Crepuscular activity of adult Sericesthis geminata (Coleoptera: Scarabaeidae): Influence of circadian rhythmicity and light intensity

Subterranean Sericesthis geminata (Boisduval) beetles emerge from the soil daily during the flight season. Emergence and flight are initiated within 15 min after sunset. The beetles are active above the soil surface as the intensity of illumination decreases from 240 lux to 0.7 lux.

If young adult beetles still in their pupal cells in the soil are placed under constant, low‐intensity illumination, they first emerge at any time of day, showing no cyclical diurnal activity pattern. When such beetles are exposed to diurnal fluctuations in illuminance, the first emergence and flight occur at dusk. These beetles subsequently show a diurnal rhythm in their activity, even when exposed to constant environmental conditions. This endogenous activity cycle has a period of about 22 h, and is synchronised with diurnal fluctuations in light intensity. It is reset in response to a change in the photoperiod.

The data suggest that, after initial emergence from the soil, daily crepuscular activity is initiated by an endogenously controlled activity rhythm which causes the beetles to burrow to the soil surface shortly before dusk. At the soil surface they are exposed to fluctuations in the duration and intensity of illumination which may reset the endogenous rhythm, affecting the time of subsequent emergence.     

Rapporti Fra Endosperma ed Embrione Nella Germinazione di Pinus Pinea L.: Nota i: Effetti del Grado di Maturità del Seme

Abstract

Endosperm embryo interrelationships during germination of PINUS PINEA L. 1rst note. — Seeds and excised embryos have been cultured in vitro in the dark. Experiments with ripe seeds and embryos have been paralleled with exper. with unripe ones (6 months before natural seed dispersal). The results are as follows:

Both ripe and unripe seeds germinate in the dark into green seedlings.

In both types of seedlings the rootlet is the only part which rapidly increases in length, actually growing, but the growth speed of the root is greater in ripe seeds than in the unripe ones.

Both ripe and unripe excised embryos grow slowly, with greenles cotyledons and dwarf roots, showing a very slight geotropic curve.

The root stops growing more sharply in ripe embryos than in unripe ones.

The hypothesis is raised that the rootlet reaches its full growing power, under the endosperm control, and that this control encreases more and more, as the seed approaches its full maturity.     

Differentiation of species of Terebratella (Brachiopoda: Terebratellinae)

Abstract

Terebratella sanguinea and T. incollSpicua have been differentiabed on foramen position and ornament. Further comparison shows that the valves of T. sanguinea are more strongly curved than those of T. inconspicua, a condition resulting in a longer pedicile, a larger beak, and hinge plates with greater elevation. The relationship between hinge plate ccndition and shell curvature is evident in other terebratellid genera.     

Laboratory rearing of potato cyst nematode; a method suitable for pathotyping and biological studies

A method is described for the laboratory rearing of potato cyst nematode, Globodera rostochiensis (Wollenweber, 1923) Mulvey & Stone, 1976 and G. pallida (Stone, 1973) Mulvey & Stone, 1976. Potato root systems were grown in 500 ml of sand in closed, clear plastic canisters. The enclosed system inhibited foliage growth and stabilised moisture balance. Root systems were sustained by the seed tubers, but supplementary nutrient was added. Potato cyst nematode eggs were inoculated into the sand after root initiation. At optimum rearing temperatures of 15–20°c the life cycle was completed within 8–12 weeks. The cyst‐to‐cyst multiplication factor was 10–20‐fold. The method has the advantage of not requiring light, and rearing canisters can be stacked in standard incubators. Its high reliability renders the method particularly suited to pathotype analysis.     

Monochromatic light increases anthocyanin content during fruit development in bilberry

Background

Light is one of the most significant environmental factors affecting to the accumulation of flavonoids in fruits. The composition of the light spectrum has been shown to affect the production of phenolic compounds during fruit ripening. However, specific information on the biosynthesis of flavonoids in fruits in response to different wavelengths of light is still scarce. In the present study bilberry (Vaccinium myrtillus L.) fruits, which are known to be rich with anthocyanin compounds, were illuminated with blue, red, far-red or white light during the berry ripening process. Following the illumination, the composition of anthocyanins and other phenolic compounds was analysed at the mature ripening stage of fruits.

