Long-term feeding on greenhouse cucumber affects life table parameters of two-spotted spider mite and its predator Phytoseiulus persimilis 

2018 ◽  
Vol 23 (12) ◽  
pp. 2304 ◽  
Author(s):  
Flora Bahari ◽  
Yaghoub Fathipour ◽  
Ali Asghar Talebi ◽  
Zahra Alipour

Bio-ecological parameters of the two-spotted spider mite (TSSM), Tetranychus urticae Koch and its predators depend on the quality of its host plants. In this study, the life table parameters of TSSM and its main predator Phytoseiulus persimilis Athias-Henriot during different generations (1st, 5th, and 10th generations) were determined on the susceptible (‘Beth-Alpha’) and resistant (‘HED’) greenhouse cucumber cultivars. The results indicated that the longest total development time of TSSM was allocated to the first generation on the susceptible cultivar, but there was no significant difference among different generations on the resistant cultivar. The total development time of the 1st and 10th generations of P. persimilis on each of the susceptible and resistant cultivars had not significant difference. Total fecundity of TSSM was higher in the 10th generation on both cultivars tested than that of the former generations. However, the total fecundity of the predator drastically reduced after long-term rearing (10 generations) on both cultivars. The intrinsic rate of increase (r) of the 1st, 5th, and 10th generations of TSSM on the susceptible cultivar was 0.178, 0.238 and 0.319 day-1, respectively, and 0.157, 0.166 and 0.168 day-1 on the resistant cultivar, respectively which indicates the significantly negative effect of the resistant cultivar on this parameter. In P. persimilis, the value of the intrinsic rate of increase in the first and tenth generations on the susceptible cultivar was 0.275 and 0.267 day-1, respectively, and on the resistant cultivar was 0.244 and 0.210 day-1, respectively. By understanding these interactions in the long term, we will be able to develop suitable strategies for biological control of TSSM on cucumber. 

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.


Author(s):  
Samira Khodayari ◽  
Maryam Hashemian Shalilvand

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is an important pest of pepper (Capsicum annuum L.). Control of this pest is usually dependent on chemical pesticides. The use of resistant plant cultivars in conjugation with other control tactics generates more effective and long lasting results in management of many pests. In this study we used two-sex life table to evaluate the performance of T. urticae on five pepper cultivars (11983, ES4, Hashemi, Mahali and USL) before and after blooming of host plants. The results showed that the immature time, adult longevity and fecundity differed significantly among cultivars. Before blooming on 11983, the values for the intrinsic rate of increase (r) and the finite rate of increase (λ) were 0.0645 and 1.066 day-1 respectively, which were significantly the lowest; the highest r and λ values was recorded on ES4 which were 0.1347 and 1.144 day-1 respectively. After blooming there was no significant difference in these values among cultivars except for Mahali in which these values were significantly the highest (0.0751 and 1.078 day-1 respectively). Comparing between the phenological stages of host plants (before and after blooming) indicated that after blooming all of the tested pepper cultivars were more resistant to T. urticae. In summary, among the different cultivars tested, the most suitable was ES4 and the least suitable was 11983 before blooming of host plants. After blooming the suitability of host plants changed and decreased significantly.


2017 ◽  
Vol 22 (1) ◽  
pp. 148 ◽  
Author(s):  
Ya Ying Li ◽  
Xiao Fan ◽  
Guo Hao Zhang ◽  
YI QING LIU ◽  
HAN QIU CHEN ◽  
...  

