Activity patterns and egg production in Coccophagus bartletti, an aphelinid parasitoid of scale insects

ABSTRACT.

• 1 Daily patterns of oviposition and host-feeding were examined in Coccophagus bartletti Annecke & Insley. Females began to host-feed and oviposit during the second or third day after emergence. Thereafter, both activities occurred regularly.
• 2 During long observation periods (5 h) most oviposition (93%) and host-feeding (90%) occurred within the first 3.5 h of wasps first encountering hosts. Experiments demonstrated that levels of activity were low for the rest of the day, and nocturnal oviposition occurred only if wasps had no alternative.
• 3 Dissection of female wasps that had been exposed to hosts, or withheld from them, for given periods of time, revealed that activity levels are governed by egg availability. Dispersal activity may also be influenced by the physiological state of the ovaries.
• 4 Production of a full complement of eggs (at 24±1°C (12 h L) and 18±1°C (12 h D)) took 48h or longer after host-feeding, and if wasps were withheld from hosts and provided with honey, the effects of egg resorption could be detected after about 10 days. Trends in oögenesis and oösorption in C. bartletti females seem not to conform with interpretations of oögenesis-oösorption cycles in other parasitoids.
• 5 The pattern of activity exhibited by C. bartletti females is not inflexible, but the major aspects mentioned above are species-specific. In general, information is needed about daily and hourly patterns of parasitoid oviposition and host-feeding before experiments are designed to test theories of parasitoid behaviour. Interpretation may otherwise rest on assumptions about their physiological condition.

     

Plasmalemma- and tonoplast-ATPase activity in mesophyll protoplasts,vacuoles and microsomes of the Crassulacean-acid-metabolism plant Kalanchoe daigremontiana

Adenosine-triphosphatase activity on the plasmalemma and tonoplast of isolated mesophyll protoplasts, isolated vacuoles and tonoplast-derived microsomes of the Crassulacean-acid-metabolism plant Kalanchoe daigremontiana Hamet et Perr., was localized by a cytochemical procedure using lead citrate. Enzyme activity was detected on the cytoplasmic surfaces of the plasmalemma and tonoplast. The identity of the enzymes was confirmed by various treatments differentiating the enzymes by their sensitivity to inhibitors of plasmalemma and tonoplast H⁺-ATPase. Isolated vacuoles and microsomes prepared from isolated vacuoles clearly exhibited single-sided deposition on membrane surfaces.Abbveviations CAM Crassulacean acid metabolism - H⁺-ATPase proton-translocating ATPase     

Correlation of immunomodulatory and therapeutic activities of interferon and interferon inducers in metastatic disease

The mechanism of therapeutic activity of recombinant murine interferon-gamma (rMu IFN-gamma) and the IFN inducer polyinosinic-polycytidylic acid solubilized with poly-L-lysine in carboxy methyl cellulose (pICLC) in treating metastatic disease was investigated by comparing effector cell augmentation with therapeutic activity in mice bearing experimental lung metastases (B16-BL6 melanoma). Effector cell functions in spleen, peripheral blood, and lung (the organ with tumor) were tested after 1 and 3 weeks of rMu IFN-gamma or pICLC administration (intravenous, three times a week). In these studies, natural killer (NK), lymphokine-activated killer (LAK), cytolytic T lymphocytes (CTL) (against specific and nonspecific targets), and macrophage tumoricidal and tumoristatic activities were measured. rM IFN-gamma and pICLC had therapeutic activity and immunomodulatory activity in most assays of immune function examined. Specific CTL activity of pulmonary parenchymal mononuclear cells (PPMC), but not in splenocytes or peripheral blood lymphocytes (PBL), during week 3 and not during week 1, correlated with the therapeutic activity of rMu IFN-gamma and of pICLC. Macrophage tumoricidal activity in PPMC, but not in alveolar macrophages, also correlated with the therapeutic activity of rMu IFN-gamma, but the opposite was true for the therapeutic activity of pICLC. NK activity of PPMC, but not of splenocytes or PBL, during week 1 correlated with the therapeutic activity of pICLC; in contrast, NK activity at any site did not correlate with the therapeutic activity of rMu IFN-gamma. LAK activity at any site did not correlate with the therapeutic activity of either agent.     

