共查询到19条相似文献，搜索用时 46 毫秒
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《作物研究》2017,(5)
从野外采集红珠凤蝶的老熟幼虫,进行室内繁殖以及室内室外饲养,对卵、幼虫各龄期、蛹以及成虫的生物学特性以及幼虫各个龄期的主要形态特征进行观察和记录,同时在实验过程中探究了温度对红珠凤蝶卵、幼虫和蛹的发育历期的影响,并计算出发育起点温度和有效积温。结果表明:(1)红珠凤蝶在长沙地区1年发生4~5代,以蛹越冬;(2)幼虫各个龄期的头宽、体长以及形态特征有差异;(3)25±1℃温度条件下,红珠凤蝶完成一代的历期为49.3 d,此时卵的孵化率和幼虫存活率有最高值,分别为98.2%和96.8%;(4)发育起点温度,卵5.9±1.8℃,幼虫9.8±2.0℃,蛹5.7±1.6℃,总有效积温664.0℃,最适发育温度25℃。 相似文献
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橘小实蝇Bactrocera dorsalis(Hendel)是我国南方水果生产上危害最为严重的害虫之一。对橘小实蝇在18,20,25,28,30℃下卵、幼虫、蛹的发育历期及室内条件下成虫羽化、取食、交配、产卵等生物学特性的研究,结果表明,橘小实蝇卵、幼虫、蛹的发育历期随温度的降低而延长,其发育最适温度为25～28℃。在25℃下,卵、幼虫、蛹的平均发育历期分别为1.5,16和13d;在28℃下,卵、幼虫、蛹的平均发育历期分别为1.3,14和12.5d。橘小实蝇的防治措施多使用不育处理技术,引进利用"性诱剂"捕杀柑橘小实蝇技术,达到安全、环保防治的效果。 相似文献
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《中国油料作物学报》2015,(5)
为大豆田间大造桥虫发生危害的预测和防控提供依据。以大豆为寄主食料,研究了22、25、28、31、34℃共5个温度处理对大造桥虫各虫态的发育历期、发育速率、存活率和成虫繁殖的影响,测算了各虫态的有效积温。结果表明:在22~31℃范围内,各虫态发育历期均随温度升高而缩短,且卵、幼虫、预蛹及蛹期的发育速率与温度呈显著正相关;34℃高温对卵发育有明显抑制作用,1~5龄幼虫可以正常发育,但6龄幼虫无法存活;卵在22~28℃时孵化率均在98%以上,幼虫及蛹的存活率均在28℃时最高。大造桥虫卵、幼虫和预蛹的发育起点温度分别为6.68,9.10和10.97℃,有效积温分别为88.96,333.41和33.97日·度。成虫单雌产卵量在31℃时最高为754.83粒,28℃时次之为726.28粒。 相似文献
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井上蛀果斑螟（Assara inouei Yamanaka）是云南石榴上的重要害虫。为系统评价乙基多杀菌素对井上蛀果斑螟的综合控制作用,研究了乙基多杀菌素对该虫卵和初孵幼虫的直接致死效应及对存活后续虫态生长发育的影响。结果表明,浸渍法处理井上蛀果斑螟不同日龄卵后,随着乙基多杀菌素浓度和卵日龄的增大,卵孵化率显著降低,幼虫的死亡率升高。饲喂法处理井上蛀果斑螟初孵幼虫后,幼虫死亡率随药剂浓度的增大和处理后时间的延长而升高,且低剂量乙基多杀菌素对存活幼虫及其后续虫态的生存产生显著影响。低剂量乙基多杀菌素可显著延长存活幼虫的发育历期、预蛹期和蛹期,显著降低其化蛹率、蛹质量、羽化率和单雌产卵量。乙基多杀菌素对井上蛀果斑螟卵和初孵幼虫具有良好的杀虫活性,同时低剂量下对该虫的生长发育亦有明显的抑制作用,可用于控制井上蛀果斑螟的种群发展。 相似文献
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荔枝叶瘿蚊的研究 总被引：1，自引：0，他引：1
荔枝叶瘿蚊(Mayetiola sp)是国内首次报导的荔枝新害虫。在广州一年发生6代,以幼虫在被害叶上越冬。蛹期11—14天,成虫寿命1—2天,卵期2—4天,幼虫期14—39天。越冬幼虫期可达240余天。成虫产卵于嫩叶背面,幼虫孵出后侵入叶肉并发育形成疱状突起的虫瘿,通常一叶多瘿。幼虫老熟后离瘿入土化蛹,大多数是被蛹,但也有围蛹。本文描述了各期虫态的形态特征。温湿度及荔枝品种对叶瘿蚊种群数量影响极大,“三月红”对其幼虫有高度的生理抗性。目前已发现5种瘿内幼虫的寄生蜂。每年春天,于越冬幼虫离瘿入土或成虫羽化出土前用辛硫磷进行土表施药,对压低第一代虫口密度效果显著;氧化乐果或喹硫磷、杀虫双、杀虫单、敌杀死等与敌百虫混合喷雾对卵及初孵幼虫均有明显的防效。 相似文献
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在63%～100%相对湿度范围内，稻茎毛眼水蝇卵、幼虫和蛹历期差异不显著。幼虫、蛹存活率和世代存活率、成虫产卵量、寿命和种群增长指数随湿度增加呈抛物线变化趋势。当相对湿度分别为80.87%、77.76%、81.26%、78.61%、78.80%、80.70%时，其幼虫、蛹和世代存活率最高，产卵量最多，寿命最长，种群增长指数最大。 相似文献
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棉铃虫取食棉花和玉米对其生长发育和繁殖的影响 总被引：3，自引：0，他引：3
在室内用棉花生殖器官(蕾、铃)和玉米生殖器官(雌、雄穗)分别饲养棉铃虫,观察两种食料对棉铃虫生长发育和繁殖的影响。结果表明,(1)取食棉花棉铃虫的幼虫发育历期为18.21天,比取食玉米的长4.39天,差异达极显著水平;(2)取食玉米棉铃虫的雌雄蛹发育历期,较取食棉花的分别长1.0～1.5天,达显著差异;(3)取食棉花棉铃虫的雌雄蛹重分别比取食玉米的高0.033g和0.0342g,差异达极显著水平;(4)取食棉花棉铃虫的化蛹率、羽化率分别比取食玉米棉铃虫高18％和40％以上,而取食玉米棉铃虫蛹的死亡率是取食棉花的约4倍;(5)两种食料对棉铃虫成虫繁殖力的影响存在显著差异,取食棉花棉铃虫成虫的单雌产卵量和单雌抱卵量比取食玉米要高出400粒左右;(6)两种食料对幼虫存活、成虫交配、成熟卵产出以及卵孵化等方面的影响差异均不显著。 相似文献
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In order to investigate psychoacoustic characteristics of fibers, and to compare them with sound physical parameters, each
sound of 25 different fabrics consisted of a single fiber such as wool, cotton, silk, polyester, and nylon was recorded. Sounds
of specimens were transformed into critical band diagram and psychoacoustic characteristics including loudness and sharpness
