scholarly journals Relative fitness of avermectin-resistant strain of Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae)

2017 ◽  
Vol 22 (2) ◽  
pp. 184 ◽  
Author(s):  
Xia Chen ◽  
Yan-Xuan Zhang ◽  
Yu-Ping Zhang ◽  
Hui Wei ◽  
Jian-Zhen Lin ◽  
...  

The predacious mite Neoseiulus cucumeris (Oudemans) is an effective natural enemy of pest insects and mites. To identify the relative fitness of the avermectin-resistant strain of N. cucumeris, the life history parameters of avermectin resistant (R) and susceptible (S) strains of N. cucumeris were observed under experimental conditions (25 ± 1°C, 90 ± 5% RH and L: D = 14:10 h) feeding upon Tetranychus truncatus (Ehara). Fertility, net reproductive rates (R0 /female), intrinsic rates of increase (r/day) and development durations of the two strains were compared. The abamectin resistant strain of N. cucumeris had significantly shorter developmental duration and longevity than the sensitive stain. However, the mean fecundity of the resistant strain was significantly higher than that of the susceptible strain. The net reproductive rate (R0=30.3833 offspring), the intrinsic rate of increase (r=0.2231 d-1) and the finite rate of increase (λ=1.2499 d-1) of the resistant strain were only slightly higher than those of the susceptible strain (R0=29.5333 offspring, r=0.2130 d-1, λ=1.2373 d-1); the differences were not significant. However, the mean generation time (T=15.1768 d) of the resistant strain was significantly shorter than that of the susceptible strain (T=16.0314 d).

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Zhang Yu-ping ◽  
Lu Yong-yue ◽  
Zeng Ling ◽  
Liang Guang-wen

Life tables were established for trichlorphon-resistant and susceptibleBactrocera dorsalisstrains based on the laboratory observations. Trichlorphon-resistantB. dorsalisstrain had longer pupal and preoviposition periods, and mean generation time compared to the trichlorphon susceptible strain. Lower fecundity, emergence rate, and probability of standard fecundityPF, and shorter female and male longevity also were apparent in the trichlorphon resistant strain. Based on the life tables, the life population trend index (I) of the resistant strain was 86.80, while that of the susceptible strain was 116.97. The net reproduction rate (R0) and the intrinsic rate of increase (rm) of the resistant strain were 1565.33 and 0.0164, while those of susceptible strain were 2184.00 and 0.0173, respectively. The results from this research revealed that the resistant strain was at a reproductive and developmental disadvantage relative to the susceptible strain.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0250311
Author(s):  
Aonan Zhang ◽  
Lin Zhu ◽  
Zhenghao Shi ◽  
Tianying Liu ◽  
Lanlan Han ◽  
...  

The soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) is a primary pest of soybeans and poses a serious threat to soybean production. Our studies were conducted to understand the effects of different concentrations of insecticides (imidacloprid and thiamethoxam) on A. glycines and provided critical information for its effective management. Here, we found that the mean generation time and adult and total pre-nymphiposition periods of the LC50 imidacloprid- and thiamethoxam-treatment groups were significantly longer than those of the control group, although the adult pre-nymphiposition period in LC30 imidacloprid and thiamethoxam treatment groups was significantly shorter than that of the control group. Additionally, the mean fecundity per female adult, net reproductive rate, intrinsic rate of increase, and finite rate of increase of the LC30 imidacloprid-treatment group were significantly lower than those of the control group and higher than those of the LC50 imidacloprid-treatment group (P < 0.05). Moreover, both insecticides exerted stress effects on A. glycines, and specimens treated with the two insecticides at the LC50 showed a significant decrease in their growth rates relative to those treated with the insecticides at LC30. These results provide a reference for exploring the effects of imidacloprid and thiamethoxam on A. glycines population dynamics in the field and offer insight to agricultural producers on the potential of low-lethal concentrations of insecticides to stimulate insect reproduction during insecticide application.