Traditional estimating only by measuring the lethal effect of acaricides may underestimate the total effects of acaricides on the pest mites. In order to investigate the sublethal effect of bifenazate on life history and population parameters of the two-spotted spider mite, Tetranychus urticae Koch, the newly emerged females were treated with two lethal concentrations of bifenazate: LC10 (4.92 μg/mL) and LC20 (8.77 μg/mL). Subsequently, the development and fecundity of the progeny generations were observed. Compared to the control, exposure to the 10% lethal concentrations (LC10) and LC20 of bifenazate severely affected the parental generation of T. urticae, including survival rate (reduced 9% and 13%), oviposition period (reduced 77.6% and 83.1%), fecundity per female (decreased 89.2% and 76.9%) and longevity (decreased 79.2% and 83.1%). Besides, the population parameters of the progeny generation from the treated females were also investigated. The results showed that the progeny generation had lower intrinsic rate of increase (rm) and finite rate of increase (λ), longer mean generation time (Tc) compared to the control. The results suggested that the sublethal effects of bifenazate on population growth of T. urticae were significant, and the results of this study could be used as a guide for the rational use of bifenazate in the field for better managing pest mites.


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. 


2017 ◽  
Vol 9 (8) ◽  
pp. 119
Author(s):  
Fernanda De Cássia Neves Esteca ◽  
Camila Do Nascimento Dainese ◽  
Luis Rodolfo Rodrigues ◽  
André Luiz Lourenção ◽  
Francisco Antonio Passos ◽  
...  

The two-spotted spider mite, Tetranychus urticae Koch, is one of the main strawberry pests in Brazil and many other countries. The objective of this study was to compare the resistance of eight strawberry genotypes (‘Albion’, ‘IAC Guarani’, ‘IAC Princesa Isabel’, ‘Oso Grande’, IAC T-0104, IAC 12, IAC 4 and IAC 1.13) to the two-spotted spider mite, by assessing injury level, biological parameters and host preference of the mite. To facilitate the interpretation of the results, leaf trichomes of each genotype were quantified. Thirty days after the artificial infestation of the genotypes with the mite, IAC T-0104, IAC 12 and ‘IAC Princesa Isabel’ showed the lowest injury levels. ‘IAC Princesa Isabel’, IAC 4 and IAC T-0104 were distinguished from other genotypes by the highest mean generation time (T) of the mite, while ‘IAC Guarani’ was distinguished by the lowest T value. Significantly lower values of intrinsic rate of increase (rm), finite rate of increase (λ) and net reproductive rate (Ro) were determined on ‘IAC Princesa Isabel’ and IAC 1.13. The mite showed preference for ‘IAC Guarani’, as inferred by the larger number of females when offered the chance to select the detached host leaflets. Trichome density was highest on IAC 1.13 and lowest on IAC T-0104, IAC 12, ‘Albion’ and ‘Oso Grande’. The results suggested that ‘IAC Princesa Isabel’, IAC T-0104 and IAC 12 are resistant, IAC 4 and IAC 1.13 are moderately resistant, and ‘IAC Guarani’, ‘Oso Grande’ and ‘Albion’ are susceptible to the mite.


2018 ◽  
Vol 29 (1) ◽  
pp. 1-12
Author(s):  
Li-Yuan Cheng ◽  
Yan Chang ◽  
Zhen-Zhen Chen ◽  
Yong-Yu Xu

The influence of fluctuating temperatures on the development and fecundity of two aphids, Megoura crassicauda Mordvilko and Aphis craccivora Koch, were determined by collecting life table data at a constant temperature (22 °C) and two fluctuating temperatures (22 ± 3 °C and 22 ± 5 °C). The longevity of M. crassicauda decreased significantly at 22 ± 3 °C and 22 ± 5 °C, while there was no significant difference in the longevity of A. craccivora among the three treatments. The fecundity and intrinsic rate of increase (r) of M. crassicauda decreased significantly at both fluctuating temperatures, while A. craccivora showed the opposite tendency. These results showed that the fluctuating temperatures had negative impacts on the life history traits of M. crassicauda, but were beneficial for A. craccivora. Data obtained under constant temperatures may not reveal accurately enough the biotic responses of pests in the field.