Results

All the three monochromatic light treatments had significant positive effect on the accumulation of total anthocyanins in ripe fruits compared to treatment with white light or plants kept in darkness. The elevated levels of anthocyanins were mainly due to a significant increase in the accumulation of delphinidin glycosides. A total of 33 anthocyanin compounds were detected in ripe bilberry fruits, of which six are novel in bilberry (cyanidin acetyl-3-O-galactose, malvidin acetyl-3-O-galactose, malvidin coumaroyl-3-O-galactose, malvidin coumaroyl-3-O-glucose, delphinidin coumaroyl-3-O-galactose, delphinidin coumaroyl-3-O-glucose).

Conclusions

Our results indicate that the spectral composition of light during berry development has significant effect on the flavonoid composition of ripe bilberry fruits.

     

The relation between the occurrence of polysety and the number of archegonia in female inflorescences of Dicranum majus and D. scoparium.

Abstract

Inflorescences of Dicranum scoparium contain 7–9 archegonia on average compared with 13–15 in D. majus. In D. majus polysety was observed in 55% of fertile shoots. There is no evidence that the occurrence of polysety in D. majus is associated with any increase in the number of archegonia. This was interpreted to show that all inflorescences contained four or five ripe archegonia at the time of fertilization. Since monosetous inflorescences were more common than polysetous ones, it was concluded that the supply of antherozoids was not saturating for fertilization. In D. scoparium polysety was observed in only 5% of fertile shoots.     

Abstracts of papers and posters presented at the 33rd conference of the New Zealand society for Parasitology,at Massey University,Palmerston North, 24 October 2006

Abstract

Eight species of Recent Braohiopoda dredged from the fiords of south-western New Zealand in 1946 included first records for Fiordlarrd of Crania, Amphithyris, and Liothyrella. Amphithyris richardsonae n.sp. is described from a live-collected individual from 74 m, Long Sound, Preservation Inlet; it differs from A. buckmani Thomson and A. hallettensis Foster in shape, attachment, and details of ornament. Ventml valves fTom 101 m, Dagg Sound, characterised by coarse punctation and an ornament of hollow spines are treated as Platidiidae genus and species indeterminate.     

An analysis of the reproductive pattern in the sea star Astropecten irregularis (Pennant) from the Bristol Channel

Summary

The reproductive cycle in Astropecten irregularis is described, making use of a range of statistical techniques detailed previously. Analysis of gonad weights proved more satisfactory than the use of gonad indices, as the latter are not independent of animal size. When examining the course of oogenesis, standardised residuals in an (R × C) contingency table are much easier to interpret than size/frequency polygons.

The species has an annual cycle with spawning in June or July, but the gonads are small even when the animals are gravid, and the annual cycle in gonad weights is more marked in males. Proliferation of oogonia may apparently occur at any time of year, and the ripe ovary contains many small, previtellogenic oocytes. There is an annual cycle of small magnitude in the size of the pyloric caecum, with a peak in December.     

Reproductive traits and relative gonad expenditure of the sexes of the free spawning Chiton articulatus (Mollusca: Polyplacophora)

ABSTRACT

Reproductive studies of an intertidal free-spawning population of Chiton articulatus (Mollusca: Polyplacophora) from Puerto Angel, Oaxaca, Mexico were undertaken during 2011. We used gonad histology and gonadal indices to assess the relative gonad expenditure of the sexes (RGES) and other reproductive traits, accounting for individual and seasonal variation within this population. At this location, C. articulatus is gonochoric, without sexual dimorphism, except internally by gonad colour (testis is ‘salmon’ coloured and ovary olive green). Annual and monthly sex ratios (m/f) do not differ significantly from 1:1. Highest population-level gonadosomatic index (GSI) corresponded to maximum (peak) ripe stage (i.e. maximum gonad investment), with a first peak in May with a high value (8.4 ± 0.5) and a second peak during August-September with a lower value (4.7 ± 0.3). GSI fluctuated throughout year implying that gonad expenditure may be seasonally constrained, but with overall synchrony between sexes of ripe and spawning stages. July to December was the main reproductive season with some facultative spawning occurring off-season. Ripe and spawning RGES did not differ between sexes, suggesting that either sperm competition is intense and/or that sperm limitation is high. Early spawning individuals may quickly replenish their gametes for a second phase of gamete release later.

Abbreviations: RGES: relative gonad expenditure of the sexes; GSI: gonadosomatic index; GDS: gonad developmental stages; MiMI: microscopic maturity index; SST: sea-surface temperature.     

