scholarly journals Statistik demografi Dolichotetranychus floridanus Banks pada dua kultivar nanas (Ananas comosus (L.) Merr.)

2021 ◽  
Vol 10 (4) ◽  
pp. 660-667
Author(s):  
Ariffatchur Fauzi ◽  
Sugeng Santoso ◽  
Ali Nurmansyah
Keyword(s):  
Life Cycle ◽  
Population Growth ◽  
Generation Time ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Ananas Comosus ◽  
Reproduction Rate ◽  
Fruit Crops ◽  
Net Reproductive Rate ◽  
Pest Infestation

Pineapple is one of important fruit crops in Indonesia. One of important problems in pineapple production is pest infestation.. This study aims to investigate the biology, demography, and life cycle of Dolichotetranychus floridanus Banks on two pineapple cultivars (Queen and Cayenne). Observation of mite development (eggs-adults) were conducted every 6 hours.  Adults were observed everyday to record the fecundity.  The life table was constructed from the survivor and fecundity of D. floridanus. Based on this table, the variables of population growth, including gross reproduction rate (GRR), net reproductive rate (R0), mean generation time (T) and increase intrinsic rate (r) were determined. The results showed that the GRR, R0, and r of D. floridanus in the Queen cultivar were higher than Cayenne cultivar, while the T in the Queen cultivar was lower. Queen cultivar more suitable for D. floridanus than Cayenne cultivar.

Life cycle and calculation of the intrinsic rate of natural increase of two bacterivorous nematodes, Panagrolaimus sp. and Poikilolaimus sp. from chemoautotrophic Movile Cave, Romania

Nematology ◽  
2007 ◽  
Vol 9 (2) ◽  
pp. 271-284 ◽  
Author(s):  
Daniel Muschiol ◽  
Walter Traunspurger
Keyword(s):  
Life Cycle ◽  
Body Length ◽  
Generation Time ◽  
Microbial Mats ◽  
Somatic Growth ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Net Reproductive Rate ◽  
Movile Cave

AbstractThe life cycle and somatic growth of two bacterivorous nematodes, Panagrolaimus sp. and Poikilolaimus sp., isolated from chemoautotrophic microbial mats in Movile Cave, Romania, were studied in monoxenic cultures at 20°C with Escherichia coli as the food source. A method is described that allows simultaneous investigation of the somatic growth pattern, age-specific fecundity, and age-specific mortality of single individuals with high accuracy. Somatic growth curves of the species are presented. During juvenile development, both species showed a strict linear increase in body length, whereas body weight increased exponentially. Growth was continuous without lag phases. The relationships between fresh weight, W (μg), and body length, L (mm), were W = 1.6439L2.7672 for Poikilolaimus sp. and W = 0.2085L4.0915 for Panagrolaimus sp. Life tables and fecundity schedules for the two species are presented. In addition, demographic parameters were calculated. For Panagrolaimus, the intrinsic rate of natural increase (rm), calculated according to the Lotka equation, was 0.309, the net reproductive rate (R0) 64, the mean generation time (T) 13.8 days and the minimum generation time (Tmin) 9.5 days. The corresponding values for Poikilolaimus were rm = 0.165, R0 = 108, T = 26.2 and Tmin = 19.5. Panagrolaimus produced fewer progeny than Poikilolaimus during its life but exhibited faster population growth due to its faster maturation. It showed a distinct post-reproductive period, whereas Poikilolaimus remained fertile until death.

A demographic study of the life cycle of Tisbe furcata (Baird, 1837) (Copepoda: Harpacticoida)

1981 ◽  
Vol 61 (3) ◽  
pp. 691-705 ◽  
Author(s):  
Marc Bergmans
Keyword(s):  
Life Cycle ◽  
Generation Time ◽  
Harpacticoid Copepod ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Net Reproductive Rate ◽  
Life Table Data ◽  
Table Data ◽  
Stable Stage

