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Life History Traits of Tetranychus piercei, T. truncatus, and T. bambusae (Acari: Tetranychidae) Collected From Bangladesh
Abstract
Tetranychus piercei McGregor, T. truncatus Ehara, and T. bambusae Wang and Ma are considered as major pests of many agricultural crops in Bangladesh. T. piercei and T. truncatus has a diverse host plants although T. bambusae infest only bamboo leaves. We compared the development, survivorship, and life table parameters of T. piercei and T. truncatus on bean leaves and T. bambusae on bamboo leaves at 25ºC, 60-70% RH, and a photoperiod of 16: 8 h (light: dark). The development time from egg to adult female of T. piercei and T. truncatus was 10.2 and 8.8 days when feeding on bean leaves, respectively, whereas it takes 9.5 days for female T. bambusae when feeding on Bambusa sp. leaves. Mated females of T. piercei, T. truncatus, and T. bambusae laid on average 186.9, 132.5, and 46.3 eggs for the oviposition period of 22.3, 13.5, and 20.2 days, respectively. The intrinsic rate of increase (rm) was 0.268 for T. piercei, 0.295 for T. truncatus, and 0.178 for T. bambusae. The finite rate of increase (λ) was 1.31, 1.34, and 1.20 individuals/female/day for T. piercei, T. truncatus, and T. bambusae, respectively. The doubling time (Dt) was lowest in T. truncatus (2.4 days) compare to T. piercei (2.6 days) and T. bambusae (3.9 days). The two polyphagous Tetranychus mites collected in Bangladesh are found to have similar life table parameters fall within the parametric range of other Tetranychus mites found in various regions irrespective of food sources. This is the first report of life table parameters of monophagous T. bambusae.
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Online databases are becoming a standard tool to study taxonomy, biodiversity, and ecology. We have developed a comprehensive database for the family Tetranychidae (spider mites). The Tetranychidae is one of the most important families of the Acari in terms of economic impact, because it comprises several agricultural pest species of major relevance, such as the cosmopolitan Tetranychus urticae. The aim of the web site is to gather information on all described spider mites in the world. The main goal is to provide a synthetic view of the biodiversity of this mite family. 1,280 literature references are included, from 1758 to present. 1,257 species, more than 11,745 host plants, and 5,380 geographical data are recorded in 17 tables. The database includes taxonomic data relating the history of nomenclature, geographical distribution, and host plants for all species examined. Three types of query are available to retrieve this information: (1) ‘By Species’ allows to search on species names and synonyms; (2) ‘Advanced’ performs a cross search including taxonomical, geographical, and host-plant information; and (3) ‘Bibliography’ allows searching references combining one, two, or three authors, and it displays all nomenclatural, host plant, and geographical data for the selected reference.
Hsin Chi and H si Liu (1985) Two New Methods for the Study of Insect Population Ecology. Bull. Inst. Zool., Academia Sinica 24(2): 225-240. Based on the stage-frequency distribution, a multiple column matrix was used to express the age - stage-structure of animal populations with metamorphosis. Using this new method, the growth process of insect and mite populations (both female and male were included) can be studied with proper stage grouping. Algorithms of population growth and the calculation of intrinsic rate of increase and stable age-stage- distribution were described in detail. For the simulation work of field population ecology, a multidimension al matrix was used to display the spatial distribution of host plants and the age -stage-structure of pest population. Computer programs were designed to simulate the growth and dispersion of field population at the same time. These methods made a way to approach to the agroecosystem simulation. In the last forty years, since the matrix
The passion fruit plant is a host for several different phytophagous mites, mainly those belonging to the Tarsonemidae, Tenuipalpidae and Tetranychidae families. Among the Tetranychidae species are Tetranychus mexicanus (McGregor, 1950) and Tetranychus desertorum Banks, 1900. The occurrence of Tetranychus marianae McGregor, 1950 was detected on yellow passion fruit Passiflora edulis Sims f. flavicarpa Degener plants under field and greenhouse conditions at the headquarters of Embrapa Cassava & Fruits Tropical Research in Cruz das Almas County, State of Bahia, Northeast Brazil. Prior records of T. marianae on the passion fruit crop in Brazil as well as the biological aspects of this species are unknown. The study on the biology of T. marianae on P. edulis f. flavicarpa was carried out under controlled environmental condition of 25 ± 1ºC temperature, 80 ± 10% RH and 12 hours photophase. The egg to adult time span lasted 10.73 ± 0.18 days, with a 92% survival figure. The sexual ratio was 81% females. The mean female longevity was 24.53 days and the daily mean oviposition was 3.69 eggs/female. The intrinsic rate of increase (rm) was 0.172; the finite rate of increase (l) was 1.187 individuals/female/day; the mean time span of one generation (T) was 22.81 days; and the net rate of reproduction (Ro) was 50.14.
