scholarly journals Fertility Life Tables of Plastanoxus westwoodi (Kieffer) (Hymenoptera: Bethylidae) on Cryptolestes pusillus (Schon.) (Coleoptera: Cucujidae)

1970 ◽  
Vol 16 ◽  
pp. 25-28
Author(s):  
MM Rahman ◽  
W Islam ◽  
KN Ahmed

Plastanoxus westwoodi is an efficient ectoparasitoid of larvae and pupae of the red flat grain beetle Cryptolestes pusillus. Fertility life tables and effects of host instar on life table parameters of P. westwoodi on C. pusillus were studied in the laboratory. Generally adult females lived for 13-16 days. Oviposition commenced on the 1st day of adult emergence and continued till death or 1-2 days before the death of a parasitoid. The intrinsic rate of natural increase (rm) was found to be 0.2291 per female per day. The net reproductive rate (R0) was 64.07; the innate capacity for increase (rc) was 0.2096. The finite rate of increase (λ) was calculated as 1.4735 per female per day, while corrected generation time (T) was computed as 18.16 days. Key words: Plastanoxus westwoodi, Cryptolestes pusillus, Oviposition, Life table, Biological control   DOI:10.3329/jbs.v16i0.3737    J. bio-sci. 16: 25-28, 2008   

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.


1983 ◽  
Vol 115 (1) ◽  
pp. 93-105 ◽  
Author(s):  
John V. Boyne ◽  
Fred P. Hain

AbstractExperiments were conducted on Fraser fir, Abies fraseri (Pursh) Poir, seedlings or cut terminals. Results indicate that Oligonychus ununguis (Jacobi) responds most favorably to temperatures approximating 26 °C and to relative humidity levels approaching 50 to 60%. Developmental time, time to 50% mortality, net reproductive rate, mean generation time, intrinsic rate of natural increase, finite rate of increase, and days for populations to double were computed for each temperature and relative humidity regime. Simulated rainfall severely limits population density on Fraser fir seedlings.


Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 181
Author(s):  
Weiwei Sun ◽  
Miao Cui ◽  
Liyuan Xia ◽  
Qing Yu ◽  
Yang Cao ◽  
...  

Cheyletus malaccensis Oudemans is a predatory mite inhabiting grain depots in China. The relationship between temperature and the population growth rate of C. malaccensis is useful for predicting its population dynamics. Age-stage, two-sex life tables of the predator, C. malaccensis, reared on Acarus siro were constructed under laboratory conditions at 22, 24, 28, 30, and 32 °C, 75% relative humidity, and a 0:24 h (L:D) photoperiod. Increasing temperature shortened the development time of the immature stages. The complete generation time of C. malaccensis ranged from 11.10 d to 27.50 d. Life table parameters showed that 28 °C was the optimum temperature for the growth and development of C. malaccensis; populations could increase rapidly at this temperature. The highest net reproductive rate (R0 = 290.25) and highest fecundity (544.52) occurred at 28 °C. Temperature significantly affected the intrinsic rate of increase (r), fecundity, and finite rate of increase (λ). The values of age-specific fecundity (high to low) were 28 °C > 24 °C > 30 °C > 32 °C > 22 °C, while the values of age-stage-specific fecundity had the same trend.


2020 ◽  
Vol 25 (3) ◽  
pp. 512-524
Author(s):  
Marjan Heidarian ◽  
Yaghoub Fathipor ◽  
Amin Sedaratian-jahromi

