Survival and reproduction of resident and immigrant female root voles (Microtus oeconomus)

1998 ◽  
Vol 76 (4) ◽  
pp. 763-766 ◽  
Author(s):  
Edda Johannesen ◽  
Harry P Andreassen
Keyword(s):  
Reproductive Rate ◽  
Spatially Explicit ◽  
Vital Rates ◽  
Place Of Birth ◽  
Net Reproductive Rate ◽  
Microtus Oeconomus ◽  
Root Vole ◽  
Significant Difference ◽  
Survival And Reproduction ◽  
Different Populations

Many spatially explicit population models assume that residents and immigrants have equal vital rates (survival and reproduction). We tested this assumption by using root vole (Microtus oeconomus) populations in an experimental setting where habitat patches were embedded in an uninhabitable transition habitat. Place of birth and matrilineal relations were known for all animals in 12 different populations. Females were classified as residents or immigrants depending on whether they stayed and reproduced in their natal patch or settled and reproduced in a foreign patch. We compared survival probabilities, derived from the Jolly-Seber-Cormack model, and reproductive parameters between resident and immigrant root vole females. We found no difference between residents and immigrants for any of the parameters examined. Nor did we find any significant difference in net reproductive rate (R0) derived from Leslie models utilizing estimated demographic parameters for residents and immigrants. We conclude that the assumption of equal vital rates may be justified, at least at the spatial scale considered in this study.

Variation in life-cycle between three rare and endangered floodplain violets in two regions: implications for population viability and conservation

Biologia ◽  
2009 ◽  
Vol 64 (1) ◽  
Author(s):  
Rolf Eckstein ◽  
Jiří Danihelka ◽  
Annette Otte
Keyword(s):  
Species Conservation ◽  
Reproductive Rate ◽  
Population Viability ◽  
Life Cycles ◽  
Habitat Destruction ◽  
Vital Rates ◽  
Net Reproductive Rate ◽  
Demographic Traits ◽  
Unequivocal Identification ◽  
Rare And Endangered

AbstractWe studied the demography of Viola elatior, V. pumila, and V. stagnina, three rare and endangered Central European floodplain species, to (i) analyse variation in life-cycles among congeners and between regions (Dyje-Morava floodplains, Czech Republic; Upper Rhine, Germany), (ii) to define sensitive stages in the life-cycles, and (iii) to identify possible threats for population viability and species conservation.Matrix models were based on the fate of marked individuals from a total of 27 populations over two years. We analysed population growth rate (λ), stage distribution, net reproductive rate (R 0), generation time, age at first reproduction, and elasticity and calculated a life table response experiment (LTRE).Most populations were declining and λ did not differ between species or regions during the observed interval. Despite higher probabilities for survival and flowering in the Dyje populations, R 0 was higher in the Rhine populations. Also other demographic traits showed consistent differences between regions and/or species. Complex life-cycles and large variation in λ precluded unequivocal identification of sensitive stages or vital rates for conservation. Variation between regions may be a consequence of differences in habitat quality.Our results suggest that deterministic processes such as reduced management, succession, habitat destruction, and lack of disturbance through reduced or eliminated flooding present the strongest threat for the viability and persistence of populations of the three floodplain violets as compared with stochastic processes. However, the persistent seed bank of the species may buffer populations against environmental variation and represents a reservoir for recovery after resumption of suitable land-use management.

Development, survival and reproduction of a potential biological control agent, Lasioseius japonicus Ehara (Acari: Blattisociidae), on eggs of Drosophila melanogaster (Diptera: Drosophilidae) and Sitotroga cerealella (Lepidoptera: Gelechiidae)

2020 ◽  
Vol 25 (8) ◽  
pp. 1461-1471
Author(s):  
Lixia Xie ◽  
Na Zhang ◽  
Xinran Wu ◽  
Kai Liu ◽  
Chenlin Liu ◽  
...  
Keyword(s):  
Generation Time ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Sitotroga Cerealella ◽  
Finite Rate ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Survival And Reproduction ◽  
The Mean

