Percentage Of Mating Research Articles

Mating Disruption of a Flighted Spongy Moth, Lymantria Dispar Japonica (Motchulsky) in Japan.

Mating disruption of a flighted spongy moth, Lymantria dispar japonica (Motchulsky)(Lepidoptera: Lymantridae), with a synthetic version of its sex pheromone, (+)-disparlure ([7R,8S] -cis-7,8-epoxy-2- methyloctadecane), was tested in the forests in Japan. Pheromone trap catches and the percentage mating of tethered females were measured in the pheromone-treated and untreated control forests. The attraction of male moths to pheromone traps placed at a height of 1.5m was significantly disrupted when the pheromone dispensers were placed at 1.5m height, but many moths were captured in control plots. Mating of tethered females placed at 1.5m was inhibited entirely, while 44% of females were mated in an untreated control forest. We report the first trial of mating disruption against a flighted spongy moth, and these results suggest that mating disruption with the synthetic sex pheromone appears promising for reducing damage caused by L. dispar japonica.

Enhancement of Mating Performance of Sterile Males of Melon Fly,<i>Zeugodacus cucurbitae</i> (Coquillett) Through Methoprene and Cue Lure

The male pupae of Melon fly, Zeugodacus cucurbitae were irradiated at 30 Gy of gamma radiation using Cobalt-60 source. Freshly emerged sterile males (30 Gy) were exposed to different regimes of methoprene and yeast hydrolysate as protein source. Sterile males of 10, 12 and 14 days old were exposed to different regimes of cue lure and yeast hydrolysate. Mating parameters such as lek initiation, lek participation, male calling, mating success and female acceptance index (FAI) were recorded. Sterile males of exposed to methoprene and fed with yeast hydrolysate (M+P+) become sexually matured at three days earlier when compare to protein deprived males (M+P-). High percentage of M+P+ males were engaged in lekking and calling behavior. Sterile males treated with methoprene and fed on protein diet had high percentage of matings with female acceptance index (FAI) of 0.8. Sterile males fed on yeast hydrolysate up to 12-days of age and then accessed to cue lure (P+CL+) had greater mating propensity with frequent mating (43.0%) and FAI of 0.84.

Performance of Apis cerana colonies with queens reared by different methods for revival of traditional beekeeping in Kashmir valley

Kashmir valley has enormous potential of beekeeping. The colony performance of Apis cerana indica is determined by its foraging efficiency. The economy of the colony depends on the performance of the colony. The focus of the study was to determine the queen bee rearing techniques, accurate measurement in selection and offer the best technique in queen bee rearing for beekeepers. The experiment, a first step in the valley, was carried out in farmers apiary at Harwan Srinagar-Kashmir during 2018-19 with three bee raising methods viz., Miller (T1), Division (T2) and Supersedure (T3). The efficiency and potential of supersedure queen was determined in comparison to other naturally raised queen in Apis cerana colonies. The results showed that supersedure queens performed well as naturally produced queen. The highest rate of mating percentage (83.33%) was recorded in supersedure method (T3). The maximum brood area (1024 cm2) during 2nd fortnight of April, pollen area (198.00 cm2) in 1st week of March and honey store area (2422 cm2) during 1st fortnight of May, were recorded in split method of queen rearing (T2). The minimum brood area (844.00 cm2) was recorded in supersedure method of queen rearing (T3). Significant differences were observed among all the treatments.

Flight activity promotes reproductive processes in the fall armyworm, Spodoptera frugiperda

The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), has invaded many countries in Africa and Asia since 2016, posing a major threat to world food security. Long-distance migration and strong reproductive ability form the biological basis of its rapid population expansion, but the relationship between the flight and reproduction of FAW has not been studied in depth. Here, an empirical assessment of this relationship in an invasive FAW population in China found that 1–3-day-old adults which had undergone 10-h tethered flights had a significantly shorter pre-oviposition period and greater oviposition synchronization, but did not show any differences in fecundity, oviposition period, mating percentage or other reproductive variables. Further studies on moths after 1.25–15-h tethered flights indicated that the reproductive process of adults could be fully triggered by flight activity longer than 2.5 h. Dissection of the reproductive organs also showed that tethered flight promoted ovarian and testicular development of FAW. These results show that appropriate moth flight activity significantly speeds up the reproductive process of FAW, which increases our knowledge on its migratory biology in relation to regional outbreaks.