for each sound were calculated based on Zwicker’s models. Physical parameters such as the level pressure of total sound (LPT),
level ranges (ΔL), frequency differences (Δf), AR coefficients (ARC, ARF, ARE) were obtained in fast fourier transform (FFT) spectrum. Nylon taffeta showed higher values
for loudness than 2.5 sone corresponding to human low conversation, while most silk fibers generated less louder showing lower
values for loudness than 1.0 sone. Wool fibers had higher loudness mean value than that of cotton, while the two fibers didn’t
differ in LPT. Loudness showed high positive correlation coefficients with both LPT and ARC. Sharpness values were higher
for wool fiber group than other fibers. Sharpness was not concerned with loudness, LPT, and ARC, but the fabrics with higher
values for sharpness tended to show higherΔL. 相似文献
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Twisted Copper Filaments (TCF) have been made by a yarn covering process in order to transmit signals and powers for electronic textiles. The 560 den. poly urethane filaments were covered in S-twist direction by urethane-coated copper wires. Two TCF twisted in Z direction were further covered in S direction by PET filaments to make final hybrid structure yarns (HSY). The HSY prepared was proportionally increased in apparent resistance along with measurement length, and showed resistivity of 0.00414 Ω·m. The number of ply was critical in terms of resistance variation, showing a linear increase of resistance with ply number. The twist factor, however, was not so significant without a slight decrease for severe twist level. Resonance Frequency, S11 (reflection), S21 (transmission) were measured and compared in order to examine the feasibility of applying to electrical signal transmission for wearable textiles. As expected, amplitude of resonance frequency was significantly decreased mainly due to increase of capacitance caused by length increase. It has been shown that S11 and S21 has been increased and decreased, respectively due to increase of transmission distance. While resonance frequency has been kept along with the ply number, S11 and S21 were decreased and increased, respectively according to decrease of copper fiber. Final filaments were found to be changed in resonance frequency mainly due to the change of di-electricity and thus capacitance caused by PET covered on it. It have been concluded that while resonance frequency was primarily determined by filament length and dielectric constant of covering yarns, S11 and S21 were mainly determined by measurement length and ply number. 相似文献
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Summary Microtubers can be stored longer, transported and handled easier than plantlets, but they have some disadvantages related
to long dormancy. Dormancy, number of sprouts per tuber and loss of microtubers under different storage temperatures were
studied. Microtubers of four genotypes originated from different tuberization treatments (photoperiod combinations) were observed.
We found that dormancy depended on cultivar and — in some cases — on the photoperiod treatment applied during tuberization.
