The effects of spirotetramat on the demographic parameters of Neoseiulus californicus (Phytoseiidae)

2018 ◽  
Vol 23 (10) ◽  
pp. 1952 ◽  
Author(s):  
Niloufar Sangak Sani Bozhgani ◽  
Katayoon Kheradmand ◽  
Ali asghar Talebi

Knowledge of the effects of pesticides on biological control agents is mandatory for the successful implementation of IPM programs. The aim of this study was to evaluate the effects of spirotetramat on the life table parameters of Neoseiulus californicus, under laboratory conditions [25 ± 2ºC, 70 ± 5% RH and 16:8 (L:D) h]. The experiments were carried out based on the leaf-dip technique. The experimental concentrations including 10000, 20000 and 30000 ppm of the spirotetramat were used in this study. The raw data was analyzed based on the age-stage, two-sex life table theory. The longevity, total life span, oviposition period, and total fecundity significantly decreased after exposure to concentrations of 20000 and 30000 ppm. The oviposition period was scored 26 days in the control cohort, which reduced to 22.87 days in the 30000 ppm. The total fecundity ranged between 29.45 and 39.46 (offspring/individual). Among the examined concentrations, the lowest values of the gross and net reproductive rates were 21.96 and 17.69 (offspring/individual), observed for the cohort treated with 30000 ppm concentration. Our findings showed the r and λ of N. californicus were not influenced by the different concentrations. The mean generation time (T) for control was the highest; the values for T varied from 18.35 days at control to 16.36 days at 30000 ppm. Therefore, it was concluded that spirotetramat can be introduced as a compatible pesticide alongside the predatory mite, N. californicus, which is an excellent tool that can be incorporated into the integrated pest management of T. urticae.

2020 ◽  
Vol 25 (1) ◽  
pp. 103-112
Author(s):  
José Cláudio Barros Ferraz ◽  
Paulo Roberto Ramalho Silva ◽  
Matheus Pinheiro Amaranes ◽  
José Wagner da Silva Melo ◽  
Debora Barbosa de Lima ◽  
...  

The mite Oligonychus punicae has potential for development in Eucalyptus spp. in clonal minigardens. However, there is no information on its biological and reproductive parameters on eucalyptus species. The objective of this study is to evaluate the biological and reproductive performance of O. punicae on different species of eucalyptus cultivated in a clonal minigarden. Development time, survival, longevity, fecundity and life table parameters of O. punicae were determined on six species of eucalyptus (Eucalyptus urophylla, Eucalyptus brassiana, Eucalyptus grandis, Eucalyptus tereticorinis, Eucalyptus pellita and Corymbia citriodora). All eggs of O. punicae originated females and completed the cycle in all hosts. Differences were observed in development, longevity, pre-oviposition, oviposition and post-oviposition, and fecundity of females of O. punicae when different eucalyptus species were used as hosts for O. punicae. The best performance of O. punicae was observed on E. tereticornis, while the worst performance was observed on C. citriodora, on which the net reproductive rates (R0) ranged from 5.09 to 44.85, the intrinsic rate of population increase (rm) ranged from 0.09 to 0.19, the finite rate of population increase (λ) ranged from 1.10 to 1.21, and the mean generation time (T) ranged from 0.09 to 0.19. These results suggest that E. tereticornis is an excellent host for O. punicae.


