Geographic variation in the effects of temperature and photoperiod on dormancy induction, development time, and predation in the tree-hole mosquito, Toxorhynchites rutilus septentrionalis (Diptera: Culicidae)

1979 ◽  
Vol 57 (8) ◽  
pp. 1612-1618 ◽  
Author(s):  
R. M. Trimble ◽  
Stephen M. Smith
Keyword(s):  
Photoperiodic Response ◽  
Prey Consumption ◽  
Northern Population ◽  
Tree Hole ◽  
Critical Daylength ◽  
Laboratory Colonies ◽  
Effects Of Temperature ◽  
Toxorhynchites Rutilus ◽  
Two Populations ◽  
Dormancy Induction

Critical daylength for dormancy induction was similar for laboratory colonies of a northern (Delaware) and a southern (Louisiana) population of Toxorhynchites rutilus septentrionalis. The threshold daylength for dormancy induction was greater in the northern population and the photoperiodic response of the northern population was less affected by high temperature.Although photoperiod did not affect the duration of preadult development in the southern population, the duration of preadult development of the northern population varied in a nonlinear fashion with photoperiod at 27 °C and increased with decreasing daylength at 19 °C.The duration of the third instar was consistently longer in dormant than in active larvae of both populations.The pattern of prey consumption during larval development was similar in dormant and active larvae. Prey consumption terminated 24 h prior to pupation in active larvae; dormant larvae continued to feed at a low rate. Similar numbers of prey were consumed during development by active and dormant larvae.The differences in the biologies of the two populations are discussed in relation to climatological differences in the environments from which each population was derived.

Geographic variation in development time and predation in the tree-hole mosquito, Toxorhynchites rutilus septentrionalis (Diptera: Culicidae)

1978 ◽  
Vol 56 (10) ◽  
pp. 2156-2165 ◽  
Author(s):  
R. M. Trimble ◽  
Stephen M. Smith
Keyword(s):  
Development Time ◽  
Adult Emergence ◽  
First Instar ◽  
Emergence Success ◽  
Tree Hole ◽  
Daily Rate ◽  
Proportional Increase ◽  
Laboratory Colonies ◽  
Toxorhynchites Rutilus ◽  
Biological Differences

In laboratory colonies of a northern (Newark, DE) and southern (Lake Charles, LA) population of Tx. r. septentrionalis the proportional increase or decrease in total development time with changes in temperature did not vary significantly. Between 13 and 27 °C, development of the third- and fourth-instar larvae, pupae, and preadults was completed more rapidly in the Delaware population. By contrast, Louisiana eggs embryonated more rapidly than Delaware eggs. Survival from the first instar to adult emergence was similar in both populations between 13 and 29 °C; however, all Louisiana larvae that pupated also emerged, whereas the emergence success of Delaware pupae declined with each 2 °C decrease in temperature between 23 and 13 °C. Louisiana larvae consumed more prey during development because they took longer to develop and because their daily rate of prey consumption was greater than that of Delaware larvae. Louisiana larvae partly consumed and killed without consuming more prey during development. These differences are discussed in relation to climatological and possible biological differences in the environments from which each population was derived.

scholarly journals Male parental investment reflects the level of partner contributions and brood value in tree swallows

2017 ◽  
Author(s):  
Ádám Z. Lendvai ◽  
Çağlar Akçay ◽  
Mark Stanback ◽  
Mark F. Haussmann ◽  
Ignacio T. Moore ◽  
...  
Keyword(s):  
Parental Care ◽  
Interesting Case ◽  
Temporary Increase ◽  
Southern Population ◽  
Tree Swallows ◽  
Parental Effort ◽  
Northern Population ◽  
Nestling Begging ◽  
Two Populations ◽  
Partial Compensation

AbstractBiparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each other’s parental care to maximize their own fitness, predicting no change, partial compensation, or matching effort as a response. Here, we present an experiment in tree swallows (Tachycineta bicolor) in which we increased the parental care of females by presenting them, but not their mates, with additional nestling begging calls using automated playbacks. We performed this experiment in two populations differing in future breeding opportunities and thus the intensity of conflict over current parental care. We found that in response to a temporary increase in female parental effort, males in the northern population with lower sexual conflict matched the increased effort, whereas males in the southern population did not. We also found that increases in parental care during playbacks were driven by the females (i.e., females initiated the increased effort and their mates followed them) in the northern population but not the southern population. These results support the idea that with incomplete information about the brood value and need, cues or signals from the partner might become important in coordinating parental care.

