Colonization of growing fruit by the armored scales Lepidosaphes beckii, Parlatoria pergandii and Aonidiella aurantii (Hom., Diaspididae)

Abstract:  The process of invasion of the fruit surface by three species of armored scale insects [ Lepidosaphes beckii (Newman), Parlatoria pergandii Comstock and Aonidiella aurantii (Maskell)], was studied in citrus orchards in València, Spain. Three periods of intense crawler migration were detected annually for L. beckii and P. pergandii . Abundance of crawlers increased throughout the year and they moved outwards in the tree canopy. The fruit was continuously invaded during the period of fruit growth, starting at a very early stage of fruit development, by crawlers of the first generation of all the three species. Differences in fruit invasion and settling behaviour were found between the three species. First-generation crawlers tended to settle under the fruit calyx in L. beckii and P. pergandii , and on the exposed fruit surface in A. aurantii . During the second generation, most A. aurantii scales originated from reproducing females already settled on the fruit, whereas in L. beckii and P. pergandii new scales came preferentially from other tree substrates or from females settled under the fruit calyx. These findings suggest changes to optimize the timing of chemical sprays for controlling the scales.     

Natural enemies of Toxoptera aurantii (Boy.) (Homoptera: Aphididae) on cocoa in Ghana

Natural enemies of the black citrus aphid, Toxoptera aurantii (Boy.), on cocoa in Ghana are identified. Biology of some of the natural enemies is followed. Behaviour of the coccinellid and syrphid predators is studied in detail. Effectiveness of the predators in reducing the aphid populations is discussed.     

红圆蚧的空间分布及其自然种群生命表

调查了红圆蚧在不同定居地（果、叶、枝条和树干）的密度分布。结果表明,红圆蚧密度在果和树干上较高,在枝条和叶片上较低。红圆蚧的生命表研究说明,红圆蚧以各种虫态越冬,但低温对其存活影响很大。越冬成蚧存活率仅有１８．３％,各世代累积存活率在０．５４％￣３．８％之间变化。     

Molecular relationships between populations of South African citrus thrips (Scirtothrips aurantii Faure) in South Africa and Queensland, Australia

Abstract   In response to the recent establishment of a population of South African citrus thrips ( Scirtothrips aurantii Faure) in Australia, we used DNA sequence data to examine whether this population is distinct from populations in South Africa. Mitochondrial and internal transcribed spacer (ITS2) DNA from populations from different host plants in Australia and South Africa showed no clear separation between populations that was entirely congruent with host plant or country of origin. Analysis of the ITS2 data was confounded by the presence of multiple different copies of the spacer in some populations. Neither the presence or absence, nor the sequence of these copies was clearly diagnostic for any one population. These preliminary data suggest that the Australian population is not a distinct species or subspecies from the populations of S. aurantii on either citrus or Bryophyllum in South Africa.     

Note surProspaltella aurantii How. [Hym., Aphelinidae] parasite deQuadraspidiotus pyri Licht. dans les Alpes-Maritimes [Hom., Diaspidinae]

Summary American species ofProspaltella, P. aurantii How. unknown in Europe was studied in Alpes-Maritimes onQ. pyri living on fig-trees. In this country, host has two annual generations, and it overwinters like a second stage larvae, while in the same time, three generations occur for parasite. In the particular climatic conditions of this study, the efficiency of this parasite is complete before two years owing to the destruction of the male progeny.      

蚜害茶树挥发物组分变化的聚类分析

舒茶早(Camellia sinensis cv. ‘shuchazao’)是皖西南产区一种茶树品种。为研究茶蚜取食为害诱导的茶树挥发物释放特征,运用气相色谱-质谱联用技术,比较了健康茶梢和蚜害茶梢的挥发物组成和相对含量。结果显示,健康茶梢挥发物种类(16种)和相对含量较少,而蚜害茶梢挥发物种类(24种)较为丰富且相对...     

Corrections to Morris and Mound (2004) 'Molecular relationships between populations of South African citrus thrips (Scirtothrips aurantii Faure) in South Africa and Queensland, Australia'

Abstract  Contrary to the statements by Morris and Mound (2004), Scirtothrips aurantii were first found outside the quarantine facility on mother-of-million plants ( Bryophyllum spp.) sourced from the western suburbs of Brisbane and in January 2003 the distribution of the thrips in south-eastern Queensland was from at least 20 km south-east and 70 km west of the detection site. Some records in South Africa of thrips from mother-of-million plants may not refer to this species.     

Biology of Campoletis chlorideae (Uchida) (Hym., Ichneumonidae) developing in Bt-treated, Bt-resistant Helicoverpa armigera (Hübner) (Lep., Noctuidae) larvae

Abstract:  Life history parameters in two generations of endoparasitoid Campoletis chlorideae (Uchida) were examined using Bacillus thuringiensis (Bt)-resistant Helicoverpa armigera (Hübner) larvae feeding on B. thuringiensis toxin Cry1Ac. In the laboratory, Bt toxin was fed to Bt-resistant host larvae continuously in case of Bt treatment and only before or after the host larvae were parasitized in Bt–P and P–Bt treatments, respectively. C. chlorideae pupae developed faster in Bt treatment than non-Bt treatment. The shortened pupal stage duration was mainly because of the feeding of host larvae on Bt-diet before being parasitized. Body length of adult male C. chlorideae developed inside Bt-treated Bt-resistant (Bt–Bt) H. armigera larvae significantly decreased, especially in host larvae feeding on Bt-diet after being parasitized. However, survival, pupal mortality and adult longevity of C. chlorideae were almost unaffected in Bt-resistant H. armigera larvae feeding on Bt-toxin. Furthermore, Bt-treated host larvae had the same effect on the F₁ progeny of C. chlorideae as the previous generation, and there was no significant difference between generations. This experiment suggests that there is very limited effect on the life history parameters in two generations of C. chlorideae parasitizing Bt–Bt H. armigera larvae. But both generations of C. chlorideae are affected when Bt-resistant H. armigera larvae fed on Bt toxin for different durations.     

红圆蚧3种寄生蜂的寄生作用研究

研究了红圆蚧（Ａｏｎｉｄｉｅｌｌａａｕｒａｎｔｉｉ）３种寄生蜂（盾蚧长缨蚜小蜂Ｅｎｃａｒｓｉａｃｉｔｒｉ－ｎａ,岭南黄蚜小蜂Ａｐｈｙｔｉｓｌｉｎｇｎａｎｅｓｉｓ,印巴黄蚜小峰Ａｐｈｙｔｉｓｍｅｌｉｎｕｓ）在不同温度、不同寄生物密度、不同寄主密度组合下的功能反应．攻击率印巴蜂最大,岭南蜂次之,长缨蚜小蜂蜂最小．３种寄生蜂在不同温度下的攻击率都近于正态分布．建立了含干扰效应、温度效应的功能反应模型,两个模型的各参数均有明确的生物学意义,模拟效果好．