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1.
《Chronobiology international》2013,30(3):159-164
Two species of spiny mice of the genus Acomys—the golden spiny A. russaturs and the common spiny A. cuhirinus—are syrnpatnc in the and and hot parts of the Rift Valley in Israel. The coexistence of these two species is due to exclusion of A. russatus mice by A. cuhirinus mice from nocturnal activity. The aim of this research was to study if odor signals released by A. cahirinus mice can play a role in the exclusion of A. russatus mice. A. russatus mice with an implanted transmitter recording body temperature (Tb) were kept alone in a metabolic chamber under constant conditions of ambient temperature (27°C) and photoperiod (12 h light: 12 h dark). After 5 days of recording, chemical signals from an A. cuhirinus mouse were added through the air tube going into the metabolic chamber of the A. russatus mice. This treatment caused a shift of ~ 2 h inTb daily rhythm of the naive tested A. russutus mice, whereas no shift was observed in A. russatus mice that had been kept in the same room with the A. cahirinus mouse before measurements. These results strongly support the idea that chemical signals released by A. cahirinus mice can entrain the Tb rhythms of A. russatus mice. Therefore, it may be assumed that the exclusion of A. russatus mice from nocturnal activity by A. cuhirinus mice could be achieved through the odor released by the latter. 相似文献
2.
Two species of the genus Acomys coexist in arid zones of southern Israel. Acomys russatus is distributed in extremely arid areas, while A. cahirinus is common in both Mediterranean and arid regions. Individuals of both species from a rodent community in the Ein Gedi Nature
Reserve were implanted with temperature-sensitive transmitters. Body temperature (T
b) rhythms were recorded in free-ranging mice at four different seasons of the year. A. cahirinus (30–45 g) showed a nocturnal rhythm of T
b throughout the year. In the activity phase during the night T
b increased to 38.2°C. During the day T
b decreased to 34°C. This species displayed this pattern in summer also when ambient temperatures rose above T
b. The T
b of A. russatus (45–65 g) varied between 34.8 and 41°C during the hot season, showing a bimodal temperature rhythm with maximal values in
the morning and in the evening. Measurements of activity in this species showed inactivity during the hottest period of a
summer day. In winter A. russatus showed no clearly detectable diurnal or ultradian rhythm in T
b, which remained constant between narrow limits of 35.2 and 36.8°C.
Received: 21 December 1998 / Accepted: 15 March 1999 相似文献
3.
Light masking has been studied almost exclusively in the laboratory. The authors populated four field enclosures with locally coexisting nocturnal Acomys cahirinus and diurnal A. russatus, and monitored their body temperatures (T(b)) using implanted temperature-sensitive radio transmitters. A 3-h light pulse was initiated at the beginning of two consecutive nights; preceding nights were controls. A. cahirinus T(b) and calculated activity levels decreased significantly during the light pulse, demonstrating a negative light masking response (light effect on T(b): -0.32 °C?±?0.15 °C; average calculated activity records during the light pulse: 7?±?1.53, control: 9.8?±?1.62). Diurnal A. russatus did not respond to the light pulse. We conclude that light masking is not an artifact of laboratory conditions but represents a natural adaptive response in free-living populations. 相似文献
4.
Dawn Cory Toussaint Andrew E. McKechnie 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2012,182(8):1129-1140
Bats in hot roosts experience some of the most thermally challenging environments of any endotherms, but little is known about how heat tolerance and evaporative cooling capacity vary among species. We investigated thermoregulation in three sympatric species (Nycteris thebaica, Taphozous mauritianus and Sauromys petrophilus) in a hot, semi-arid environment by measuring body temperature (T b), metabolic rate and evaporative water loss (EWL) at air temperatures (T a) of 10?C42?°C. S. petrophilus was highly heterothermic with no clear thermoneutral zone, and exhibited rapid increases in EWL at high T a to a maximum of 23.7?±?7.4?mg?g?1?h?1 at T a????42?°C, with a concomitant maximum T b of 43.7?±?1.0?°C. T. mauritianus remained largely normothermic at T as below thermoneutrality and increased EWL to 14.7?±?1.3?mg?g?1?h?1 at T a????42?°C, with a maximum T b of 42.9?±?1.6?°C. In N. thebaica, EWL began increasing at lower T a than in either of the other species and reached a maximum of 18.6?±?2.1?mg?g?1?h?1 at T a?=?39.4?°C, with comparatively high maximum T b values of 45.0?±?0.9?°C. Under the conditions of our study, N. thebaica was considerably less heat tolerant than the other two species. Among seven species of bats for which data on T b as well as roost temperatures in comparison to outside T a are available, we found limited evidence for a correlation between overall heat tolerance and the extent to which roosts are buffered from high T a. 相似文献
5.
