Photoperiodic control of development in the pitcher-plant mosquito, Wyeomyia smithii

1972 ◽  
Vol 50 (6) ◽  
pp. 713-719 ◽  
Author(s):  
William E. Bradshaw ◽  
L. Philip Lounibos
Keyword(s):  
Larval Instar ◽  
Pitcher Plant ◽  
Photoperiodic Control ◽  
Wyeomyia Smithii ◽  
Diapause Termination ◽  
Environmental Consequences ◽  
The Third ◽  
Short Day ◽  
Critical Daylength ◽  
Short Days

Wyeomyia smithii diapause in the third larval instar. Long days avert or terminate and short days promote or maintain diapause. Diapause occurs early in the third instar and may be terminated by photoperiodic stimuli without the intervention of chilling or other factors. Fifty percent termination of diapause requires about 3 long days and another [Formula: see text] days are consumed in the third instar for postdiapause development. The critical daylength is identical for both the initiation and termination of diapause, 14.75 h of light per day. But, the photoperiodic clock monitoring diapause decisions is several times as accurate during initiation as in termination, reflecting the more drastic environmental consequences of development misdirection in the fall than in the spring. This accuracy is further enhanced by a prolongation of the second instar under short-day conditions. The doubling in the duration of the second instar exhibits the same critical daylength properties as diapause determination.The third instar is divisible into four distinct developmental periods: prediapause, diapause, termination of diapause, and postdiapause. Methods for quantifying these periods are presented. Similar manipulations could be employed for other diapausing arthropods, regardless of the stage at which dormancy occurs or the cues used in its regulation.

A second diapause in Wyeomyia smithii: seasonal incidence and maintenance by photoperiod

1975 ◽  
Vol 53 (2) ◽  
pp. 215-221 ◽  
Author(s):  
L. P. Lounibos ◽  
W. E. Bradshaw
Keyword(s):  
Larval Instar ◽  
Fourth Instar ◽  
Continuous Exposure ◽  
Seasonal Incidence ◽  
Wyeomyia Smithii ◽  
The Third ◽  
Critical Photoperiod ◽  
Plant Habitat ◽  
Short Days

Wyeomyia smithii ordinarily diapauses in the third larval instar, but a second, photoperiodically maintained developmental arrest may occur in the fourth instar. Two years of sampling from a Massachusetts bog revealed that the fourth-instar diapause phenotype is most abundant in the spring after the termination of third-instar diapause, and in the fall when a new overwintering generation of third instars accumulates in the pitcher-plant habitat. Fourth-instar larvae from this population cannot, however, survive the winter. This mortality during winter is apparently balanced by advantages that a second diapause confers upon the mosquito population in the spring.Fourth-instar diapause may be induced from diapausing third-instar larvae in the laboratory by a brief exposure to long days followed by short days, or by a long-term exposure to short days at 25 °C. Continuous exposure to long days readily terminates fourth-instar diapause. The critical photoperiod and number of long days required for the termination of diapause is similar for larvae which diapause in either the third or fourth instar.

Tagesperiodische antagonistische Schwankungen der Blauviolett- und Gelbrot-Empfindlichkeit als Grundlage der photoperiodischen Diapause-Induktion bei Pieris brassicae

1960 ◽  
Vol 15 (4) ◽  
pp. 205-213 ◽  
Author(s):  
Erwin Bünning ◽  
Gabriele Joerrens
Keyword(s):  
Dark Period ◽  
Red Light ◽  
Pieris Brassicae ◽  
Light Period ◽  
Measuring Process ◽  
The Third ◽  
Long Day ◽  
Critical Daylength ◽  
Qualitative Responses ◽  
Short Days

In Pieris brassicae, diapause is inhibited if long-day conditions are imposed during and immediately after the third molting. The critical daylength is approximately 14 hours. Under short-day conditions with a main light period of 6 or 12 hours’ duration, supplementary light given in the period from 14 to 16 hours after the beginning of the main light period will inhibit diapause. In contrast to this effect of late exposures to light, light given from 1 to 12 hours after the beginning of the main light period promotes diapause. Experiments with extremely long light periods (10—35 hours), but always with a dark period of 10 hours, show that these diurnal fluctuations in quantitative and qualitative responses to light can continue endogenously for several days. Thus, this time-measuring process operates through the mechanism of endogenous diurnal oscillations in just the same way as do photoperiodic reactions in plants.The inhibition of diapause by light in the second half of the diurnal oscillation (under long days or by light interruptions in the dark period) and the promotion by light in the first half (under short days) occur only with light of short wavelengths: ultraviolet, violet, and blue up to about 550 mμ. Yellow and red light act in the opposite fashion, giving diapause inhibition in the first half of the cycle and promotion in the second half. In white light the violet reaction predominates, so that diapause is promoted by short days and inhibited by long days.

