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

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.

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Biology and life tables of Telenomus remus (Hymenoptera: Scelionidae) as parasitoid of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/948/1/012041 ◽

2021 ◽

Vol 948 (1) ◽

pp. 012041

Author(s):

Oktaviani ◽

N Maryana ◽

Pudjianto

Keyword(s):

Life Table ◽

Spodoptera Frugiperda ◽

Intrinsic Rate ◽

Immature Stage ◽

Intrinsic Rate Of Increase ◽

Reproduction Rate ◽

Rate Of Increase ◽

Net Reproduction ◽

Lepidoptera Noctuidae ◽

Telenomus Remus

Abstract Telenomus remus (Hymenoptera: Scelionidae), is an endoparasitoid on eggs of Spodoptera frugiperda (J. E. Smith). S. frugiperda. The information of T. remus as a natural enemy of S. frugiperda is very limited. The research objective is to determine some biological aspects of T. remus, i.e. longevity, fecundity, and life table variables. The demographic statistics using the jackknife method. T. remus is collected from the field identified as T. remus. The immature stage of T. remus reached 8.13 days, the longevity of the male was 10.07 days, while a female was 10.29 days with a fecundity of 75 eggs, and a sex ratio of male and female was 1:2.16. T. remus life table, i.e. gross reproduction rate (GRR) was 74.67 individuals/generation, net reproduction rate (R0) was 45260.60 females/females/generation, with generation period (T) was 8.62 days, and intrinsic rate of increase (r) was 1.24 females/female/day. The success parasitization of T. remus reaches 91%.

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Development and Fitness of the Parasitoid, Encarsia formosa (Hymenoptera: Aphelinidae), on the B and Q of the Sweetpotato Whitefly (Hemiptera: Aleyrodidae)

Journal of Economic Entomology ◽

10.1093/jee/toz200 ◽

2019 ◽

Vol 112 (6) ◽

pp. 2597-2603 ◽

Cited By ~ 2

Author(s):

Yanyan He ◽

Yicong Liu ◽

Ke Wang ◽

Youjun Zhang ◽

Qingjun Wu ◽

...

Keyword(s):

Life Table ◽

Intrinsic Rate ◽

Intrinsic Rate Of Increase ◽

Reproduction Rate ◽

Host Feeding ◽

Encarsia Formosa ◽

Developmental Duration ◽

Rate Of Increase ◽

Table Analysis ◽

Net Reproduction

Abstract Encarsia formosa Gahan is an important endoparasitoid of the whitefly, Bemisia tabaci Gennadius. In the present study, we compared the fitness and population parameters of E. formosa when parasitizing the two most invasive and destructive whitefly species in China, the B and Q of B. tabaci. We also studied whether natal host influenced on parasitism and host-feeding capacities of E. formosa on B. tabaci B versus Q. Age–stage life table analysis indicated that E. formosa developmental duration was shorter, fecundity was higher, and longevity was greater on B. tabaci B than on Q. The life table parameters, including the intrinsic rate of increase (r), finite rate of increase (λ), net reproduction rate (R0), and the mean generation time (T), indicated that the fitness of E. formosa on B. tabaci B is higher than B. tabaci Q. We also found that the host species used to rear E. formosa affected the parasitoid’s subsequent parasitism and host feeding on B. tabaci B and Q. When E. formosa were reared on B. tabaci B, its subsequent parasitism rate on third-instar nymphs was significantly higher on B. tabaci B than on Q. These results will be useful for managing the biological control of B. tabaci in the field.

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Insecticidal activity and sublethal effects of Beauveria bassiana (Bals.-Criv.) Vuill. isolates and essential oils against Aphis gossypii Glover, 1877 (Hemiptera: Aphididae)

Acta agriculturae Slovenica ◽

10.14720/aas.2020.115.2.1306 ◽

2020 ◽

Vol 115 (2) ◽

pp. 463

Author(s):

Mahdieh MOUSAVI ◽

Youbert GHOSTA ◽

Nariman MAROOFPOUR

Keyword(s):