The spider mite Tetranychus pueraricola infests kudzu vines throughout Japan and causes conspicuous brownish feeding scars. It is possibility that T. pueraricola may get out of hand after invasion of agricultural leguminous crops. To better evaluate its potential severity as a pest, we determined the development, survivorship and life-history parameters of T. pueraricola on kidney bean. At temperatures between 15 and 30° C more than 89% of eggs hatched and of the newly hatched larvae ca. 89% attained maturity. There was no significant difference in eclosion rate of eggs or survival rate of immature stages among the temperatures. The lower threshold temperature from egg to oviposition was 10.9° C and the thermal constant was 147.1 degree-days. Based on these data, the maximum number of generations that can theoretically complete development under average field conditions in Ibaraki, Central Japan is between 11 and 14 generations per year. At 25° C, females laid on average 125 eggs during a mean oviposition period of 12.6 days. The intrinsic rate of natural increase (r(m)) was 0.102 at 15° C, 0.179 at 20° C, 0.299 at 25° C and 0.377 at 30° C. Thus, T pueraricola has the second highest r(m)-value among tetranychid mites reported so far at 25° C, with T .okinawanus having the highest (0.316). This indicates that T. pueraricola has the potential to become a serious pest on agricultural crops.
Raw data analysis of an age-stage, two-sex life table, incorporating variable development rates among individuals, is described, using data obtained from rearing the potato tuberworm, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae). The intrinsic rate of increase is calculated with respect to both sexes. The stable age-stage distribution, stable age distribution, and the stable stage distribution are also calculated. Different results are obtained when the same data are analyzed using the traditional age-specific life table (Leslie matrix or Birch's method). These differences occur because the traditional age-specific life table deals only with female populations and does not take variable development rates among individuals into account. The relationship between the net reproduction rate and mean female fecundity in the age-stage, two-sex life table is described by a simple formula.
Development and reproductive traits of Tetranychus macfarlanei Baker & Pritchard (Acari: Tetranychidae) were investigated on kidney bean, Phaseolus vulgaris L., at eleven constant temperatures. Tetranychus macfarlanei was able to develop and complete its life cycle at temperatures ranging from 17.5 to 37.5°C. At 15 and 40°C, a few eggs (2–4%) hatched but further development was arrested. Development from egg to adult was slowest at 17.5°C and fastest at 35°C for both females and males. Using Ikemoto and Takai’s linear model, the estimated lower developmental thresholds for egg-to-female adult, egg-to-male adult and egg-to-egg development were 12.9–13.0°C. The thermal constants for the respective stages were 110.85, 115.99 and 125.32 degree-days (DD). The intrinsic optimum temperatures (T
Φ) calculated by non-linear SSI model were determined as 24.4, 24.4 and 24.2°C for egg-to-female adult, egg-to-male adult and egg-to-egg development, respectively. The net reproductive rate (R
0) was highest at 25°C (167.4 females per female) and lowest at 17.5°C (42.6 females per female). The intrinsic rate of natural increase, r
m, increased linearly with the rising of temperature from 0.102 at 17.5°C to 0.441 day−1 at 35°C. These values suggested that T. macfarlanei could be growing quickly in response to increasing temperatures from 17.5 to 35°C and provide a basis for predicting its potential geographical range.