The ecology of a beech forest on Mt. Sanpoiwadake,Hakusan National Park,Japan II. The correlation of the subassociation within the Lindero membranaceae-fagetum crenatae association and environmental parameters

Detailed examination of a sample plot covered by the Lindero membranaceae-Fagetum crenatae association on Mt. Sanpoiwadake, Hakusan National Park, revealed a number of correlations between the distribution of subassociations and environmental factors. The subassociations on the south-facing slopes receive deep snow cover in winter with rapid melting in the spring. They occur on porous, freely draining soils, typical of the general range of brown forest soils. Conversely, on the north-eastern slopes there are widespread late-snow patches which delay leaf development and expansion and which provide an abundant water supply well into early summer. Under these conditions, bleached soil horizons have developed with iron pan formation, resulting in poor soil drainage, strongly correlated with quite different plant communities.     

Microbeam analysis of Ca exchange and uptake in the fine roots of spruce: influence of pH and aluminum

Summary A novel stable isotope labelling procedure for microbeam analysis was developed to monitor exchange and uptake of nutrients, primarily Mg, K and Ca, by root tips at the cellular level. Initially root samples were analysed from 2-year-old spruce trees, originating both from a nursery and from a polluted forest site, (1) for the cortex cell wall accessibility and nutrient binding properties, (2) for the influence of low pH and elevated aluminum concentrations on Ca binding to cortex cell walls, and (3) for long-range transport into the secondary xylem, proximal to the labelled root tip. In nursery control plants, Ca is localized mainly in the apoplast of the cortex. Exchange of Mg, K, Ca in the cell wall of the cortex and the primary xylem with label in incubation solutions is almost completed to equilibration within 30 min. In the secondary xylem we could detect Mg, K, and Ca from labelling solutions in minute amounts after 30 min, and as a major fraction after 48 h. This indicates that stable isotope labelling can be used to study both ion-exchange properties of the apoplast and long-range transport. Slight acidification of the labelling incubation media to pH 4.5 reduced Ca binding to the cortex cell walls slightly, but acidification to the extreme value of pH 2.3 reduced binding 41%. A combination of pH 4.5 and increased free aluminum reduced the binding by 83%. In a preliminary attempt to analyse the nutrient binding capability of the root-tip apoplast from pollution affected trees, we exposed fine roots of 2-year-old spruce from an acidified and polluted site showing typical low levels of Ca and Mg in the cortical cell walls to Ca-enriched media. Under these conditions the Ca content of cortex cell walls doubled upon incubation at pH 4.7, reaching 40% of the total binding capacity of our nursey control plants.     

Major and trace elements in the twig axes of Norway spruce and the relationship between twig axis and needles

Summary The concentrations of 23 elements have been determined by instrumental neutron activation analysis in the needles and axes of 1-year-old spruce twigs from 12 different sites. Although the twigs had been washed with toluene and tetrahydrofuran prior to analysis, it was found that the amounts of eight elements (Al, Cr, Eu, Fe, La, Sc, Th and V) present were predominantly due to aerosol particles still being retained on the surface of the axes. The results of the remaining 15 elements (Ba, Br, Ca, Cl, Co, Cs, Hg, K, Mg, Mn, Na, P, Rb, Sr and Zn) were not or only slightly influenced by this effect and are considered to represent their inherent concentrations within the axes. With most of these latter 15 elements there are highly significant and linear correlations between the concentrations in the needles and in the axis, which testify to the great similarity of needles and axis of a twig. The axis/needles ratios are constant for every element (except K), but the individual elements show considerable differentiation, as evidenced by their ratios, which have values between 0.5 and 2.8. Inter-element correlations in the axes are mainly found within two groups of elements. With Na, Cl and Br these correlations are probably due to different pollution levels of the different sites, whereas with Mn, Co, Rb and Cs they are due to the pH of the soil. The activity of ¹³⁷Cs from the Chernobyl fallout represents independent confirmation of the results obtained with the stable elements. With twigs sprouted before the deposition of the fallout, ¹³⁷Cs acts as a tracer for aerosol particles, whereas it forms a tracer for the stable Cs inherent to the plant with twigs sprouted after the deposition.     

