Shorter Adult Longevity Research Articles

Development of pulse beetle Callosobruchus maculatus Fab. (Coleoptera: Bruchidae) in different pulses

Development of pulse beetle (Callosobruchus maculatus Fab.) was studied on nine different pulses viz., mungbean, urdbean, mothbean, greenpea, cowpea, horsegram, chickpea, wal and pigeonpea under laboratory conditions. The study indicated that chickpea was most preferred host by C. maculatus as it recorded highest number of eggs (290.67/100 grains), shortest total developmental period (21.33 days) and highest number of adult emergence (163/100 grains), whereas horsegram was least preferred host as it recorded lowest number of eggs (23.67 / 100 grains), lowest number of adult emergence (4.33/ 100 grains) and shortest adult longevity (4 days). The highest adult longevity was recorded in wal (10 days) followed by chickpea and mungbean (9.33 days). In the case of the incubation period, mungbean and cowpea recorded shortest incubation period (2.67 days) and followed by chickpea, green pea and pigeonpea (3.33 days) whereas it was highest in urdbean (4.67 days) followed by horsegram (4.33 days). Percent adult emergence was lowest in the case of horsegram (18.29%) followed by mothbean (19.86%) and was highest in wal (74.92%).

Categorization of resistance against the fall armyworm, Spodoptera frugiperda (J.E. Smith) in select maize inbred lines

Seven maize inbred lines were evaluated for resistance against fall armyworm, Spodoptera frugiperda (J.E. Smith). Non-preference for oviposition in no- and multi-choice tests and feeding non-preference of neonates in multi-choice test was observed in lines CML 338, CM 500 and CML 72. Antibiosis was observed in CML 338, CML 72 and CML 71, in terms of significantly prolonged larval period (18.22–19.56 days), lower larval (111.52–131.80 mg) and pupal weights (105.65–127.67 mg), shorter adult longevity and lower fecundity as compared to susceptible inbred lines, BML 6 and LM 24. Larvae fed on CML 338 and CML 71 had significantly higher mortality and lower nutritional indices. Significantly higher foliar damage rating was observed on younger plants (10 days old) in all test inbred lines, as compared to older plants (20 and 30 days old) during 2020 and 2021. The mean foliar damage rating by fall armyworm larvae varied significantly among the test inbred lines being significantly lower in CML 338 and CML 71 compared to BML 6 and CM 500 that had higher damage at all crop stages when recorded at 7, 14 and 21 days after release. Functional Plant Loss Index (FPLI) was significantly lower in CML 338 and CML 71 (12.18–18.58%) followed by CML 72 (24.87%). Regression of FPLI on fall armyworm larval dry weight indicated presence of antibiosis and tolerance in CML 338, CML 71 and CML 72 towards fall armyworm. Overall, maize inbred lines CML 338, CML 71 and CML 72 with moderate resistance may be used for resistance breeding programme against this insect pest.

Salicylic acid and fertilizers affect the performance of Panonychus citri (McGregor) (Acari; Tetranychidae) on citrus seedlings

ABSTRACT The citrus red mite, Panonychus citri (McGregor), is one of the most important pests of citrus trees. The use of non-selective and wide-spectrum insecticides leads to a reduction in the natural enemy presence against this pest and turns P. citri into a serious pest in citrus orchards. In the present study, the induction of resistance was carried out in two-year-old citrus seedlings using a foliar application of amino acid, humic acid, potassium, vermiwash, and salicylic acid (SA) against P. citri. The data indicated a lower survival rate, longer immature duration, shorter adult longevity, and lower fecundity due to an increase in the resistance of citrus. The developmental time of immature stages, survival, and fecundity was lowest in combined treatments, intermediate in individual treatments, and highest in control and vermiwash treatments. Population growth parameters of P. citri including net reproductive rate, intrinsic rate of increase, finite rate of increase, and generation time were lower when the mites fed on combined treatments, especially on potassium+SA. These results suggest that the application of a combination of fertilizer and SA on citrus trees can lead to a significant reduction in caused damage by citrus red mites. http://www.zoobank.org/urn:lsid:zoobank.org:pub:unique-alpha-numeric-id