Schizotetranychus smirnovi Wainstein is an important phytophagous pest of almond trees which causes serious damage in southwestern Iran. Scolothrips longicornis Priesner has been considered as an efficient predatory thrips that feeds on this spider mite and hence its efficiency for controlling S. smirnovi should be evaluated. In the current study, all main biological parameters of S. longicornis fed on S. smirnovi were determined under laboratory conditions. Data analysis was performed using both female age-specific and age-stage, two-sex life table theories. Duration of incubation, larval, pre-pupal, pupal and pre-adult periods of male predators were 4.73, 3.18, 1.05, 1.86 and 10.82 days, respectively. These periods in female individuals lasted 4.57, 3.92, 1.04, 1.87 and 11.00 days, respectively. Our findings showed that each female laid an average of 62.74 eggs during its ovipositional period (13.61 days). Using the age-stage, two-sex life table, the values of the net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ) and mean generation time (T) were estimated to be 26.236 (eggs/individual), 0.171 (day-1), 1.186 (day-1) and 19.130 (days), respectively. Using the female age-specific life table, these parameters had different values. Our findings revealed that S. longicornis has a reliable capability to increase its population by feeding on S. smirnovi. This information can expand our knowledge for assessing biological efficiency of this predatory thrips in sustainable management of the destructive mite pest. 


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fatemeh Jafarbeigi ◽  
Mohammad Amin Samih ◽  
Mehdi Zarabi ◽  
Saeideh Esmaeily

The sweetpotato whitefly,Bemisia tabaci(Genn.) (Hem.: Aleyrodidae), is an important pest of agriculture in subtropical and tropical areas. In this study, we used the age-stage two-sex life table to evaluate the sublethal effects of the herbal extracts taken fromFumaria parvifloraLam. (Fumariaceae),Teucrium poliumL. (Lamiaceae),Calotropis procera(Willd.) R. Br. (Asclepiadaceae), andThymus vulgarisL. (Lamiaceae) as well as the two commercial synthetic insecticides, pymetrozin and neemarin. The whiteflies were exposed to each insecticide using leaf-dip method. Analysis of life table parameters revealed significant differences (P≤0.05) in the net reproductive rate (R0,NRR), intrinsic rate of increase (rm), and finite rate of increase (λ) among different insecticides. The lowest values of the three population parameters,R0,r, andλ, were observed on whiteflies treated with pymetrozin (2.455, 0.036, and 1.036),T. polium(2.828, 0.044, and 1.045), and neemarin (2.998, 0.046, and 1.047), respectively. Results of this study highlights the satisfactory insecticidal effects of the extract taken fromT. poliumonB. tabaci, which is comparable to the two commonly used synthetic insecticides.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247978
Author(s):  
Maria Pobożniak ◽  
Małgorzata Gaborska ◽  
Tomasz Wójtowicz

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.


2019 ◽  
Vol 24 (9) ◽  
pp. 1620-1630 ◽  
Author(s):  
Zahra Alipour ◽  
Yaghoub Fathipour ◽  
Azadeh Farazmand ◽  
Mostafa Khanamani

Herbivores' host plant resistance may also affect performance of their predators. The effect of susceptible ('Yellow') and resistant ('Roulette') rose cultivars on demographic parameters of the two-spotted spider mite (TSSM), Tetranychus urticae Koch and its predators Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) was determined under laboratory conditions. The obtained data were analyzed using the two-sex life table theory. The development rate of different life stages of TSSM and its predators on the susceptible and resistant rose cultivars were significantly different. Total development time of juvenile stages of TSSM and A. swirskii on the resistant cultivar was longer than that on the susceptible one, although no significant differences were obtained in the case of P. persimilis. By using the two-sex life table, the intrinsic rate of increase (r) of TSSM on the susceptible and resistant cultivars was 0.205 and 0.143 day-1, respectively. In addition, the net reproductive rate (R0) of TSSM on the susceptible and resistant cultivars was 26.46 and 11.47 eggs per individual, respectively; however, the mean generation time (T) of TSSM on these cultivars was 15.92 and 16.92 days, respectively. Furthermore, the value of the intrinsic rate of increase (r) in P. persimilis on the susceptible and resistant cultivars was 0.217 versus 0.163 day-1as well as in A. swirskii on the mentioned cultivars was 0.147 versus 0.117 day-1, respectively. There was no significant difference between the values of the net reproductive rate (R0) in P. persimilis on the susceptible and resistant rose cultivars, but in A. swirskii the value of this parameter on the susceptible cultivar was significantly higher than that on the resistant one. The mean generation time (T) in both predators on the resistant cultivar was longer than the susceptible one. In conclusion, resistance of the rose cultivar negatively affected the population growth parameters of TSSM and its both predators.