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.


Insects ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 542
Author(s):  
Anna Skourti ◽  
Nickolas G. Kavallieratos ◽  
Nikos E. Papanikolaou

Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is an important pest of stored products. Insecticidal treatment is a common practice for the control of this notorious insect pest. Most studies are focused on the immediate and/or delayed mortality effects, while there are no data on the effects of insecticides on the population fitness. This study deals with the effect of chlorfenapyr on T. castaneum, investigating the cost of exposure of different developmental stages on population performance, by using life table statistics and a survival analysis method. For this purpose, eggs, larvae, and parental adult females of T. castaneum were exposed to chlorfenapyr and birth or death rates were calculated daily. The exposure of eggs and larvae to chlorfenapyr was detrimental for T. castaneum and they did not complete development. When parental females were exposed to chlorfenapyr, the progeny survival curve, biological features, as well as the life table parameters did not differ significantly compared to the control treatment. Thus, egg hatching, larval and pupal developmental periods, female and male longevities for the control treatment, and the progeny of the females that were exposed to chlorfenapyr were 4.66 and 4.76 days, 25.85 and 25.71 days, 5.00 and 5.26 days, 87.33 and 104.22 days, and 76.87 and 91.87 days, respectively. In addition, the mean values of the net reproductive rate, the intrinsic rate of increase, the mean generation time and the doubling time for the control treatment and the progeny of the parental females which were exposed to chlorfenapyr were 14.3 and 9.3 females/female, 0.038 and 0.028 females/female/day, 1.039 and 1.029, 70.0 and 76.9 days, and 18.5 and 24.9 days, respectively. We expect these results to have bearing on the management of T. castaneum, since the repeatedly insecticidal applications could be reduced in storage facilities.


2014 ◽  
Vol 86 (2) ◽  
pp. 723-732 ◽  
Author(s):  
DÉBORA G. MONTEZANO ◽  
ALEXANDRE SPECHT ◽  
DANIEL R. SOSA-GÓMEZ ◽  
VÂNIA F. ROQUE-SPECHT ◽  
TARCISO M. BORTOLIN ◽  
...  

This study aimed to evaluate the biotic potential, life table parameters and fertility of Spodoptera albula (Walker, 1857) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photo phase). The longevity, pre, post and oviposition periods, fecundity and fertility of 13 couples were evaluated. The longevity of females (13.500 days) was significantly higher than those of males (11.154 days). The mean durations of the pre, post and oviposition periods were 2.615, 1.769 and 9.385 days, respectively. The mean fecundity was 1.417.69 eggs and mean fertility was 1.340.401 larvae, per female. On average, females copulated 1, 231 times. A strong positive correlation was observed between the number of copulations and fecundity (r = 0.847, p <0.001), as well as a strong negative correlation between the number of copulations and the duration of the pre-oviposition period (r = -0.762, p = 0.002), and longevity (r = -0.788, p = 0.001). The biotic potential of S. albula was estimated at 8.768 x 1022 individuals / female / year. The net reproductive rate (Ro) was 353,904 times per generation and the mean generation time (T) was 37.187 days. The intrinsic rate of increase (rm) was 1,105, with a finite rate of increase (λ) of 3,019.


Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Jun Jiang ◽  
Li-Li Xu ◽  
Wen-Yuan Yu ◽  
Shi-Ze Zhang ◽  
Tong-Xian Liu