Akanthomyces dipterigenus acts as a potential biocontrol agent by causing mortality and inhibiting population growth of Bemisia tabaci

Bemisia tabaci is a worldwide pest, and has developed severe resistance to many insecticide. Therefore, it is great significance to find new substitute for chemical insecticide to control B. tabaci. In this study, selected efficient strains by comparing the virulence of Akanthomyces dipterigenus, Cordyceps javanica, Purpureocillium lilacinum, Penicillium camemberti, Metarhizium anisopliae, and Beauveria bassiana against 2nd-instar nymphs of B. tabaci and bioassays were conducted on various developmental stages of B. tabaci using highly pathogenic strain. Additionally, the effects of medium lethal concentration of high-efficiency strains on the biological parameters of B. tabaci were also studied. The bioassay showed that six entomopathogenic fungi have significant effects on the 2nd-instar nymphs of B. tabaci, the median lethal concentration (LC50) of A. dipterigenus against 2nd-instar nymphs of B. tabaci was only 6.54 × 103 (3.35 × 103–1.13 × 104) conidia mL−1, which was lower than that of the other five fungi, and the median lethal time (LT50) was the shortest. In addition, A. dipterigenus also had lethal effects on eggs, nymphs and adults of B. tabaci, among which the mortality rate of 2nd-instar nymphs was the highest. The fungal treatment affected the population parameters of B. tabaci, R0, r, and λ were significantly reduced, T was significantly prolonged, and had higher preadult mortality and shorter adult longevity, but had no significant effect on the total fecundity. These findings highlight the potential of using A. dipterigenus as a sustainable and eco-friendly alternative to chemical insecticides for controlling B. tabaci populations in agricultural settings.

Population growth of Tetranychus truncatus (Acari: Tetranychidae) on different drought-tolerant potato cultivars.

Tetranychus truncatus Ehara (Acari: Tetranychidae) has become one of the major phytophagous pests in China in recent years, and is found on a wide range of host plants. However, little information is available on the population performance of this arthropod pest on potatoes. In this study, we explored the population growth of T. truncatus on two drought-tolerant potato (Solanum tuberosum L.) cultivars under laboratory conditions using the age-stage, two-sex life table. Tetranychus truncatus completed its entire life history on both potato cultivars tested, Holland 15 and Longshu 10. There was no significant difference between two potato cultivars in developmental duration. Tetranychus truncatus had shorter adult longevity (20.61 days), adult female longevity (20.41 days), and total female longevity (33.66 days) on Longshu 10 than Holland 15 (21.16 days, 21.19 days, and 34.38 days, respectively). However, it exhibited a higher preadult survival rate, higher fecundity (F = 88.32 eggs per female), and relatively higher population parameters when reared on Longshu 10 than on Holland 15 (F = 75.70 eggs per female). Growth projection also showed that the population size of T. truncatus on Longshu 10 (expand 750-fold) was larger than that on Holland 15 (expand 273-fold) after 60 days. Our results demonstrate that the drought-sensitive potato variety, Holland 15, is relatively resistant to T. truncatus compared with the drought-tolerant variety, Longshu 10, and suggest that T. truncatus exhibited a trade-off between longevity and reproduction on both potato cultivars. Our findings provide information on population prediction, which may aid the management of this pest mite species of potatoes.

Characterization of Indoxacarb Resistance in the Fall Armyworm: Selection, Inheritance, Cross-Resistance, Possible Biochemical Mechanisms, and Fitness Costs.