The life-cycle of the harpacticoid copepod Tisbe furcata (Baird, 1837) at 18 C was studied quantitatively. Stage durations were determined by two different methods, using synchronous cohorts. Combined nauplius stages last for 80·4 h; the successive copepodite stages take 23·0, 23·2, 28·0 (♀) to 23·2 (♂), 33·4 (♀) to 24·2 (♂) and 48·8 (♀) to 34·7 (♂) h, respectively. Females develop more slowly but more synchronously than males. Age-specific survival and fertility rates were used to calculate the stable stage distribution in an exponentially growing population. From life-table data the following demographic parameters were computed: intrinsic rate of natural increase rm = 0·233 day−1; net reproductive rate Ro = 94; minimum generation time Tmin = 14·9 days; parameters related to ‘generation time’: T = 19·5 days, = 16·4 days, Tc = 25·4 days.

Plant Resistance in Some Modern Soybean Varieties May Favor Population Growth and Modify the Stylet Penetration of Bemisia tabaci (Hemiptera: Aleyrodidae)

2021 ◽  
Author(s):  
Mauricélia F Almeida ◽  
Clébson S Tavares ◽  
Euires O Araújo ◽  
Marcelo C Picanço ◽  
Eugênio E Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Bemisia Tabaci ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Genetically Engineered ◽  
Population Increase ◽  
Net Reproductive Rate ◽  
Bt Toxin ◽  
Demographic Performance

Abstract Complaints of severe damage by whiteflies in soybean fields containing genetically engineered (GE) varieties led us to investigate the role of transgenic soybean varieties expressing resistance to some insects (Cry1Ac Bt toxin) and to herbicide (glyphosate) on the population growth and feeding behavior of Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae). In the laboratory, the whiteflies reared on the GE Bt soybeans had a net reproductive rate (R0) 100% higher and intrinsic rate of population increase (rm) 15% higher than those reared on non-GE soybeans. The increased demographic performance was associated with a higher lifetime fecundity. In electrical penetration graphs, the whiteflies reared on the GE soybeans had fewer probes and spent 50% less time before reaching the phloem phase from the beginning of the first successful probe, indicating a higher risk of transmission of whitefly-borne viruses. Data from Neotropical fields showed a higher population density of B. tabaci on two soybean varieties expressing glyphosate resistance and Cry1Ac Bt toxin. These results indicate that some GE soybean varieties expressing insect and herbicide resistances can be more susceptible to whiteflies than non-GE ones or those only expressing herbicide resistance. Most likely, these differences are related to varietal features that increase host-plant susceptibility to whiteflies. Appropriate pest management may be needed to deal with whiteflies in soybean fields, especially in warm regions, and breeders may want to consider the issue when developing new soybean varieties.

scholarly journals Resistance and tolerance of ten carrot cultivars to the hawthorn-carrot aphid, Dysaphis crataegi Kalt., in Poland

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247978
Author(s):  
Maria Pobożniak ◽  
Małgorzata Gaborska ◽  
Tomasz Wójtowicz
Keyword(s):  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Reproductive Period ◽  
Field Resistance ◽  
Intrinsic Rate Of Increase ◽  
Demographic Parameters ◽  
Reproduction Rate ◽  
Net Reproductive Rate ◽  
Rate Of Increase

Damage caused to cultivated carrots by the hawthorn-carrot aphid, Dysaphis crataegi Kalt. (Hemiptera: Aphididae) is one of the factors limiting carrot production in Poland. Planting resistant and tolerant cultivars could reduce yield losses due to the damage caused by this pest. This study was conducted to evaluate the resistance and/or tolerance of 10 carrot genotypes to hawthorn-carrot aphid. Their field resistance was determined under field conditions based on five indicators, namely, mean number of alates (migrants) per plant and mean percentage of plants colonized by them, mean seasonal number of aphids per plant, mean number of aphids per plant and mean percentage of infested plants at peak abundance. Antibiosis experiments were conducted under laboratory conditions and pre-reproductive, reproductive time, fertility, and demographic parameters, represented by the net reproduction rate (Ro), intrinsic rate of increase (rm) and mean generation time (T), were calculated. Five cultivars, Afro F1, Nipomo F1, Samba F1, White Satin F1, and Yellowstone showed field resistance. Antibiosis experiments revealed significant differences among the carrot cultivars in the length of the reproductive period, female fecundity in the time equal to the pre-reproduction time, and total progeny of hawthorn-carrot aphid. The intrinsic rate of natural increase (rm) for apterous aphids varied significantly, ranging between 0.181 (Nipomo F1) and 0.343 females/female/day (White Satin F1). Additionally, the estimated net reproductive rate (R0) was the lowest on Nipomo F1, and this genotype was determined to be resistant. Our results suggest that a very high density of trichomes on the leaf petioles (71.94 trichomes/cm2) could adversely affect the feeding, bionomy, and demographic parameters of hawthorn-carrot aphid on the cultivar Nipomo F1. In addition, Napa F1 and Kongo F1 demonstrated high tolerance. Considering all the results collectively, four genotypes, Afro F1, Kongo F1, Napa F1 and Nipomo F1, were relatively resistant/tolerant to the hawthorn-carrot aphid.