Essential Oils ◽

Life Table ◽

Beauveria Bassiana ◽

Insecticidal Activity ◽

Aphis Gossypii ◽

Population Increase ◽

Intrinsic Rate Of Increase ◽

Reproduction Rate ◽

Net Reproductive Rate ◽

Rate Of Increase

The cotton aphid, Aphis gossypii Glover, 1877, is a polyphagous species and one of the most important pests of cucumber crops in Iran. In this study, virulence of three Beauveria bassiana (Bals.-Criv.) Vuill isolates, IRAN 108, IRAN 429C and LRC 137, as well as insecticidal activity of two essential oils extracted from Matricaria chamomilla L. and Cuminum cyminum L. were evaluated against adult stage of A. gossypii under laboratory conditions. The data for life table were analyzed using the age-stage, two-sex life table theory. Results showed that all isolates were pathogenic on aphid, but their virulence was varied in different isolates. The lowest calculated LC50 was belonged to IRAN 429C (3.9 × 104conidia ml-1). The lowest LT50 was obtained at concentration of 108 and 107 conidia ml-1 for IRAN 429C (2.9 and 3.55 days, respectively). M. chamomilla essential oil had the lowest LC50 and LT50 values (19 µl l-1 air and 11.4 h), respectively. Longevity and population growth parameters, including the intrinsic rate of increase (rm), gross reproduction rate (GRR), net reproductive rate (R0), generation time (T) and finite rate of population increase (λ), were affected negatively by both agents. According to the results obtained in this study, both entomopathogenic fungi and essential oils could be used as an alternative to chemical insecticides in aphid IPM programs.

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

Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management) ◽

10.29244/jpsl.10.4.660-667 ◽

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.

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The effects of some botanical insecticides and pymetrozine on life table parameters of silver leaf whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae)

Pesticidi i fitomedicina ◽

10.2298/pif1301047b ◽

2013 ◽

Vol 28 (1) ◽

pp. 47-55 ◽

Cited By ~ 7

Author(s):

Reihaneh Barati ◽

Gholamreza Golmohammadi ◽

Hamid Ghajarie ◽

Mehdi Zarabi ◽

Raziyeh Mansouri

Keyword(s):

Life Table ◽

Bemisia Tabaci ◽

Intrinsic Rate ◽

Intrinsic Rate Of Increase ◽

Botanical Insecticides ◽

Reproduction Rate ◽

Distilled Water ◽

Life Table Parameters ◽

Net Reproductive Rate ◽

Rate Of Increase

The objective of this research was to assess the effects of extracts of two medicinal plant species: Allium sativum (Linn) and Calotropis procera (Aiton), and a formulation containing azadirachtin on life table parameters of silver leaf whitefly (SLW), Bemisia tabaci biotype B (Gennadius) (Hemiptera: Aleyrodidae), grown on greenhouse tomato plants. The effects were compared to that of pymetrozine, a synthetic insecticide. Bioassays were carried out in a greenhouse under controlled conditions of 27 ? 2?C, R.H. of 55 ? 5% and 16:8 h (L:D) photo period. All treatments significantly affected the survivorship and fertility of SLW female adults, reducing the net reproduction rate, mean generation time and intrinsic rate of increase of this insect. The net reproductive rate [R0] values for the populations treated with garlic extract, milkweed extract, pymetrozine, azadirachtin, control for extracts (ethanol + distilled water) and control for pesticides (distilled water) were 23.58, 19.32, 10.78, 8.23, 49.66, 57.55; the intrinsic rate of increases [rm] were 0.134, 0.139, 0.110, 0.090, 0.177, 0.178; the mean generation times [T] were 23.49, 21.23, 21.66, 23.50, 22.06, 22.69; the doubling times [DT] were 5.14, 4.95, 6.27, 7.56, 3.91, 3.87, and the finite rates of increase [?] were 1.144, 1.149, 1.116, 1.094, 1.193, 1.195, respectively. Azadirachtin had the highest effect on the life table parameters of SLW. Our findings indicated that, although herbal extracts were not effective as much as the chemical insecticides, they can be effective in pest control. Therefore, they are suitable choices for replacing chemical insecticides and for alternative use with azadirachtin in SLW IPM program.

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

TROPICAL WETLAND JOURNAL ◽

10.20527/twj.v3i2.46 ◽

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.

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Demography of Cacopsylla chinensis (Hemiptera: Psyllidae) Reared on Four Cultivars of Pyrus bretschneideri (Rosales: Rosaceae) and P. communis Pears With Estimations of Confidence Intervals of Specific Life Table Statistics

Journal of Economic Entomology ◽

10.1093/jee/toaa149 ◽

2020 ◽

Vol 113 (5) ◽

pp. 2343-2353 ◽

Cited By ~ 5

Author(s):

Mingfeng Wei ◽

Hsin Chi ◽

Yongfu Guo ◽

Xianwei Li ◽

Longlong Zhao ◽

...

