Life table and economic threshold concept for ecologically sustainable management of Diacrisia casignetum Kollar (Lepidoptera: Arctiidae) on Jute

ENTOMON ◽  
2019 ◽  
Vol 44 (2) ◽  
pp. 103-110
Author(s):  
Nayan Roy

Life table and economic threshold (ET) level of Diacrisia casignetum Kollar on jute was calculated in West Bengal condition during 2016-2018 for environmentally benign management and better production of jute. The demographic data of D. casignetum always construct type-III survivorship curve like most of the insects. Potential fecundity (Pf) and total fertility rate (Fx) were 384.667±5.487 and 30893.60±1063.586, respectively. The average intrinsic rate of natural increase (rm) and the daily finite rate of increase (ë) were 0.106±0.001 and 1.111±0.003 respectively with the generation time (Tc) of 41.520±0.069 and doubling time (DT) of 6.563±0.021 days. Their mean population momentum factor of increase (PMF) was 19.676±0.605 including vital index (VI) and trend index (TI) of 0.522±0.003 and 92.359±2.648, respectively with different levels of significance. The economic injury level (EIL) and ET based on percent yield loss of jute were 7.119±2.166 and 6.385±1.969 pests per plant, respectively. At single pest observation per plant, the possible time taken to reach EIL (Ti) and ET (Tt) were 6.377±3.292 and 5.377±3.292 days, respectively which will be useful for better cultivation of jute and other subsequent crops.

2017 ◽  
Vol 22 (12) ◽  
pp. 2068 ◽  
Author(s):  
Md. Tarikul Islam ◽  
Mahbuba Jahan ◽  
Tetsuo Gotoh ◽  
Mohammad Shaef Ullah

The effects of three economically important host plants, jute (Corchorus capsularis L.), bean (Lablab purpureus L.) and papaya (Carica papaya L.), on the development, reproduction and demographic parameters of the spider mite Tetranychus truncatus Ehara (Acari: Tetranychidae) were investigated under laboratory conditions of 30 ± 1°C, 60–80% RH and a photoperiod of 16L: 8D using age-stage, two-sex life table analysis. Both male and female T. truncatus successfully completed development from egg to adult on the three host plants. The development time from egg to adult for female T. truncatus was longer on Jute than on bean and papaya. Male and female longevities were higher on jute and bean than on papaya. Fecundity of T. truncatus was higher on jute than on bean and papaya. Adult pre-oviposition period was lower on bean and the number of oviposition days were higher on jute. The net reproduction rate of T. truncatus was significantly higher on jute than on bean and papaya, whereas intrinsic rate of natural increase and the finite rate of increase were higher on bean than on the other two host plants. The mean generation time of T. truncatus was higher on jute than on bean and papaya. These results based on the intrinsic rate of natural increase indicate that jute and bean were more suitable than papaya as hosts for T. truncatus, to helping develop management and control strategies for this pest.


1970 ◽  
Vol 16 ◽  
pp. 25-28
Author(s):  
MM Rahman ◽  
W Islam ◽  
KN Ahmed

Plastanoxus westwoodi is an efficient ectoparasitoid of larvae and pupae of the red flat grain beetle Cryptolestes pusillus. Fertility life tables and effects of host instar on life table parameters of P. westwoodi on C. pusillus were studied in the laboratory. Generally adult females lived for 13-16 days. Oviposition commenced on the 1st day of adult emergence and continued till death or 1-2 days before the death of a parasitoid. The intrinsic rate of natural increase (rm) was found to be 0.2291 per female per day. The net reproductive rate (R0) was 64.07; the innate capacity for increase (rc) was 0.2096. The finite rate of increase (λ) was calculated as 1.4735 per female per day, while corrected generation time (T) was computed as 18.16 days. Key words: Plastanoxus westwoodi, Cryptolestes pusillus, Oviposition, Life table, Biological control   DOI:10.3329/jbs.v16i0.3737    J. bio-sci. 16: 25-28, 2008   


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.


Author(s):  
Tania Ivorra ◽  
Borja García-Martínez ◽  
Anabel Martínez-Sánchez

Abstract To better understand the population dynamics and dispersal ability of insect species, it is often helpful to derive a life table containing fundamental demographic data. The aim of this study was to determine a life table for the predatory necrophagous species Synthesiomyia nudiseta (van der Wulp, 1883) on a pig liver diet and under controlled laboratory conditions (29.5 ± 2. 5°C, RH 50 ± 15%, and a photoperiod of 12:12). This species has medical and veterinary importance and its distribution extends in tropical and subtropical areas and now it has been established in the southwestern of Europe. The mean adult longevity was 36. 18 ± 2. 06 d and the net reproduction rate, R, was 27.65 offspring/female, the mean generation time, T, was 22. 09 d, the finite rate of increase, λ, was 1. 16 d−1, and the intrinsic rate of increase, r, was 0. 15 d−1. These results indicate that S. nudiseta cannot be considered an r-strategist as the most common synanthropic necrophagous blowflies due to its predatory behavior; however, its invasive and colonist abilities are discussed. This is the first life table study of this species from Palearctic region to analyze the effect of its dispersal ability.