Wube T Fares F Haim A 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2008,151(4):499-504
Increased dietary salinity suppressed reproduction of the xeric adapted golden spiny mouse, Acomys russatus. Testicular and uterine mass were reduced, suppressed spermatogenesis and vaginal closure were observed. The anti-diuretic hormone, vasopressin (VP), was suggested to mediate such effects. However, increased dietary salinity did not affect reproductive status of a mesic adapted population of the common spiny mouse, A. cahirinus. In the present study, the effect of exogenous VP on the reproductive status and energy balance of both males and females of A. russatus and of a mesic population of A. cahirinus was tested. Vasopressin (Sigma, 50 µg/kg) was injected intraperitoneally in three-day intervals for four weeks. In VP-treated A. russatus, spermatogenesis was significantly suppressed while the change in testis mass did not show significant difference. Both control and VP-treated females lost body mass (Wb) significantly and the latter also exhibited a higher energy expenditure compared to their male counterparts. VP did not affect reproductive status in both sexes of A. cahirinus. Also it did not have a significant effect on Wb, energy intake, and energy expenditure in this species. Our results support the idea that VP mediates the effects of increased diet salinity on reproduction in A. russatus. The results also reinforce previous knowledge that different physiological systems could be integrated by a single biochemical signal. 相似文献
6.
《Chronobiology international》2013,30(7):1401-1419
Many mammals display predictable daily rhythmicity in both neuroendocrine function and behavior. The basic rest-activity cycles are usually consistent for a given species and vary from night-active (nocturnal), those mostly active at dawn and dusk (i.e., crepuscular), and to day-active (diurnal) species. A number of daily rhythms are oppositely phased with respect to the light/dark (LD) cycle in diurnal compared with nocturnal mammals, whereas others are equally phased with respect to the LD cycle, regardless of diurnality/nocturnality. Pineal produced melatonin (MLT) perfectly matches this phase-locked feature in that its production and secretion always occurs during the night in both diurnal and nocturnal mammals. As most rodents studied to date in the field of chronobiology are nocturnal, the aim in this study was to evaluate the effect of light manipulations and different photoperiods on a diurnal rodent, the fat sand rat, Psammomys obesus. The authors studied its daily rhythms of body temperature (Tb) and 6-sulphatoxymelatonin (6-SMT) under various photoperiodic regimes and light manipulations (acute and chronic exposures) while maintaining a constant ambient temperature of 30°C?±?1°C. The following protocols were used: (A) Control (CON) conditions 12L:12D; (A1) exposure to one light interference (LI) of CON-acclimated individuals for 30?min, 5?h after lights-off; (A2) short photoperiod (SP) acclimation (8L:16D) for 3 wks; (A3) 3 wks of SP acclimation with chronic LI of 15?min, three times a night at 4-h intervals; (A4) chronic exposure to constant dim blue light (470nm, 30 lux) for 24?h for 3 wks (LL). (B) The response to exogenous MLT administration, provided in drinking water, was measured under the following protocols: (B1) After chronic exposure to SP with LI, MLT was provided once, starting 1?h before the end of photophase; (B2) after a continuous exposure to dim blue light, MLT was provided at 15:00?h for 2?h for 2 wks; (B3) to CON animals, MLT was given intraperitoneally (i.p.) at 14:00?h. The results demonstrate that under CON acclimation, Psammomys obesus has robust Tb and 6-SMT daily rhythms in which the acrophase (peak time) of Tb is during the photophase, whereas that of 6-SMT is during scotophase. LI resulted in an elevation of Tb and a reduction of 6-SMT levels. A significant difference in the response was noted between acute and chronic exposure to LI, particularly in 6-SMT levels, which were lower than CON after LI and higher after chronic LI, implying an acclimation process. Constant exposure to blue light abolished Tb and 6-SMT rhythms in all the animals. MLT administration resumed the Tb daily rhythm in these animals, and had a recovery effect on the chronic LI-exposed animals, resulting in a Tb decrease. Altogether, the authors show in this study the different modifications of Tb rhythms and MLT levels in response to environmental light manipulations. These series of experiments may serve as a basis for establishing P. obesus as an animal model for further studies in chronobiology. (Author correspondence: hagitsc@research. haifa. ac. il) 相似文献
7.