Deltocephalinae of New Zealand (Homoptera: Cicadellidae)

The subfamily Deltocephalinae is represented in New Zealand by 3 tribes, 9 genera, and 20 species, of which 3 genera and 13 species are new to science. All taxa are described, and keys are given for their separation. Three of the genera are endemic, 3 are Australian, 2 are Holarctic, and 1 is cosmopolitan. Nesoclutha and Macrosteles are recorded in New Zealand for the first time, and the presence of Deltocephalus is authenticated. Fourteen species are endemic, 4 are Australian, 1 is widespread in the Pacific area, and 1 is Holarctic. Nesoclutha pallida, Macrosteles fieberi, and Deltocephalus hospes are recorded in New Zealand for the first time.     

Rapporti Fra Endosperma ed Embrione Nella Germinazione di Pinus Pinea L.

Abstract

Endosperm embryo interrelationships during germination of PINUS PINEA L. (2nd Note). — Experiments have been performed with unripe fresh seeds paralleled with unripe stored seeds (50 days of storage).

The effect of storage is very similar to the effect of further permanence on the tree.

It is confirmed the importance of the endosperm in the germination process already put in evidence in the 1rst note.

The relationships existing between endosperm and embryo during the germination of the seed become more and more strict as the seed ripens, so that in a ripe seed the embryo develops in a normal seedling only in connection of its own endosperm.

In an unripe seed the embryo is uncompletely controlled by its endosperm.

Some remarks have been made about the degree of maturity of the different parts of the embryo.     

Diet and Feeding Ecology of <Emphasis Type="Italic">Ateles chamek</Emphasis> in a Bolivian Semihumid Forest: The Importance of <Emphasis Type="Italic">Ficus</Emphasis> as a Staple Food Resource

We describe temporal patterns of food consumption by Peruvian spider monkeys (Ateles chamek) in a semihumid forest in lowland Bolivia. We assessed dietary composition in relation to temporal variation in abundance, duration, and synchrony of different food items in their home range. We collected data from September 2003 to September 2004, in the forestry concession La Chonta, Department of Santa Cruz. Throughout the period of detailed feeding data collection (February-September 2004), Ateles chamek used Ficus as a staple food resource. Figs constituted almost 50% of their diet in terms of total time spent feeding, and subjects consumed them to a great extent even during times of high overall food availability. This is contrary to the general expectation that for Neotropical frugivores, Ficus is a fallback food in times of fruit scarcity, rather than a staple food resource. Surprisingly, despite being considered ripe fruit specialists, Ateles chamek spent 18% of their feeding times eating unripe figs. Ateles chamek consumed unripe figs all through the year, including periods when ripe figs and other ripe fruit were abundant. We identify other important fallback foods for Ateles chamek in the forest, in particular the ripe fruit of Myrciaria sp.     

Flower abscission in mutant tomato plants

The effect of two mutations of the tomato known as Never ripe (Nr) and ripening inhibitor (rin) on abscission of the flowers was investigated. In the presence of ethylene the rate of abscission of normal and rin explants was similar, while that of Nr explants was delayed. The appearance and subsequent increases in both polygalacturonase (EC 3.2.1.15) and -1-4-glucanase (EC 3.2.1.4) enzyme activities were similar in normal and rin explants, but retarded in Nr explants. Of these two, only polygalacturonase activity was exclusively associated with abscission-zone tissue.Abbreviations PG Polygalacturonase - Nr Never ripe mutation - rin ripening inhibitor mutation     

A <Emphasis Type="Italic">Colletotrichum gloeosporioides</Emphasis>-induced esterase gene of nonclimacteric pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis>) fruit during ripening plays a role in resistance against fungal infection