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.

Photoperiodic Time Measurement and Effects of Temperature on Flowering in Chenopodium rubrum L

1979 ◽  
Vol 6 (3) ◽  
pp. 417 ◽  
Author(s):  
RW King
Keyword(s):  
Floral Induction ◽  
Temperature Shift ◽  
Time Measurement ◽  
Pharbitis Nil ◽  
Temperature Sensitive ◽  
Hyoscyamus Niger ◽  
Temperature Range ◽  
Critical Daylength ◽  
Effects Of Temperature ◽  
Two Parameters

The critical dark period length (c. 8 h darkness) required for induction of flowering of C. rubrum is insensitive to temperature (Q10 c. 1.0) over the temperature range 10-25°C. However, the period of a rhythm controlling floral induction is shown to be temperature sensitive (Q10 c. 1.4) over the temperature range 9-22°C. The discrepancy in temperature dependence of these two parameters of photoperiodic time-measurement could reflect differences in their rates of adjustment after a temperature shift. By contrast, at least two other species (Pharbitis nil and Hyoscyamus niger) show marked temperature sensitivity of their critical daylength. Thus, there may be more than one time- keeper in the photoperiodic control of flowering.

Effects of Temperature On Emergence of Juveniles and Root Invasion in Two Populations of Heterodera Lespedezae

Nematologica ◽  
1987 ◽  
Vol 33 (3) ◽  
pp. 328-334
Author(s):  
R.B. Malek ◽  
D.I. Edwards ◽  
H.H. Fagbenle
Keyword(s):  
Effects Of Temperature ◽  
Two Populations

scholarly journals Photothermal response of sympodium development and flowering in potato (Solanum tuberosum L.) under controlled conditions

1994 ◽  
Vol 42 (4) ◽  
pp. 311-329
Author(s):  
C.J.M. Almekinders ◽  
P.C. Struik
Keyword(s):  
Solanum Tuberosum L ◽  
Photoperiodic Response ◽  
Flower Primordia ◽  
Flower Production ◽  
Lateral Shoots ◽  
Shoot Production ◽  
Number Of Leaves ◽  
Effects Of Temperature ◽  
Phytotron Experiments ◽  
Increasing Temperature

In two phytotron experiments with different potato cultivars (experiment 1: cv. Atzimba and Van Gogh; experiment 2: cv. Spunta and Desiree), a study was made of the effects of temperature (15-27 degrees C) and photoperiod (long day, LD, or short day, SD) on sympodial development and shoot, leaf and flower production. In experiment 1, data on the entire shoot were collected, whereas in experiment 2 only leaf and flower production of the main and secondary stems were measured. In experiment 1, increasing the temperature in both SD and LD treatments, and increasing the photoperiod at 15 degrees C increased the number of lateral shoots, and the numbers of inflorescences and leaves of the sympodium and of the entire shoot. In experiment 2, the number of flower primordia and survival of flower primordia of individual inflorescences increased with the photoperiod and with temperature up to 23 degrees. At 27 degrees, flower development was suppressed. Total leaf and flower production per plant were largely a function of lateral shoot production. Increasing temperature and photoperiod increased the number of leaves of individual shoots in most treatments. However, the effects on leaf and flower production of individual shoots were relatively small, except for the effect of a temperature increase from 23 to 27 degrees in experiment 2. The photoperiodic response of the time till flowering of individual shoots was facultative SD or daylength-neutral, depending on the cultivar and stem position.