《Chronobiology international》2013,30(4):782-806
This study investigated the physiological function of suppressed melatonin through thermoregulation in a cold environment. Interactions between thermoregulation directly affected by exposure to a cold environment and indirectly affected by endogenous melatonin suppression by bright-light exposure were examined. Ten male subjects were exposed to two different illumination intensities (30 and 5000 lux) for 4.5?h, and two different ambient temperatures (15 and 27°C) for 2?h before sleep under dark and thermoneutral conditions. Salivary melatonin level was suppressed by bright light (p?<?0.001), although the ambient temperature condition had no significant effect on melatonin. During sleep, significant effects of pre-sleep exposure to a cold ambient temperature (p?<?0.001) and bright light (p?<?0.01) on rectal temperature (Tre) were observed. Pre-sleep, bright-light exposure led to an attenuated fall in Tre during sleep. Moreover, Tre dropped more precipitously after cold exposure than thermoneutral conditions (cold: ?0.54?±?0.07°C/h; thermoneutral: ?0.16?±?0.03°C/h; p?<?0.001). Pre-sleep, bright-light exposure delayed the nadir time of Tre under thermoneutral conditions (p?<?0.05), while cold exposure masked the circadian rhythm with a precipitous decrease in Tre. A significant correlation between the Tre nadir and melatonin level (r?=??0.774, p?<?0.05) indicated that inter-individual differences with higher melatonin levels lead to a reduction in Tre after cold exposure. These results suggest that suppressed endogenous melatonin inhibits the downregulation of the body temperature set-point during sleep. (Author correspondence: ishibasi@design. kyushu-u. ac. jp) 相似文献
8.
The proliferation parameters of the Walker carcinoma were estimated from both in vivo and in vitro measurements. The transplantable Walker carcinoma 256 was grown in male inbred BD1 rats. During exponential growth, 5-6 days after transplantation, a PLM curve was performed, yielding estimates of Tc ? 18.0 hr, Ts ? 6.4 hr, TG2+M? 4.1 hr. With the double labelling technique in vitro under 2.2 atm oxygen we obtained: Tc ? 18.2hr, Ts ? 8.2 hr, TG2+M? 2.0hr. From pulse cyto-photometry DNA content histograms the fractions of cells in the cell cycle phases were calculated using a computer program: fG1? (47.6 ± 1.1)%, fs? (34.1 ± 1.0)%, fG2+M? (18.3 ± 1.5)%. These fractions remained constant between the fifth and the twelfth day after transplantation. At that time the tumour growth had already slowed down appreciably. The growth fraction determined by repetitive labelling was 0.96 on the fifth and 0.93 on the seventh and eleventh day. The cell loss factor was φ? 17% during exponential tumor growth and increased to about 100% between the tenth and twelfth day. The agreement of the cell kinetic data determined by autoradiography from solid tumours in vivo (PLM, continuous labelling) and autoradiography as well as pulse cytophotometry from in vitro experiments (excised material) was satisfactory. 相似文献
9.