1983 ◽  
Vol 115 (1) ◽  
pp. 93-105 ◽  
Author(s):  
John V. Boyne ◽  
Fred P. Hain

AbstractExperiments were conducted on Fraser fir, Abies fraseri (Pursh) Poir, seedlings or cut terminals. Results indicate that Oligonychus ununguis (Jacobi) responds most favorably to temperatures approximating 26 °C and to relative humidity levels approaching 50 to 60%. Developmental time, time to 50% mortality, net reproductive rate, mean generation time, intrinsic rate of natural increase, finite rate of increase, and days for populations to double were computed for each temperature and relative humidity regime. Simulated rainfall severely limits population density on Fraser fir seedlings.


2020 ◽  
Vol 25 (8) ◽  
pp. 1373-1383
Author(s):  
Zarir Saeidi ◽  
Alireza Nemati ◽  
Elham Riahi

In the current study, development, reproduction, and longevity of Schizotetranychus smirnovi Wainstein concerning seven different temperatures including 13±1, 15±1, 20± 1, 25±1, 27±1, 30 ±1 and 35 ±1°C, relative humidity 50 ± 10 % and a photoperiod of 14:10 (L:D) h. were investigated. Due to mite inability to settle on leaf disk, almond young branches were used for conducting life table experiments. Our results indicated that higher and lower temperatures caused a steeper decline in survivorship. The highest survival rate was observed at 25 and 27°C. The mean total development time was significantly decreased with increasing the temperatures; while adult longevity for both female and males significantly decreased. Furthermore, offspring production did not occur at 35°C. The highest values of the intrinsic rate of increase (r) and finite rate of increase (λ) were 0.2563 and 1.2922 d-1 at 27°C, while their lowest values were obtained at 13°C. Again high temperature (30°C) caused a decline in both the reproductive rate and growth rate of this mite species. The longest mean generation time (T) (58.55 d) was at 13 °C and it declined significantly with increasing temperature. The most striking result emerging from our data is that 27°C is the most desirable temperature for not only development but also the reproduction of S. smirnovi. Finally, our obtained information provides a better understanding of the life history of S. smirnovi and its ability to survive and reproduce under different temperature regimes which can be used in the management of this pest.


2020 ◽  
Vol 25 (3) ◽  
pp. 512-524
Author(s):  
Marjan Heidarian ◽  
Yaghoub Fathipor ◽  
Amin Sedaratian-jahromi

Schizotetranychus smirnovi Wainstein is an important phytophagous pest of almond trees which causes serious damage in southwestern Iran. Scolothrips longicornis Priesner has been considered as an efficient predatory thrips that feeds on this spider mite and hence its efficiency for controlling S. smirnovi should be evaluated. In the current study, all main biological parameters of S. longicornis fed on S. smirnovi were determined under laboratory conditions. Data analysis was performed using both female age-specific and age-stage, two-sex life table theories. Duration of incubation, larval, pre-pupal, pupal and pre-adult periods of male predators were 4.73, 3.18, 1.05, 1.86 and 10.82 days, respectively. These periods in female individuals lasted 4.57, 3.92, 1.04, 1.87 and 11.00 days, respectively. Our findings showed that each female laid an average of 62.74 eggs during its ovipositional period (13.61 days). Using the age-stage, two-sex life table, the values of the net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ) and mean generation time (T) were estimated to be 26.236 (eggs/individual), 0.171 (day-1), 1.186 (day-1) and 19.130 (days), respectively. Using the female age-specific life table, these parameters had different values. Our findings revealed that S. longicornis has a reliable capability to increase its population by feeding on S. smirnovi. This information can expand our knowledge for assessing biological efficiency of this predatory thrips in sustainable management of the destructive mite pest. 


2012 ◽  
Vol 05 (03) ◽  
pp. 1260018 ◽  
Author(s):  
YUAN-SHUN TAN ◽  
JU-HUA LIANG ◽  
SAN-YI TANG

Non-smooth system including impulsive strategies at both fixed and unfixed times are analyzed. For the model with fixed impulsive effects, the global stability of pest eradication periodic solution and the dominance of dynamic behavior are investigated. This indicates that the model with fixed moments has the potential to protect the natural enemies from extinction, but under some conditions may also serve to extinction of the pest. The second model is constructed according to the practices of IPM, that is, when the pest population reaches the economic injury level, a combination of biological, cultural, and chemical tactics that reduce pests to tolerable levels is used. Numerical investigations imply that there are several different types of periodic solutions and their maximum amplitudes are always less than the given economic threshold. The results also show that the time series at which the IPM strategies are applied are quite complex, which means that the application and realization of IPM in practice are very difficult.


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