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.

scholarly journals Biology and life table parameters of Metaphycus marensis Chirinos & Kondo, 2019, an encyrtid parasitoid of guava cottony scale in Venezuela

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
D.T. Chirinos ◽  
R. Castro ◽  
J. Castro ◽  
I. Perez-Almeida ◽  
T. Kondo
Keyword(s):  
Life Cycle ◽  
Life Table ◽  
Generation Time ◽  
Field Experiments ◽  
Biological Control Agent ◽  
Reproductive Rate ◽  
Natural Increase ◽  
Type I ◽  
Life Table Parameters ◽  
Net Reproductive Rate

The guava cottony scale, Capulinia linarosae (Hemiptera: Eriococcidae) is an important pest of guava, Psidium guajava, in Venezuela and northern Colombia. Metaphycus marensis (Hymenoptera: Encyrtidae) is a new primary parasitoid species recently described associated with this pest. Studies were conducted on oogenesis, life cycle, survival, daily fecundity and life table parameters of Metaphycus marensis Chirinos & Kondo (Hymenoptera: Encyrtidae): intrinsic rate of natural increase (rm), generation time (T) and net reproductive rate (Ro). Females of M. marensis are synovigenic and this parasitoid goes through four larval instars and completes its life cycle in about 12.7 days. Survival was of type I, where mortality was initially detected by encapsulation of eggs and larvae. Metaphycus marensis was able to multiply its population 28.7 times (Ro) with rm of 0.242 in 13.9 days (T). The short generation time of the parasitoid in relation to its eriococcid host could represent a desirable attribute as a natural enemy. However, the low fecundity and the encapsulation by the host must be analyzed through field experiments in order to evaluate its effectiveness as a biological control agent for C. linarosae.

scholarly journals Tabel Hidup Nyamuk Vektor Filariasis Limfatik Culex quinquefasciatus (Diptera: Culicidae) di Laboratorium

2019 ◽  
Vol 18 (2) ◽  
pp. 73
Author(s):  
Tri Ramadhani ◽  
Vina Yuliani ◽  
Upik Kesumawati Hadi ◽  
Susi Soviana ◽  
Zubaidah Irawati
Keyword(s):  
Lymphatic Filariasis ◽  
Culex Quinquefasciatus ◽  
Generation Time ◽  
Control Program ◽  
Wuchereria Bancrofti ◽  
Reproductive Rate ◽  
Reproduction Rate ◽  
Net Reproductive Rate ◽  
Vector Control Program ◽  
Vector Borne