Keyword(s):

Survival Rate ◽

Life Table ◽

Confidence Intervals ◽

Intrinsic Rate ◽

Intrinsic Rate Of Increase ◽

Reproduction Rate ◽

Finite Rate ◽

Preoviposition Period ◽

Rate Of Increase ◽

Net Reproduction

Abstract The psyllid Cacopsylla chinensis (Yang & Li) (Hemiptera: Psyllidae) is a serious pest of pears in China. To determine and contrast the fitness of the psyllid on two endemic cultivars of Pyrus bretschneideri (i.e., BHXS and BSL) and two introduced cultivars of Pyrus communis (i.e., CB and CRB), we analyzed data on the development, survival, and fecundity from C. chinensis individuals reared on the four cultivars. The age-stage, two-sex life table theory was used in order to enable the inclusion of males in the analysis as well as a means of identifying the variation in developmental durations among individuals. Results indicated that C. chinensis can successfully develop and reproduce on all four pear cultivars. However, based on the lower preadult survival rate, longer preadult duration, longer total preoviposition period (TPOP), and lower fecundity that occurred on both cultivars of P. communis, these two cultivars are less favorable hosts for C. chinensis than the P. bretschneideri cultivars. The lower intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0) on CB and CRB pears showed these two introduced cultivars are more resistant to C. chinensis than the endemic BHXS and BSL pears. These resistant cultivars would be appropriate candidates for managing C. chinensis. We used the bootstrap technique to estimate the uncertainty of the population parameters (r, λ, R0, etc.), while also demonstrating that it can be used for estimating the 0.025 and 0.975 percentile confidence intervals of the age of survival rate.

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Effects of Imunit Insecticide on Biological Characteristics and Life Table Parameters of Spodoptera cilium (Lepidoptera: Noctuidae)

Insects ◽

10.3390/insects12121138 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1138

Author(s):

Marzieh Hatami ◽

Masumeh Ziaee ◽

Ali Asghar Seraj ◽

Mehdi Mehrabi-Koushki ◽

Jacek Francikowski

Keyword(s):

Life Table ◽

Intrinsic Rate ◽

Developmental Time ◽

Reproductive Rate ◽

Management Program ◽

Population Increase ◽

Oviposition Period ◽

Fluorescent Light ◽

Reproduction Rate ◽

Offspring Generation

Imunit is a mixture of alpha-cypermethrin + teflubenzuron, and has been launched for controlling caterpillars. In this study, the effects of Imunit at LC50 and LC30 were investigated on parental and offspring generation of S. cilium, according to age-stage, two-sex life table. The experiments were conducted by leaf dipping method at 25 °C and 60 ± 5% relative humidity, under a cycle of 16 h fluorescent light and 8 h darkness. LC30 and LC50 concentrations of Imunit increased the immature developmental time of S. cilium in the offspring generation, while the LC50 of Imunit significantly reduced the developmental time of adults. The adult pre-oviposition period and total pre-oviposition period considerably increased when offspring were treated with LC50 of Imunit. In offspring of S. cilium exposed to LC50 and LC30 concentrations of Imunit, the gross reproductive rate (GRR), net reproduction rate (R0), the intrinsic rate of population increase (r), and the finite rate of population increase (λ) significantly reduced compared to the control. This study showed that the application of Imunit at LC50 could suppress the S. cilium population and can be used in the integrated management program of this pest.

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

Journal of Economic Entomology ◽

10.1093/jee/toab008 ◽

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.

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Ambient Humidity Affects Development, Survival, and Reproduction of the Invasive Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), in China

Journal of Economic Entomology ◽

10.1093/jee/toab056 ◽

2021 ◽

Author(s):

Limei He ◽

Shengyuan Zhao ◽

Abid Ali ◽

Shishuai Ge ◽

Kongming Wu

Keyword(s):

Spodoptera Frugiperda ◽

Fall Armyworm ◽

Intrinsic Rate ◽

Intrinsic Rate Of Increase ◽

Reproduction Rate ◽

Ambient Humidity ◽

Rate Of Increase ◽

Population Forecasting ◽

Survival And Reproduction ◽

Net Reproduction

Abstract Ambient humidity can directly affect the water balance in insects. The migratory fall armyworm, Spodoptera frugiperda Smith, has spread to more than 60 countries and regions in Africa, Asia, and Oceania that have a great difference in average ambient humidity. Understanding the effects of ambient humidity changes on its development, survival, and reproduction can help to predict its population dynamics in different habitats. Therefore, we evaluated the effects of atmospheric relative humidity (RH) on the development, survival, and reproduction and soil moisture on the pupation and emergence of fall armyworm. As a result, survival and pupal mass increased significantly with increasing RH. Among the five RHs tested, 80% RH was the most suitable for fall armyworm with the highest intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0). The population growth at the different RHs in decreasing order was 80 > 100 > 60 > 40 > 20%. A relative moisture (RM) of soil from 6.80 to 47.59% was suitable for fall armyworm pupation, survival, and eclosion, but fall armyworm could not pupate normally in soil with 88.39 and 95.19% RM. The survival and emergence rate of fall armyworm pupae were reduced by irrigation that increased the RM after the mature larvae entered the soil. These findings may be helpful for refining laboratory rearing protocols, population forecasting, and management of fall armyworm.

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