2017 ◽  
Vol 22 (10) ◽  
pp. 1698 ◽  
Author(s):  
Sahar Saemi ◽  
Hasan Rahmani ◽  
Aurang Kavosi ◽  
Hsin Chi

To better understand the effect of individual- and group-rearing conditions on predator performance, we studied the life table and predation rate of the predatory mite, Phytoseiulus persimilis Athias-Henriot, after the mites had been individually- or group-reared on two-spotted spider mites, Tetranychus urticae, eggs at 25±1°C, 65±5% RH and a photoperiod of 16: 8 (L:D) h. The net reproductive rate (R0), intrinsic rate of increase (r), net predation rate (C0), finite predation rate (ω) in the individually-reared predators were 40.61 offspring, 0.2594 d-1, 437.3 T. urticae eggs, and 4.8668 preys/d, respectively. Similar values were obtained when the predators were reared in groups (R0 = 43.10 offspring, r = 0.2837 d-1, C0 = 420.9 T. urticae eggs, and ω = 5.9054 preys/d). Mean adult longevities were 28.42 and 25.29 d for group-reared male and female predators, respectively; these values were significantly shorter than those of individual-reared mites (49.87 d for male and 36 d for female). Our results showed that P. persimilis mites could be group-reared in biological control programs without negative effect on their growth and predation potential. 


2018 ◽  
Vol 23 (8) ◽  
pp. 1627
Author(s):  
Atefeh Dahmardeh ◽  
Malihe Latifi ◽  
Rohollah Saberi Riseh

In this study the effects of soil application of potassium phosphite, amino acid complex, and biolog siderophoric on the life table parameters of Tetranychus urticae have been investigated on bean plants, under laboratory conditions. The results revealed significant differences in the total developmental times, oviposition periods, and fecundity of T. urticae among the treatments. The shortest total developmental time and longevity was observed in biolog siderophoric treatment. The intrinsic rate of increase, the net reproductive rate, the finite rate of increase and the mean generation times of T. urticae were remarkably different among the treatments and lower than in the control. The lowest values of these parameters were observed in the biolog siderophoric treatment, which suggests that this inducer could be employed toward a sustainable management of T. urticae.


2018 ◽  
Vol 53 (8) ◽  
pp. 900-908 ◽  
Author(s):  
Leandro Carvalho da Silva ◽  
Daniel Rodrigues Nere ◽  
Ervino Bleicher ◽  
Antônio Vinícius Correa Barbosa ◽  
Eraldo José Madureira Tavares

Abstract: The objective of this work was to evaluate the resistance of advanced semi-erect cowpea (Vigna unguiculata) lines, by means of a screening assay for resistance and the elaboration of fertility-life tables of Aphis craccivora (Hemiptera: Aphididae). The experiments were carried out in a screenhouse. For the resistance trial, 15 advanced cowpea lines were used, as well as two standard genotypes for resistance and two for susceptibility, which were arranged in six blocks. After resistance was determined, two lines with the highest and lowest resistance were selected for the development of the fertility-life tables which were used to estimate demographic parameters. The MNCO4-762F-03 and MNCO4-762F-09 cowpea lines were classified as resistant, for which cowpea aphids showed the lowest values (in parentheses, respectively) for: net reproductive rate (RO = 3.0 and 2.5), intrinsic rate of increase (rm = 0.16 and 0.15), and finite rate of increase (λ = 1.18 and 1.16). The highest values were obtained for the 'Vita-7', MNCO4-795F-168, and 'BRS Tumucumaque' genotypes. The MNCO4-762F-03 and MNCO4-762F-09 lines show antibiosis-type resistance, which directly affects the reproductive potential of the cowpea aphid population.


Sign in / Sign up

Export Citation Format

Share Document