Lasioseius japonicus is a species of soil-dwelling predatory mite with great potential for controlling insect pests and has a broad application prospect in biological control. This study was conducted under indoor conditions to explore the development, survival and reproduction of L. japonicus on two diets. Through the construction of two-sex life table of L. japonicus, it was revealed that, when it preyed on eggs of Drosophila melanogaster, the intrinsic rate of increase (r) was 0.2614 d-1, the net reproductive rate (R0) was 57.76 offspring, the finite rate of increase (λ) was 1.2988 d-1, and the mean generation time (T) was 15.49 d. When preying on eggs of Sitotroga cerealella, the intrinsic rate of increase (r) of L. japonicus was 0.1560 d-1, the net reproductive rate (R0) was 20.96 offspring, the finite rate of increase (λ) was 1.1690d-1, and the mean generation time (T) was 19.41 d. In addition, the life expectancy and population growth trend of L. japonicus were simulated based on the above two alternative prey species. The results showed that feeding on the eggs of D. melanogaster is more beneficial to the growth and reproduction of L. japonicus.

Time of joining affects the performance of young Angus and Angus multiply Friesian cattle in the south-west of Western Australia. 1. Liveweight, body condition, and reproductive performance in heifers and first-calvers

1993 ◽  
Vol 33 (5) ◽  
pp. 511
Author(s):  
GJ Sawyer ◽  
J Milligan ◽  
DJ Barker
Keyword(s):  
Reproductive Performance ◽  
Post Partum ◽  
Reproductive Rate ◽  
Grazing Pressure ◽  
Net Reproductive Rate ◽  
South West ◽  
Significant Difference ◽  
Breeding Herd ◽  
Conception Date ◽  
Friesian Cattle

A 3-year study using 183 Angus and 173 Angus x Friesian first-calf heifers joined at about 15 months of age was conducted to determine the effects of time of calving and breed on liveweight and condition, heifer reproductive performance, oestrus activity after calving, and subsequent conception. Pasture on offer and supplements were also measured. Calving times used were April (conventional calving time), March (4 weeks earlier), and May (4 weeks later). There was no significant effect of time of calving on net reproductive rate in heifers of either breed, but the number of stillbirths and dystocias in later calved Angus were greater than in Angus x Friesian. Protracted and difficult calvings were more prevalent in heifers of both breeds calving early. Highest pregnancy rates of 93-94% corresponded with the highest average liveweights at conception in nulliparous heifers of both breeds that were mated to first-calve later. Angus x Friesian first-calvers consistently returned to oestrus before Angus after their first calving. In a year when grazing pressure on depleted dry pasture residues caused significant liveweight loss in both breeds, the crossbreds commenced cycling, on average, 20-32 days before the Angus. Regression of calving date and length of the post-partum anoestrous interval (PPAI) was -0.54 days/day for Angus and -0.3 1 days/day for Angus x Friesian. There was no significant difference between breeds for time to conception. The regression of second conception date on first calving date was 0.10 days/day in Angus and 0.17 days/day in Angus x Friesian. Heavier first-calvers of both breeds returned to oestrus earlier; each extra 10 kg in liveweight was associated with shorter PPAI by 3.9 days in Angus and 1.7 days in Angus x Friesian crossbreds. Heavier first-calvers of both breeds also conceived earlier; however, about twice as much weight was required to reduce the time to conception in the larger Angus x Friesian crossbreds than in the Angus. Times to first oestrus and to conception were negatively and linearly related to condition only in Angus first-calvers. Conception rates after first calving did not differ between time-of-calving groups or breeds in 2 years, but in a difficult year and if calved later, only 73% of Angus and 61 % of Angus x Friesians were pregnant after 90 days of joining. We conclude that there is little justification on the grounds of reproductive performance for varying the time of calving of heifers from that of the main breeding herd.

scholarly journals Life History Evaluation of Ooencyrtus lucidus, a Newly Described Egg Parasitoid of Bagrada hilaris

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 292
Author(s):  
Fatemeh Ganjisaffar ◽  
Thomas M. Perring
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Intrinsic Rate ◽  
Developmental Time ◽  
Egg Parasitoid ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Significant Difference