Influence of a raised slatted area in front of the nest on leg health, mating behaviour and floor eggs in broiler breeders

European farms for broiler breeders often have raised slatted areas in front of the nests, but in other regions of the world no raised slatted areas are provided. This study aimed to investigate the effects of a raised slatted area on leg health, mating behaviour and floor laying behaviour. Ten groups of 33 broiler breeder hens and three males were housed in two pen types: with or without a raised slatted area in front of the nests. Each pen had one plastic and one wooden nest. Between 25 and 31 weeks of age, ten marked hens per pen were weighed and assessed weekly on foot pad dermatitis, hock burn and wounds. At the end of week 31, animals were euthanized and bone strength of the tibia and humerus of these individuals was assessed. At 24, 27 and 30 weeks of age, mating behaviour was observed for an hour per pen, noting both numbers of successful and unsuccessful copulations. The number of eggs laid in the nests and on the floor was recorded daily between 20 and 31 weeks of age. Foot pad dermatitis scores were affected by age, but not by pen type. Generally, there were only minor issues with foot pad dermatitis (scores <11 on a 0–100 scale), probably due to the young age of the hens. Body weight was not affected by pen type, while the prevalence of hock burns was too low to analyse and no difference in bone strength was found for the tibia and the humerus. Overall, mating behaviour was less frequent in pens with raised slats than in pens without raised slats (29 ± 2 vs 35 ± 3 times/h) and more frequent at 27 weeks of age than at 24 and 30 weeks of age (38 ± 1 vs 31 ± 4 and 27 ± 2 times/h). The pens with raised slats had a lower percentage of floor eggs than pens without raised slats (11.2 ± 0.4 vs 19.3 ± 0.5%). The wooden nest was preferred over the plastic nest as on average 63% of the eggs were laid in the wooden nest. This study shows that providing raised slats decreases mating behaviour and percentage of floor eggs, although its effects on leg health remain inconclusive.

Juvenile hormone regulates the shift from migrants to residents in adult oriental armyworm, Mythimna separata

In migratory insects, increasing evidence has demonstrated juvenile hormone (JH) is involved in regulating adult reproduction and flight. Our previous study demonstrated that the switch from migrants to residents in Mythimna separata could be induced by adverse environmental conditions during a sensitive period in adulthood (the first day post-emergence), but the role of JH in this switch is not clear. Here, we found a significantly different pattern of JH titers between migrants and residents, with migrants showing a slower release of JH during adulthood than residents. Application of JH analogue (JHA) in the 1-day-old adults, significantly accelerated adult reproduction and suppressed flight capacity. The pre-oviposition period and period of first oviposition of migrants treated with JHA were significantly shorter, while the total lifetime fecundity and mating percentage increased. The flight capacity and dorso-longitudinal muscle size of the migrants were decreased significantly when treated with JHA. The effect of JHA on reproduction and flight capacity indicate that JH titers during the sensitive period (first day post-emergence) regulates the shift from migrants to residents in M. separata.

Effects of light intensity on mating of the black soldier fly (Hermetia illucens, Diptera: Stratiomyidae)

The irradiance (W/m2) of light to which groups of black soldier fly adults were exposed in screen cages was manipulated by varying the distance between the cages and a 100 W, white light-emitting diode (LED) chip on a 14L:10D photoperiod. After combining the sexes at the beginning of a light period (photophase), the mating status of all individuals was noted every 10 min for two consecutive photophases. Of all matings, 92% occurred during the first photophase. Mating pairs were nearly motionless and the duration of 93% of couplings was ≥20 min, so essentially all matings were observed. Cumulative probability of mating increased from an estimated 23% at an irradiance of 0.92 W/m2 to 70% at 431 W/m2. Over the same range of irradiances, average time of mating initiation decreased from an estimated 6.4 h to 3.4 h post photophase initiation so that the percentage of matings initiated 15:00 or later decreased from 50 to 0%. Consequently, the occurrence of matings more than 7 hours after photophase initiation was associated with reduced lifetime probability of mating. Peaks in the flux spectrum of the LED at 440 (indigo/blue) and 540 nm (green) coincided with published measurements of the wavelengths at which two of the classes of photoreceptors in the retina of the black soldier fly are maximally sensitive. This study suggests that mating success of reared black soldier fly can be dramatically increased by exposing the adults to light that is particularly rich in wavelengths near 440 and/or 540 nm and has an irradiance that is an appreciable fraction of the intensity of full sunlight.

