scholarly journals Praon volucre (Hymenoptera: Braconidae: Aphidiinae), a natural enemy of Macrosiphum euphorbiae (Hemiptera: Aphididae): Life table and intrinsic rate of population increase

2011 ◽  
Vol 108 (4) ◽  
pp. 575-580 ◽  
Author(s):  
Juracy Caldeira LINS ◽  
Vanda Helena Paes BUENO ◽  
Diego Bastos SILVA ◽  
Marcus Vinicius SAMPAIO ◽  
Joop C. van LENTEREN
Author(s):  
Elania Clementino Fernandes ◽  
Mariana Macedo Souza ◽  
Dori Edson Nava ◽  
Janisete Gomes Silva ◽  
Elton Lucio Araujo

Abstract Tetrastichus giffardianus is a gregarious koinobiont endoparasitoid of tephritids, including Ceratitis capitata, which is one of the most important fruit pests worldwide. The objective of this study was to evaluate the effect of constant temperatures on the biology and development of the egg-adult period of T. giffardianus in larvae/pupae of C. capitata to construct a fertility life table. The study was carried out in climatic chambers at constant temperatures of 15, 20, 25, 30, and 35 ± 1°C, 70 ± 10% relative humidity and a photophase of 12 h. Complete egg and larval development occurred only at temperatures of 20, 25, and 30°C. The mean longevity of males and females was inversely proportional to temperature. The time of development of the pre-imaginal period was influenced by temperature and ranged from 41 days at 20°C to 11 days at 25°C. The best T. giffardianus performance occurred at 25°C when the intrinsic rate of increase was 0.21, the mean generation time was 20.43 days, the time required to double the population was 3.33 days, and the finite rate of population increase (λ) was 1.23. The results of this study provided information for the establishment of mass rearing and an evaluation of the adaptability of T. giffardianus to different environments, which is necessary for the use of this parasitoid in the biological control of tephritid pests, particularly C. capitata.


2020 ◽  
Vol 25 (1) ◽  
pp. 103-112
Author(s):  
José Cláudio Barros Ferraz ◽  
Paulo Roberto Ramalho Silva ◽  
Matheus Pinheiro Amaranes ◽  
José Wagner da Silva Melo ◽  
Debora Barbosa de Lima ◽  
...  

The mite Oligonychus punicae has potential for development in Eucalyptus spp. in clonal minigardens. However, there is no information on its biological and reproductive parameters on eucalyptus species. The objective of this study is to evaluate the biological and reproductive performance of O. punicae on different species of eucalyptus cultivated in a clonal minigarden. Development time, survival, longevity, fecundity and life table parameters of O. punicae were determined on six species of eucalyptus (Eucalyptus urophylla, Eucalyptus brassiana, Eucalyptus grandis, Eucalyptus tereticorinis, Eucalyptus pellita and Corymbia citriodora). All eggs of O. punicae originated females and completed the cycle in all hosts. Differences were observed in development, longevity, pre-oviposition, oviposition and post-oviposition, and fecundity of females of O. punicae when different eucalyptus species were used as hosts for O. punicae. The best performance of O. punicae was observed on E. tereticornis, while the worst performance was observed on C. citriodora, on which the net reproductive rates (R0) ranged from 5.09 to 44.85, the intrinsic rate of population increase (rm) ranged from 0.09 to 0.19, the finite rate of population increase (λ) ranged from 1.10 to 1.21, and the mean generation time (T) ranged from 0.09 to 0.19. These results suggest that E. tereticornis is an excellent host for O. punicae.


Acarologia ◽  
2017 ◽  
Vol 57 (3) ◽  
pp. 601-605
Author(s):  
R. Pereira de Lima ◽  
Marcello M. Bezerra ◽  
Gilberto J. de Moraes ◽  
Imeuda Furtado

Tetranychus bastosi Tuttle, Baker and Sales was described from Ceará state, northeastern Brazil. It has so far been reported from 25 plant species, among which cassava (Manihot esculenta Crants), common bean (Phaseolus vulgaris L.) and papaya (Carica papaya L). Although there is no information about its impact on crop yield, high population levels have been observed on some crops, leading to suppose that damage might occur in some occasions. In this study, fertility life table parameters were calculated for T. bastosi on cassava, common bean and papaya at 25 ± 2 °C, 70 ± 5% RH and photoperiod of 12/12 h. The best performance of T. bastosi occurred on C. papaya and P. vulgaris, on which the intrinsic rate of population increase reached 0.184 and 0.183 female/female/day, respectively. These results agree with the most common occurrence of this mite on papaya and on common bean than on cassava.


Author(s):  
Shan Jiang ◽  
Yi-Long Xi ◽  
Han Zhu ◽  
Bing-Xing Zhang ◽  
Jin-Hang Yu

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.