Respiration of thermogenic inflorescences of skunk cabbage Symplocarpus renifolius in heliox
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The respiration rate of the thermogenic inflorescences of Japanese skunk cabbage Symplocarpus renifolius can reach 300 nmol s?1 g?1, which is sufficient to raise spadix temperature (Ts) up to 15 ° C above ambient air temperature (Ta). Respiration rate is inversely related to Ta, such that the Ts achieves a degree of independence from Ta, an effect known as temperature regulation. Here, we measure oxygen consumption rate (?o 2) in air (21% O2 in mainly N2) and in heliox (21% O2 in He) to investigate the diffusive conductance of the network of gas‐filled spaces and the thermoregulatory response. When Ts was clamped at 15 ° C, the temperature that produces maximal ?o 2 in this species, exposure to high diffusivity heliox increased mean ?o 2 significantly from 137 ± 17 to 202 ± 43 nmol s?1 g?1 FW, indicating that respiration in air is normally limited by diffusion in the gas phase and some mitochondria are unsaturated. When Ta was clamped at 15 ° C and Ts was allowed to vary, exposure to heliox reduced Ts 1 ° C and increased ?o 2 significantly from 116 ± 10 to 137 ± 19 nmol s?1 g?1, indicating that enhanced heat loss by conduction and convection can elicit the thermoregulatory response. 相似文献
10.
This study compares the thermal ecology of male bearded dragon lizards (Pogona barbata) from south-east Queensland across two seasons: summer (1994–1995) and autumn (1995). Seasonal patterns of body temperature
(T
b) were explored in terms of changes in the physical properties of the thermal environment and thermoregulatory effort. To
quantify thermoregulatory effort, we compared behavioral and physiological variables recorded for observed lizards with those
estimated for a thermoconforming lizard. The study lizards' field T
bs varied seasonally (summer: grand daily mean (GDM) 34.6 ± 0.6°C, autumn: GDM 27.5 ± 0.3°C) as did maximum and minimum available
operative temperatures (summer: GDM T
max 42.1 ± 1.7°C, T
min 32.2 ± 1.0°C, autumn: GDM T
max 31.7 ± 1.2°C, T
min 26.4 ± 0.5°C). Interestingly, the range of temperatures that lizards selected in a gradient (selected range) did not change
seasonally. However, P. barbata thermoregulated more extensively and more accurately in summer than in autumn; lizards generally displayed behaviors affecting
heat load nonrandomly in summer and randomly in autumn, leading to the GDM of the mean deviations of lizards' field T
bs from their selected ranges being only 2.1 ± 0.5°C in summer, compared to 4.4 ± 0.5°C in autumn. This seasonal difference
was not a consequence of different heat availability in the two seasons, because the seasonally available ranges of operative
temperatures rarely precluded lizards from attaining field T
bs within their selected range, should that have been the goal. Rather, thermal microhabitat distribution and social behavior
appear to have had an important influence on seasonal levels of thermoregulatory effort.
Received: 28 April 1997 / Accepted: 29 December 1997 相似文献
11.
12.
Moloud Gholamzadeh Chitgar Roya Khosravi Jalal JalaliSendi Mohammad Ghadamyari 《Archives Of Phytopathology And Plant Protection》2013,46(7):781-788
Sublethal effects of Thymus vulgaris were investigated on life-table parameters of Tetranychus urticae Koch (Acari: Tetranychidae) in the laboratory conditions at 25?±?1?°C, 70?±?10% RH and a 14:10?h (L:D) photoperiod. Bioassay was conducted to assess the effect of different concentrations of T. vulgaris essential oil on two-spotted spider mite. LC50 and LC20 of T. vulgaris on T. urticae were calculated as 18.86 and 6.24?μl/litre air for 24?h after treatment. In the sublethal effects, after 24?h exposure to LC50 concentration, mortality, fecundity and longevity of the females that survived from treatment were determined. Results showed that T. vulgaris caused significant reductions in fecundity and longevity of adults. Life-table assay indicated that the intrinsic rate of increase (r m), net reproductive rate (R 0), finite rate of increase (λ), mean generation time (T), significantly reduced in treated females compared to control. These results suggest that T. vulgaris could be incorporated in integrated pest management programmes of T. urticae. 相似文献
13.