We investigated the effect of temperature on development and demographic parameters such as the intrinsic rate of natural increase (r
m) of the two spider mite species Tetranychus merganser Boudreaux and T. kanzawai Kishida at eleven constant temperatures ranging from 15 to 40°C at intervals of 2.5°C. Both male and female T. merganser and T. kanzawai completed development from egg to adult at temperatures ranging from 15 to 37.5°C. The longest developmental duration of immature stages was found at 15°C and the shortest developmental duration was found at 35°C for both species. Using linear and non-linear developmental rate models, the lower thermal thresholds for egg-to-adult (female and male) and egg-to-egg development were estimated as 12.2–12.3°C for T. merganser and as 10.8°C for T. kanzawai. The highest developmental rates were observed at around 35°C, whereas the upper developmental thresholds were around 40°C for both species. In fact, at 40°C, a few eggs of either species hatched, but no larvae reached the next stage. The r
m-values of T. merganser ranged from 0.072 (15°C) to 0.411 day−1 (35°C), whereas those of T. kanzawai ranged from 0.104 (15°C) to 0.399 (30°C). The r
m-values were higher for T. kanzawai than for T. merganser at temperatures from 15 to 30°C, but not at 35°C (0.348 day−1). Total fecundity of T. merganser was also higher than that of T. kanzawai at 35°C. These results indicate that higher temperatures favor T. merganser more than T. kanzawai.
The tomato red spider mite Tetranychus evansi Baker et Pritchard occurs on solanaceous plants, and causes serious damage to a variety of crops in Africa and Europe. In 2001 this species was also found in Japan, on nightshade (Solanum nigrum L.), and its invasion to solanaceous of agricultural importance is feasible. To evaluate its potential severity as a pest, the present study assessed the life-history parameters, such as the rate of development and the intrinsic rate of natural increase (r
m), on S. nigrum for T. evansi collected on seven sites worldwide. Increasing temperatures between 15 and 32.5°C significantly increased the developmental rate of the seven strains while immature developmental duration was about the same at 32.5–40°C. The rate of egg-to-adult development [(% hatch) × (% survival)] exceeded 88% at temperatures between 15 and 37.5°C. The lower thermal thresholds (LT) were 11.9–12.5°C for both egg-to-adult and egg-to-egg development. The optimum developmental temperatures ranged from 36.7 to 43.8°C and the upper developmental threshold (UT) ranged from 45.2 to 59.4°C. The r
m-values became higher with temperature increasing from 15 to 35°C. The r
m-values at 25°C ranged from 0.265 to 0.277 which are relatively high for species of the genus Tetranychus. These results indicate that T. evansi after invasion into Japan has the potential to become a serious pest on solanaceous crops, just the same as in Africa and Europe.
Life tables of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), were studied on leaf discs and whole leaves of the common bean plant, Phaseolus vulgaris L. Data were analyzed based on the age-stage, two-sex life table theory. Durations of deutonymph stage, total preadult stage, and preoviposition period of mites reared on whole leaves (1.22, 7.6, and 0.29 d, respectively) were significantly shorter than those reared on leaf discs (1.73, 8.2, and 0.89 d, respectively). The lifetime fecundities were 22.81 and 12.05 offspring on whole leaves and leaf discs, respectively. Although hooked trichomes on the lower surface of the bean leaf contribute to adult mortality, spider mites successfully survive and reproduce on bean plants. The intrinsic rate of increase on whole leaves (0.235 d(-1)) was higher than that on leaf discs (0.159 d(-1). Higher intrinsic rate and fecundity found in mites reared on whole leaves may be due to the higher nutritional quality of whole leaves over leaf discs. We suggest that whole leaves should be used in future studies to better simulate realistic life history characteristics. The advantages of using age-stage, two-sex life tables over female age-specific life tables are discussed.
