Short-term variations in catches of the pea moth,Cydia nigricana, in interacting pheromone traps

Short-term variations in the relative catch in each of two or three interacting pheromone traps for the pea moth,Cydia nigricana (F.), were investigated for traps aligned along the wind. The proportional catch in each trap varied widely, although the mean values accorded with previous estimates. Over consecutive short intervals during a single trapping period the proportion caught in the centre trap of a three-trap line was constant. The proportion caught in the upwind trap of two-and three-trap lines showed trends in time. These trends differed between trapping periods, but two lines of traps operated simultaneously gave similar results to each other. It is suggested that these results, which are predicted by a model based on various components of moth orientation behaviour, are caused by changes in systematic behavioural processes, not random effects. Possible mechanisms are discussed.

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Variations à court terme des captures deCydia nigricana dans des pièges à phéromones en interaction

Résumé Des données antérieures concernant les interactions entre des pièges à phéromone alignés le long du vent ont été utilisées pour déduire les caractéristiques du comportement d'orientation deC. nigricana. Ces données ont été introduites dans un modèle de simulation quantitative qui prédisait que quand les captures totales sur une ligne ont été regroupées sur une période globale de piégage, la proportion capturée dans chaque piège devrait aussi avoir des valeurs moyennes semblables, mais varie plus largement que précédemment indiqué. Les simulations concernant des intervalles consécutifs beaucoup plus courts pendant la même période de piégage ont suggéré une forme spécifique de cette variation.Cette note signale des variations à court terme dans la proportion capturée au piège qui confirment ces prédictions. Nous montrons que sur des intervalles consécutifs brefs pendant une simple période de piégage, la proportion capturée dans le piège central d'une ligne de 3 pièges est contstante, bien que sa valeur change suivant les périodes de piégage. La proportion capturée dans le piège face au vent de 2 ou 3 lignes de pièges suit cette tendance dans le temps, ce qui est généralement bien représenté avec des courbes simples. Ces tendances changent suivant les périodes de piégage, mais des lignes de pièges fonctionnant simultanément fournissaient des résultats similaires. On suggère que ces résultats sont dus à des changements dans des processus comportementaux systématiques et non à des effects aléatoires. Les mécanismes possibles sont discutés.

     

Effect of 2450 MHz microwave exposure on behavioural thermoregulation in mice

1. 1.|The purpose of this study was to determine the threshold specific absorption rate (SAR) during exposure to 2450 MHz continuous wave (CW) microwaves that affected thermoregulatory behaviour in mice.

2. 2.|A Plexiglas shuttle box was placed inside a waveguide imposed with a temperature gradient. The temperature gradient allowed the mice to select a particular section of the shuttle box which was, presumably, related to their state of thermal comfort. Exposing the mice to 2450 MHz inside the waveguide at SARs of 0–5.3 W kg⁻¹ for 1 h caused no significant change in their preferred ambient temperature.

3. 3.|Increasing SAR from 5.3 to 18.1 W kg⁻¹ caused the animals to shift their position to the cooler end of the shuttle box.

4. 4.|Following termination of microwave exposure animals that had selected a cool ambient temperature returned to the warm side of the shuttle box.

5. 5.|It is concluded that for mice exposed to radiation at 2450 MHz the thermoregulatory behaviour is significantly affected at SARs of 5.3 to 9.9 W kg⁻¹.

An airflow olfactometer for measuring olfactory responses of hymenopterous parasitoids and other small insects

ABSTRACT. A new type of airflow olfactometer is described, and results given of experiments using it to measure behavioural olfactory responses of hymenopterous parasitoids. Compared with Y-tube olfactometers it shows several advantages. In its exposure chamber four separate abutting odour fields are presented so that the test insect can readily enter and re-enter them. More than one odour (or different concentrations of one odour) can be tested at the same time, thereby providing complex preference test situations. The various behavioural measures that can be assessed in the apparatus are examined and discussed.     

An odd activity of an ant (Cataglyphis bicolor); ≪visiting≫

Summary An unexplained form of behaviour connecting nests of an antCataglyphis bicolor F. is described. Individuals from one nest visit another wandering around the nest entrance, for periods of up to half an hour or more. Their behaviour is quite distinct from any seen in normal foraging. These individuals come from the upper end of the range of size; more frequently but not always from a larger to a smaller nest. Nests are normally antagonistic. These ants back away rapidly from an ant of the nest visited.     

Spring migration of some anadromous freshwater fish species in the northern Bothnian Sea

Quantitative estimations of spring migrating fish have been made in the mouth part of the small coastal river Ängerån which flows into the northern Bothnian Sea (63°35N, 19°50E). In 1981 nearly 3 000 fish were counted ascending to the spawning grounds in the lower reaches of the Ängerån. These species, such as pike, perch, roach and ide, adapted to the oligohaline environment in the Bothnian Sea for most of the year, migrate to spawn in the coastal stream. The reason for these migrations can be interpreted to indicate that the Ängerån offers more favourable water temperature conditions at spawning time compared with the Bothnian Sea, which is ice-covered up to the beginning of May. The most important result of the investigation in the Ängerån is that these fish species, in the same way as the salmonids, return to theirhome-stream every year as adults.Andreasson & Petersson (1982) listed 69 species of fish in the oligohaline Gulf of Bothnia (Table 1) where salinity varies from 2 near the mouth of the River Torneäly to 6 in the vicinity of the Åland Islands (Fig. 1). The fish fauna comprises freshwater and marine species, fish migrating between brackish and freshwater rivers and streams, and recently introduced non-endogenous species.Andreasson & Petersson (1982) designated only five species as anadromous migrators, whereas our studies show that 11 species migrate from the sea to spawn in the Ängerån, a small river discharging into the northern Bothnian Sea (Fig. 2). Earlier reports on these migrations have been given by Berglund (1978) and Johnson (1978, 1982) and for another small stream in the area by Berg (1982).The present paper describes the annual spring migrations of pike, perch, roach and ide between the northern Bothnian Sea and the Ängerån, for the year 1981.     