Latar belakang: Kelangsungan hidup nyamuk merupakan aspek yang penting dalam penularan penyakit tular vektor. Culex quinquefasciatus merupakan vektor filariasis limfatik yang disebabkan oleh wuchereria bancrofti. Pengetahuan kehidupan nyamuk berperan penting dalam keberhasilan program pengendalian vektor. Tujuan penelitian ini mendiskripsikan tabel hidup nyamuk Cx. quinquefasciatus di laboratorium.Metode: Penelitian diawali dengan koleksi larva Cx. quinquefasciatus di  Kota Pekalongan, kemudian diidentifikasi dan kolonisasi dalam kondisi laboratorium. Parameter yang diukur meliputi masa inkubasi, ekslosi, eksdisis, ketahanan hidup, laju reproduksi, waktu generasi dan laju pertumbuhan intrinsik.  Hasil: Cx. quinquefasciatus mempunyai siklus hidup 12.5 hari. Umur telur, larva, dan pupa masing-masing adalah 2.07; 10.2; dan  2.25 hari. Nyamuk jantan mempunyai ketahanan hidup yang lebih pendek dibandingkan betina. Laju reproduksi  bersih (Ro) sebesar 196.75, laju pertumbuhan intrinsik 0.35  dan waktu generasi (T) 14.91 hari.Simpulan: Pertumbuhan populasi Cx. quinquefasciatus  dapat diatur dan dikendalikan oleh kelulusan hidup dan mortalitas. ABSTRACTTitle: The Live Table of Vector Lymphatic Filariasis Culex quinquefasciatus (Diptera: Culicidae) in the LaboratoryBackground: The survival of a mosquito is an important aspect in the transmission of vector borne disease. Culex quinquefasciatus, which is a vector of lymphatic filariasis caused by wuchereria bancrofti. The knowledge of mosquito life is important in providing the foundation for the success of the vector control program. The research  aim to describe the life table Cx. quinquefasciatus in the laboratoryMethods:. This study was originated from the collecting larve  of Cx. quinquefasciatus from Pekalongan City, which were then identified and colonized under laboratory conditions. Parameters measured include the incubation period, ekslosi, eksdisis, survival rate, reproduction rate, and generation time.Results:The results showed that Cx. quinquefasciatus has a 12.5 day life cycle. Egg, larva, and pupa respectively were 2.07; 10.2; and 2.25 days. The males have a shorter survival period compared to  the  females. The net  reproductive  rate  (Ro)  was  196.75;  the  intrinsic  growth  rate  (rm)  was  0.35  and  the average generation time (T) was 14.91 days.Conclusion : The population growth of Culex quinquefasciatus can be regulated and controlled by life graduation and mortality 

scholarly journals THE LIFE TABLE OF Spodoptera pectinicornis Hampson AS BIOLOGICAL CONTROL AGENT OF WATER LETTUCE (Pistia stratiotes L.) WEED

2017 ◽  
Vol 3 (2) ◽  
pp. 7-13
Author(s):  
Lyswiana Aphrodyanti ◽  
Abdul Haris ◽  
Lidia Luisa Momongan
Keyword(s):  
Biological Control ◽  
Life Table ◽  
Generation Time ◽  
Biological Control Agent ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Control Agent ◽  
Water Lettuce ◽  
Net Reproductive Rate ◽  
Rate Of Growth

The table of life can provide information on birth (natality), death (mortality) and the opportunity to breed, so it can be used as a parameter of the behavior of population development.The purpose of this study was to determine the calculation of life table of S. pectinicornis Hampson as biological control agent of water lettuce (P. stratiotes) weed.The table of life is done by observing survival ability, mortality and fecundity of S. pectinicornis of a cohort of 300 eggs by looking at all the stages from egg, larva, pupa, and imago, and fecundity of female imago per day. The research was conducted in a condition of unlimited food resources and environment free of natural enemies. Parameters observed were gross reproductive rate (GRR), net reproductive rate (Ro), average of generation time (T), intrinsic rate of growth (r), and limited rate of growth (λ). The research result of the life table calculation showed that GRR value was 350.29, the value of net reproductive rate (Ro) was 19.59 descendants, the average of generation time (T) was 29.47 days, the value of intrinsic rate of accretion (r) was 0.10 and the value of limited rate of accretion (λ) was 1.11.

