Two mechanisms in the biological clock ofPieris brassicae L.: an oscillator for diapause induction; an hour-glass for diapause termination

1985 ◽  
Vol 41 (12) ◽  
pp. 1613-1615 ◽  
Author(s):  
J. Claret
Keyword(s):  
Biological Clock ◽  
Diapause Induction ◽  
Diapause Termination

scholarly journals Geographic Variation of Diapause Induction and Termination in the Spider Mite Tetrαnychus urticαe: Α mini-review

2017 ◽  
Vol 12 ◽  
pp. 5 ◽  
Author(s):  
S. Koveos ◽  
A. Veerman
Keyword(s):  
Geographic Variation ◽  
Spider Mite ◽  
Wide Distribution ◽  
Mite Species ◽  
Climatic Conditions ◽  
Diapause Induction ◽  
Diapause Termination ◽  
Long Day ◽  
Critical Daylength ◽  
Tetranychus Urticae Koch

In eight strains of the spider mite Tetranychus urticae Koch (Acari: Tetranychidae), originating from different localities in Europe, the critical daylength for diapause induction and termination was almost the same in each strain but varied with the latitudinal origin of the strains; critical daylength was shorter in strains originating from lower latitudes and longer in those from higher latitudes. Diapause intensity, measured as the period of chilling required for diapause termination under a short day photoperiod (LD 10:14) and 19°C, again varied with the latitudinal origin of each strain, being higher the more northern the origin of the strain. An exception were two mountain strains which showed a longer critical daylength and a deeper diapause than expected on the basis of their latitudinal origin. The number of long-day (LD 17:7) cycles required for 50% diapause termination after a certain period of chilling was higher in the northern and lower in the southern strains. These results indicate that geographic strains of T urticae may differ considerably in their diapause attributes, which may be explained as an adaptation to local climatic conditions. The great plasticity of the diapause response may, among other factors, have been responsible for the wide distribution of this mite species.

INDUCTION AND TERMINATION OF DIAPAUSE IN THE FACE FLY, MUSCA AUTUMNALIS (DIPTERA: MUSCIDAE), IN THE LABORATORY

1978 ◽  
Vol 110 (6) ◽  
pp. 617-622 ◽  
Author(s):  
E. T. N. Caldwell ◽  
R. E. Wright
Keyword(s):  
Late Summer ◽  
Diapause Induction ◽  
Total Darkness ◽  
Diapause Termination ◽  
Critical Photoperiod ◽  
The Face ◽  
Musca Autumnalis

AbstractDiapause induction studies showed that face flies, Musca autumnalis De Geer, from a recently established colony, entered diapause more readily than those that had been colonized for many years. Photoperiods of less than 16 h of light induced diapause at 16° and 27 °C but more flies entered diapause at 16°C. Maximum numbers of flies entered diapause under total darkness at 16°C, but the critical photoperiod corresponding to natural periods of daylight in late summer was 15 h of light at 16°C. Diapause termination studies indicated that 4 months’ exposure to 5 °C under total darkness was required for the termination of diapause.

Photoperiodism of diapause induction and diapause termination inOstrinia furnacalis

2014 ◽  
Vol 153 (1) ◽  
pp. 34-46 ◽  
Author(s):  
Hui-Zhong Yang ◽  
Xiao-Yun Tu ◽  
Qin-Wen Xia ◽  
Hai-Min He ◽  
Chao Chen ◽  
...  
Keyword(s):  
Diapause Induction ◽  
Diapause Termination

The effect of photoperiod on diapause induction, and temperature on diapause termination in embryos of Aedes campestris Dyar and Knab (Diptera: Culicidae)

1977 ◽  
Vol 55 (1) ◽  
pp. 129-134 ◽  
Author(s):  
P. Tauthong ◽  
R. A. Brust
Keyword(s):  
Diapause Induction ◽  
Geographical Region ◽  
Northern Population ◽  
Diapause Termination

Populations of Aedes campestris from Manitoba and Saskatchewan were found to be either multivoltine or univoltine depending upon the geographical region from which the adults were collected. Three southern populations (from 49–52° N) were found to be totally multivoltine, whereas a northern population (58° N) was found to be partially (36%) univoltine. The latter fraction was designated as univoltine because the eggs entered an obligatory diapause after oviposition. When univoltine eggs were placed at 30 °C for a period of 10 days, 59% of the eggs hatched when subjected to a hatching stimulus.Facultative dispause was induced in eggs of multivoltine populations of A. campestris, by subjecting fully embryonated eggs to photoperiods of less than 14 h per day. For example, after 30 days at 8 h light: 16 h dark 73% of the eggs entered diapause.

The brain structure and neurosecretory cells of noctuid moth Anadevidia peponis: Noctuidae

1990 ◽  
Vol 48 (3) ◽  
pp. 436-437
Author(s):  
M. Sato ◽  
Y. Ogawa ◽  
M. Sasaki ◽  
T. Matsuo
Keyword(s):  
Biological Clock ◽  
Virgin Female ◽  
Basic Structure ◽  
Fixed Time ◽  
Neurosecretory Cells ◽  
Nerve Cells ◽  
Noctuid Moth ◽  
The Right ◽  
20 Nm ◽  
The Brain

A virgin female of the noctuid moth, a kind of noctuidae that eats cucumis, etc. performs calling at a fixed time of each day, depending on the length of a day. The photoreceptors that induce this calling are located around the neurosecretory cells (NSC) in the central portion of the protocerebrum. Besides, it is considered that the female’s biological clock is located also in the cerebral lobe. In order to elucidate the calling and the function of the biological clock, it is necessary to clarify the basic structure of the brain. The observation results of 12 or 30 day-old noctuid moths showed that their brains are basically composed of an outer and an inner portion-neural lamella (about 2.5 μm) of collagen fibril and perineurium cells. Furthermore, nerve cells surround the cerebral lobes, in which NSCs, mushroom bodies, and central nerve cells, etc. are observed. The NSCs are large-sized (20 to 30 μm dia.) cells, which are located in the pons intercerebralis of the head section and at the rear of the mushroom body (two each on the right and left). Furthermore, the cells were classified into two types: one having many free ribosoms 15 to 20 nm in dia. and the other having granules 150 to 350 nm in dia. (Fig. 1).

The Biological Clock and Sleep in the Elderly

2006 ◽  
Vol 19 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Myriam Juda ◽  
Mirjam Münch ◽  
Anna Wirz-Justice ◽  
Martha Merrow ◽  
Till Roenneberg
Keyword(s):  
Circadian Rhythms ◽  
Biological Clock ◽  
The Elderly ◽  
Early Morning ◽  
Behavioral Changes ◽  
Older Age ◽  
Age Related ◽  
Theoretical Considerations ◽  
Sleep Difficulties ◽  
Circadian Biology

Abstract: Among many other changes, older age is characterized by advanced sleep-wake cycles, changes in the amplitude of various circadian rhythms, as well as reduced entrainment to zeitgebers. These features reveal themselves through early morning awakenings, sleep difficulties at night, and a re-emergence of daytime napping. This review summarizes the observations concerning the biological clock and sleep in the elderly and discusses the documented and theoretical considerations behind these age-related behavioral changes, especially with respect to circadian biology.

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