Sexual size dimorphism and sexual selection in primates

Abstract In most animals, females are larger than males. Paradoxically, sexual size dimorphism is biased towards males in most mammalian species. An accepted explanation is that sexual dimorphism in mammals evolved by intramale sexual selection. I tested this hypothesis in primates, by relating sexual size dimorphism to seven proxies of sexual selection intensity: operational sex ratio, mating system, intermale competition, group sex ratio, group size, maximum mating percentage (percentage of observed copulations involving the most successful male), and total paternity (a genetic estimate of the percentage of young sired by the most successful male). I fitted phylogenetic generalised least squares models using sexual size dimorphism as the dependent variable and each of the seven measures of intensity of sexual selection as independent variables. I conducted this comparative analysis with data from 50 extant species of primates, including Homo sapiens, Pan troglodytes, and Gorilla spp. Sexual dimorphism was positively related to the four measures of female monopolisation (operational sex ratio, mating system, intermale competition, and group sex ratio) and in some cases to group size, but was not associated with maximum mating percentage or total paternity. Additional regression analyses indicated that maximum mating percentage and total paternity were negatively associated with group size. These results are predicted by reproductive skew theory: in large groups, males can lose control of the sexual behaviour of the other members of the group or can concede reproductive opportunities to others. The results are also consistent with the evolution of sexual size dimorphism before polygyny, due to the effects of natural, rather than sexual, selection. In birds, the study of molecular paternity showed that variance in male reproductive success is much higher than expected by behaviour. In mammals, recent studies have begun to show the opposite trend, i.e. that intensity of sexual selection is lower than expected by polygyny. Results of this comparative analysis of sexual size dimorphism and sexual selection intensity in primates suggest that the use of intramale sexual selection theory to explain the evolution of polygyny and sexual dimorphism in mammals should be reviewed, and that natural selection should be considered alongside sexual selection as an evolutionary driver of sexual size dimorphism and polygyny in mammals.

Daily rhythmicity in the sexual behaviour of Monema flavescens (Lepidoptera: Limacodidae)

Daily rhythmicity in the sexual behaviour of Monema flavescens Walker (Lepidoptera: Limacodidae) was studied under laboratory conditions. There was a distinct diel periodicity in female calling, male responsiveness and mating behaviour of M. flavescens. As females aged there was an advance in the onset and more time spent calling. One day old females started calling 4 h after the onset of the scotophase, and 5 to 6 day old females called during the first hour of the scotophase. About 34.5% of females called on the night they emerged (1 day old) and the peak in calling of 97.8% was recorded for 2 day old females, after which the incidence of calling decreased rapidly with advancing age. Wind tunnel and copulation tests showed that males were sexually mature on the third night and female moths on the second night. The highest value for the percentage mating was recorded for 3 day old virgin females 4 to 6 h after the onset of the scotophase. In field tests, traps baited with 2 day and 3 day old virgin females captured more males than any other trap and most males were captured 4 to 6 h (1 to 2 day old), 3 to 5 h (3 to 4 day old) and 2 to 4 h (5 to 6 day old) after the onset of the scotophase. These results indicate that there is a daily rhythm in the reproductive behaviour of M. flavescens and provides a better understanding of its sexual behaviour.

(Z, E)-9, 12-Tetradecadienyl Acetate (ZETA) disrupts mating of Ephestia cautella : Presentation

The tropical warehouse moth Ephestia cautella is a major pest of stored products in Sri Lanka, and difficult to control using currently-available insecticides. The sex pheromone (Z, E)-9, 12- tetradecadienyl acetate (ZETA) emitted by the females attracts males of this species. Hence it can potentially be used in the management programs but the limited information on pheromone concentration and air movement impede the potential use of this pheromone in pest management programs. This experiment was conducted to determine the effects of ZETA concentration and air movement on the mating disruption of E. cautella. The male and female moths of E. cautella were introduced into a cubicle in which ZETA was placed at different concentrations. Later, the female moths were dissected to determine the presence/absence of spermatophore. All the pheromone concentrations tested recorded lower mating percentages than the hexane control. Mating disruption varied with the pheromone concentration and the availability of air flow. This study reveals that ZETA can be used to disrupt mating in E. cautella.