Population dynamics, production, and prey consumption of fathead minnows (Pimephales promelas) in prairie wetlands: a bioenergetics approach

1998 ◽  
Vol 55 (1) ◽  
pp. 15-27 ◽  
Author(s):  
W G Duffy
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Pimephales Promelas ◽  
Standing Stock ◽  
Prey Consumption ◽  
Fathead Minnows ◽  
Prairie Wetlands ◽  
Net Production ◽  
Commercial Harvest ◽  
Two Populations

I assessed the population dynamics of fathead minnows (Pimephales promelas) in prairie wetlands and developed a bioenergetics model to estimate their production and prey consumption. I sampled populations in four wetlands weekly from late May through June and biweekly during July and August using a Kushlan 1-m2 throw trap. I imposed commercial harvest on two populations; the other two populations served as controls. Weekly population density estimates ranged from 52 000 to 356 000 ·ha-1 during early June and from 5400 to 19 700 ·ha-1 in late August. Simulated commercial harvest did not influence population density, mortality rates, or size of fathead minnows. Standing stock biomass differed among wetlands sampled, ranging from 144 to 482 kg ·ha-1 in early June and from 1 to 33 kg ·ha-1 during late August. However, differences were attributed to differential predation pressure rather than harvest pressure. Net production during the period ranged from 71.5 to 202.7 kg ·ha-1. Daily net production was greatest in early June (2.6-13.5 kg ·ha-1 ·day-1) and then declined during July and August (0.1-1.2 kg ·ha-1 ·day-1). Total mass of prey consumed by fathead minnows ranged from 332.7-1104.8 kg ·ha-1 among wetlands.

Geography of larval dormancy in the tree-hole mosquito, Aedes triseriatus (Say)

1981 ◽  
Vol 59 (6) ◽  
pp. 1014-1021 ◽  
Author(s):  
Christina M. Holzapfel ◽  
William E. Bradshaw
Keyword(s):  
Photoperiodic Response ◽  
Late Winter ◽  
Aedes Triseriatus ◽  
Embryonic Diapause ◽  
Rate Of Development ◽  
Larval Diapause ◽  
Tree Hole ◽  
Critical Photoperiod ◽  
Response To Temperature ◽  
Fail Safe

Among Aedes triseriatus from 30–40° N latitude, photoperiod and temperature mediate the onset and maintenance of larval diapause. Photoperiod has a significant effect not only on the initiation and maintenance of diapause but also on the rate of postdiapause development, both directly and by modifying response to temperature. The critical photoperiod for larval diapause is shorter than that for controlling rate of development. Over most of the range considered, both the critical photoperiod for the induction and maintenance of larval diapause and that for rate of development are shorter than the critical photoperiod governing embryonic diapause. Based on relative photoperiodic response and censuses of overwintering populations, we conclude that larval diapause in A. triseriatus is mainly a backup or fail-safe system for embryonic diapause and that the major adaptive significance of larval diapause relates to the modulation of late winter and spring development rather than to overwintering, per se.

Effects of gravidity on the locomotor performance and escape behaviour of two lizard populations: the importance of habitat structure

Behaviour ◽  
2010 ◽  
Vol 147 (1) ◽  
pp. 133-150 ◽  
Author(s):  
José Díaz ◽  
Camila Monasterio ◽  
Pablo Iraeta ◽  
Alfredo Salvador
Keyword(s):  
Habitat Structure ◽  
High Elevation ◽  
Laying Date ◽  
Locomotor Performance ◽  
Before And After ◽  
Psammodromus Algirus ◽  
Effects Of Temperature ◽  
Selection For ◽  
Gravid Females ◽  
Two Populations

AbstractIn lizards, locomotor costs of gravidity may depend on habitat structure and refuge availability. We compared the locomotor performance and escape tactics in the laboratory, before and after oviposition, of two populations of Psammodromus algirus separated by 700 m altitude. When gravid, females escaped using a larger number of slower and shorter runs, and had lower temperatures at the time of trial, than after oviposition. Some of these effects differed between populations: when gravid, but not after oviposition, low-elevation females ran shorter distances at a slower average speed than high-elevation ones. Low-elevation females laid their clutches earlier than high-elevation ones, which conditioned their lower speed when gravid in simultaneous running trials. However, their escape distances were still shorter after controlling for the effects of temperature and laying date. In the field, refuge availability was lower at the low-elevation site, where females spent more time inside refuges and perching above ground. The shorter escape distance of low-elevation females may, thus, represent a behavioural response to minimize detectability, especially if predator avoidance depends primarily on whether or not the lizard is seen by the predator. Such behavioural adjustments might inhibit selection for evolutionary shifts in the performance of gravid females.

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