scholarly journals Effects of constant and fluctuating temperatures on development and reproduction of Megoura crassicauda and Aphis craccivora (Hemiptera: Aphididae)

2018 ◽  
Vol 29 (1) ◽  
pp. 1-12
Author(s):  
Li-Yuan Cheng ◽  
Yan Chang ◽  
Zhen-Zhen Chen ◽  
Yong-Yu Xu
Keyword(s):  
Intrinsic Rate ◽  
Aphis Craccivora ◽  
Intrinsic Rate Of Increase ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Life Table Data ◽  
Aphis Craccivora Koch ◽  
Negative Impacts ◽  
Table Data ◽  
Fluctuating Temperatures

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.

RESISTANCE TO APHIS CRACCIVORA (HOMOPTERA:APHIDIDAE) IN SELECTED VARIETIES OF COWPEA

1985 ◽  
Vol 20 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Frank J. Messina ◽  
J. A. A. Renwick ◽  
Joyce L. Barmore
Keyword(s):  
United States ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Susceptible Variety ◽  
Aphis Craccivora ◽  
Intrinsic Rate Of Increase ◽  
Southern United States ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Aphis Craccivora Koch

Nearly 200 varieties of cowpea, Vigna unguiculata (L.) Walp, were screened for resistance to the cowpea aphid, Aphis craccivora Koch. Three varieties known to be resistant in West Africa were highly susceptible to an aphid population from the southern United States. Four other varieties, however, inhibited growth of the southern United States population both in the laboratory and in the field. Life-table comparisons using a resistant and a susceptible variety revealed a three-fold difference in the intrinsic rate of increase and a more than twenty-fold difference in the net reproductive rate. High nymphal mortality and low fecundity on resistant plants were largely responsible for these differences.

Demography of Mythimna separata (Lepidoptera: Noctuidae) at outdoor fluctuating temperatures

2021 ◽  
pp. 1-9
Author(s):  
Bo-Liao Li ◽  
Mei-Mei Li ◽  
Tian-Tian Li ◽  
Jun-Xiang Wu ◽  
Xiang-Li Xu
Keyword(s):  
Larval Instar ◽  
Intrinsic Rate ◽  
Immature Stage ◽  
Early Summer ◽  
Intrinsic Rate Of Increase ◽  
Mythimna Separata ◽  
Rate Of Increase ◽  
Table Data ◽  
Lepidoptera Noctuidae ◽  
Fluctuating Temperatures

Abstract The oriental armyworm Mythimna separata (Walker) (Lepidoptera: Noctuidae) is a major migratory pest of cereal crops in East Asia, South Asia and Australia. To comprehensively understand the ecological tolerance of M. separata, we collected life table data of individuals from four consecutive generations reared under outdoor natural fluctuating temperatures from 15 April to 17 October 2018 in Yangling, Shaanxi, China. The results showed that the immature stage in early summer and summer were shorter than in spring and autumn. High mortality in late larval instar and pupal stages was observed in the summer generation. The adult pre-oviposition period in autumn was longer than the other seasons. The population in the earlier two seasons had heavier pupae and higher fecundity than the population in the latter two seasons. The intrinsic rate of increase and the finite rate of increase was the highest in early summer (r = 0.1292 day−1, λ = 1.1391 day−1), followed by spring (r = 0.1102 day−1, λ = 1.1165 day−1), and was the lowest in summer (r = 0.0281 day−1, λ = 1.0293 day−1). The results of this study would be useful to predict the population dynamics of M. separata and deepen our standing of the adaptiveness of this migratory pest in natural fluctuating ambient environments.

scholarly journals Prey Density Dependent Life Table of Aphidoletes Aphidomyza Rondani (Dip., Cecidomyiidae) Feeding on Aphis Craccivora Koch (Hem., Aphididae) under Laboratory Conditions

2013 ◽  
Vol 53 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Khadijeh Madahi ◽  
Ahad Sahragard ◽  
Reza Hossieni
Keyword(s):  
Life Table ◽  
Prey Density ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Aphis Craccivora ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Density Dependent ◽  
Rate Of Increase ◽  
Aphis Craccivora Koch

Abstract The life table provides an integrated and comprehensive description of development times, survivorship, and reproduction of a population. Life table parameters of aphidophagous midge, Aphidoletes aphidimyza Rondani (Dip., Cecidomyiidae) on different densities (5, 10, 20, 40, 60, 80) of third instar nymphs of Aphis craccivora Koch as prey, were studiedat (25±1°C, 70±5% relative humidity (RH) and a photoperiod of 16L : 8D h). There were no significant differences among the adult pre-ovipositional periods (APOP) at different prey densities. The total pre-ovipositional period (TPOP) of female A. aphidimyza was reduced significantly as prey density increased. The oviposition period was significantly different at varying prey densities. It was 4.333±0.211 and 5.625±0.324 days at the lowest and highest prey densities, respectively. Female longevity was also significantly different at varying prey densities. Fecundity was directly dependent on prey density (R2 = 0.990). The lowest fecundity was obtained at a density of 5 prey (52.5±1.544 eggs) and the highest was at a density of 80 prey, per day (121.375±4.301 eggs). The intrinsic rate of increase (r) was prey density dependent (R2 = 0.958), and ranged from 0.122±0.017 to 0.193±0.014 d-1 as prey density increased. The net reproductive rate (R0) was significantly increased as prey density increased. The peak reproductive values showed that female aphidophagous midges at the age of 15, 16, 17, 18, and 19 days made the highest contribution to the population at different prey densities. It was concluded that the increase in the densitits of third instar nymphs of A. craccivora had significant effects on demographic parameters of A. aphidimyza