Blood Biochemical Components and Progesterone Hormone on Day of Estrus in Crossbred Cattle in Egypt

Deficiencies or excess minerals such as P, Cu, and Zn are associated with subnormal fertility and anoestrus conditions in cows. This study was conducted in a veterinary unit in Menufiya, Egypt. Eighteen head of crossbred cows were randomly selected at random at estrus time (estrus group) and as a control 14 head of crossbred cows were selected from newly-calving dams at about 6-12 hours after calving (control group). The aim of this study was to use the components of biochemistry and progesterone hormone on estrus day of crossbreeding cattle in Egypt. The information from this study will be used to confirm estrus time to improve mating percentage. In blood plasma, the concentrations of all biochemical components and progesterone concentrations in estrus animals are higher than control cows except globulin. The results showed that blood plasma from control animal obtained Mg, Ca / P ratio, Co, Cu, Zn, Se, and Mo concentration is higher than estrus cattle. On the other hand, blood plasma concentrations of Na, K, Ca, P, Mn, and Fe are higher in estrus cattle. The progesterone concentration of estrus cattle is lower during summer than in winter. In estrus cows, higher plasma macro-elements were found in winter than in summer except for K, Ca and Ca/P ratio. On the other side of estrus cattle, all trace elements of blood plasma are higher in winter than in summer except Zn, Mn, Se, and Fe.

The Timing of Calling and Mating in Heterolocha jinyinhuaphaga and the Influence of Environmental Determinants

We investigated the periodicities of calling and mating of Heterolocha jinyinhuaphaga (Lepidoptera: Geometridae) and the effects of temperature, relative humidity, and photoperiod on the timing of these behaviors. Females called on the first night after emergence, mainly during the second half of scotophase. The calling percentage increased on the second night and peaked on the third night, before decreasing. Mating had similar rhythms but peaked 1 h later than calling. As the moth aged, the mean onset times of calling and mating were advanced. Temperature, relative humidity, and photoperiod all affected the calling and mating. We found that 25°C was the most suitable temperature for calling and mating, whereas at higher or lower temperatures, the total calling percentage and the total mating percentage decreased, the onset time of calling was delayed, and mating duration decreased. Increased the relative humidity facilitated calling and mating. However, lengthened photoperiods inhibited the calling and mating.

Delay in Mating Reduces Reproductivity but Increases Life Span in Tobacco Cutworm, Spodoptera litura Fabricius (Lepidoptera: Noctuidae).

A pheromone-mediated mating disruption is a vital tool in the management of insect population dynamics that not only prevents mating but also delays mating in the target insect. Here, we examined the effect of delayed mating on the longevity and reproductive performance of the global pest, Spodoptera litura Fabricius (Lepidoptera: Noctuidae). Delayed mating was imposed on both sexes simultaneously, males only, and females only. The results showed that a 30-40% reduction in the successful mating rate of S. litura was caused by 7-d delay in mating. Increased mating ages of both sexes of S. litura resulted in a significant decrease in 3-d-old delayed mating, followed by an increase in mean duration of copulation. Furthermore, delayed mating had a significantly negative influence on the number of S. litura eggs produced. Mating delay imposed on both sexes simultaneously had a significantly greater effect on longevity and the number of eggs than when it was applied to either sex alone, and females were more severely affected by delayed mating than males in terms of longevity. Percentage of mating, fecundity, and female longevity were all significantly correlated with the number of days delayed mating. However, the hatching rate of eggs was not significantly affected by an increased delay in mating. Overall, our results indicated that delayed mating in both females and males drastically reduced the females' reproductive output, which itself was affected more by increasing the age at mating of females than males.

Influence of adult diet and exposure to methyl eugenol in the mating performance of Bactrocera correcta