Combined effects of oxytetracycline concentration and algal food level on the life-table demography of Brachionus calyciflorus (Rotifera)

2018 ◽  
Vol 54 ◽  
pp. 28
Author(s):  
Shan Jiang ◽  
Yi-Long Xi ◽  
Han Zhu ◽  
Bing-Xing Zhang ◽  
Jin-Hang Yu
Keyword(s):  
Life Expectancy ◽  
Life Table ◽  
Generation Time ◽  
Intrinsic Rate ◽  
Brachionus Calyciflorus ◽  
Population Increase ◽  
Reproduction Rate ◽  
Net Reproductive Rate ◽  
Environmental Concentration ◽  
Net Reproduction

Oxytetracycline (OTC) is commonly used for aquaculture and livestock, and its environmental concentration has increased to a considerable level and displays potential environmental risk. In the present study, the life-table demography of Brachionus calyciflorus exposed to sublethal concentrations (30.0, 60.0, 90.0, 120.0, 150.0 and 180.0 mg L−1) of OTC was investigated at 1.0 × 106, 2.0 × 106 and 4.0 × 106 cells mL−1 of Scenedesmus obliquus. The results showed that at each algal density, OTC concentration affected significantly life expectancy at hatching, net reproductive rate, generation time and intrinsic rate of population increase (P < 0.01), but did not affect proportion of mictic offspring of the rotifers (P > 0.05). Compared to the controls, and at 2.0 × 106 cells mL−1 of S. obliquus, treatments with OTC at 30.0–150.0 and 60.0–120.0 mg L−1 significantly prolonged life expectancy at hatching and generation time, treatments with OTC at 30.0–120.0 and 30.0–90.0 mg L−1 increased net reproduction rate and intrinsic rate of population increase, respectively, but the reverse was also true for those with OTC at 180.0 mg L−1. Higher and lower algal densities decreased the magnitude of stimulatory effects of lower concentrations of OTC but enhanced that of inhibitory effects of high concentration of OTC on the survival, asexual reproduction and population growth of the rotifers. At the three algal densities, net reproduction rate was more sensitive to OTC than the other endpoints, and significant concentration- effect relationship existed between OTC concentration and each of all the life-table demographic parameters except the proportion of mictic offspring.

scholarly journals LIFE TABLE PARAMETERS OF THE PERFORMANCE OF PROCTOLAELAPS GIZAENSIS SP. NOV. (ACARI: MESOSTIGMATA: MELICHARIDAE) ON FIVE DIFFERENT DIETS

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Sally Farouk Allam ◽  
Riham Abdel Aziz Mahmoud ◽  
Mourad Fahmy Hassan ◽  
Hassan Ali Taha
Keyword(s):  
Life Cycle ◽  
Sugar Cane ◽  
Intrinsic Rate ◽  
Cane Sugar ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Palm Trees ◽  
Rate Of Increase ◽  
The Mean

The predatory mite Proctolaelaps gizaensis was found under palm trees and core of palm associated with mites, Rhizoglyphus robini, collembolan and other arthropods. The incubation period is affecting by different diets at 27±2ºC and 65-70%, the shortest period was 1.61 days when reared on sugar cane + pollen +chitosan), and the duration of larval female increased than male. Statistical analysis showed significant effects on the duration of the total immature stages with different diets. At the same temperature, life cycle durated 11.32 days for female and 10.10 days for male reared on sugar cane, but when add pollen to sugar cane, this period was 12.56 days for female opposed to 11.6 days for male. The shortest period of life cycle was recorded when reared on (sugar cane + chitosan), whereas the longest period was recorded when the mite reared on (sugar cane +pollen+ chitosan). Fecundity was affected by rearing on different diets, the mean total number of deposited eggs 84.7, 88.9, 48 and 16.75 eggs when reared on (sugar cane), (sugar cane + pollen), (sugar cane + pollen +chitosan) and (sugar cane + chitosan) respectively. The most suitable diet was sugarcane with pollen followed by sugarcane at 27±2ºC and 65-70% R.H. for increasing female fertility. The net reproductive rate (R0 ) reached highest value when it reared on sugarcane+ pollen (35.076 females /female). However, the shortest value was obtained when it reared on Sugarcane+ Chitosan being 6.384 females /female. For the mean generation time (T), this period decreased with the add chitosan to (sugarcane) and (sugarcane+ pollen), it were averaged values 12.588 and 17.305. While, these values increased when reared on sugarcane (18.157) and sugarcane+ pollen (19.910).When the values of intrinsic rate of increase (rm) were converted into finite rate of increase (?), the population of P. gizaensis had the capacity decrease by 1.216, 1.195, 1.191 and 1.158 times/female/day when fed on obvious diets respectively. Th

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