Experimental formulations ofBacillus sphaericus for the control of anopheline and culicine larvae

Summary Four experimental formulations ofBacillus sphaericus Neide (2362 isolate) were evaluated for larvicidal activity against culicine and anopheline larvae in several natural and artificial habitats. A granular formulation (5% primary powder) was tested against natural populations of mosquitoes in two simulated habitats in Florida and in maturing and reflooded rice fields in Louisiana. Larvae ofCulex quinquefasciatus Say were reduced by 97 and 99% after application of the granules at the rate of 10 kg/ha to polluted tanks and 2.5 kg/ha to sod-lined potholes, respectively. Anopheline andPsorophora columbiae (Dyar and Knab) larvae were reduced by 68 and 92–100%, respectively, after application of 5 kg granules/ha to rice fields. A flowable concentrate (12.8% primary powder) applied to unpolluted and organically enriched habitats in Florida at 0.25 kg/ha reduced populations ofCulex spp. by 93–100% and 99%, respectively. Sustained-release briquets (5% primary powder) applied at the rate of one half briquet/1.8 m² sod-lined potholes reduced larval populations ofCx. quinquefasciatus by 88–95% for up to 2 weeks in open sunlight. Sustained-release pellets (30% primary powder) applied to small woodland pools in Memphis, TN at the rate of four pellets/pool virtually eliminated larval populations ofCx. restuans Theobald for over 8 days. Variable persistance of larvicidal activity was noted for the other treatments depending on the formulation, target species and habitat.     

An inexpensive insoluble chromogenic substrate for the determination of proteolytic activity

Summary A new insoluble chromogenic substrate for the determination of proteolytic activity was developed. This substrate was prepared by incorporating black drawing ink into casein and heating this complex at 200°C for 4 h. It is especially suitable for determining the activity of alkaline bacterial proteinases.     

A hypothesis on p34cdc2 sequestration based on the existence of Ca(2+)-coordinated changes in H+ and MPF activities during Xenopus egg activation [corrected]

The entry into, and exit from, mitosis are controlled by a universal M-phase promoting factor (MPF) composed of at least p34cdc2 and a cyclin. Embryonic systems are convenient for studying the association and dissociation of the active MPF complex because oocytes and eggs are naturally arrested at a specific point of the cell cycle until progression to the next point is triggered by a hormonal signal or sperm. In amphibians, eggs prior to fertilization are arrested at metaphase 2 of meiosis due to the presence of a stabilized MPF complex. Fertilization (egg activation) produces a transient increase in intracellular free Ca2+, a propagating Ca2+ wave, that specifically triggers the destruction of cyclin, leading to MPF inactivation and entry into the first embryonic inter-phase. We have recently shown that intracellular pH (pHi) variations in amphibian eggs, a large increase at fertilization and small oscillations during the embryonic cell cycle, were temporally and functionally related to the corresponding changes in MPF activity. In addition, the recent finding that the pHi increase at fertilization in Xenopus eggs is a propagating, Ca(2+)-dependent pH wave which closely follows the Ca2+ wave, together with the absence in the egg plasma membrane of pHi-regulating systems responsible for that pHi increase, suggest the existence of cortical or subcortical vesicles acidifying in the wake of the Ca2+ wave, thus producing the pH wave.(ABSTRACT TRUNCATED AT 250 WORDS)