scholarly journals Effects of temperature on a Chinese population of Amblyseius andersoni (Acari: Phytoseiidae) fed with Tetranychus urticae

Acarologia ◽  
2019 ◽  
Vol 59 (4) ◽  
pp. 475-483
Author(s):  
Yu-Jing Li ◽  
Qing-Yan Liu ◽  
Jing Chang ◽  
Yong-Hong Jia ◽  
Rui-Xia Meng

The development and fecundity of Amblyseius andersoni (Chant) fed with Tetranychus urticae Koch was studied at five different temperatures (17, 20, 25, 30 and 35 °C) and life parameters of the population were calculated. The development, reproduction, longevity, and life table parameters of A. andersoni were significantly affected by the different temperatures. The duration of the egg, larval, protonymph, deutonymph and total immature stages were reduced when the temperature increased. The total oviposition of A. andersoni was highest at 25 °C and lowest at 35 °C, and the daily average oviposition increased as the temperature increased, but few eggs were laid at 17 °C. The values of the intrinsic rate of increase (rm, 0.108--0.200), net reproduction rate (R0, 18.71--36.47) and the mean generation time (T, 14.68--29.73) significantly differed among the five temperatures. The highest net reproduction rate (R0 = 36.47) was obtained at 25 °C. The results of this study indicated that A. andersoni has a high inherent potential for the control of the T. urticae at certain temperatures.

Author(s):  
Limei He ◽  
Shengyuan Zhao ◽  
Abid Ali ◽  
Shishuai Ge ◽  
Kongming Wu

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.


2021 ◽  
Vol 948 (1) ◽  
pp. 012041
Author(s):  
Oktaviani ◽  
N Maryana ◽  
Pudjianto

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%.


2019 ◽  
Vol 112 (6) ◽  
pp. 2597-2603 ◽  
Author(s):  
Yanyan He ◽  
Yicong Liu ◽  
Ke Wang ◽  
Youjun Zhang ◽  
Qingjun Wu ◽  
...  

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.


2021 ◽  
Vol 948 (1) ◽  
pp. 012044
Author(s):  
L Sari ◽  
N Maryana ◽  
P Hidayat

Abstract Spodoptera frugiperda is a species of armyworm that attacks maize crops globally and is a dangerous new invasive pest in Indonesia. Biological control, which employs natural enemies, is one method of controlling this pest. One of the natural enemies found in the field is the egg parasitoid of the Trichogrammatidae family. This study aimed to determine the reproductive capacity of the parasitoid on S. frugiperda eggs. The tested parasitoids were collected from S. frugiperda eggs on corn cultivations in Tenjolaya Village, Bogor Regency, West Java Province. The identification results showed that the parasitoid species used in this study was Trichogramma chilotraeae. The development periods of eggs, first instar larvae, second instar larvae, and pupae in the laboratory were 1.16 days, 1.18 days, 1.39 days, and 3.28 days, respectively. The reproductive capacity of T. chilotraeae on S. frugiperda eggs, referred to as the net reproduction rate (Ro), was 28.13, gross reproduction rate (GRR) was 30.43. the average time for one generation (T) was 9.07. The intrinsic rate of increase (r) was 5.54, and Doubling time (DT) was 1.88. Thus, the egg parasitoid of T. chilotraeae was not very effective as a potential biological agent for S. frugiperda.