Ooencyrtus lucidus Triapitsyn & Ganjisaffar (Hymenoptera: Encyrtidae) was recently recovered from fresh sentinel eggs of Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae) in California. In the present study, life history traits of O. lucidus were studied at 26 ± 0 . 5 ∘ C, 40 ± 10 % RH, and a photoperiod of 14 L: 10 D hours. Results showed that 95.2% of the parasitized eggs yielded successful emergence of adults. The total immature developmental time was 14.27 and 13.95 days for females and males, respectively. The sex ratio of O. lucidus was 0.5 (females/offspring). Mated females laid on average 6.0 eggs per day and 222.7 eggs during their mean ovipositional period of 37.3 days. There was no significant difference in reproduction parameters between mated and non-mated females. The net reproductive rate ( R 0 ) was 103.8 females/female/generation, the intrinsic rate of increase ( r m ) was 0.171 females/female/day, the finite rate of increase ( λ ) was 1.187 population multiplication/day, the mean generation time (T) was 27.1 days, and the doubling time (DT) was 4.0 days. The highest longevity was observed in mated and non-mated females fed with honey, and they lived for 70.8 and 70.1 days, respectively. Providing females with host eggs in addition to honey, reduced their longevity by 24% in mated and 28% in non-mated individuals. Non-mated females and males deprived of honey only lived for 3.5 and 2.5 days after emergence, respectively. Our results indicate that O. lucidus has sufficient life history traits to make it a promising egg parasitoid for the biological control of B. hilaris.

scholarly journals How long-term mass rearing affects the quality of the Trichogramma embryophagum (Hartig) (Hymenoptera: Trichogrammatidae) reared on Sitotroga cerealella (Olivier) eggs

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Farzaneh Sadat ◽  
Alireza Nazari ◽  
Shahriar Jafari ◽  
Zahra Rafiei Karahroudi
Keyword(s):  
Biological Control ◽  
Mass Rearing ◽  
Reproductive Rate ◽  
Adult Longevity ◽  
Biological Traits ◽  
Sitotroga Cerealella ◽  
Net Reproductive Rate ◽  
Significant Difference

Abstract Background Maintaining the quality and efficacy of biological control agents during long-term mass rearing plays a crucial role in the success of a biological control program. In this study, the biological traits of a local population colony of Trichogramma embryophagum (Hartig) with rearing on Sitotroga cerealella (Olivier) eggs for over 40 generations (G) were assessed. Results Female adult longevity was significantly different among generations, ranging from 7.98 d in G5 to 5.19 d in G40. The reared wasps showed highest fecundity (60.50 eggs/female) in G5 compared to the other generations. The female sex ratio varied from 63.16% in G5 to 49.31% in G40. Significant differences were observed in population growth parameters and the highest gross reproductive rate (GRR) (40.96 eggs/individual) and net reproductive rate (R0) (38.21 eggs/individual) were found in G5. However, a non-significant difference was found in the intrinsic rate of natural increase (r) until the 10th generation, but its values significantly declined with increasing the generation numbers. The finite parasitism rate (ω) ranged from 0.468 host/parasitoid/day in G5 to 0.274 host/parasitoid/day in G40. Conclusions The results showed that the quality of T. embryophagum reared under continuous laboratory conditions declined after 10 generations, and for use of them in biological control programs under field conditions, the reared population should be refreshed by adding wild individuals from time to time.

scholarly journals LIFE AND FERTILITY TABLES OF Pineus boerneri ANNAND (HEMIPTERA: ADELGIDAE) ON Pinus spp. (PINACEAE)

FLORESTA ◽  
2016 ◽  
Vol 46 (2) ◽  
pp. 251
Author(s):  
Josiane Teresinha Cardoso ◽  
Sonia Maria Noemberg Lazzari
Keyword(s):  
Intrinsic Rate ◽  
Pinus Elliottii ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Reproductive Capacity ◽  
Nymphal Stage ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Pinus Spp

Biological parameters of Pineus boerneri were evaluated in laboratory using seedlings of Pinus taeda and Pinus elliottii. The nymphs were observed along their development. The total life cycle was not significantly different on P. taeda and P. elliottii, being, respectively, 69 and 65 days. The same trend was observed for mean fecundity, being about 40 eggs/female on P. taeda and 53 on P. elliottii. However, when daily mean fecundity was considered, the difference was significant, being 1.3 eggs/female/day on P. taeda and 1.8 on P. elliottii. The nymphal mortality was greater on P. taeda (50%) than on P. elliottii (28%). These results reflected on life expectancy which was higher on P. elliottii for the nymphal stage, but for the adult stage there was no significant difference between both host plants. The intrinsic rate of natural increase and the finite rate of increase were similar, indicating that P. boerneri shows the same reproductive capacity on both hosts, despite the net reproductive rate being much greater on P. elliottii (23.8 eggs/female) than on P. taeda (15.4). The highest nymphal survival and reproductive rates on P. elliottii indicate that this host plant is more suitable for the development of P. boerneri.

