The effect of temperature and photoperiod on the induction of larval diapause in the mosquito Aedes togoi (Theobald) (Diptera: Culicidae)

1987 ◽  
Vol 65 (9) ◽  
pp. 2262-2265 ◽  
Author(s):  
Brian E. Galka ◽  
Reinhart A. Brust
Keyword(s):  
Larval Stage ◽  
Fourth Instar ◽  
Effect Of Temperature ◽  
Larval Diapause ◽  
Critical Photoperiod ◽  
Aedes Togoi

Aedes togoi (Theobald) from Vancouver, B.C., may enter diapause in either the egg or larval stage. Larval diapause occurred in the fourth instar, when immatures were maintained at 16 °C or less, at photoperiods shorter than 12 h light/day. The critical photoperiod was calculated as 10.9L:13.1D at 16 °C. Larvae that failed to pupate after 40 days following hatching were recorded as being in diapause. At light periods greater than 12 h at 16 °C, there was no larval diapause and, at 14 °C, 100% of the larvae diapaused at 10L:14D. Temperatures of 18 °C or higher, at 10L:14D, prevented larval diapause.

The effect of temperature and photoperiod on the induction of embryonic diapause in the mosquito Aedes togoi (Theobald) (Diptera: Culicidae)

1987 ◽  
Vol 65 (9) ◽  
pp. 2266-2271 ◽  
Author(s):  
Brian E. Galka ◽  
Reinhart A. Brust
Keyword(s):  
Effect Of Temperature ◽  
Embryonic Diapause ◽  
Critical Photoperiod ◽  
Aedes Togoi

Aedes togoi (Theobald) from Vancouver, B.C., enters embryonic diapause when immatures, adults, and eggs are maintained at temperatures ranging from 22 to 28 °C, at photoperiods shorter than 15 h light/day. There was little to no embryonic diapause when the population was maintained at 24 °C and 17L:7D. The critical photoperiod was 14.4L:9.6D at 22 °C. A decrease in the frequency of diapause was observed as (i) temperature of the pupae, adults, and eggs increased from 18 to 28 °C when larvae were maintained at 24 °C 17L:7D; (ii) temperature of the egg stage increased from 15 to 30 °C, at 10L:14D, and stages preceding the egg stage were maintained at 24 °C 17L:7D; (iii) stages preceding the egg stage were maintained at 24 °C 17L:7D and the photoperiod was increased from 10L:14D to 18L:6D; (iv) temperature of the egg stage increased from 18 to 25 °C, at 10L:14D, and stages preceding the egg stage were maintained at 24 °C 17L:7D.

Inhibition of development of Ostertagia ostertagi – effect of temperature on the infective larval stage

Parasitology ◽  
1982 ◽  
Vol 85 (1) ◽  
pp. 27-32 ◽  
Author(s):  
M. G. Smeal ◽  
A. D. Donald
Keyword(s):  
Low Temperature ◽  
Larval Stage ◽  
Effect Of Temperature ◽  
Ostertagia Ostertagi ◽  
Effective Stimulus ◽  
Low Temperature Storage ◽  
Temperature Storage

SUMMARYPopulations of Ostertagia ostertagi established from fresh larvae and from larvae stored at 4 °C for up to 12 weeks contained about 10% inhibited early 4th-stage larvae. This value rose to 21% after 16 weeks, due to an increase in numbers of inhibited larvae while adult numbers remained unchanged. Storage at 15 °C had no effect. In the case of larvae stored at 4 °C for 8 weeks, increasing the larval dose to 90000 had no significant effect on the proportion of the dose which was inhibited. The response to low temperature storage was much weaker than in previously reported studies on British populations, which accords with our earlier conclusion that low temperature cannot be the effective stimulus for inhibition in Australia.