2021 ◽  
Vol 26 (2) ◽  
pp. 496-508
Author(s):  
Firdevs Ersin ◽  
Ferit Turanli ◽  
Ibrahim Cakmak

Typhlodromus recki (Acari: Phytoseiidae) was collected from aubergines, pepper, black nightshade and jimsonweed plants infested with spider mites from a pesticide-free vegetable garden in Denizli, Turkey. The biology and life table parameters for T. recki feeding on Tetranychus urticae (Acari: Tetranychidae) at different temperatures (15, 20, 25, 30 and 35 °C) were determined. The results showed that total preadult periods of T. recki at 15, 20, 25, 30 and 35 °C were 19.6±0.51, 9.4±0.16, 7.6±0.14, 5.7±0.14 and 4.5±0.08 days, respectively. The longest oviposition period was 23.5 days at 20 °C. Total fecundity of T. recki significantly differed between the constant temperatures and the highest was observed at 20 °C (28.6 eggs/female) and 25°C (23.5 eggs/female). Although females survived for 26 days at 35 °C, only four females laid eggs for 1 day. Thus, 35 °C is not suitable for the reproduction of T. recki. Total longevity of female was the longest at 15°C (59.5 days) and 20 °C (51.3 days) whereas male total longevity was the longest at 15°C (53.2 days). The intrinsic rate of increase (r) and finite rate of increase (λ) were numerically the highest at 30 °C (0.17 and 1.18 d-1), but there was no statistical difference observed between 25 and 30 °C for both r and λ values. The net productive rate was significantly highest at 20, 25 and 30 °C. The longest mean generation time occurred at 15 °C (42.6 days) and the shortest was at 35 °C (8.0 days). After some field trials, Typhlodromus recki could potentially be considered in the biological control agent of T. urticae.


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.


2020 ◽  
Vol 113 (5) ◽  
pp. 2343-2353 ◽  
Author(s):  
Mingfeng Wei ◽  
Hsin Chi ◽  
Yongfu Guo ◽  
Xianwei Li ◽  
Longlong Zhao ◽  
...  

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.


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.


Acarologia ◽  
2018 ◽  
Vol 59 (1) ◽  
pp. 12-20
Author(s):  
Nabi Alper Kumral ◽  
Pınar Hephızlı Göksel ◽  
Elif Aysan ◽  
Ayşenur Kolcu

The life table parameters of Tetranychus urticae were evaluated on 7 eggplant cultivars namely, Anamur, Aydin Siyahi, Balikesir 76, Kemer, Pala 49, Topan 374, Yalova Topan, in controlled laboratory conditions in day ight for 16 hours 27 +/- 1 °C temperature, 65% relative humidity. Assays were conducted on eggplant leaflets in Petri dishes. There was a significant difference in the durations of egg and juvenile development of T. urticae. However the survival rates of T. urticae were not significantly different on the tested eggplant cultivars. The values of the natural rate of increase, rm, (0.218-0.269), net reproduction rate, R0, (26.74-45.51) and the mean generation time, T, (13.31-15.45) significantly differed among eggplant cultivars. Notably, the shortest development duration as indicated by the lowest rm and R0 values were observed on Pala 49 followed by Anamur and Balikesir 76 cultivars.


Author(s):  
Yingchao Ji ◽  
Guohua Li ◽  
Chenggang Zhou ◽  
Shuyan Yin

Abstract Temperature is one of the main factors affecting insect growth, development and reproduction. The effects of temperatures (10, 15, 20, 25 and 30°C) on the development and reproduction of Cinara cedri Mimeur (Hemiptera: Aphidoidea: Lachnidae) fed on Cedrus deodara (Roxb.) G. Don were evaluated in this study. With the increase of temperature from 10 to 30°C, the development duration at different development stages gradually shortened. There was a significant positive correlation between the developmental rates and temperature, following a quadratic regression model. The lower developmental threshold temperature (C) and effective accumulated temperatures (K) for completing a generation were 4.13°C and 263.4 degree-days, respectively. The highest fecundity was observed at 20°C with 25.74 first-instar nymphs/female. Both the highest intrinsic rate of increase (r, 0.11 ± 0.03) and net reproduction rate (R0, 19.06 ± 2.05) were observed at 20°C, whereas the lowest values of r (0.05 ± 0.01) at 10°C and R0 (5.78 ± 0.88) at 30°C were observed. The results suggest that temperature significantly affects the biology of C. cedri and the optimal temperature for its development is 20°C.


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