Biology of tree-hole mosquitoes: photoperiodic control of development in northern Toxorhynchites rutilus (Coq.)

1975 ◽  
Vol 53 (7) ◽  
pp. 889-893 ◽  
Author(s):  
William E. Bradshaw ◽  
Christina M. Holzapfel
Keyword(s):  
Rapid Growth ◽  
Fourth Instar ◽  
Photoperiodic Control ◽  
The Third ◽  
Winter Conditions ◽  
Tree Hole ◽  
Critical Photoperiod ◽  
Northern Portion ◽  
Toxorhynchites Rutilus ◽  
Short Days

Carnivorous larvae of the tree-hole mosquito, Toxorhynchites rutilus, were collected from the northern portion of their range. Long days were found to promote rapid growth and metamorphosis from egg to adult; short days retard development during the second and third instars and evoke diapause in the fourth. All larvae exposed continuously to long days from embryos to the third or fourth instar developed without entering diapause. Diapause-averting long days experienced earlier in development could be reversed in at least some individuals by subsequent short days. Among laboratory-reared larvae or those caught early in the fall, the critical photoperiod for the maintenance of diapause is around 13 h of light per day. Among larvae caught in midwinter, diapause is not maintained in all larvae at any photoperiod and in 50% or less of the larvae at photophases shorter than 12.5 h. Winter conditions in the northern part of the range of T. rutilus appear to play a prominent role in the maintenance and termination of diapause.

INDUCTION AND TERMINATION OF DIAPAUSE IN WYEOMYIA SMITHII (DIPTERA: CULICIDAE), AND LARVAL SURVIVAL STUDIES AT LOW AND SUBZERO TEMPERATURES

1972 ◽  
Vol 104 (12) ◽  
pp. 1937-1950 ◽  
Author(s):  
K. W. Evans ◽  
R. A. Brust
Keyword(s):  
Larval Mortality ◽  
Larval Survival ◽  
Wyeomyia Smithii ◽  
Ground Temperatures ◽  
The Third ◽  
Laboratory Conditions ◽  
Subzero Temperatures ◽  
Critical Daylength ◽  
Survival Studies

AbstractDiapause in Wyeomyia smithii (Coquillett) was shown to be a function of photoperiod, and independent of temperature. The critical daylength for a population from Pinawa, Man., was 15 hr light per diem. The photoperiodic cues are monitored by the early instars, with diapause being expressed in the third instar. Development is also limited by temperatures below 15 °C even when the critical daylength is exceeded.Survival at low and subzero temperatures is aided by the diapause state. However, larvae are unable to withstand extended periods of subzero temperatures, even in the diapause condition. At −5 °C, 60% mortality occurred after 8 weeks under laboratory conditions. In the field, where ground temperatures averaged −3.7 °C during the five coldest months, larval mortality averaged 45% after four winter months.Once diapause is established, larvae consume very little food. Diapause larvae appear to be as active as non-diapause larvae, and also appear to be feeding constantly. However, the amount of food ingested is negligible compared to non-diapause larvae.

Photoperiodism in Orthopodomyia signifera

1973 ◽  
Vol 51 (3) ◽  
pp. 355-357 ◽  
Author(s):  
William E. Bradshaw
Keyword(s):  
North Carolina ◽  
Rapid Development ◽  
Larval Instar ◽  
Developmental Rate ◽  
Photoperiodic Response ◽  
The Third ◽  
Tree Hole ◽  
Fourth Larval Instar ◽  
Lower Temperature ◽  
Short Days

Larvae of the tree-hole mosquito, Orthopodomyia signifera, were collected from North Carolina and subjected to long- and short-day photoperiods. Long days at 25 °C permit rapid molting of fourth instar larvae to pupae. Lower temperature (15 °C) modifies developmental rate but does not appear to block photoperiodic response to long days. Short days at 25 °C may halt development, may retard development, or may permit rapid development in either the third or fourth larval instar. O. signifera is probably polymorphic for both the stage at which diapause may occur and for the depth or firmness with which it is established.

scholarly journals Identifying new variation at the J locus, previously identified as e6, in long juvenile ‘Paranagoiana’ soybean

2021 ◽  
Author(s):  
Nour Nissan ◽  
Elroy R. Cober ◽  
Michael Sadowski ◽  
Martin Charette ◽  
Ashkan Golshani ◽  
...  
Keyword(s):  
Single Gene ◽  
Pcr Amplification ◽  
Gene Control ◽  
Grain Yields ◽  
Short Day ◽  
Exon 4 ◽  
Short Days ◽  
Kasp Markers