The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a voracious insect pest that is difficult to control due to resistance to insecticides and Bt proteins. We assessed cross-resistance, resistance mechanism, and fitness costs based on the life history traits of S. frugiperda. We established an S. frugiperda strain selected for resistance to indoxacarb (Ind-SEL) from a field-collected population and an unselected strain, Ind-UNSEL. Results indicated that after 24 generations of selection, the resistance to indoxacarb was increased by 472.67-fold as compared to the Ind-UNSEL. There was high cross-resistance to deltamethrin (31.23-fold) with very low or negligible cross-resistance to chlorantraniliprole, emamectin benzoate, and/or methoxyfenozide in the Ind-SEL population. Butoxide synergist increased susceptibility to indoxacarb, indicating that P450 enzymes may be involved in indoxacarb resistance. Significantly longer developmental time of larvae extended pupal duration, shorter adult longevity, and lower fecundity were observed in Ind-SEL as compared with the Ind-UNSEL population. The Net reproductive rate (R0) was the only growth parameter that differs between crosses of Ind-SEL♂ × Ind-UNSEL♀ (176 ± 46) and Ind-SEL♀ × Ind-UNSEL♂ (328 ± 57). On the other hand, all population growth parameters differ between Ind-SEL and Ind-UNSEL strains. Our work contributes to the growing body of research that demonstrates the importance of strain genetics in fitness cost experiments and helps resistance management programs make decisions.

Development of Cigarette beetle [Lasioderma serricorne (Coleoptera :Anobiidae)] on spice plants and wheat flour

In this study, the development of Lasioderma serricorne (F.) (Coleoptera: Anobiidae) was investigated on five different foods (Mentha piperita, Thymus vulgaris, Salvia officinalis, Rosmarinus, officinalis and flour). Trials were carried out at a temperature of 28±2°C and 70-75% relative humidity. Effects of foods on development adult longevity and egg hatching ratio of Lasioderma serricorne were investigated. As a result, all of the Lasioderma serricorne larvae left on the Rosmarinus officinalis plant have not completed their development and died. The shortest larval development time was in flour (37.35 days) and the longest in Mentha piperita (62.96 days). The shortest Pupal development time was seen in Salvia officinalis (4 days), while the longest was seen in Thymus vulgaris (4,42 days). Mentha piperita (10,50 days) had the shortest adult longevity and was the longest flour (15,5 days). When the egg development time was examined, it was seen that the shortest time was in Thymus vulgarris (5,42 days) and the longest time was in flour (5,97 days). The rate of larvae that completed its development was highest in flour (92%) and lowest in Salvia officinalis (5%). The rate of pupae that completed its development was highest in flour (80,30%) and lowest in Salvia officinalis (37.50%). In the percentages of hatched eggs, it was observed that the lowest opening was in thyme with 56.27% and the highest opening was in flour with 88.89 %.

Susceptibility of Certain Egyptian Wheat Cultivars to Greenbug, Schizaphis graminum (Rondani) (Homoptera: Aphididae) Infestation

The greenbug (Schizaphis graminum) (Homoptera: Aphididae) is a major aphid species attacking cereal crops and responsible for viral disease transmission of the plant. Host plant resistance is a strong pillar in Integrated Pest Management (IPM) for reducing the damage of this pest. This study was carried out at Plant Protection Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt during 2019-2020 to study the susceptibility of five Egyptian wheat cultivars (Beni Suef 5, Gimmiza 11, Giza 168, Misr 1 and Sids 12) to greenbug infestation. The results indicated that in the host preference (free choose) experiment, Sids 12 cultivar was resistant (R) against aphid, while Giza 168 and Misr 1 were moderately resistant (MR) cultivars, on contrast Beni Suef 5 and Gimmiza 11 were susceptible (S) for aphid infestation. The nymphs fed on Beni Suef 5 cultivar had significantly shorter developmental time (7.6 days), highest survival (96.1%) and shorter adult longevity (9.7 days) with average offspring 45.8 aphids/ female, than other four wheat cultivars, while nymphs reared on Sids 12 had significantly longest developmental time (9.2 days), lowest survival (86.3%) and longest adult longevity (12.2 days) with average offspring 31.4 aphids/female. Feedingof S. graminum on tested wheat cultivars leaves significantly reduces the growth parameters (shoot length, wet and dry weights) and photosynthetic pigments content. Results from this study are important for plant breeding programs that have the objective of producing aphid resistant cultivars.

