Water,a powerful attractant for the gravid females of Plodia interpunctella and Cadra cautella

Summary In the sex pheromone controlling experiments, not only large number of the males of the almond moth and Indian meal moth, but also great number of ovipositional females were caught. The increased catch of the fertilized females was due to the presence of detergent in the water.     

The effect of skim milk on plasma cholesterol in rats.

From the 15th day of birth, newborn rats were offered rat chow mixed with water or skim milk. The former also received tap water, the latter skim milk. In the latter group, plasma cholesterol was lowered in 43- and 64-day-old males and in 64-day-old females.     

Schistosoma mansoni: a chemoattractive factor released by males and its receptor in females

Chemoattraction between developing (23- to 28-day-old) and adult (10- to 12-week-old) Schistosoma mansoni males and females has been described previously. We report here on in vitro attraction of mature worms to released products of worms of the opposite sex. In the absence of a stimulus worms migrated randomly and did not show any preference in their orientation. Males were not significantly attracted to released products of females. Females exhibited greatest attraction to released products of males, and some attraction to the lipid fraction of released products of males. The aqueous fraction of male-released products slightly repelled females. Prior exposure to released products of males rendered females unresponsive to subsequent exposure, suggesting receptor saturation. These findings have important potential implications for the control of schistosomiasis by intercepting attraction and mating between males and females.     

Schistosoma mansoni: A chemoattractive factor released by males and its receptor in females

Chemoattraction between developing (23- to 28-day-old) and adult (10- to 12-week-old)Schistosoma mansoni males and females has been described previously. We report here on in vitro attraction of mature worms to released products of worms of the opposite sex. In the absence of a stimulus worms migrated randomly and did not show any preference in their orientation. Males were not significantly attracted to released products of females. Females exhibited greatest attraction to released products of males, and some attraction to the lipid fraction of released products of males. The aqueous fraction of male-released products slightly repelled females. Prior exposure to released products of males rendered females unresponsive to subsequent exposure, suggesting receptor saturation. These findings have important potential implicatons for the control of schistosomiasis by intercepting attraction and mating between males and females.     

Stimulation der Eiablage unbegatteter Weibchen des MondspinnersActias selene durch ein Männchen-Pheromon

Summary Mated females ofActias selene lay their eggs quicker than virgin females. Of the latter, virgins kept isolated in a separate room lay their eggs later than virgins kept in a room where males are present. Antennaless virgin females kept in the same room as males behave like isolated virgin females. It is concluded that the males produce an olfactory active sex pheromone that stimulates oviposition in females.     

Infecundity and dominant lethal mutations induced inMusca domestica L. by sodium azide (NaN3)

Summary Results of our study suggest that sodium azide is effective in the induction of sterility and dominant lethal mutations in both sexes ofM. domestica L. When treated males were crossed with nontreated females, 100% dominant lethal mutations and 72.3% infecundity were found, whereas in the crosses of nontreated males and treated females, 82.5% dominant lethal mutations and 33.1% infecundity were found. This showed that males are more sensitive to sodium azide than females.     

Sex differences in human circadian rhythms: Intrinsic periods and sleep fractions

Summary The period of freerunning circadian rhythms is significantly shorter and the fraction of sleep is significantly larger in human females than in males, as long as the rhythms run internally synchronized. The sex difference in the period could be a property either of the whole circadian system or of only one of the oscillators in a multi-oscillator system. The sex difference in the sleep fraction could be a fixed property of the sleep-wake rhythm or could depend on interactions in the multi-oscillator system. To investigate these questions, a sample of 33 long-term experiments, in which the rhythms ran internally synchronized in one section and internally desynchronized in another section, were analyzed. The periods of rhythms in rectal temperature were different in females and males during internal synchronization, but became identical during internal desynchronization. In contrast, sex differences in sleep-wake periods were more pronounced when the rhythms were desynchronized than when they were internally synchronized. This result provides evidence that the sex difference in periodicity is a property only of the sleep-wake rhythm; the intrinsic periods of temperature rhythms are identical in females and males, whereas those of sleep-wake rhythms are distinctly shorter in females than in males. In the state of internal synchronization, the joint period is a compromise between the intrinsic periods of the rhythms involved, and therefore it shows a small but significant sex difference. Moreover, the transition from internally synchronized to desynchronized rhythms is combined with a highly significant reduction in the sleep fraction, which is considerably greater in females than in males. These results suggest that the occurrence of internal desynchronization strongly affects the sleep-wake rhythm, and that the influence of rhythm disorders is considerably greater in females than in males.     

Mating competitiveness and fertility of thiotepa-sterilized flies

Summary In the present investigation, an attempt has been made to study the mating competitiveness and fertility of males as well as females ofDacus dorsalis Hendel (Diptera: Tephritidae) treated topically with thiotepa. In the mixed population, treated flies of either sex were found to be sexually more vigorous than untreated flies. However when the mating competitiveness of either sex was determined separately using various methods, treated males were found not to differ significantly in sexual competitiveness from untreated flies. Receptivity of treated and untreated females to males was also studied by the single choice method. Thiotepa-treated and untreated females were found to be equally receptive to males.     