Estimation of phenological stages and physiological states of grasslands from remote sensing data

Two radiometers measuring reflectance factors have been used at a height of 1.50 m above some grasslands in C. France. The results show that both spectral data are sensitive to the photosynthetic activity of the grassland. Measurements made in April, May, June and July show that grasslands have quite different spectral behaviour according to soil conditions or to grazing level. Grasslands on dry or wet soils may be separated from those of normal soils for which overgrazing and trampling affecting the growth of species, are shown by the different spectral values. Such on the ground remote sensing measurements may then be proposed for evaluating the range of growth and development of different grasslands.Convention C.N.E.S./I.N.A.P-G. ref.: 80/CNES/24 I thank CNES and IGN for the facilities given to assume this experiment. Many thanks to Lynn Erselius, who revised the text. Mr. Lecordix, a student from the Ecole Nationale des Sciences Géographiques and Mr. Besnard, a student from the Orsay University (Plant Biology) helped in the collection and handling of spectral resp, floristical data.     

Blue adaptation: An experimental tool for the study of visual receptor mechanisms and behaviour of Drosophila

Physiological and behavioural studies with Drosophila to elucidate visual mechanisms have exploited the bi-stability of the visual pigment in the peripheral retinula cells R1–6, and the off-on switch action of blue and orange light. Measurements of flicker fusion and response waveform from both receptor and lamina regions prior and subsequent to blue adaptation, which induces a prolonged depolarising afterpotential and loss of visual function in R1–6, show these retinula cells to have a high fusion frequency and R7/8, the central retinula cells, a lower fusion frequency. Such measurements also allow analysis of the extracellular response in terms of contributing cells, and its potential for studying the fly's ability to respond to various potential visual cues such as a rotating plane of polarised light. Blue adapted flies fail to fixate normally a black stripe, confirming a role for R1–6 in orientation behaviour requiring a competent degree of acuity.Based on material presented at the European Neurosciences Meeting, Florence, September 1978     

Effects of dissolved organic matter from sewage sludge on the atrazine sorption by soils

The effects of dissolved organic matter (DOM), water soluble organic matter derived from sewage sludge, on the sorption of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-trazine) by soils were studied using a batch equilibrium technique. Six paddy soils, chosen so as to have different organic carbon contents, were experimented in this investigation. Atrazine sorption isotherms on soils were described by the linear equation, and the distribution coefficients without DOM (Kd) or with DOM (Kd*) were obtained. Generally, the values of Kd*/Kd initially insoil-solution system form. Critical concentrations of DOM (DOMnp) were obtained where the value of Kd* was equal to Kd. The presence of DOM with concentrations lower than DOMnp promoted atrazine sorption on soils (Kd* ＞ Kd), whereas the presence of DOM with concentrations higher than DOMnp tended to inhibit atrazine sorption (Kd* ＜ Kd). Interestingly, DOMnp for tested soils was negatively correlated to the soil organic carbon content, and the maximum of Kd*/Kd (i.e.Kmax) correlated positively with the maximum of DOM sorption on soil (Xmax). Further investigations showed that the presence of hydrophobic fraction of DOM evidently promoted the atrazine sorption on soils, whereas the presence of hydrophilic DOM fraction obviously tended to inhibit the atrazine sorption. Interactions of soil surfaces with DOM and its fractions were suggested to be the major processes determining atrazine sorption on soils. The results of this work provide a reference to the agricultural use of organic amendment such as sewage sludge for improving the availability of atrazine in soils.     

Treatment of Brain Trauma with Liposomal Superoxide Dismutase

Brain trauma was induced in rats by impact of a steel bar on the head with a force such that damage (as measured by neurological scoring) was reversible in fourteen days. Systemic treatment (intraperitoneal injections) with free bovine copper superoxide dismutase or a liposomal form of the enzyme considerably shortened recovery time to less than half Tests included cranial nerves - cornean and aural reflexes. and sensorial motricity functions — gripping reflexes. displacement reactions, recovery and flexion reflexes, equilibrium tests and spontaneous mobility. Normalisation of EEG recordings was also greatly accelerated in the case of treated animals. No changes of brain glutathione peroxidase, glutathione transferase or Mn superoxide dismutase in traumatized animals were observed. However a slight decrease in Cu-SOD occurs. Cerebral lipoperoxidation is increased in the traumatized animals compared with controls. This increase is reduced on treatment of the rats with liposomal SOD (or the free enzyme). Very small amounts of the exogenous SOD pass the brain barrier. the permeability of which is increased in traumatized animals. The enzyme is particularly concentrated in the cortex. Despite apparent total neurological recovery at 15 days for untreated traumatized animals. significant differences in EEG recordings, in percentage cerebral water content and in histological examination of brain tissue of these controls compared with treated animals were observed with a net improvement in the latter case. The results obtained with this model suggest that clinical treatment of coma states and brain traumas with liposomal superoxide dismutase may have certain advantages over orthodox treatments