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 292
Author(s):  
Fatemeh Ganjisaffar ◽  
Thomas M. Perring

Ooencyrtus lucidus Triapitsyn & Ganjisaffar (Hymenoptera: Encyrtidae) was recently recovered from fresh sentinel eggs of Bagrada hilaris (Burmeister) (Hemiptera: Pentatomidae) in California. In the present study, life history traits of O. lucidus were studied at 26 ± 0 . 5 ∘ C, 40 ± 10 % RH, and a photoperiod of 14 L: 10 D hours. Results showed that 95.2% of the parasitized eggs yielded successful emergence of adults. The total immature developmental time was 14.27 and 13.95 days for females and males, respectively. The sex ratio of O. lucidus was 0.5 (females/offspring). Mated females laid on average 6.0 eggs per day and 222.7 eggs during their mean ovipositional period of 37.3 days. There was no significant difference in reproduction parameters between mated and non-mated females. The net reproductive rate ( R 0 ) was 103.8 females/female/generation, the intrinsic rate of increase ( r m ) was 0.171 females/female/day, the finite rate of increase ( λ ) was 1.187 population multiplication/day, the mean generation time (T) was 27.1 days, and the doubling time (DT) was 4.0 days. The highest longevity was observed in mated and non-mated females fed with honey, and they lived for 70.8 and 70.1 days, respectively. Providing females with host eggs in addition to honey, reduced their longevity by 24% in mated and 28% in non-mated individuals. Non-mated females and males deprived of honey only lived for 3.5 and 2.5 days after emergence, respectively. Our results indicate that O. lucidus has sufficient life history traits to make it a promising egg parasitoid for the biological control of B. hilaris.


Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 560
Author(s):  
Konstantinos Athanasiadis ◽  
Maria L. Pappas ◽  
George D. Broufas

Chrysoperla agilis Henry et al. is one of the five cryptic species of the carnea group found in Europe. They are known to widely occur in agricultural fields and survive and reproduce in a wide range of temperatures. The reproductive biology of the cryptic species is poorly known, especially regarding the number of matings required for the females’ maximum reproductive output. We recorded the egg production and longevity of virgin females, as well as of females that had access to males for 1 week or for their lifetime. Longevity of C. agilis females with access to males was similar whether these were present for 1 week or for their lifetime (64.8 and 66.1 days, respectively). On the other hand, oviposition was higher in the long-term exposure to males (302.1 vs. 421.1 eggs, respectively). Virgin females lived longer (94.1 days) than mated females and laid a low number (54.5) of (unfertile) eggs. Egg hatchability and progeny sex ratio were similar in treatments with males. Nevertheless, the highest value (0.1321) of intrinsic rate of increase (rm) was recorded when females were continuously exposed to males. These results are relevant to biological control and could be applicable in mass-rearing C. agilis and predicting its population dynamics in the field.


2021 ◽  
Vol 39 (1) ◽  
pp. 5-10
Author(s):  
Edenilson B Ribeiro ◽  
Maria Aparecida Castellani ◽  
Daniel Júnior de Andrade ◽  
Renato de M Prado ◽  
Larissa Adelita SC Souza ◽  
...  

ABSTRACT Silicon is an inducer of plant resistance to arthropod pests, being a promising strategy for integrated management. The aim of this study was to evaluate the effect of silicon on biological, reproductive and population aspects of parental and F1 generations of the two-spotted spider mite on strawberry plants. Potassium silicate, nanosilica and water were applied to the plants. Two-spotted spider mite females were confined to strawberry leaf disks for oviposition and, after hatching, larvae were observed until the emergence of adults. Once adults had been obtained, couples were formed in order to evaluate pre-oviposition, oviposition, longevity and fertility, with an estimated net reproduction rate, intrinsic rate of increase, finite rate of increase and the necessary time for doubling the generation. Silicon prolonged the duration of some immature stages of the mites in parental and F1 generations, did not affect the duration of the whole biological cycle, though. The periods of pre-oviposition, oviposition and longevity of the parental generation and the longevity and oviposition of F1 generation of the two-spotted spider mite were negatively affected by potassium silicate and nanosilica. The population parameters of the parental generation of the mites indicated that nanosilica is able to lead to a long-run decrease of this pest population.


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