Knowledge of population growth potential is crucial for studying population dynamics and for establishing management tactics for pest control. Estimation of population growth can be achieved with fertility life tables because they synthesize data on reproduction and mortality of a population. The five main parameters associated with a fertility life table are as follows: (1) the net reproductive rate (Ro), (2) the intrinsic rate of increase (rm), 3) the mean generation time (T), (4) the doubling time (Dt), and (5) the finite rate of increase (lambda). Jackknife and bootstrap techniques are used to calculate the variance of the rm estimate, which can be extended to the other parameters of life tables. Those methods are computer-intensive, their application requires the development of efficient algorithms, and their implementation is based on a programming language that encompasses quickness and reliability. The objectives of this article are to discuss statistical and computational aspects related to estimation of life table parameters and to present a SAS program that uses jackknife to estimate parameters for fertility life tables. The SAS program presented here allows the calculation of confidence intervals for all estimated parameters, as well as provides one-sided and two-sided t-tests to perform pairwise or multiple comparison between groups, with their respective P values.
The laboratory study at 28 degrees C showed that on four different corn cultivars, the durations of ovum, nymph and pre-oviposition, adult longevity, fecundity, egg production per day, net reproductive rate (R0), finite rate of increase (lambda), intrinsic rate of increase (rm), mean generation time (T), and the days needed to double population size (DDP) of Tetranychus truncatus were significantly different. The hatching rate on Zea mays cv. Zhongdan 2, Nongda 108, Chidan 202 and Badan 3 was 95.8%, 94.0%, 90.0% and 84.0%, and the survival rate on these cultivars was 90.5%, 86.0%, 84.0%, and 72.0%, respectively. All the survival curves were of Deevey I . The net reproductive rate (R0) was the highest on Zhongdan 2, and the lowest on Badan 3. The mite displayed a decreasing preference in order of Zhongdan 2 > Nongda 108 > Chidan 202 > Badan 3.
Observations on the development, survivorship and reproduction of Tetranychus piercei McGregor reared on fresh banana leaves were conducted at 16, 20, 24, 28, 32 and 36°C. The developmental time from egg to adult varied from 7.2 d at 32°C to 33.1 d at 16°C. The developmental threshold temperatures of egg, larva, protonymph, deutonymph, preoviposition and a whole generation were 11.2, 9.8, 11.9, 12.5, 13.3 and 10.7°C, respectively. The effective accumulated temperatures were 72.3, 33.6, 22.2, 27.8, 17.7 and 163.6 day-degrees, respectively. Within the range of 16 to 36°C, the relationships between developmental and survival rates of all immature stages, average number of eggs/female, longevity of adults and temperatures showed parabolic trends. Survival rate was the highest (96.1%) at 32°C; whereas at 36 and 16°C it decreased to 79.1 and 66.4%, respectively. The highest number of eggs (35.8 eggs/female) was recorded at 28°C; and the lowest at 16°C (17.9 eggs/female). Female longevity was the longest (34.5 d) at 20°C and the shortest (8.2 d) at 36°C. The net reproductive rate (R0) was the highest (23.6525) at 28°C and the lowest (5.1044) at 36°C. The intrinsic rate of increase (rm) and finite rate of increase (λ) reached maximal values (0.3488 and 1.4174 respectively) at 32°C, whereas minimal values (0.0724 and 1.0752 respectively) were at 16°C. The mean generation time and time for population doubling were the shortest at 36 and 32°C, respectively, which were 7.2192 d and 1.9871 d. The highest population trend index (25.28) was obtained at 28°C and the lowest (4.88) at 36°C. These population parameters and population trend indices increased with temperatures in a parabolic function. The results suggest
that T. piercei could develop and reproduce within a wide range of temperatures, and that temperatures from 25.8-32°C are the most suitable conditions for the development, survival and reproduction of the mite.