GEOGRAPHIC DIFFERENTIATION IN THE DEVELOPMENT OF AEDES SIERRENSIS (DIPTERA: CULICIDAE) IN NATURE

1980 ◽  
Vol 112 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Robert G. Jordan
Keyword(s):  
Laboratory Data ◽  
Fourth Instar ◽  
Geographic Differentiation ◽  
Critical Photoperiod ◽  
Geographic Populations ◽  
Treehole Mosquito ◽  
Aedes Sierrensis

AbstractThe critical photoperiod for fourth instar diapause of the western treehole mosquito, Aedes sierrensis, varies among geographic populations. When reared together in the field at different latitudes, larvae from northern (ca. 45°N), central (ca. 39°N), and southern (ca. 33°N) populations all develop more rapidly through the early instars at more southerly latitudes. The order of pupation dates among the populations, however, depends on their critical photoperiods, and can be predicted from laboratory data on photoperiodism.

FACTORS AFFECTING LARVAL DIAPAUSE IN DENDROCTONUS RUFIPENNIS (COLEOPTERA: SCOLYTIDAE)

1977 ◽  
Vol 109 (11) ◽  
pp. 1485-1490 ◽  
Author(s):  
E.D.A. Dyer ◽  
P.M. Hall
Keyword(s):  
Life Cycle ◽  
Larval Development ◽  
Larval Instar ◽  
Fourth Instar ◽  
Dendroctonus Rufipennis ◽  
Factors Affecting ◽  
Temperature Changes ◽  
Larval Diapause ◽  
Laboratory Results ◽  
Development Threshold

AbstractThe effect of daily day-degrees C in relation to brood age was investigated to determine its influence on the induction of larval (prepupal) diapause in Dendroctonus rufipennis (Kirby). Daily day-degrees of less than about 9° above the development threshold (6.1°C) induced diapause in most of the broods while diapause was averted by daily day-degrees C of 10 or more above the threshold. Induction of diapause occurred no later than third larval instar; temperature changes during the fourth instar produced no change in aversion or induction of diapause. Laboratory results reveal that field temperatures during larval development determine whether most beetles have a 1- or 2-year life cycle.

EFFECT OF TEMPERATURE AND STAGE OF DEVELOPMENT ON SUSCEPTIBILITY OF AEDES EUEDES AND AEDES STIMULANS (DIPTERA: CULICIDAE) LARVAE TO TEMEPHOS

1983 ◽  
Vol 115 (6) ◽  
pp. 623-628 ◽  
Author(s):  
B. V. Helson ◽  
G. A. Surgeoner
Keyword(s):  
Maximum Concentration ◽  
Fourth Instar ◽  
Effect Of Temperature ◽  
Recommended Dosage ◽  
Stage Of Development ◽  
First Instar ◽  
Early Instar ◽  
Increasing Temperature

AbstractIn laboratory trials, the susceptibility of Aedes euedes Howard, Dyar and Knab and Aedes stimulans (Walker) larvae to temephos (Abate®), was positively correlated with increasing temperature. Early instar larvae were more susceptible than late instars. Susceptibility differed 36 times from the fourth instars at 4 °C (24 h LC50 = 16.92 ppb) to the first instars at 19 °C (24 h LC50 = 0.47 ppb) the extremes of instar and temperature tested. The minimum recommended dosage of temephos (6 ppb) was ca. 9 times the LC90 of first instar A. stimulans and A. euedes at 19 °C. By contrast, the 24 h LC90 of 67.4 ppb for the fourth instar of A. stimulans at 4 °C was ca. 4 times the maximum concentration of temephos (18 ppb) currently recommended for Aedes spp. control. However, in simulated pool studies, satisfactory control of A. stimulans was achieved by 72 h posttreatment at the highest recommended dosage.

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.

scholarly journals Studies on male recombination in a Southern Greek Drosophila melanogaster population: (a) Effect of temperature. (b) Suppression of male recombination in reciprocal crosses

1977 ◽  
Vol 29 (3) ◽  
pp. 231-238 ◽  
Author(s):  
George Yannopoulos ◽  
Michael Pelecanos
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Larval Stage ◽  
Effect Of Temperature ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Cytoplasmic Factor ◽  
Male Recombination ◽  
The City ◽  
North Western

SUMMARYA second chromosome of Drosophila melanogaster (symbol 31.1) isolated from a natural population of North-Western Peloponnesus (at a distance of 8 km from the city of Patras) was found to induce recombination in heterozygous males, both in the second and third chromosomes. The present study also revealed the following points. (1) The phenomenon is temperature-sensitive with higher male recombination at 29 °C than at 25 or 15 °C. (2) The temperature-sensitive period is during the larval stage where premeiotic divisions of germ cells take place. (3) Suppression of male recombination in both the second and third chromosomes occurred when 31.1/CyL4 females were used in the matings, and (4) the suppression of male recombination is caused by a cytoplasmic factor of the CyL4/Pm stock.