The Guava fruit fly Bactrocera correcta is serious pest attacking Dragon fruit (Hylocereus undatus and Hylocereus polyrhizus ). The study on the impact of (i) Protein in adult diet on sexual maturity of Guava fruit fly; (ii) Methyl eugenol (ME) feeding on sterilized male of Guava fruit fly; and (iii) Longevity of sterilized males and females feeding on different diets. All those trials were conducted for both sterile males and laboratory flies reared at Plant Protection Research Institute, Hanoi, Viet Nam. The initial results showed that the first age of sexual maturation of laboratory reared females are 7 days old and 8 days old when fed on a mix diet of hydrolyzed yeast: sugar (1:4) and only sugar diet, respectively. Four days after emergence, females on hydrolyzed yeast fed diet died. The highest percentage of mating for the period of 20 first days after emergence was recorded 7.19% at 11 days old of flies fed on sugar; 40.08% at 10 days old of flies fed on hydrolyzed yeast and sugar. The longevity of sterilized males was 30.7 days, 28.1 days and 3.2 days as feeding on mix of hydrolyzed yeast: sugar, sugar only and hydrolyzed yeast alone, respectively. Likewise, the longevity of females was 32.5 days on hydrolyzed yeast: sugar diet, 30.5 days on sugar only diet and 3.7 days on hydrolyzed yeast only diet. The percentage of sterile males feeding on ME at 3 days old was only 5% and reached 40% at 8 days old with feeding times of 44 seconds and 4 minutes 27 seconds respectively.

Fitness of Mass-Reared Males of Anastrepha obliqua (Diptera: Tephritidae) Resulting From Mating Competition Tests in Field Cages

The sterile insect technique uses males that have been mass-reared in a controlled environment. The insects, once released in the field, must compete to mate. However, the mass-rearing condition supposes a loss of fitness that will be noticeable by wild females. To compare the fitness of wild males and mass-reared males, three competition settings were established. In setting 1, wild males, mass-reared males and wild females were released in field cages. In setting 2, wild females and wild males were released without competition, and in setting 3, mass-reared males and mass-reared females were also released without competition. Male fitness was based on their mating success, fecundity, weight and longevity. The fitness of the females was measured based on weight and several demographic parameters. The highest percentage of mating was between wild males and wild females between 0800 and 0900 h in the competition condition, while the mass-reared males started one hour later. The successful wild males weighed more and showed longer mating times, greater longevity and a higher number of matings than the mass-reared males. Although the mass-reared males showed the lowest percentage of matings, their fecundity when mating with wild females indicated a high fitness. Since the survival and fecundity of wild females that mated with mass-reared males decreased to become similar to those of mass-reared females that mated with mass-reared males, females seem to be influenced by the type of male (wild or mass-reared).

Effect of 200 Gy as Gamma Sterilising Radiation on Reproductive Performance and Life Span of Male Moths, Spodoptera litura (Fabr.)

The lepidopteran Spodoptera litura is an insect pest of scientific and economic importance. This insect pest is polyphagous pest of major crops like tobacco, cotton, rice and tomato. The characteristics like high reproductive capacity and ability to migrate over large distance in adult stage have resulted in it becoming a pest of many agricultural crops throughout its geographical range. In order to control this pest we need to suppress its reproductive potential. The present study reports the results from a laboratory experiment in which behavioural components of reproductive performance and life span of male moths (treated with 200 Gy of gamma radiation) were observed. When treated with 200 Gy of gamma radiation the mating percentage and copulation period observed were significantly different among treated and control group with p? 0.05. Survival period analysis also showed a statistically significant difference among treated and control group with p? 0.0001. Present results showed a significant variation in reproductive performance among radiation treated and control group suggesting the effect of 200 Gy as sterilising dose of gamma radiation on mating behaviour in male moths. Survival period analysis further supports significant effects of sterilising dose of gamma radiation on longevity of male moths.

Mating Disruption of a Carpenter Moth, Cossus insularis (Lepidoptera: Cossidae) in Apple Orchards with Synthetic Sex Pheromone, and Registration of the Pheromone as an Agrochemical.

Mating disruption of the carpenter moth, Cossus insularis (Staudinger) (Lepidoptera: Cossidae), with a synthetic version of its sex pheromone, a mixture of (E)-3-tetradecenyl acetate and (Z)-3-tetradecenyl acetate, was tested for three successive years in apple (Malus domestica Borkh.) orchards. Pheromone trap catches, percentage mating of tethered females and females enclosed with males in a mating cage, and tree damage were measured in both the pheromone-treated and untreated control orchards. The attraction of male moths to pheromone traps at heights of 1.5, 3, and 5m was strongly disrupted when the pheromone dispensers were placed at 1.5m height. Mating of tethered females placed at 1m was completely inhibited, and the mating of tethered females at a height of 3m was significantly reduced by the treatment in comparison to matings in an untreated control orchard. Similarly, mating of pairs of moths enclosed in mating cages was significantly reduced by the synthetic pheromone treatment in comparison to controls. The percentage of damaged trees in the pheromone-treated orchard also decreased significantly over the course of the experiment. These results suggest that mating disruption with the synthetic sex pheromone appears promising for reducing damage caused by C. insularis in apple orchards in Japan, and a commercial mating disruption product has been developed and registered.