2021 ◽  
Author(s):  
Ali KAYAHAN ◽  
Qasim Hussein AHMED ◽  
İsmail KARACA

Abstract The purple scale predator, Rhyzobius lophanthae Blaisdell (Coleoptera: Coccinellidae) is known as coccidophagous ladybird predator, and effective against scales’ insects. The present study aimed to evaluate the optimum temperature for the species to be more efficient. In this study, the life table parameters of R. lophanthae were determined on different temperatures at 4, 16, 18, 20, 22, 24, 26, 28, 30 and 32 °C and 60% RH, by calculations using RmStat-3 software according to Euler-Lotka equation. The results showed that the intrinsic rates of increase (rm) were 0.016, 0.022, 0.030, 0.052, 0.056, 0.068, 0.120, 0.142, 0.132, 0.021 females/females/day, respectively, while the net reproductive rates (R0) were 7.082, 9.514, 11.960, 50.906, 54.150, 49.525, 56.883, 80.944, 31.149, 1.882 females/females/generation, respectively. The mean generation times (T0) were 125.966, 104.602, 84.009, 75.742, 71.511, 57.568, 33.801, 30.866, 25.978, 30.759 days, respectively. Total productivity rates (GRR) were 34.865, 39.210, 48.216, 201.990, 209.469, 166.207, 177.779, 303.751, 105.751, 12.622 egg/female, respectively. The study concluded that 26-30 °C was the optimum temperature range for the efficient role of R. lophanthae under laboratory conditions. From the results, it is still needed to do more studies on the interactions of pests, predators with environmental conditions.


Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 629
Author(s):  
Ya-Ling Wang ◽  
Qi-Nian Jin ◽  
Xiang-Ping Wang

Henosepilachna vigintioctopunctata (F.) is a serious pest of numerous solanaceous crops in many Asian countries. The purpose of this study was to clarify the effects of delayed mating on mating success, fecundity, fertility, pre-oviposition period, oviposition period, adult longevity, and population life table parameters (including net reproductive rate, intrinsic and finite rates of increase, doubling time, and mean generation time) of H. vigintioctopunctata. Beginning three days after emergence for both sexes, mating was delayed an additional 0, 2, 4, 6, or 8 days. We compared the data when mating was delayed for males only with the data when mating was similarly delayed for females only. Reproductive and life table parameters were calculated from the two data sets and compared. The results showed that the preoviposition and oviposition period of adults was significantly reduced by delayed mating, while the preoviposition period was not significantly different in adults mated at older ages. The mating success rate, fecundity, and proportion of hatching eggs decreased with increasing mating age. Longevity was not affected by the age at mating. Mating delay also affected the life table parameters of H. vigintioctopunctata, with a similar trend observed in the net reproductive rate and intrinsic and finite rates of increase, all of which decreased gradually as the number of delay days increased. The population doubling time increased with increases in mating age. The results also showed that delayed mating was an effective measure to consider in controlling H. vigintioctopunctata. It is hoped that our data will provide a scientific basis and contribute technical guidance for forecasting and integrated management of this pest.


2020 ◽  
Vol 25 (3) ◽  
pp. 411
Author(s):  
Mohammadreza Havasi ◽  
Katayoon Kheradmand ◽  
Hadi Mosallanejad ◽  
Yaghoub Fathipour

Knowledge of the effects of pesticides on biological control agents is necessary for the successful implementation of integrated pest management programs. Laboratory bioassays were conducted to evaluate the effects of Biomite®, a natural acaricide, on the life table parameters of Neoseiulus californicus McGregor (Acari: Phytoseiidae), as one of the most important natural enemies of Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions at 25 ± 2°C, 65 ± 5% RH and a photoperiod of 16:8 (L:D) h. The raw data were analyzed based on the two-sex life table theory. Biomite® concentrations LC10 and LC20 gradually and significantly reduced the longevity and total life span of both sexes, as well as total fecundity. Besides, concentration LC20 significantly reduced the gross reproductive rate (GRR) and the net reproductive rate (R0). However, the intrinsic rate of increase (r) and the finite rate of increase (λ) were not significantly affected. Thereby, due to an unfavorable shortened in life history characters of N. californicus such as total life span, reproductive periods and biological parameters (such as R0 and GRR), as a consequence of Biomite® treatment, it can be concluded that this acaricide should not be used with N. californicus in integrated pest management programs.