Abstract Key message A previously identified soybean maturity locus, E6, is discovered to be J, with the long juvenile allele in Paranagoiana now deemed j−x. Abstract Soybean grown at latitudes of ~20° or lower can produce lower grain yields due to the short days. This limitation can be overcome by using the long juvenile trait (LJ) which delays flowering under short day conditions. Two LJ loci have been mapped to the same location on Gm04, J and E6. The objective of this research was to investigate the e6 allele in ‘Paranagoiana’ and determine if E6 and J are the same locus or linked loci. KASP markers showed that e6 lines did not have the j−1 allele of LJ PI 159925. A population fixed for E1 but segregating for E6, with e6 introgressed from Paranagoiana, showed single gene control for flowering and maturity under short days. Sequencing Glyma.04G050200, the J gene, with long amplification Taq found that the e6 line ‘Paranagoiana’ contains a Ty1-copia retrotransposon of ~10,000 bp, inserted within exon 4. PCR amplification of the cDNA of Glyma.04G050200 also showed differences between the mRNA sequences (presence of insertion in j−x). Hence, we conclude that the loci E6 and J are one locus and deem this new variation found in Paranagoiana as j−x.

scholarly journals Epistasis Underlying a Fitness Trait Within a Natural Population of the Pitcher-Plant Mosquito, Wyeomyia smithii

Genetics ◽  
2004 ◽  
Vol 169 (1) ◽  
pp. 485-488 ◽  
Author(s):  
William E. Bradshaw ◽  
Brian P. Haggerty ◽  
Christina M. Holzapfel
Keyword(s):  
Natural Population ◽  
Pitcher Plant ◽  
Wyeomyia Smithii ◽  
Fitness Trait

EFFECTS OF FENITROTHION INSECTICIDE ON INHABITANTS OF LEAVES OF THE PITCHER PLANT, SARRACENIA PURPUREA L.

1987 ◽  
Vol 119 (7-8) ◽  
pp. 647-652 ◽  
Author(s):  
W.L. Fairchild ◽  
D.C. Eidt ◽  
C.A.A. Weaver
Keyword(s):  
Sarracenia Purpurea ◽  
Pitcher Plants ◽  
Pitcher Plant ◽  
Wyeomyia Smithii ◽  
Metriocnemus Knabi

AbstractBy injecting fenitrothion into fluid in leaves of pitcher plants, Sarracenia purpurea L., it was determined that the mosquito, Wyeomyia smithii (Coquillett), and the midge, Metriocnemus knabi (Coquillett), are under some risk from fenitrothion forest sprays at the rate of 210 g AI/ha. Wyeomyia smithii is slightly more susceptible than is M. knabi. Other leaf inhabitants, mites and rotifers, were not affected by initial concentrations of fenitrothion in the fluid (up to 9.6 μg/L) that did affect the mosquito and the midge.

The Post-embryonic Development of the Tracheal System in Drosophila melanogaster

1957 ◽  
Vol s3-98 (41) ◽  
pp. 123-150
Author(s):  
JOAN M. WHITTEN
Keyword(s):  
Drosophila Melanogaster ◽  
Adult Stage ◽  
Larval Instar ◽  
Pupal Stage ◽  
Tracheal System ◽  
True Nature ◽  
The Third ◽  
Air Sacs ◽  
Abdominal Region ◽  
Pupal Cuticle

The fate of the tracheal system is traced from the first larval instar to the adult stage. The basic larval pattern conforms to that shown for other Diptera Cyclorrhapha (Whitten, 1955), and is identical in all three instars. According to previous accounts the adult system directly replaces the larval: the larval system is partly shed, partly histolysed, and the adult system arises from imaginal cell clusters independently of the preceding larval system. In contrast, it is shown here that in the cephalic, thoracic, and anterior abdominal region there is a definite continuity in the tracheal system, from larval, through pupal to the adult stage, whereas in the posterior abdominal region the larval system is histolysed, and the adult system is independent of it in origin. Moreover, in the pupal stage this region is tracheated by tracheae arising from the anterior abdominal region and belonging to a distinct pupal system. Moulting of the tracheal linings is complete at the first and second larval ecdyses, but incomplete at the third larval-pupal and pupal-adult ecdyses. In consequence, in both pupal and adult systems there are tracheae which are secreted around preexisting tracheae, others formed as new ‘branch’ tracheae, and those which have been carried over from the previous instar. In the adult the newly formed tracheae of the posterior abdominal region fall into a fourth category. Most of the adult thoracic air sacs correspond to new ‘branch’ tracheae of other instars. The pre-pupal moult and instar are discussed with reference to the tracheal system and tentative suggestions are made concerning the true nature of the pre-pupal cuticle. There is no pre-pupal tracheal system. Events traced for Drosophila would seem to be general for Cyclorrhapha, both Acalypterae and Calypterae. The separate fates of the anterior and posterior abdom inal systems, in contrast with the straightforward development in Dipterc Nematocera, would appear to mark a distinct step in the evolution of the system in Diptera.

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