Reproductive behavior of the masson pine caterpillar, Dendrolimus punctatus (Lepidoptera: Lasiocampidae) under laboratory conditions

The pine caterpillar, Dendrolimus punctatus Walker (Lepidoptera: Lasiocampidae), is one of the most serious defoliators of pine trees (Pinus spp.) in China. Despite this, little is known with regard to the reproductive behavior of this insect. In the present study, we investigated the circadian rhythm of adult eclosion, mating and oviposition under laboratory conditions. The age at which moths mate and the frequency and duration of mating bouts were recorded. Eclosion and mating behavior were limited to nocturnal hours. Male and female eclosion peaked between 3 and 4 h, and between 4.5 and 5.5 h after the initiation of scotophase, respectively. Mating behavior peaked between 10 and 11.5 h after the initiation of scotophase. Most ovipositions occurred during the scotophase, displaying one distinct peak between 3 and 3.5 h after the initiation of scotophase. More than 70 % of matings occurred on the first scotophase after adult eclosion and the percentage of successful matings declined dramatically with moth age, indicating age was an important factor in the mating success of this species. If males or females paired with newly ecloced virgin partners after each successful mating, 57.6 % of males and 24.2 % of females mated more than once, mating an average of 2.0 ± 0.2 and 1.3 ± 0.1 times, respectively, suggesting males are generally polygynous, while females are monandrous. The copulation duration of this moth lasted on average 16.6 ± 0.1 h and was not influenced by moth age and female mating frequency, but was negatively influenced by male mating frequency. These data provide basic information to further study the mating system of D. punctatus, and could lead to the development of behavior-based pest control strategies of this species.

Molecular and cytogenetic evaluation for potential genotoxicity of hydrocortisone

ObjectiveTo assess the risk of hydrocortisone sodium succinate through different end points of genotoxicity. MethodsThe study examined the induction of chromosomal aberrations in bone marrow cells, morphological sperm abnormalities, the effect on dominant lethal gene and protein synthesis. Hydrocortisone was given intraperitoneally at three dose levels 26, 39 and 52 mg/kg body weight which was equivalent to the therapeutic doses in man. ResultsThe results showed that single dose treatment with different doses had no effect on chromosomal aberrations. The dose of 52 mg/kg body weight induced significant percentage of chromosomal aberrations in bone marrow cells after repeated treatment for 7 and 14 days. Significant effect of morphological sperm abnormalities was demonstrated only after treatment with the dose of 52 mg/kg body weight. For examining the dominant lethal mutation, male mice were injected with dose of 39 mg/kg body weight for 5 consecutive days. Mating between treated males and virgin untreated females were performed at different time intervals. The results showed that the percentage of fertile mating at 1–7 and 8–14 days reduced to 50% and 60% respectively compared with control group while no effect was recorded at 15–21 days. The percentage of dominant lethal mutation reached 0.32%, 4.4% and 0% in mating intervals respectively indicating pronounced effect of hydrocortisone at the interval 8–14 days which represented by the late spermatids. The results also showed that the repeated treatment with the dose of 52 mg/kg body weight inhibited protein synthesis which contributed to the cytotoxic effect of the drug. ConclusionsIt is concluded that long term treatment with large doses of hydrocortisone may have genotoxic effect.