Generally, the dormacy was long and was greatly elongated by low storage temperature. One of the photoperiod treatments shortened
while the other treatment prolonged the rest-period compared to the control, maybe due to a change in temperature accompanying
the change in daily light (photoperiod combination). Besides, these treatments affected the number of sprouts per tuber. There
was no significant difference in duration of dormancy between different tuber-size groups, but the loss increased significanctly
with a decrease in tuber size. Based on this information we can use microtubers more effectively in the seed potato production
programme. 相似文献
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With the rapid development of molecular biological technology,transfering foreign genes into crops has become an increasing routine,and making it possible to induce the genes encoding C4 photosynthesis enzyme into C3 plants. 相似文献
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通过15N标记方法研究氮素的吸收、分配、再分配与油菜早熟的内在关系。研究结果表明,早熟油菜品种中油116(ZY116)生育期比中晚熟油菜品种中双11号(ZS11)短9d,在营养生长期和生殖生长期分别短5d和4d。早熟品种ZY116在全生育期吸收的氮素比中晚熟品种ZS11更多的向籽粒中转移,而中晚熟品种ZS11则是花期吸收的氮素向角果皮中转移的更多,角果期氮素从角果皮转移到籽粒的更少,均达显著水平。早熟品种中油116在营养生长阶段吸收的氮素在后期的分配速度明显快于ZS11,如ZY116苗期吸收的氮素从花期生长到角果期时再分配速度为3.22mg/d,从角果期生长到收获期时再分配速度为3.71mg/d,而ZS11分别为2.48mg/d和3.10mg/d。 相似文献
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With the rapid development of molecular biological technology,transfering foreign genes into crops has become an increasing routine,and making it possible to induce the genes encoding C4 photosynthesis enzyme into C3 plants. 相似文献
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超级稻协优9308营养特性与施肥技术 总被引：13，自引：0，他引：13
与普通水稻不同 ,超级稻协优９３０８生长量大 ,对氮、磷、钾的吸收量大 ,且穗大粒多 ,花后物质生长量大 ,要求叶片有较好的光合作用功能。这对超级稻高产提出了新的施肥要求。施肥是水稻生长和产量形成的重要调控手段之一。施肥不足往往造成水稻生长量小、穗型小、产量不高。而施肥过量和不当也造成群体过大 ,植株上部叶片过大、过长 ,引起倒伏 ,导致减产。同样施肥过量也会造成肥料流失 ,导致肥料利用率低 ,引起环境污染。合理施肥是高产高效的重要措施 ,也是农业可持续生产的重要手段。为此 ,我们对超级稻协优９３０８进行了施肥试验。一… 相似文献
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Fresh ryegrass and lucerne were macerated and compressed into thin mats over a 4-week period at two yield levels. The mats were left lo dry outside during the day. and inside overnight, and compared with unconditioned crops. Under a low swath yield of 4 t DM ha−1 , mats required 0·7-1·4 mm pan evaporation lo reach 70% moisture, suitable for wilted silage, compared with 1·8-3·8 mm pan evaporation for unconditioned crops. On an average non-rainy day. mats were ready to harvest as wilted silage after 2–5 h, whereas the unconditioned crop required between 6 h and 36 h of wilting. With a high swath yield of 8 t DM ha−1 , mats required 1·4-3·0 mm pan evaporation to reach 70% moisture compared with 2·4-5·1 mm for unconditioned windrows. Low-yield mats reached 20% moisture, suitable for hay, in 2 d of drying, after 4·5-5·3 mm of pan evaporation. The thickness and cohesion of the mats were measured to assess their sensitivity to mechanical handling. The effect of controlled rainfall on mats was also investigated. Since mat making was most effective in low-yield crops, it could become a useful complement to low-input, extensive forage production. Mat making could eliminate most silage effluent losses; it could re introduce haymaking of ryegrass as a viable system under certain circumstances. 相似文献
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Demand for the fabric wipes is growing continuously. Wipes in industry are used for cleaning purpose. Cleaning involves rubbing
action, so it is very important to know how much frictional force is encountered during the cleaning action. In this study
the effects of normal load, sliding speed on frictional characteristics of nonwoven and woven wipes, both dry and wetted with
different liquids, against glass and floor tile surfaces have been reported. With the increase in the normal load the coefficient
of friction goes on decreasing for both nonwoven and woven wipes and this trend is observed in both dry and wet wipes. The
coefficient of friction of both nonwoven and woven wipes against glass surface is in general higher than the floor tile surface.
The wipes wetted with water shows an increase in coefficient of friction as compared to dry sample, but there is reduction
in the coefficient of friction when the wipe samples are wetted with vegetable oil. In case of dry wipes, the coefficient
of friction in case of nonwoven wipe is higher than the woven wipe. In case of woven wipes, the ranges of coefficient of friction
either due to change in liquid type, normal load or sliding speed are in general smaller than that in case of nonwoven fabrics. 相似文献