Artificial radiofrequency driven life-table parameters of perilla seed bugs (Nysius sp.) (Heteroptera: Lygaeidae)

Abstract The genus Nysius (Hemiptera: Lygaeidae) are polyphagous pests of various plants that damage seeds, foliage, and flowers. Here, we studied the life-table parameters and adult performances of Nysius plebeius Distant and Nysius hidakai Nakatani after exposure to five radiofrequencies: 0 (control), 5, 10, 20, and 30 kHz in infested perilla seeds. In addition, we measured the follow on effects of treatment for four generations (Parent, F1-, F2-, and F3-generation), for both Nysius species. Radiofrequency application significantly affected the life-table parameters of both Nysius species. Radiofrequency exposures affected bug oviposition, developmental period, adult weight, and longevity. Exposure also negatively affected the fecundity of subsequent generations; total developmental period from egg to adult emergence was longer while adult longevity was shorter in the radiofrequency treatments than in the untreated control. Low radiofrequency levels had the greatest effect on the life-table parameters of Nysius species, with the lowest rate of adult emergence and the shortest adult longevity at 5 kHz. The potential of using Nysius bug susceptibilities to radiofrequency as an alternative to chemical treatment is discussed.

Optimal clutch size for quality control of bisexual and Wolbachia-infected thelytokous lines of Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) mass reared on eggs of a substitutive host, Antheraea pernyi Guérin-Méneville (Lepidoptera: Saturniidae).

Trichogramma dendrolimi has been widely used in augmentative biocontrol of lepidopteran pests in China. In mass production of T. dendrolimi using Antheraea pernyi eggs as substitutive hosts, which are large in size, as clutch size is a parameter of importance to produce high quality parasitoids. Here, we aimed to determine the optimal clutch size for the bisexual Wolbachia-uninfected line (TdB) and Wolbachia-infected thelytokous line (TdT) of T. dendrolimi reared on A. pernyi eggs. A medium clutch size of 42.75 to 62.27 for TdB and 52.93 to 57.14 for TdT was optimal to maximize fitness-correlated traits of parasitoid individual. The optimal clutch sizes with maximized parameters included adult emergence rate, adult body size, adult longevity, fecundity, and sum of fecundity of all females per brood were 58.31 (86.00%), 42.75 (231.11 μm), 50.92 (2.69 days), 62.27 (150.89 eggs), and 83.25 (7926.33 eggs) for TdB and 57.14 (94.54%), 52.93 (236.97 μm), 53.64 (2.62 days), 56.80 (161.01 eggs), and 70.10 (8579.71 eggs) for TdT. The TdT had a shorter adult longevity, longer development time, and higher adult emergence rate than did its non-infected bisexual counterpart. A medium brood size in a A. pernyi egg host was optimal to produce offspring parasitoids with higher fitness parameters for both bisexual Wolbachia-uninfected and thelytokous Wolbachia-infected lines of T. dendrolimi. The determination of optimal clutch size for T. dendrolimi will provide the reference for the quality control of T. dendrolimi production and improvement of the field performance of the wasps. © 2020 Society of Chemical Industry.

Age stage, two-sex life table of Habrobracon hebetor (Braconidae) on Spodoptera exigua (Noctuidae) reared on different sugar beet genotypes.

The present study was carried out to unveil interactive relevance among consecutive and alternate members of a tritrophic system comprised of sugar beet genotypes, beet armyworm, Spodoptera exigua (Hübner), and its parasitoid, Habrobracon hebetor (Say) using demographic parameters. To do so, H. hebetor was reared on S. exigua fed on 10 sugar beet genotypes, including SB26; SB27; SB29; SB33; SB34; (7112*SB36)*Sh-1-HSF-5; FC220; FC301; SBSI006; and HM 1339RZ in a growth chamber at 25 ± 1 °C, 60 ± 5% RH, and 16:8 (L: D) h photoperiod. The data was analyzed based on the age-stage, two-sex life table theory. Our results revealed high variation in duration of different life stages of H. hebetor on S. exigua reared on different sugar beet genotypes examined. The shortest (10.605 days) and longest (13.721 days) pre-adult period of H. hebetor was on S. exigua reared on SB26 and SB34, respectively. The longest (17.2 days) and shortest adult longevity (7.5 days) was on S. exigua reared on SB26 and SB27, respectively. The highest values of the intrinsic rate of increase (r) (0.209 day-1) and finite rate of increase (λ) (1.233 day-1) were observed on S. exigua reared on SB34 and their lowest values (0.159 and 1.172 day-1, respectively) were recorded on SB27. Resistant and susceptible genotypes to S. exigua, FC301 and (7112*SB36)*Sh-1-HSF-5, respectively, were only genotypes on which H. hebetor had greater and approximately equal r compared with S. exigua. This finding indicates high capability of H. hebetor to be successfully employed against S. exigua on sugar beet genotypes which are extremely different in resistance to this pest.