2006 ◽  
Vol 66 (3) ◽  
pp. 899-905 ◽  
Author(s):  
A. V. Teodoro ◽  
P. R. Reis

The flat-mite Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae) is considered important in citrus (Citrus spp.) and coffee plants (Coffea spp.) in Brazil, and is known as the leprosis and coffee ring spot mite, as being a vector of the Citrus Leprosis Rhabdovirus - CitLV and Coffee Ring Spot Virus - CoRSV. The objective of this work is to find out about the reproductive success of B. phoenicis on citric fruits and coffee leaves by fertility life table parameters and its biology. The experiments were carried out in laboratory conditions at 25 ± 2 °C, 70 ± 10% of relative humidity and 14 h of photophase. The lengths of embryonic and post-embryonic periods were different due to the host where the mite was reared. B. phoenicis showed better development and higher survival and fecundity in citric fruits than coffee leaves. The intrinsic rate of the population increase (r m) was 0.128 and 0.090 - females/female/day on citric fruits and coffee leaves, respectively. The citric fruits were more appropriate for the development of B. phoenicis than coffee leaves.


2019 ◽  
Vol 24 (3) ◽  
pp. 404 ◽  
Author(s):  
Jingyi Yang ◽  
Jiale Lv ◽  
Jingyue Liu ◽  
Xuenong Xu ◽  
Endong Wang

Amblyseius tsugawai is a phytoseiid species distributed in Asia. In the present study, laboratory experiments were conducted to investigate its preference to prey stages when feeding on Tetranychus urticae and Bemisia tabaci, to evaluate its development and reproduction, and to estimate its life table parameters on each of the two prey species. Our results indicate that A. tsugawai shows preference to larvae of T. urticae, and to eggs of B. tabaci. When the two preferred stages were provided together, A. tsugawai randomly selected its prey. No significant difference in developmental times of A. tsugawai was observed when reared on T. urticae (6.75 days) and B. tabaci (7.05 days). In contrast, cumulative fecundity of A. tsugawai was only 14.6% when reared on B. tabaci (4.6 eggs/female) than on T. urticae (31.5 eggs/female). Impact of prey for both females and males on reproduction were also observed. Comparing to the treatment when both parents were reared on T. urticae, A. tsugawai fecundity was reduced by ca. 48.2% when the male was reared on B. tabaci, and was reduced by 86.5% and 88.8% when the female or both parents were reared on B. tabaci, respectively. Amblyseius tsugawai is the first indigenous phytoseiid species of China to show a positive intrinsic rate of population increase (0.013) when reared on B. tabaci as the only prey. The potential of A. tsugawai in greenhouse whitefly control is discussed.


1981 ◽  
Vol 38 (5) ◽  
pp. 485-494 ◽  
Author(s):  
Richard E. Daniels ◽  
J. David Allan

The copepod Eurytemora affinis and the cladoceran Daphnia pulex were cultured at sublethal concentrations of dieldrin to test the usefulness of the intrinsic rate of population increase, r, as a bioassay statistic. The 48-h LC50 for E. affinis was 23 μg/L, but population growth rate measured by the life table method was only 12% of its control value at 5 μg/L and was zero at 10 μg/L, indicating a substantial sublethal effect. In contrast, D. pulex had a higher EC50 (251 μg/L) and showed little impairment of population growth potential below 220 μg/L. We suggest that the cladoceran was less sensitive than the copepod in both short- and long-term tests because of its simpler life cycle and larger size at hatching. The life table estimate of r appears to be an ecologically realistic measure of sublethal stress and requires an equivalent or shorter time to conduct than conventional long-term tests.Key words: acute toxicity, chronic toxicity, life table, r, toxic substances, Daphnia pulex, Eurytemora affinis, pesticide, dieldrin


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1138
Author(s):  
Marzieh Hatami ◽  
Masumeh Ziaee ◽  
Ali Asghar Seraj ◽  
Mehdi Mehrabi-Koushki ◽  
Jacek Francikowski

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.


Author(s):  
Mauricélia F Almeida ◽  
Clébson S Tavares ◽  
Euires O Araújo ◽  
Marcelo C Picanço ◽  
Eugênio E Oliveira ◽  
...  

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.


Acarologia ◽  
2018 ◽  
Vol 58 (1) ◽  
pp. 52-61
Author(s):  
Samah Ben Chaaban ◽  
Brahim Chermiti ◽  
Serge Kreiter

The old world date mite Oligonychus afrasiaticus is an important spider mite pest of the date palms Phoenix dactylifera L. mostly in North Africa and the Middle East. A population of the predaceous mite Typhlodromus (Anthoseius) athenas has been recently found in Tunisia in association with a decrease of O. afrasiaticus densities. The objective of this paper was to assess the development and reproduction abilities of T. ( A.) athenas on O. afrasiaticus under laboratory conditions at two temperatures: 27 and 32 °C. The results obtained show that females of T. (A.) athenas develop in 5 days at 27 °C and 4.1 days at 32 °C. The mean fecundity of T. (A.) athenas was 32.1 and 23.2 eggs per female at 27 and 32 °C, respectively. Life table parameters were stimated: the net reproductive rate (Ro) 27.9 and 17.9 eggs/female, the intrinsic rate of increase (rm) 0.322 and 0,344 female/female/day and the mean generation time (T) 10.3 and 8.4 days at 27 and 32 °C, respectively. At both temperatures tested, T. (A.) athenas intrinsic rate of increase was greater than that of O. afrasiaticus (rm = 0.213 at 32 °C,against rm = 0.166 day1 at 27 °C). Typhlodromus (A.) athenas would be able to develop at a wide range of temperatures feeding on O. afrasiaticus and seems to be able to potentially control it.


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