeneity from 30-36-h mycelium of the bacterium Streptomyces antibioticus. The enzyme was obtained in approximately 20% yield with a purification of 130-fold. Polyacrylamide gel electrophoresis under denaturing conditions indicates that the enzyme is composed of a single subunit with Mr of about 36,000. On chromatography in 0.5 M NaCl, the enzyme displays a molecular weight of about 37,000. The specific activity of the enzyme in S. antibioticus mycelium is maximal between 30 and 36 h following inoculation of galactose/glutamic acid medium and, at those times post-inoculation, the specific activity is essentially the same in extracts of mycelium obtained from cultures grown on glucose rather than galactose as the carbon source. The enzyme activity is stimulated by Na2EDTA (in crude extracts) and by 2-mercaptoethanol and the methyltransferase shows a strong preference for HAA as substrate as compared with a number of HAA analogs. Thin layer chromatography of ethyl acetate extracts of large-scale incubation mixtures confirms that the product of the reaction is 4-methyl-3-hydroxyanthranilic acid. The reaction product was also a substrate for phenoxazinone synthase and was incorporated into actinomycin by S. antibioticus mycelium. Kinetic parameters for the methyltransferase reaction was determined.     

Coexistence of natural enemies in a multitrophic host–parasitoid system

Abstract.  1. This study explored the temporal and spatial aspects of coexistence over many generations in a multispecies host–parasitoid assemblage.
2. The long-term interaction between the cabbage root fly, Delia radicum (Diptera: Anthomyiidae), and two of its natural enemies, Trybliographa rapae (Hymenoptera: Fitigidae) and Aleochara bilineata (Coleoptera: Staphylinidae), in a cultivated field at Silwood Park over 19 years was explored.
3. Although time series showed that the populations were regulated, the impact of the natural enemies was highly variable. Within-year determinants showed that the spatial response of the specialist parasitoid, T. rapae , was predominantly independent of host density while A. bilineata acted simply as a randomly foraging generalist parasitoid.
4. These findings are compared and contrasted with an earlier investigation of the same system when only the first 9 years of the time series were available. This study demonstrated the potential of long-term field studies for exploring hypotheses on population regulation, persistence, and coexistence.