Effect of dietary lipid on biochemical activities and fitness of house fly, Musca domestica L. (Diptera: Muscidae)

Effective control of the common house fly, Musca domestica, through manipulation of its diet is an innovation that could be pursued. A 4:1 carbohydrate-protein diet established for optimal performance in house fly and Drosophila was altered in this study with the addition of two lipid sources. The metabolic and fitness responses of fed house flies were then compared to conspecifics that were reared on the reference 4:1 diet. Generally, dietary lipids resulted in smaller and lighter progeny in addition to shorter adult longevity. This fitness reduction was accompanied by higher catalase activity and malondialdehyde concentration; an evidence of higher levels of reactive oxygen species (ROS) which have been implicated in fitness reduction. While the 4:1 carbohydrate-protein diet may be ideal for rearing purposes, addition of a lipid source (especially fish oil) would offer a level of pest control.

Effects of radiofrequency on the development and performance of Callosobruchus chinensis (Coleoptera: Chrysomelidae: Bruchinae) on three different leguminous seeds

Callosobruchus chinensis (L.) (Coleoptera: Chrysomelidae) is a common insect pest of stored legume seeds around the world. Since chemical insecticides and fumigation can have adverse effects on human health and environment, the development of a non-chemical method to replace chemical insecticides is urgently needed for the control of stored products pests. In this study, we investigated the oviposition preference, development, and adult performances of C. chinensis at five radiofrequency levels of 0 (control without frequency), 5, 10, 20, and 30 kHz on three leguminous seeds: azuki bean, cowpea, and mung bean. In addition, the effects were also studied in three successive generations (parent, F1- and F2-generations) of C. chinensis. We found that radiofrequency application had significant effects on the life history variables of C. chinensis. Radiofrequency exposures on C. chinensis not only affected developmental period, adult longevity and adult weight, but also negatively affected the fecundity of subsequent generations. The total developmental period from egg to adult emergence was longer and adult longevity was shorter in the radiofrequency treatments than in the untreated control. Reduced radiofrequency levels coincided with increased sexual development of adults. The lowest rate of adult emergence and the shortest adult longevity both occurred at 5 kHz. The outcomes of this study are discussed in terms of targeting susceptibilities to radiofrequency in storage and semi-field conditions as an alternative to chemical treatments.

Life table parameters of Iranian population, Tetranychus kanzawai (Acari: Tetranychidae) fed on soybean leaves

The effects of six ambient temperatures (15, 20, 25, 30, 35 and 37.5ºC) on life table parameters of Tetranychus kanzawai Kishida (Tetranychidae) were studied under laboratory conditions on soybean (Glycine max (L.) Merrill). Total immature developmental time of females at the above-mentioned temperatures was 28.55, 16.34, 9.01, 6.96, 5.56 and 5.65 days, respectively. A linear and two nonlinear models of Lactin and SSI were fitted to developmental rate of immature stages of T. kanzawai to predict the developmental rate as a function of temperature, as well as to estimate the thermal constant (k) and critical temperatures. The estimated k for total immature developmental time of females and males was 134.58 and 126.74 DD, respectively. The estimated Topt and Tmax by Lactin model for overall immature stages were 36.20 and 40.70ºC, respectively. Intrinsic optimum temperature (TФ) and T1 (Topt) by SSI model for total immature stages was estimated to be 23.23 and 35.71ºC, respectively. Also the estimated TL and Th of SSI model for overall immature stage were 09.21 and 38.46ºC, respectively. The longest and shortest adult longevity was observed at 15°C (60.63 days), and 37.5°C (7.34 days), respectively. Mated females laid highest and lowest eggs at 25°C (237.96 eggs) and 37.5°C (30.54 eggs), respectively. The rm values ranged from 0.356 day-1 at 30°C to 0.089 day-1at 15°C. The highest value of R0 was 163.55 offspring female-1 at 25°C. The presented information in this study provided new perspective to better management of T. kanzawai on apple trees in Iran.