Development, survival and reproduction of Stratiolaelaps scimitus (Acari: Laelapidae) on four diets 

2018 ◽  
Vol 23 (4) ◽  
pp. 779 ◽  
Author(s):  
Lixia Xie ◽  
Yi Yan ◽  
Zhi-Qiang Zhang
Keyword(s):  
Survival Rates ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Population Increase ◽  
Net Reproductive Rate ◽  
Immature Development ◽  
Combined Use ◽  
Survival And Reproduction ◽  
Artemia Cysts ◽  
Stratiolaelaps Scimitus

.The development, survival and reproduction of Stratiolaelaps scimitus (Acari: Laelapidae) were determined on four diets (Ephestia kuehniella eggs, Artemia sp. cysts, Typha orientalis pollen, and Tyrophagus curvipenis) in the laboratory at 25 ± 1°C, 80 ± 5% RH, 24 h D: 0 h L. E. kuehniella eggs and T. curvipenis were very suitable for the overall development of S. scimitus to adulthood, with over 90% survival rates. Shrimp cysts were not suitable, with 11.1% survival to adults, and T. orientalis pollen were intermediate, with 50% survival to adults.  S. scimitus immature development was the fastest on T. curvipenis (9.67 ± 0.18 days), and it was also very fast on E. kuehniella eggs, but relatively slow on T. orientalis pollen  (18.26 ± 0.68 days) and the slowest on Artemia cysts (21.36 ± 1.23 days). The female pre-ovipositional period (APOP) averaged less than 3 days on E. kuehniella eggs but over 3 days on T. curvipenis, but mated and unmated females had a similar APOP, regardless of diet. Neither diet nor mating had significant effects on the total pre-ovipositional period from birth to oviposition (around 13 days). The oviposition period averaged 1 to 2 days longer for mated females than unmated ones, regardless of diet, which had no significant effects. Mated females produced 50% more eggs than unmated females when feeding on E. kuehniella eggs, but 69% more than unmated females when feeding on T. curvipenis; the effects of mating were significant, and the effects of diet were different depending on mating status of the predators: fecundity was higher on E. kuehniella eggs (20.21 ± 1.16) than on T. curvipenis (17.07 ± 0.49) only for unmated females.  Most life table parameters (intrinsic rate of population increase r, finite rate of population increase λ, and net reproductive rate R0) were not significantly affected by diet and mating. However, the mean generation time T was shorter in unmated females than in mated ones, and more so when feeding on T. curvipenis. T. curvipenis is easy to rear, so it is considered a very promising diet for S. scimitus as it does not damage plants nor cause allergenic reactions in workers or users. Since T. curvipenis is common on plants, future studies should explore the combined use of foliar predators (e.g. Phytoseiidae) and soil predators for the biocontrol of greenhouse pests (e.g. thrips) using a shared non-pest prey such as T. curvipenis.

Efficiency of growth and wool production of young Merino ewes from a flock selected for fertility

1976 ◽  
Vol 16 (80) ◽  
pp. 315 ◽  
Author(s):  
KD Atkins ◽  
GE Robards
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Reproductive Rate ◽  
Feed Conversion ◽  
Or Efficiency ◽  
Net Reproductive Rate ◽  
Wool Production ◽  
Significant Difference ◽  
Digestible Organic Matter ◽  
Conversion Efficiencies