Wendy A. Wilson M. Justin O’Riain Robyn S. Hetem Andrea Fuller Linda G. Fick 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2010,180(7):1099-1110
The body temperature (T
b) of Cape ground squirrels (Xerus inauris, Sciuridae) living in their natural environment during winter has not yet been investigated. In this study we measured abdominal
T
b of eight free-ranging Cape ground squirrels over 27 consecutive days during the austral winter. Mean daily T
b was relatively stable at 37.0 ± 0.2°C (range 33.4 to 40.2°C) despite a marked variation in globe temperature (T
g) (range −7 to 37°C). Lactating females (n = 2) consistently had a significantly higher mean T
b (0.7°C) than non-lactating females (n = 3) and males. There was a pronounced nychthemeral rhythm with a mean active phase T
b of 38.1 ± 0.1°C and a mean inactive phase T
b of 36.3 ± 0.3°C for non-lactating individuals. Mean daily amplitude of T
b rhythm was 3.8 ± 0.2°C. T
b during the active phase closely followed T
g and mean active phase T
b was significantly correlated with mean active phase T
g (r
2 = 0.3–0.9; P < 0.01). There was no evidence for daily torpor or pronounced hypothermia during the inactive phase, and mean minimum inactive
phase T
b was 35.7 ± 0.3°C for non-lactating individuals. Several alternatives (including nocturnal huddling, an aseasonal breeding
pattern and abundant winter food resources) as to why Cape ground squirrels do not employ nocturnal hypothermia are discussed. 相似文献
14.
Information regarding passerine heterothermy and torpor is scant, although many species are small and must cope with a fluctuating
food supply and presumably would benefit from energy savings afforded by torpor. We studied whether insectivorous Dusky Woodswallows
(Artamus cyanopterus; ∼35 g) enter spontaneous torpor (food ad libitum) when held outdoors as a pair in autumn/winter. Woodswallows displayed
pronounced and regular daily fluctuations in body temperature (T
b) over the entire study period. The mean T
b ranged from ∼39°C to 40°C (photophase, day time) and ∼33°C to 36°C (scotophase, night time). However, on 88% of bird nights,
nocturnal T
b minima fell to < 35°C. The lowest T
b observed in air was 29.2°C. However, when a bird fell into water its T
b dropped further to ∼22°C; this T
b was regulated for several hours and the bird survived. Our observations suggest that heterothermy is a normal part of the
daily thermal regime for woodswallows to minimise energy expenditure. Spontaneous nocturnal torpor in captive woodswallows
suggests that torpor in the wild may be more pronounced than recorded here because free-living birds are likely challenged
by both low food availability and adverse weather. 相似文献
15.
Faeze Tavoosi Ajvad J. P. Michaud Doostmorad Zafari Mohammad Khanjani 《Biocontrol Science and Technology》2018,28(2):157-171
Gaeolaelaps aculeifer (Canestrini, 1883) is a soil-dwelling predatory mite with potential for use as a biological control agent of fungus gnats (Diptera: Sciaridae) in mushroom production. The life table, predation rate and population growth rate of G. aculeifer on a diet of larvae of the sciarid fly, Lycoriella auripila, at 23?±?1°C, 60?±?5% RH and a photoperiod of 0:24 (L:D)?h was investigated. The results revealed that the duration of egg, larva, protonymph, deutonymph, females and males of G. aculeifer were 3.8?±?0.1, 1.4?±?0.1, 3.9?±?0.1, 4.1?±?0.1, 67.7?±?2.8 and 60.3?±?3.1 days, respectively. Net reproductive rate (R0) was 54.8?±?7.1 offspring, intrinsic rate of increase (r) was 0.12?±?0.01 offspring day?1, finite rate of increase (λ) was 1.13?±?0.01 day?1and mean generation time (T) was 32.3?±?0.6 days. The predator consumed a mean of 0.08?±?0.05, 1.73?±?0.18, 3.16?±?0.28 and 75.9?±?7.1 third instar L. auripila larvae during the larval (1.3?±?0.1 days), protonymph (3.9?±?0.1 days), deutonymph (4.1?±?0.1 days) and adult (52.6?±?2.2 days) stages. Population parameters and consumption rates suggest that G. aculeifer has good potential as a biological control agent of L. auripila in mushroom production. 相似文献
16.