Influence of Different Hazelnut Cultivars on Some Demographic Characteristics of the Filbert Aphid (Hemiptera: Aphididae).

The filbert aphid Myzocallis coryli (Goeze) is a serious pest of hazelnut in North America, Italy, Spain, and Turkey. To evaluate the resistance of hazelnut to this insect, aphids were reared on five major cultivars ('Tombul,' 'Palaz,' 'Çakıldak,' 'Foşa,' and 'Mincane') under laboratory conditions. The developmental times of preadult and adult stages, total longevity, reproduction, and life table parameters were analyzed according to age-stage, two-sex life table theory, in which the stage differentiation and variable developmental rates among individuals could be described. The intrinsic rate of increase (r) and finite rate of increase (λ) varied among the cultivars. The highest values were found for aphids reared on Çakıldak (r = 0.2019 d-1, λ = 1.2238 d-1), which did not differ significantly from Mincane (r = 0.1957 d-1, λ = 1.2161 d-1), whereas these parameters were lowest for Palaz (r = 0.1622 d-1, λ = 1.1761 d-1) and Foşa (r = 0.1677 d-1, λ = 1.1826 d-1). Based on longer preadult development time, shorter adult longevity, shorter reproductive period, together with the demographic parameters, Palaz and Foşa provide a relatively unfavorable environment for the filbert aphid. The results obtained from demographic data together with estimates of pest growth potential generated by computer projection based on age-stage, two-sex life table theory, demonstrate that both Palaz and Foşa are resistant cultivars for M. coryli and can be considered in hazelnut integrated pest management and hazelnut breeding programs.

A scientific note on seasonal levels of pesticide residues in honey bee worker tissues

Honey bees (Apis mellifera L.) provide essential pollination services for agricultural production worldwide. Recent declines in honey bee populations have been attributed to a multitude of potential stressors, such as pest pressure, nutritional stress, and exposure to pesticides (vanEngelsdorp et al. 2009b). One possible explanation for bee decline is the accumulation of pesticide residues in honey bee brood comb, resulting in chronic exposure to a suite of agrochemicals which may detrimentally influence honey bee health. Wu et al. (2011) demonstrated that bees reared in brood comb containing high levels of pesticide residues exhibit increased brood mortality and shorter adult longevity.