A handfeeding experiment was conducted with weaner ewe lambs from two Merino flocks. One flock had been selected for high net reproductive rate, growth rate and wool production (fertility flock) ; the other flock was a randomly selected control flock (random flock). Single and twin born lambs from each flock were used in the experiment. Lambs were randomized into four treatment groups and offered the diet either ad libitum or at one of three levels estimated to restrict growth rate to 50, 100 and 150 g day-1. At each level of feeding, fertility flock lambs grew faster and were more efficient in converting feed to liveweight gain. Over the whole experiment the feed conversion efficiencies in g gain per kg digestible organic matter intake per day were 218 and 185 (P < 0.05) for the fertility and random flocks respectively. There were no significant differences in growth rate or efficiency of conversion of feed to liveweight gain between single-born and twin-born lambs. Random flock lambs had a significantly higher wool growth rate and were more efficient converters of feed to wool than fertility flock lambs. Gross efficiencies were 10.8 and 9.1 g clean wool per kg digestible organic matter intake per day (P < 0.05) for random and fertility flock lambs respectively. Single-born lambs grew significantly more wool than twin-born lambs but there was no significant difference between birth types in the efficiency of conversion of feed to wool.

Effects of Temperature on Demographic Parameters of Bryobia praetiosa (Acari: Tetranychidae)

2019 ◽  
Vol 113 (1) ◽  
pp. 211-221 ◽  
Author(s):  
Mohammad Shaef Ullah ◽  
Tatsuya Kamimura ◽  
Tetsuo Gotoh
Keyword(s):  
Adult Development ◽  
Symbiotic Bacterium ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Thermal Constant ◽  
Demographic Parameters ◽  
Net Reproductive Rate ◽  
Significant Difference ◽  
Effects Of Temperature

Abstract The clover mite, Bryobia praetiosa Koch (Acari: Tetranychidae), is an agricultural pest, as well as a frequent invader of hospitals and homes. However, its adaptability to different temperatures is not well understood. We used age- and stage-specific life tables to investigate the effects of temperature on demographic parameters of B. praetiosa from 15 to 35°C under a long-day photoperiod (16:8 [L:D] h). The clover mite is a thelytokous species (consisting of only females) due to its infection with the symbiotic bacterium Wolbachia. The egg-to-adult development time of female B. praetiosa decreased as the temperature increased from 15 to 32.5°C. At 35°C, females laid eggs, but no eggs hatched. The lower thermal threshold (t0) and the thermal constant (K) for egg-to-adult females were 8.7°C and 274.1 degree-days, respectively. The intrinsic optimum temperature (TØ) was 22.4°C. The oviposition period decreased with increasing temperature. Fecundity was highest at 20°C and extremely low at 30°C. The net reproductive rate (R0) decreased as the temperature increased from 15 to 30°C, but no significant difference was observed between 15 and 20°C. The intrinsic rate of natural increase (r) varied from 0.0721/d at 15°C to 0.1679/d at 25°C, and then decreased to 0.1203/d at 30°C. These results should be useful in developing management strategies for B. praetiosa.

Effects of photoperiod on development and demographic parameters of the predatory thrips Scolothrips longicornis fed on Tetranychus urticae

2020 ◽  
Vol 110 (5) ◽  
pp. 620-629
Author(s):  
Hajar Pakyari ◽  
Mark R. McNeill
Keyword(s):  
Tetranychus Urticae ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Net Reproductive Rate ◽  
Control Programs ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Scolothrips Longicornis ◽  
Almost All

AbstractThe effect of five photoperiods (0:24, 6:18; 12:12, 18:6, and 24:0 light:dark (L:D)) on the development, reproduction, and survival of the predatory thrips Scolothrips longicornis Priesner fed on the two-spotted spider mite, Tetranychus urticae Koch, was tested under laboratory conditions at 60% RH and 25°C. Development time of almost all immature stages in S. longicornis was the shortest under long day lengths (18:6 and 24:0 L:D). The adult duration of both sexes decreased with increasing light length from 6 to 24 h. The longevity of male and female decreased with increasing light length. Under a 12:12 L:D photoperiod, S. longicornis females had the longest oviposition period and longevity, highest net reproductive rate (R0 = 15.37), intrinsic rate of natural increase (r = 0.141), and finite rate of increase (λ = 1.151). Life table parameters showed a significant difference with various photoperiods. The consequences of the present research demonstrated that a 12:12 L:D photoperiod is the most favorable for the reproduction and development of S. longicornis fed on T. urticae, and that for mas rearing for augmentative biological control programs, would be the ideal photoperiod to maximize production.

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