Ripe fruits of pepper (Capsicum annuum) are resistant to the anthracnose fungus, Colletotrichum gloeosporioides, whereas unripe-mature fruits are susceptible. A pepper esterase gene (PepEST) that is highly expressed during an incompatible interaction between the ripe fruit of pepper and C. gloeosporioides was previously cloned. Deduced amino acid sequence of PepEST cDNA showed homology to both esterases and lipases, and contained -HGGGF- and -GXSXG- motifs and a catalytic triad. Inhibition of PepEST activity by a specific inhibitor of serine hydrolase demonstrated that a serine residue is critical for the enzyme activity. Expression of PepEST gene was fruit-specific in response to C. gloeosporioides inoculation, and up-regulated by wounding or jasmonic acid treatment during ripening. PepEST mRNA and protein was differentially accumulated in ripe vs. unripe fruit from 24 h after inoculation when C. gloeosporioides isinvading into fruits. Immunochemical examination revealed that PepEST accumulation was localized inepidermal and cortical cell layers in infected ripe fruit, but rarely even in epidermal cells in infected unripe one. Over-expression of PepEST in transgenic Arabidopsis plants caused restriction of Alternaria brassicicola colonization by inhibition of spore production, resulting in enhanced resistance against A.brassicicola. These results suggest that PepEST is involved in the resistance of ripe fruit against C.gloeosporioides infection.^†These authors contributed equally to the work     

Inibitori nel Sarcotesta del Seme di Ginkgo Biloba E loro Azione Rallentatrice Sullo Sviluppo dell'embrione

Abstract

Inhibitors in the sarcotesta of GINKGO BILOBA seeds and their retarding action on embryo growth. — The sarcotesta of Ginkgo biloba seeds contains some inhibitors which delay or hamper the germination of other cormophytes seeds. This has been proved with seeds of Hordeum vulgare L., Vicia sativa L., and Triticum vulgare L. germinating in water extracts of ripe sarcotesta at various concentrations.

Water extracts of ripe sarcotesta at various concentrations have an anti-mitotic action on root apices of Allium cepa L., resulting in a marked preprophasic inhibition, chromosome stickiness, more or less evident c.-metaphases, and other effects. The water extracts were kept at their original pH (4–4,2) or alkalinized up to a pH of 6,4–6,6.

Indirect statistical evidence, which appears to be highly significant if tested with Student's t, shows that: i) in the seeds of Ginkgo themselves these inhibitors delay embryo development; ii) in the individual seeds of a same plant the inhibitory capacity of the sarcotesta affects embryo development at an earlier or later stage depending on how soon the sarcotesta ripens; iii) the action of the sarcotesta on the embryo decreases with a decreasing water content of the former.

The seeds of Ginkgo biloba do not go through a dormant phase but germinate as soon as the embryo is fully developed. It was already known that temperatures not sufficiently high have a retarding action on embryo growth in this species. This fact together with the presence of inhibitors in the sarcotesta can be interpreted as a biological defense against the danger of the seeds germinating in autumn and the seedlings or young plants dying during severe winter condition.     

Cultura in Vitro di Ovuli di Pinus Pinea L.

Abstract

Pinus Pinea ovules cultured in vitro. — The degree of growth and autonomical differentiation of Pinus pinea L. proembryo has been studied by means of controlled cultures in vitro of excised ovules.

Proembryos in vitro undergo involution and initials of their growth points change back into parenchimatoides cells.

Completely differentiated embryos cultivated in vitro behave as if they were not physiologicaly ripe in all their parts. Embryos cultured in august, september and october develop into rocotless seedlings. Only embryos cultured in november have roots able to elongate where germinating, but in a still scarce degree in comparison with hypocotile and cotiledons. Hypocotil root ratio is inverted as regards what happens in nature.

The primary endosperm of Pinus pinea L. cultivated in vitro undergoes surface diffuse proliferation.

A case of polyembriony has been observed.     

Phytosociological,phenological and photosynthetic analyses of the vegetation of a highly polluted site

Abstract

This work describes an ecological study on the vegetal component in a pilot area (hill A5) of a highly contaminated site (ACNA Cengio, Savona, Italy). The following analyses were performed: (i) phytosociological analysis of the vegetal component; (ii) phenological and synphenological analyses; (iii) evaluation of photosynthetic efficiency; and (iv) evaluation of the degree of mycorrhization. Most representative phytocoenoses belonged to the Artemisietea vulgaris, Galio-Urticetea and Molinio-Arrhenatheretea classes; the site was completely and densely covered by vegetation, but characterized by a rather poor floristic richness. Most plants were visibly suffering, as confirmed, at the physiological level, by fluorescence analysis of photosynthetic rate. Some important phenological phases were shorter than normal or even absent. Most plants were modestly colonized by arbuscular – mycorrhizal fungi, but the fungal structures within the roots were normal. Species belonging to the Leguminosae were, together with those belonging to the Graminaceae, the most representative; the former showed an almost normal photosynthetic efficiency, whereas other families did not.