Photoperiodic control of the maintenance and termination of larval diapause in Wyeomyia smithii (Coq.) (Diptera: Culicidae) with notes on oogenesis in the adult female

1971 ◽  
Vol 49 (8) ◽  
pp. 1065-1073 ◽  
Author(s):  
Stephen M. Smith ◽  
Reinhart A. Brust
Keyword(s):  
Ice Cores ◽  
Instar Larva ◽  
Wyeomyia Smithii ◽  
Larval Diapause ◽  
Short Day ◽  
Northwestern Ontario ◽  
Long Day ◽  
Two Generations ◽  
Critical Photoperiod ◽  
Third Instar Larva

Some aspects of overwintering and oogenesis in the pitcher-plant mosquito, Wyeomyia smithii (Coq.), were examined. The species was shown to overwinter in a diapause state as a third-instar larva. The diapausing larvae overwinter within the frozen ice cores of the host plant but they were nevertheless shown to be intolerant of prolonged periods of freezing at temperatures only a few degrees below 0 °C. The winter survival of the species probably depends almost entirely on the insulating benefits of a snow cover. Larval diapause was stable under short-day conditions but was very rapidly broken when the larvae were exposed to long-day photoperiods. The critical photoperiod required to break larval diapause in a population from the Kenora region of Ontario was between [Formula: see text] and 15 h of light per diem. This critical photoperiod did not change during a prolonged period of overwintering. Larvae which experienced 5 or fewer long-day cycles remained in diapause when they were returned to short-day conditions but diapause was irreversibly broken in larvae exposed to 8 or more long-day cycles in succession. Data on growth rates of larvae as a function of temperature and photoperiod were used to predict the seasonal cycle of W. smithii in northwestern Ontario where the species is probably restricted to a maximum of two generations per year. All females of W. smithii were autogenous for the first ovarian cycle and adult diets of carbohydrate did not affect fecundity. Unlike other mosquitoes, the female of W. smithii was found to be precocious, emerging with the ovarian follicles already initiated with development of the follicles up to stage IIIa of Christophers.

Larval diapause, size, and autogeny in the mosquito Aedes togoi (Diptera, Culicidae) from tropical to subarctic zones

1994 ◽  
Vol 72 (8) ◽  
pp. 1462-1468 ◽  
Author(s):  
Teiji Sota
Keyword(s):  
Larval Development ◽  
Adult Size ◽  
Larval Diapause ◽  
Canadian Population ◽  
Aedes Togoi ◽  
L 14 ◽  
Developmental Traits ◽  
Two Populations

Larval development of nine populations of Aedes togoi (Theobald) collected from tropical to subarctic zones was studied under photoperiods of 16 h light (L) : 8 h dark (D) and 10 h L : 14 h D at 15 °C. Larvae that did not pupate within 60 days were regarded as diapausing. Larval diapause did not occur in all populations at 16 h L : 8 h D. At 10 h L : 14 h D, four populations from tropical and subtropical zones included no diapausing larvae, whereas 60–99% of individuals from five northern populations of Japan and Canada were diapausing. Adult size increased with latitude of original locality. The proportion of autogenous females among those developed at 16 h L : 8 h D and 15 °C decreased with original latitude, whereas that among females from nondiapausing larvae reared at 10 h L : 14 h D and 15 °C was consistently high throughout the latitudes. At 10 h L : 14 h D and 15 °C, larval developmental characters of F1 and F2 hybrids between Malaysian (no diapause) and Japanese (diapausing) populations were intermediate between the parental populations. Expression of autogeny of the hybrids was similar to that of the Malaysian strain. A Canadian population, which might have been introduced from Japan, showed developmental traits similar to those of two populations from temperate Japan.

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