1987 ◽  
Vol 119 (4) ◽  
pp. 361-364 ◽  
Author(s):  
J.J. Turgeon ◽  
N. Nelson ◽  
E.G. Kettela

AbstractStudies on the reproductive biology of the spruce budmoth, Zeiraphera canadensis Mut. & Free., were conducted in northern New Brunswick. Observations of adults under insectary conditions revealed that peak mating occurred around midnight, and that copulation lasted on average 4.3 h. The age of males and females at mating as well as their longevity is provided for both years. The pre-oviposition period was similar for both years, 6.1 and 6.3 days in 1984 and 1985, respectively. The oviposition period decreased from 6.1 days in 1984 to 4.4 days in 1985. The total fecundity was 32.9 eggs per female in 1984 and 21.8 eggs per female in 1985. The mean age-specific oviposition rate under 1984 field conditions is also presented. The importance of these results in determining the proper timing of adulticidal sprays against Z. canadensis is discussed.


2020 ◽  
Vol 25 (1) ◽  
pp. 125-138
Author(s):  
Mohammadreza Havasi ◽  
Katayoon Kheradmand ◽  
Hadi Mosallanejad ◽  
Yaghoub Fathipour

Knowledge of the effects of pesticides on biological control agents is necessary for the successful implementation of integrated pest management programs. Laboratory bioassays were conducted to evaluate the effects of Biomite®, a natural acaricide, on the life table parameters of Neoseiulus californicus McGregor (Acari: Phytoseiidae), as one of the most important natural enemies of Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions at 25 ± 2°C, 65 ± 5% RH and a photoperiod of 16:8 (L:D) h. The raw data were analyzed based on the two-sex life table theory. Biomite® concentrations LC10 and LC20 gradually and significantly reduced the longevity and total life span of both sexes, as well as total fecundity. Besides, concentration LC20 significantly reduced the gross reproductive rate (GRR) and the net reproductive rate (R0). However, the intrinsic rate of increase (r) and the finite rate of increase (λ) were not significantly affected. Thereby, due to an unfavorable shortened in life history characters of N. californicus such as total life span, reproductive periods and biological parameters (such as R0 and GRR), as a consequence of Biomite® treatment, it can be concluded that this acaricide should not be used with N. californicus in integrated pest management programs.


2016 ◽  
Vol 56 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Mehdi Mollashahi ◽  
Ahad Sahragard ◽  
Jafar Mohaghegh-Neyshabouri ◽  
Reza Hosseini ◽  
Hossein Sabouri

AbstractA life table can be used as an important and appropriate tool to evaluate the susceptibility or resistance level of different host plant cultivars to insect pests. In the current study, we determined the suitability or inferiority of five different canola cultivars (Hayula420, Hayula401, Hayula50, Hayula60, RGS) to Nysius cymoides, under laboratory conditions. Data were analysed based on the age-stage, two-sex life table theory. Nysius cymoides which fed on Hayula420 had the longest nymphal period, while those which fed on Hayula50 had the shortest nymphal period. Developmental times (sum of incubation and nymphal periods) was longest for those which fe d on Hayula420 and the shortest for those which fed on Hayula50. The adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), mean fecundity, and adult longevity of adults reared on different canola cultivars showed significant differences. The highest and lowest net reproductive rates (R0) were obtained for those which fed on Hayula420 (11.40 offspring per individual) and Hayula401 (5.47 offspring per individual), respectively. The highest value (0.0395 d-1) for the intrinsic rate of increase (r) was obtained for those which fed on Hayula 60 cultivar and the lowest value (0.0261 d-1) for those which fed on Hayula401 cultivar. The shortest and longest mean generation times (T) were obtained for those which fed on RGS and H401 cultivars, respectively. The lowest and highest values of life expectancy (exj) were obtained for those which fed on RGS and Hayula420 cultivars, respectively. The results showed that Hayula401 and RGS were not susceptible cultivars to N. cymoides. These cultivars showed higher resistance to N. cymoides, while Hayula60, Hayula420, and Hayula50 were found to be suitable cultivars but with lower resistance to N. cymoides, respectively.


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