Serum cholesterol levels in a Nigerian population sample

Serum cholesterol was determined in 104 healthy Nigerians (57 males and 47 females). The average cholesterol concentration was 187 +/- 72.8 mg/100 ml (mean +/- SD) with a range of 60-480 mg/100 ml. Cholesterol levels were higher in males than in females and increased with age. Distribution of cholesterol level was generally skew to the left.     

Blockierung der Gravidität bei der Maus durch den Geruch männlicher Wurfgeschwister

Summary The incidence of the pregnancy-block caused in recently inseminated mice by the odour of strange males was not reduced when the strange males were litter mates of the stud males and/or of the females.     

Volatile sex pheromone in the female German cockroach

Virgin German cockroach adult females release an attractant that can be extracted with organic solvents and trapped from air blown over sexually receptive females. Behavioral assays with an olfactometer showed that the attractant was produced exclusively by adult females and it elicited behavioral responses in adult males, confirming its function as a female sex pheromone. Using behavioral and electrophysiological assays, we localized the site of pheromone production on the tenth abdominal tergite where an adult female-specific gland is found. Females whose glands were ablated were significantly less attractive to males than sham-operated control females.     

A visual stimulus in the courtship ofDrosophila suzukii

Summary The males ofDrosophila suzukii have a specific black spot on their wings and this was surgically removed. In this situation, the males were almost normally accepted by the females when they were stored under a diurnal light-dark cycle, but they were somewhat discriminated against by the females previously exposed to continuous light.     

Central aromatization of testosterone in testicular feminized mice

Summary Aromatization of testosterone was examined in hypothalamic and cerebral cortex tissues from 32 mice-10 normal males, 10 normal females, 2 carrying the testicular feminized gene (Tfm) and 10 Tfm with the modifying (o^hv) gene. Total aromatization was 1.5 times greater in normal males than females. In both forms of Tfm, conversions were equal and similar to normal females.This work was supported by the Medical Research Council of Canada.     

Residual influences on fecundity in drosophilid species

A residual influence of males and females on oviposition has been examined in 7 drosophilids. There was evidence for oviposition deterrence in Drosophila funebris, with males as well as females producing the inhibitory effect. In contrast, male residues stimulated oviposition in Zaprionus tuberculatus. Male residues also stimulated oviposition and appeared to serve as an aggregation cue in D. melanogaster.     

The role of assortative mating among age-classes inDrosophila melanogaster: preliminary results

Summary A series of experiments on age-related mating success and productivity provides evidence for assortative mating among three out of four age-classes inD. melanogaster. The preferred mating does not always result in the highest productivity. Three age classes of males contribute to reproduction while only females of the youngest age-class are involved. The progeny size is more affected by the age of the females than that of males. It is assumed that these findings must have important implications for generation overlap in natural populations.     

Male production induced by antibiotic treatment inEncarsia formosa (Hymenoptera: Aphelinidae), an asexual species

The production of large numbers of males in the thelytokous speciesEncarsia formosa was induced by feeding antibiotics to their mothers. The males induced by antibiotic treatment produce sperm and sometimes mate with females, but insemination does not occur.     

Plasma triglyceride and β-hydroxybutyric acid levels in red-sided garter snakes (Thamnophis sirtalis parietalis) at emergence from hibernation

Measurement of plasma levels of triglycerides and -hydroxybutyric acid in females and males of the red-sided garter snake (Thamnophis sirtalis parietalis) suggest that the former may provide a useful physiological marker of condition. Levels of triglycerides at emergence from hibernation during a month of natural aphagia were significantly greater in females than in males and she-males, a subset of the male population that mimics females. Higher levels of triglycerides in the females may be attributed to their greater body mass per unit length, which was correlated with the level of triglycerides. Plasma triglyceride levels declined in females within one month of emergence, at the onset of feeding, and were unrelated to mating.     

Residual influences on fecundity in drosophilid species

Summary A residual influence of males and females on oviposition has been examined in 7 drosophilids. There was evidence for oviposition deterrence inDrosophila funebris, with males as well as females producing the inhibitory effect. In contrast, male residues stimulated oviposition inZaprionus tuberculatus. Male residues also stimulated oviposition and appeared to serve as an aggregation cue inD. melanogaster.     

Sex-dependence in triglyceride metabolism in response to dietary carbohydrates.

In humans, as well as in mice, fed on high carbohydrate diets, there was a significant sex difference in the plasma tirglycerides in that males had higher levels than females. This was mainly due to the difference in their removal rate of circulating triglycerides in the animals of both sexes. In mice, males had higher levels of liver triglycerides as well as higher rate of incorporation of U- 14C-glucose into liver triglycerides when compared to females.     

Die mit Hilfe der Beringungsmethode erzielten Ergebnisse über Lebensdauer und jährliche Verlustziffern beiMyotis myotis Borkh

Summary (1) The greatest age ofMyotis myotis hitherto ascertained by means of the marking method, is 12 years.(2) The annual loss, observed with striking regularity, amounts to 40%.(3) It is remarkable that in the first years of control the number of losses of females is far higher than that of males. This observation coincides with the ascertained fact that the reported number of females found dead is nearly double the corresponding number of males.(4) According to the notifications of dead animals found the months most rich losses are May and June. Evidently the females are particularly exposed to peril by the development of the embryo which takes place at that time, and by the breeding of their young ones.