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苹果糠片盾蚧种群空间分布型研究 总被引：4，自引：2，他引：2
用Ｌｌｏｙｄ 的平均拥挤度（ ｍ） 和平均聚块性指标（ｍ／ ｍ） 、Ｔａｙｌｏｒ 幂法则、以及Ｉｗａｏ 的ｍ － ｍ 回归分析法分析了苹果糠片盾蚧种群空间分布型, ３ 种方法得出同样的结论, 即糠片盾蚧在苹果树上的空间分布为聚集分布． 并且４ 至６ 月糠片盾蚧呈现出扩散—聚集—扩散—聚集—扩散的规律性．７ 月份以后, 随着虫口密度降低, 糠片盾蚧呈现聚集趋势． 相似文献
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黑点蚧种群田间分布为聚集型,其聚集强度在树冠不同部位有差异;聚块性以外层、南方、上段最高,内层、北方、下段最低。样方1叶时为均匀分布,2叶以上为聚集分布。黑点蚧雌蚧最佳抽样方式为棋盘式;对若蚧则各种方法均可采用。 相似文献
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用Lloyd 的平均拥挤度(m) 和平均聚块性指标(m/m)、Taylor 幂法则、以及Iwao的m-m回归分析法分析了苹果糠片盾蚧种群空间分布型,3种方法得出同样的结论,即糠片盾蚧在苹果树上的空间分布为聚集分布。并且4至6月糠片盾蚧呈现出扩散-聚集-扩散-聚集-扩散的规律性。7月份以后,随着虫口密度降低,糠片盾蚧呈现聚集趋势。 相似文献
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Juan R. Boyero Raúl Ruiz-López Néstor Rodríguez José M. Vela Ramón Moreno Felipe Pascual 《国际虫害防治杂志》2013,59(3):217-225
Abstract We studied the influence of two orange tree varieties on the fecundity of two hemipteran diaspidid scale insect species: Cornuaspis beckii (Newman) and Parlatoria pergandii Comstock. Samples of females were taken at 7 – 40 day intervals from two orange orchards [Citrus sinensis (L.) Osbeck], one of the Navel Lane Late cultivar and the other of the Valencia Late cultivar. Different categories for the egg stage were considered: preoviposited, oviposited and hatched eggs. Average fecundity in C. beckii was significantly higher than that of P. pergandii. Significant differences between the two orange varieties were evident for some egg categories, with a higher fecundity in Navel Lane Late than in Valencia Late. The temporal pattern of fecundity in relation to accumulated temperature was studied by two methods: (i) comparing the parameter r of a logistic function that related egg-days to accumulated degree-days, and (ii) comparing the parameters b and c of a sinusoidal function that relates the variation egg-days/degree-days to accumulated degree-days. The comparison of such parameters (indicators of changes in the temporal patterns of fecundity) did not show significant differences between orange varieties. Our results suggest that some type of physiological difference between Navel Lane Late and Valencia varieties could be responsible for the differential fecundity of diaspines. Nevertheless, currently we cannot recommend changes in the management of diaspine in citrus orchards. 相似文献
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糠片蚧卵发育的起点温度为6.78℃,孵化积温为102.2日度。在15—34℃温度范围内,发育速率随温度升高而加快,孵化率则降低。在28℃恒温下,世代历期为42天,雌蚧产卵期可达50余天,平均每雌产卵55.5粒,种群趋势指数Ⅰ=11.0,内禀增长率 r_m=0.259,存活曲线为 DeveeyⅢ型。雌成蚧是田间存在的主要形式。越冬后第一、二代幼蚧发生比较整齐,是药剂防治的关键时期。 相似文献
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George J. Stathas 《Phytoparasitica》2001,29(3):207-214
The present study was carried out in southern Greece during 1993-1995 on sour orange trees infested with the diaspididParlatoria pergandii Comstock. The activity of the natural enemies of the scale, the composition of their population during the year as well as their relation with hymenopterous parasitoids of coccinellids, were studied.P. pergandii was parasitized by a hymenopterous endoparasite of the genusEncarsia and the extent of parasitization ranged between 5.2% and 14.1%. The observed predators were the coccinelidsChilocoms bipustulatus Linnaeus andRhyzobius lophanthae Blaisdell and the nitidulidCybocephalus fodori Endrödy-Younga. The predominant predator wasR. lophanthae (84.3% of the larvae and 73.3% of the adults), which was active throughout the whole year in all of its developmental stages. Second most abundant was the predatorC. bipustulatus (15.7% of the larvae and 20% of the adults) and third the predator C.fodori (6.7% of the adults). Larvae ofC. bipustulatus were observed to be parasitized by the hymenopterous parasitoidsHomalotylus flaminius Dalman (Encyrtidae) andTetrastichus coccinellae Kurdjumov (Eulophidae). The parasitization percentage increased gradually from 4% in mid June to 94% around the end of September. Laboratory tests confirmed that the above mentioned parasitoids cannot infest larvae or nymphs ofR. lophanthae. 相似文献
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