Life table gives the most comprehensive description on the survival, stage differentiation and reproduction of a population and is thus the most important basis of population ecology and pest management. In this study, we constructed life tables for Bactrocera cucurbitae on cucumber (Cucumis sativus L.) in the laboratory and under simulated field conditions. To assess the variability of the life tables, we carried out two experiments under each treatment. Means, variances and standard errors of life table parameters were estimated for each of the two experiments by using the jackknife technique. At 25°C, the intrinsic rates of increase (r) found for the two experiments were 0.1354 and 0.1002 per day, and the net reproductive rates (R 0) were 206.3 and 66.0 offspring, respectively. For cucumbers kept in the field and covered with leaves, the r and R 0 for the two experiments were 0.0935 and 0.0909 per day, and 17.5 and 11.4 offspring, respectively. However, if cucumbers were kept in the field but were not covered, the r and R 0 for the two experiments were 0.1043 and 0.0904 per day, and 27.7 and 10.1 offspring, respectively. Our results revealed significant variability between the experiments under both laboratory and field conditions; this variability should be taken into consideration in the data collection and application of life tables. However, our mathematical analysis shows that the application of the jackknife technique will result in biologically unrealistic R 0,i‐pseudo and consequently overestimation of the variance of R 0. According to our analysis, we suggest that the jackknife technique should not be used for the estimation of variability of the net reproductive rate.
The common cutworm, Spodoptera litura (Fabricus), is the most serious pest of peanuts in Taiwan. In order to devise an ecology-based and cost effective control program, we collected life table data and consumption rates from larvae reared indoors at a constant temperature of 25 °C, or outdoors at ambient temperatures during the spring and fall of 2010. Computer simulation was then used to project the population growth and damage potential of S. litura on peanuts.
Lab reared S. litura individuals produced 3548 eggs/female , while those reared outdoors produced 3452, and 3072 eggs/female in the spring and fall, respectively. The intrinsic rate of increase was 0.1828, 0.1308, and 0.1545 d(-1) , while the net consumption rates was 194.0, 132.2, and 166.6 cm(2) at 25 °C, in spring and fall, respectively. Population projection showed a faster growth and higher damage potential of S. litura in the fall.
Population projections based on life tables and stage-specific consumption rates can reveal the stage structure and the damage potential of the pest population. Our results showed that the monitoring data obtained by using pheromone traps was not in concordance with the damage potential of the pest population. This approach offers a promising tool for pest management.
The life table of the green lacewing, Chrysopa pallens (Rambur), was studied at 22 degrees C, a photoperiod of 15:9 (L:D) h, and 80% relative humidity in the laboratory. The raw data were analyzed using the age-stage, two-sex life table. The intrinsic rate of increase (r), the finite rate of increase (lambda), the net reproduction rate (R0), and the mean generation time (T) of Ch. pallens were 0.1258 d(-1), 1.1340 d(-1), 241.4 offspring and 43.6 d, respectively. For the estimation of the means, variances, and SEs of the population parameters, we compared the jackknife and bootstrap techniques. Although similar values of the means and SEs were obtained with both techniques, significant differences were observed in the frequency distribution and variances of all parameters. The jackknife technique will result in a zero net reproductive rate upon the omission of a male, an immature death, or a nonreproductive female. This result represents, however, a contradiction because an intrinsic rate of increase exists in this situation. Therefore, we suggest that the jackknife technique should not be used for the estimation of population parameters. In predator-prey interactions, the nonpredatory egg and pupal stages of the predator are time refuges for the prey, and the pest population can grow during these times. In this study, a population projection based on the age-stage, two-sex life table is used to determine the optimal interval between releases to fill the predation gaps and maintain the predatory capacity of the control agent.
Life-history traits of the Kanzawa spider mite, Tetranychus kanzawai, were assessed and compared with those of the closely related species, T. parakanzawai. This was done by determining the intrinsic rates of natural increase, rm, of three strains of T. kanzawai and one strain of T. parakanzawai, on leaf discs from each of the four host plants (collected plants) as well as one of suitable hosts for T. kanzawai, mulberry. The rm-values of the three T. kanzawai strains varied largely from 0.187/day to 0.283/day, and the rm's on the collected hosts (tea, hydrangea and Japanese pear) were 0.043-0.096/day lower than on mulberry. The rm of the T. parakanzawai strain was only 0.008/day lower on the collected plant (kudzu vine) than on mulberry. These results seem to suggest that tea, hydrangea and Japanese pear are poor-quality plants for T. kanzawai when compared to their performance on mulberry.