光周期对两种色型豌豆蚜种群参数的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 光周期对两种色型豌豆蚜种群参数的影响 DOI: 10.5846/stxb201412092435 作者: 作者单位: 甘肃农业大学资源与环境学院 兰州,甘肃农业大学草业学院 草业生态系统教育部重点实验室 兰州 作者简介: 通讯作者: 中图分类号: 基金项目: 高等学校博士学科点专项科研基金博导类资助课题（20136202110007）；国家自然科学基金项目（31260433） Effect of photoperiod on population parameters of two color morphs of the pea aphid Acyrthosiphon pisum Author: Affiliation: College of Resource and Environmental, Gansu Agricultural University,College of Grassland Sciences, Gansu Agricultural University, Key Laboratory of Grassland Ecosystem of Ministry of Education Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探讨光周期对红绿两种色型豌豆蚜种群增长的影响，于室内模拟光周期22L：2D、16L：8D、10L：14D和4L：20D四个水平，研究了红绿两种色型豌豆蚜的发育、繁殖和生命表。结果表明：相对于其它光周期，在光周期22L：2D时，红绿两种色型豌豆蚜若蚜存活率最高，繁殖力最强；其红色型豌豆蚜种群增长内禀增长率（rm=0.3263）高于绿色型豌豆（rm=0.2863）。光周期16L：8D时，红色型豌豆蚜的若蚜存活率（72.22%）高于绿色型豌豆蚜（69.45%），而成蚜寿命（6.58d）较短；但绿色型豌豆蚜内禀增长率（rm=0.2648）高于红色型豌豆蚜（rm=0.2249），其种群繁殖力强。光周期10L：14D时，红色型豌豆蚜与绿色型豌豆蚜相比，若蚜存活率（80.55%）高，内禀增长率（rm=0.2490）高，种群增长力强，而绿色型豌豆蚜成蚜寿命（12.71d）较长。光周期4L：20D时，两种色型豌豆蚜若蚜存活率最低，繁殖力最弱，成蚜寿命显著延长；红色型豌豆蚜若蚜存活率（64.67%）高于绿色型（35.50%），成蚜没有产生后代；绿色型豌豆蚜内禀增长率（rm=-0.0366），其种群为负增长。综上，短光照条件（4L：20D）延长了两种色型豌豆蚜的若蚜发育历期及成蚜寿命，降低了若蚜存活率、繁殖力及生命表各项参数；长光照条件（22L：2D）缩短了两种色型豌豆蚜的若蚜发育历期及成蚜寿命，若蚜存活率高、繁殖力强；红色型豌豆蚜更适宜光周期10L：14D，而绿色型豌豆蚜更适宜光周期16L：8D。 Abstract:To investigate the effects of photoperiod on population growth of the red and green color morphs of the pea aphid Acyrthosiphon pisum (Harris), the development, reproduction, and life table parameters were examined for various photoperiods (22 L:2 D, 16 L:8 D, 10 L:14 D, and 4 L:20 D), controlling for light intensity (103 μmol m-2 s-1). For the 22 L:2 D photoperiod, the red and green color morphs of the pea aphid had the highest nymphal survival rates (90.28% and 88.89% respectively), the shortest duration of development (5.63 d and 6.26 d), the highest net reproductive rates (49.3472 and 47.8103), the highest average fecundity (54.56 and 55.16), the highest maximum fecundity (121 and 112 offspring per female aphid), and the highest intrinsic rate of increase (rm =0.3263 and 0.2863, respectively). Population growth was higher for the red color morph than the green color morph for the 22 L:2 D photoperiod. For the 16 L:8 D photoperiod, the red color morph of the pea aphid had a higher nymphal survival rate (72.22%) and shorter adult longevity (6.58 d) than those of the green color morph (69.45% and 7.08 d, respectively). However, the green color morph had a higher intrinsic rate of increase (0.2648 vs. 0.2249), indicating a higher population fecundity of the green color morph than the red color morph for the particular photoperiod. For the 10 L:14 D photoperiod, the red color morph had a higher nymphal survival rate (80.55%) and intrinsic rate of increase (0.2490) than those of the green color morph (79.17% and 0.2277, respectively). However, the green color morph had a longer duration of development (7.92 d) and adult longevity (12.71 d) than those of the red color morph (7.60 and 6.88 d, respectively). For the shortest photoperiod (4 L:20 D), the red and green color morphs of the pea aphid had the lowest nymphal survival rate (64.67% and 35.50%, respectively) and the longest duration of development (13.26 and 13.61 d). Moreover, the red color morph did not produce offspring and had a fecundity of zero. However, its intrinsic rate of increase, -0.0366, indicated negative population growth of the green color morph. In conclusion, extremely short durations of light (4 L:20 D) can prolong development and adult longevity, but reduces nymphal survival rate and the intrinsic rate of increase of two pea aphid color morphs. However, extremely long durations of light (22 L:2 D photoperiod) resulted in shortened development and decreased adult longevity, but an increased nymphal survival rate and fecundity for the two pea aphid color morphs. Moreover, the 10 L:14 D photoperiod was a more suitable condition with respect to population growth for the red color morph, but for the green color morph a photoperiod of 16 L:8 D was better. Therefore, the results of this study may facilitate artificial breeding of pea aphids and the prevention and treatment of pea aphid attacks on field crops. Furthermore, the mechanism underlying the response to photoperiod differed between the red and green color morphs of pea aphids. Further studies are needed to examine these mechanisms. 参考文献 相似文献 引证文献

A laboratory and field condition comparison of life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae)