Bemisia tabaci and the diamondback moth (DBM), Plutella xylostella, are two major cosmopolitan pests that often occur together and cause severe economic losses to cruciferous crops. However, little is known about how they interact with each other. To determine the effects of defense responses induced by the two pests on the biology and population dynamics of the herbivores, we studied the performance and fitness of B. tabaci and DBM when they damaged Chinese kale simultaneously and in different orders. The results showed that DBM pre-infestation shortened the developmental duration, increased longevity, oviposition days, and fecundity of B. tabaci. Meanwhile, the intrinsic rate of increase (r), net reproductive rate (R0) and finite rate of increase (λ) of B. tabaci increased significantly with dual infection as compared with only B. tabaci infestation. In contrast, B. tabaci pre-infestation reduced the longevity and oviposition days of DBM, but the population parameters r, R0, and λ did not vary significantly compared with only DBM infestation. Thus, co-infestation of B. tabaci and DBM was beneficial to the performance of the B. tabaci population. The present findings highlight that B. tabaci has become a dominant competitor when mixing with DBM on the same host plant.


2019 ◽  
Vol 11 (13) ◽  
pp. 240 ◽  
Author(s):  
Débora G. Montezano ◽  
Alexandre Specht ◽  
Daniel R. Sosa-Gómez ◽  
Vânia F. Roque-Specht ◽  
Juaci V. Malaquias ◽  
...  

The fall armyworm, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), a native to the Americas and recently reported in Africa, Germany, the Netherlands and India, is a significant pest of many crop species. Although a widespread and important pest, information on its biology and development are incomplete and require detailed study. In this study, the biotic potential and reproductive parameters of S. frugiperda were evaluated under controlled conditions (25&plusmn;1 &deg;C, 70&plusmn;10% RH and 14 hour photophase). The longevity, pre-, post- and oviposition periods, fecundity, and fertility of 30 pairs were evaluated. The longevity of females (10.87 days) was not significantly different from that of males (10.90 days). The mean durations of the pre-, post- and oviposition periods were 2.63, 0.53 and 7.70 days, respectively. The mean fecundity was 2,370.66 eggs per female and mean fertility was 2,309.03 larvae per female. On average, a female copulated 1.6 times. The biotic potential of S. frugiperda was estimated at 2.086 &times; 1029 individuals/female/year. The net reproductive rate (Ro) was 1,079.73 times per generation and the mean generation time (T) was 32.00 days. The intrinsic rate of increase (rm) was 0.22, with a finite rate of increase (&lambda;) of 1.24 per day. This study evaluates and describes the biological parameters of S. frugiperda with special emphasis on its biotic potential and reproductive parameters. This information will improve the development of integrated pest management (IPM) and insect resistance management (IRM) for this species.


2020 ◽  
Vol 25 (8) ◽  
pp. 1461-1471
Author(s):  
Lixia Xie ◽  
Na Zhang ◽  
Xinran Wu ◽  
Kai Liu ◽  
Chenlin Liu ◽  
...  

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.


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.


2019 ◽  
Vol 79 (3) ◽  
pp. 488-494 ◽  
Author(s):  
A. Specht ◽  
V. F. Roque-Specht

Abstract In this study we evaluate the biotic potential and reproductive parameters of Spodoptera cosmioides (Walker, 1858) under controlled conditions (25 ± 1 °C, 70 ± 10% RH and 14 hour photophase). Females, on average, (14.433 days) did not live significantly longer than their male counterparts (13.100 days). The mean durations of the pre-oviposition, oviposition and post-oviposition periods were 2.767, 10.600 and 1.067 days, respectively. The mean fecundity of females was 5,073.533 eggs and the mean fertility was 5,021.027 larvae. On average, females copulated 1.167 times. Fecundity was positively correlated with the number of copulations (r = 0.583, P <0.001). The number of copulations, however, was negatively correlated whit the duration of the pre-oviposition (r = -0.560, P = 0.007) and oviposition (r = -0.479, P = 0.048) periods, and overall longevity (r = -0.512, P = 0.031). The biotic potential was estimated at 6.547 x 1021 individuals/female/year. The net reproductive rate (Ro) was 2,193.722 times per generation and the mean generation time (T) was 46.407 days. The intrinsic rate of increase (rm) was 0.166, with a finite rate of increase (λ) of 1.180, per week.


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