The effects of host quality and mite density on developmental rate, survivorship and sex ratio of Tetranychus cinnabarinus were investigated. Males developed faster than females and more females than males were produced. Female mites reared on good leaves tended to produce offspring with a slightly slower developmental rate and lower sex ratio and survivorship than females from poor quality leaves. The effects were shown to be indirect influences of density. Good leaf quality during oviposition and development of offspring resulted in relatively faster developmental rates and higher survivorship of offspring but had no effect on sex ratio. The density regimes used drastically affected the traits. At high density, the mites showed a marked reduction in developmental rate, survivorship, and sex ratio as compared with mites reared in the low density regime.
The life history of the twospotted spider mite, Tetranychus urticae Koch, was studied in order to construct a life table and to establish an intrinsic rate of increase for use in population management with predators. Completion of life cycle in the laboratory required 7.5 days at 27±1°C and 95±5% RH. Mean generation time was 16.0 days and the quiescent period between deutonymph and active adult for females was 2.4 days. The reproductive rate was 7.97 eggs/ ♀ /day. A life table was constructed to estimate the population dynamics by intrinsic rate of increase (r = 0.336), mean generation time (13.6 days) and net reproductive rate (97.4).
The effect of four constant temperatures (21, 26, 31 and 36C) on biological (survival and duration of developmental stages, fecundity and longevity of females and sex ratio) and demographic parameters (R0, G, rm and ) of Tetranychus evansi was studied in the laboratory under controlled conditions: 75 10% RH and 12L : 12D. The lower thermal threshold was 10.3C. The shortest developmental time (6.3 days) was obtained at 36C. Maximum fecundity was recorded at 31C with 123.3 eggs per female. The highest intrinsic rate of increase (rm) (0.355) was obtained at 31C. The optimal temperature for population growth seems to be 34C. Rapid Science Ltd. 1998
Life history and resource utilization pattern were compared between two closely related mite species of the genusTetranychus.1.
Tetranychus urticae developed more quickly and had a higher oviposition rate thanT. kanzawai. Consequently, the potential for population increase was greater forT. urticae than forT. kanzawai but the difference was slight.
2.
T. urticae was more tolerant of a deteriorating food resource and/or over-crowding.T. kanzawai responded more sensitively to food deterioration and dispersed more quickly.
3.
There was a considerable difference between injury patterns by the two species.T. kanzawai damaged host plants more severely, causing earlier and more extensive defoliation of the plants.
4.
The maximum population size achieved byT. urticae was 2 to 3 times greater than that ofT. kanzawai on potted host plant. This showed that the former could utilize a food resource much more efficiently.
Statistics is a subject of many uses and surprisingly few effective practitioners. The traditional road to statistical knowledge is blocked, for most, by a formidable wall of mathematics. The approach in An Introduction to the Bootstrap avoids that wall. It arms scientists and engineers, as well as statisticians, with the computational techniques they need to analyze and understand complicated data sets.
Thrips are among the stealthiest of insect invaders due to their small size and cryptic habits. Many invasive thrips are notorious for causing extensive crop damage, vectoring viral diseases, and permanently destabilizing IPM systems owing to irruptive outbreaks that require remediation with insecticides, leading to the development of insecticide resistance. Several challenges surface when attempting to manage incursive thrips species. Foremost among these is early recognition, followed by rapid and accurate identification of emergent pest species, elucidation of the region of origin, development of a management program, and the closing of conduits for global movement of thrips. In this review, we examine factors facilitating invasion by thrips, damage caused by these insects, pre- and post-invasion management tactics, and challenges looming on the horizon posed by invasive Thysanoptera, which continually challenge the development of sustainable management practices.
TWOSEX-MSChart: a computer program for the age-stage, two-sex life table
- H Chi
Chi, H., 2012. TWOSEX-MSChart: a computer program for the age-stage, two-sex life
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The effects of temperature on the development and reproduction of Tetranychus truncatus
- R H Huang
- H Y Kuang
Huang, R.H.,Kuang, H.Y., 1992. The effects of temperature on the development and reproduction of Tetranychus truncatus. Acta Phytophylacica Sin. 19, 17-21.
Ecological Methods, 3rd edn
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