The enthalpy change associated with the isothermal pH-induced uncharged coil-to-helix transition ΔHh° in poly(L -ornithine) in 0.1 N KCl has been determnined calorimetrically to be ?1530 ± 210 and ?1270 ± 530 cal/mol at 10° and 25°C, respectively. Titration data provided information about the state of charge of the polymer in the calorimetric experiments, and optical rotatory dispersion data about its conformation. In order to compute ΔHh°, the observed calorimetric heat was corrected for the heat of breaking the sample cell, the heat of dilution of HCl, the heat of neutralization of the OH? ion, and the heat of ionization of the δ-amino group in the random coil. The latter was obtained from similar calorimetric measurements on poly(D ,L -ornithine). Since it was discovered that poly(L -ornithine) undergoes chain cleavage at high pH, the calorimetric measurements were carried out under conditions where no degradation occurred. From the thermally induced uncharged helix–coil transition curve for poly(L -ornithine) at pH 11.68 in 0.1 N KCl in the 0°–40°C region, the transition temperature Ttr and the quantity (?θh/?T)Ttr have been obtained. From these values, together with the measured values of ΔHh°, the changes in the standard free energy ΔGh° and entropy ΔGh°, associated with the uncharged coil-to-helix transition at 10°C have been calculated to be ?33 cal/mol and ?5.3 cal/mol deg, respectively. The value of the Zimm–Bragg helix–coil stability constant σ has been calculated to be 1.4 × 10?2 and the value of s calculated to be 1.06 at 10°C, and between 0.60 and 0.92 at 25°C. 相似文献
17.
A functional response study of Chrysoperla carnea (Stephens) larvae to different densities of sugar cane whitefly Aleurolobus barodensis (Maskell) was conducted in test tubes at 26?±?2 °C, 65?±?5 % RH. Chrysoperla carnea showed two different types of functional response in larval instars. First instar exhibits type II. However, second and third larval instars revealed type III functional response. Based on modified Holling’s disk equation, the highest searching rates (a) of 0.82?±?0.0247 h?1 was found for first instar larva. For second and third larval instars, the attack coefficient (b) were 0.002?±?0.030 and 0.0025?±?0.0424 respectively. The shortest handling time (Th) per prey was observed at third instar stage (1.574?±?0.0568 h) followed by second and first instar with 1.72?±?0.0411 h and 1.919?±?0.0568 h respectively. 相似文献
18.
Daily Rhythms of Metabolic Rate and Body Temperature of Two Murids from Extremely Different Habitats
《Chronobiology international》2013,30(5):341-349
Daily circadian rhythms of body temperature (Tb) and oxygen consumption (VO2) were measured in two murid species, which occupy extremely different habitats in Israel. The golden spiny mouse (Acomys mssalus) is a diurnal murid distributed in arid and hot parts of the great Syrio-African Rift Valley, while the broad-toothed field mouse (Apodeinns mystacinus) is a nocturnal species that inhabits the Mediterranean woodlands. In both species, the daily rhythms of Tb and VO2 are entrained by the photoperiod. Under laboratory experimental conditions (ambient temperature Ta = 33oC and photoperiod regime of 12L: 12D), Acomys russatus exhibits a tendency towards a nocturnal activity pattern, compared to the diurnal activity displayed by this species under natural conditions. Under the same photoperiod regime and at Ta = 28oC, Apodemus mystacinus displays nocturnal activity, as observed under natural conditions. The maximal values of Tb were recorded in Acomys russatus at midnight (23:50 h), while the maximal values of VO2 were recorded at the beginning of the dark period (18:20 h). In Apodemus mystacinus, the maximal values of Tb and VO2 were recorded at 23:40 and 20:00 h, respectively. The ecophysiological significance of these results is discussed further. 相似文献
19.