新疆北部棉铃虫寄主来源与庇护所评估

PDF HTML阅读 XML下载 导出引用 引用提醒 新疆北部棉铃虫寄主来源与转基因棉区庇护所评估 DOI: 10.5846/stxb201402160266 作者: 作者单位: 石河子大学,中国科学院新疆生态与地理研究所,中国科学院干旱区生物地理与生物资源重点实验室,121团农机推广站,147团农业科植保站,147团农业科植保站,石河子大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家国际科技合作专项(2011DFA33170);中国科学院院地合作专项(XBXJ-2011-029) Analysis of Larval host types of Cotton Bollworm (Helicoverpa armigera) Populations for Evaluation of Bt Refuges in Northern Xinjiang Author: Affiliation: Shihezi University,Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences,,The 121th Production and Construction Crops Agricultural Technology Extension Station,The 147th plant protection station of Agricultration Department,The 147th plant protection station of Agricultration Department,Shihezi University 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:转Bt基因抗虫棉长期大规模种植后,棉铃虫对其存在抗性风险,庇护所是延缓抗性上升的策略之一。但在新疆北部转基因棉区,庇护所提供敏感棉铃虫的生态功能尚未见评估。2013年5-9月期间在新疆北部石河子地区147团、121团利用棉田边缘的智能测报灯收集棉铃虫成虫,应用碳稳定同位素技术从群体水平(混合翅膀)分析虫源性质,从个体水平(雌蛾翅膀和对应精包)确定交配类型;同时通过解剖雌性棉铃虫体内的精包数量评估交配频率。结果表明:来源于C4植物的棉铃虫主要出现在5月下旬和8-9月期间,比例占到50%左右;6-7月接近100%的棉铃虫来自于C3植物上;经测定不同寄主来源棉铃虫的有效交配比例为10%左右;两个地方的棉铃虫交配频率一般在0.9-2.1 次,但121团的第一代和第二代均高于147团。玉米是新疆北部地区重要的庇护所,但C3和C4来源棉铃虫同存的时间比较短,有效交配比例相对比较低,影响了庇护所的抗性稀释能力。在转基因棉区的抗性管理中不仅要考虑庇护所提供敏感棉铃虫数量大小,同时需要考虑有效交配比率,这将有利深刻理解庇护所生态功能。 Abstract:Transgenic cotton, expressing an insecticidal toxin from Bacillus thuringiensis (Bt cotton), has been widely cultivated for a long period in some areas of China. Therefore, there is the potential for the cotton bollworm, Helicoverpa armigera, to develop resistance to Bt cotton toxins. The United States Environmental Protection Agency (US EPA) is rethinking the requirement for some regions to delay developing natural refuge crops where Bt cotton growth has been highly successful. The policy of establishing refuges was intended to delay pest population development of Bt-toxin resistance. Bt cotton is widely grown in Xinjiang Province, which is the largest cotton-producing area in China, but no studies have been conducted on potential refuges in this region of China. In recent years, stable carbon isotope techniques (δ13C) have been used to identify the larval host-types (i.e., whether the hosts are C3 or C4 plants) of cotton bollworm. These methods have been used to evaluate the Bt refuge function of non-cotton crops. In this study, intelligent forecast light traps were established to collect adult cotton bollworms from May to September 2013, from the 147th and 121st regiments of the Shihezi reclamation area located in northern Xinjiang. The captured moths were placed into bottles and preserved in 95% alcohol until analysis. At each of the sites, 50 males and 30 females moths were selected on the day of capture, their wings combined into two bulked samples respectively to analyze their host type (C3 or C4) using δ13C analysis. At the same time, 30 female's wings and corresponding spermatophore were separated to one single sample to analyze the mating type and percentage of mating frequency between C3 and C4 host. A total of 23 bulked samples from the 147th regiment and 25 bulked samples from the 121st regiment were tested. The proportions of C3 and C4 hosts were calculated according to a standard curve constructed in 2012. Approximately 50% of cotton bollworms were derived from C4 hosts, and approximately 50% from C3 hosts in late May and from early August to September. From June to July, 100% of cotton bollworms were derived from C4 hosts. To evaluate the mating frequency of cotton bollworms at the two sites, we selected 210 anatomically adult females in the 1st and 2nd generations from the 147th and 121st regiments. The percentage of effective mating between the two larval host-types (C3 and C4) was approximately 10%. Mating frequency ranged from 0.9 to 2.1 per adult female at the two sites, and was higher at the 121st regiment site than at the 147th regiment site. Maize is considered to be the most important natural refuge for Bt-susceptible cotton bollworms in northern Xinjiang, since maize is the main C4 host plant in this area. Thus, maize may provide refuges for susceptible cotton bollworms in the autumn of one year and the spring of the following year. There is a short period in which cotton bollworms derived from C3 and C4 hosts simultaneously co-exist, and there is a very small percentage of effective mating between cotton bollworms derived from C3 and C4 hosts. This will affect the capacity to dilute the Bt-resistance in cotton bollworms, and may be related to the non-synchronization of C3 and C4 crops and male and female cotton bollworms. 参考文献 相似文献 引证文献