Biological responses of Tetranychus urticae to five pepper cultivars at two phenological stages of host plants

2021 ◽  
Author(s):  
Samira Khodayari ◽  
Maryam Hashemian Shalilvand
Keyword(s):  
Tetranychus Urticae ◽  
Host Plants ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Adult Longevity ◽  
Phenological Stages ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Before And After ◽  
Important Pest

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.

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
Keyword(s):  
Phytoseiulus Persimilis ◽  
Intrinsic Rate ◽  
Resistant Cultivar ◽  
Intrinsic Rate Of Increase ◽  
Susceptible Cultivar ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Greenhouse Cucumber ◽  
Two Spotted Spider Mite

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. 

scholarly journals Life History Evaluation of Ooencyrtus lucidus, a Newly Described Egg Parasitoid of Bagrada hilaris

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 292
Author(s):  
Fatemeh Ganjisaffar ◽  
Thomas M. Perring
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Intrinsic Rate ◽  
Developmental Time ◽  
Egg Parasitoid ◽  
Reproductive Rate ◽  
Intrinsic Rate Of Increase ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Significant Difference

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.

scholarly journals Flupyradifurone Induces Transgenerational Hormesis Effects in the Cowpea Aphid, Aphis Craccivora (Koch)

2021 ◽  
Author(s):  
Eman Fouad ◽  
Sherifa A.N. El-Sherif ◽  
El-Sayed M. S. Mokbel
Keyword(s):  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Aphis Craccivora ◽  
Intrinsic Rate Of Increase ◽  
High Dose ◽  
Biological Traits ◽  
Transgenerational Effects ◽  
Net Reproductive Rate ◽  
Rate Of Increase ◽  
Cowpea Aphid

Abstract Insecticide induced-hormesis, a biphasic phenomenon ,with low-dose stimulation and high-dose inhibition, which effectively contributes to pest resurgence. Although cowpea aphid, Aphis craccivora (Koch) (Homoptera: Aphididae), is the most infection insect to legume crops in Egypt, its’ hormesis to flupyradifurone did not previously establish. Therefore, age-stage two-sex life analysis was used to investigate the sublethal and transgenerational effects of flupyradifurone on two successive generations of A. craccivora. Leaf-dip bioassay method revealed high toxicity of flupyradifurone against A. craccivora with LC50 value of 1.82 mg L-1 after 48 h exposure. Treatment of parent generation (F0) with LC10 and LC25 of flupyradifurone significantly increased the longevity and fecundity of the directly exposed adults. The results of transgenerational effects showed that treatment of (F0) with LC25 induced a significant hormetic effects in progeny generation (F1). Furthermore, flupyradifurone at LC25 significantly enhanced the biological traits such as intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R0) compared with the control. Similarly, both LC10 and LC25 caused a significant increase in the mean generation time T (d). Conversely ,both treatments had a significant decrease in the doubling time (DT). In conclusion, the obtained data demonstrate that exposure of (F0) to flupyradifurone at LC10 and LC25 enhanced longevity and fecundity in of the directly exposed adults of A. craccivora and induced transgenerational hormesis across the subsequent (F1) generation. These grades must be taken into consideration when using flupyradifurone against cowpea aphids.

Influence of temperature on the development and reproduction of Cinara cedri (Hemiptera: Aphidoidea: Lachninae)

2021 ◽  
pp. 1-6
Author(s):  
Yingchao Ji ◽  
Guohua Li ◽  
Chenggang Zhou ◽  
Shuyan Yin
Keyword(s):  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Threshold Temperature ◽  
Reproduction Rate ◽  
Cedrus Deodara ◽  
Developmental Threshold ◽  
Factors Affecting ◽  
Rate Of Increase ◽  
Influence Of Temperature On ◽  
Development Duration

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.

Ambient Humidity Affects Development, Survival, and Reproduction of the Invasive Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), in China

2021 ◽  
Author(s):  
Limei He ◽  
Shengyuan Zhao ◽  
Abid Ali ◽  
Shishuai Ge ◽  
Kongming Wu
Keyword(s):  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Reproduction Rate ◽  
Ambient Humidity ◽  
Rate Of Increase ◽  
Population Forecasting ◽  
Survival And Reproduction ◽  
Net Reproduction

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.

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