Abstract Life table studies are essential tools for understanding population dynamics. The life table parameters of Aphis gossypii Glover (Hemiptera: Aphididae) feeding on the host plant, Hibiscus syriacus L. were studied under laboratory (25±1°C and relative humidity of 65±5% and a photoperiod of 16L : 8D h) and field conditions (23-43°C, and relative humidity of 27-95%). The data were analysed using the age-stage, two-sex life table theory. The life table studies were started with 50 and 40 nymphs in laboratory and field conditions, respectively. Under laboratory conditions, A. gossypii reared on H. syriacus had a higher survival rate, fecundity, and longevity than those reared under field conditions. When reared under field conditions, A. gossypii had a longer nymphal developmental time, shorter adult longevity, and lower fecundity than those reared under laboratory conditions. The intrinsic rate of increase (r), net reproductive rate (R0), and the finite rate of increase (λ) under laboratory conditions, were higher than those obtained under field conditions. Nevertheless, there were no significant differences in the mean generation time T (days) between field and laboratory conditions. In the present study, the results clearly showed that life table parameters of A. gossypii were significantly different under field and laboratory conditions. These results could help us to understand the A. gossypii population dynamics under field conditions. The results could also help us make better management decisions for economically important crops

Life Tables ofBactericera cockerelli(Hemiptera: Triozidae) on Tomato Under Laboratory and Field Conditions in Southern Texas

The potato psyllid or tomato psyllid, Bactericera cockerelli (SŠulc) (Hemiptera: Triozidae), has become severely detrimental to the fresh tomato market by transmitting the plant pathogen ‘Candidatus Liberibacter psyllaurous’ (syn. solanacearum). Because suppression of insect transmitted plant diseases relies on sensible insect vector management, the life table parameters of B. cockerelli reared on tomato under both laboratory and field conditions in southern Texas were determined and the population dynamics were estimated according to the life table results. Generally, B. cockerelli reared on tomato in the laboratory had greater survival, fecundity, and longevity than those reared on tomato in the field, and the intrinsic mortality was the primary factor contributing to population decrease. In contrast, up to 74.2% of B. cockerelli were missing in the field. B. cockerelli reared under field conditions had a longer developmental time, shorter preoviposition and oviposition periods, shorter adult longevity, lower fecundity and higher mortality than those reared under laboratory conditions. Therefore, the intrinsic rate of increase (rm finite rate of increase (λ), and net reproductive rate (R0) of field-reared B. cockerelli in south Texas were lower than the laboratory reared. These results could help in the understanding of B. cockerelli population dynamics under natural conditions in tomato fields, as well as suggest possible biotic and abiotic mortality factors that may contribute to sound insect vector management, and a better understanding of the epidemiology of B. cockerelli related diseases of tomato in south Texas and elsewhere.

INFLUENCE OF SOME PLANT EXTRACTS ON CERTAIN BIOLOGICAL ASPECTS OF SESAMIA CRETICA LED. UNDER LABORATORY CONDITIONS

The influence of some plant extracts belonging to different families using different polarity solvents on certain biological aspects of 2 nd larval instar of S. cretica larvae was investigated under laboratory conditions of 31 °C & 60 R.H.. The extracted plants were tooth pick, Ammi visnaga Lam (Family: Umbelliferae), coffee tree, Coffea arabica (L. Rubiaceae) , pomegranate Punica granalum L. (Punicaceae) and taro Arum colocasia (Araceae). Data obtained showed that acetone pomegranate extract and hexan tooth pick extract caused the highest mortality percentage (88% & 85% than control). In addition, acetone coffee, acetone pomegranate and hexan tooth pick extracts caused shorter mean of larval duration, 22, 22 and 23 days, respectively. The shortest pupal duration 7 days was due to hexan tooth pick and acetone coffee extract treatments. While the shortest adult longevity (8 days) due to the treatment of hexan tooth pick extract. Also, some deformations were found in S. cretica larvae and pupae as a result of treatment with acetone coffee extract (30 and 33%, respectively). The composition of the tested plants were obtained from some scientific sites on the wide world web. From the previous results, it could be concluded that plant extracts proved to be a safe alternative pest control trend rather than tradional pesticides.