Mahmoud M. Al-Azzazy Suloiman M. Al-Rehiayani Nagdy F. Abdel-Baky 《Archives Of Phytopathology And Plant Protection》2013,46(11-12):637-648
AbstractStudies on the life history and life table parameters of Neoseiulus cucumeris Oudemans (Acari: Phytoseiidae) were carried out under laboratory conditions of 25?±?1?°C and 65?±?5% RH; 30?±?1?°C and 60?±?5% RH; 35?±?1?°C and 55?±?5% RH. As prey, immature stages of tetranychid spider mite T. urticae Koch (Acari: Tetranychidae) and the moving stages of the Tomato Russet Mite A. lycopersici (Massee) (Acari: Eriophyideae) were selected. The predatory phytoseiid mite, Neoseiulus cucumeris (Oudemans) was able to develop successfully from egg to adult stage through the entire life history on both preys. The higher of different temperatures and relative humidities shortened the development and increased reproduction and prey consumption and vice versa. The maximum reproduction (3.91, and 3.09 eggs/♀/day) was recorded at 35?°C and 65% RH, while the minimum (2.12, and 1.90 eggs/♀/day) was at 25?±?1?°C and 55?±?5% RH. when N. cucumeris fed on A. lycopersici and T. urticae, respectively. The reproductive rate on eriophyid was significantly higher than previously recorded on tetranychid. Life table parameters indicated that feeding of phytoseiid mite N. cucumeris on tomato russet mite A. lycopersici led to the highest reproduction rate (rm?=?0.268, 0.232 and 0.211 females/female/day), while feeding on T.urticae gave the lowest reproduction rate (rm?=?0.159, 0.143 and 0.131) at 35?°C and 55% RH, 30?°C and 60% RH and 25?°C and 65% RH, respectively. The population of N. cucumeris multiplied (36.81, 28.71 and 20.47) and (24.60, 19.58 and 14.62 times) in a generation time of (20.10, 23.20 and 25.14) and (22.35, 25.36 and 27.79 days) when a predator fed on A. lycopersici and T. urticae at the same temperature above mentioned, respectively. These results suggest that the two mites, particularly A. lycopersici, proved to be suitable prey for N.cucumeris, as a facultative predator. 相似文献
20.
The functional response of a predator describes the rate at which it kills its prey at different prey densities and is, therefore, an important tool to determine the efficiency of a predator in regulating the population dynamics of a prey. We investigated the functional response of Coccinella septempunctata L. (Coleoptera: Coccinellidae) to varying densities of Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). The results revealed that the linear coefficient, P1 in the reduced logistic model was found significantly negative for the 4th instar larvae and adult male and female of C. septempunctata (?0.002, ?0.004 and???0.002, respectively) indicating a type II functional response. The parameter estimates of adult male, female and 4thinstar larvae of C. septempunctata calculated through Holling's disc model revealed that the highest attack rate (a) (1.047?±?0.014), shortest handling time (Th) (0.0984?±?0.024?h) and largest maximum capture rate (T/Th) (243.902) was exhibited by female. Parameter estimates calculated through Rogers’s equation also showed the same sequence where maximum attack rate (a) of 0.00256?±?0.0003 was exhibited by female followed by 4th instar larvae (0.00251?±?0.0005). The shortest handling time (Th) (0.210?±?0.003?h) and highest maximum capture rate (T/Th) (114.17) was also exhibited by female. Comparison of functional response curves of adult male, female and 4th instar larvae revealed that maximum consumption of prey at all the densities offered was shown by female followed by 4thinstar larvae. The study manifested that C. septempunctata could be an efficient biocontrol agent of pea aphid, A. pisum. 相似文献