Paternal inheritance in mealybugs (Hemiptera: Coccoidea: Pseudococcidae)

Mealybugs have a haplodiploid reproduction system, with paternal genome elimination (PGE); the males are diploid soon after fertilization, but during embryogenesis, the male paternal set of chromosomes becomes heterochromatic (HC) and therefore inactive. Previous studies have suggested that paternal genes can be passed on from mealybug males to their sons, but not necessarily by any son, to the next generation. We employed crosses between two mealybug species—Planococcus ficus (Signoret) and Planococcus citri (Risso)—and between two populations of P. ficus, which differ in their mode of pheromone attraction, in order to demonstrate paternal inheritance from males to F2 through F1 male hybrids. Two traits were monitored through three generations: mode of male pheromone attraction (pherotype) and sequences of the internal transcribed spacer 2 (ITS2) gene segment (genotype). Our results demonstrate that paternal inheritance in mealybugs can occur from males to their F2 offspring, through F1 males (paternal line). F2 backcrossed hybrid males expressed paternal pherotypes and ITS2 genotypes although their mother originated through a maternal population. Further results revealed other, hitherto unknown, aspects of inheritance in mealybugs, such as that hybridization between the two species caused absence of paternal traits in F2 hybrid females produced by F1 hybrid females. Furthermore, hybridization between the two species raised the question of whether unattracted males have any role in the interactions between P. ficus and P. citri.     

Mating behavior of a flower-visiting longhorn beetle Zorion guttigerum (Westwood) (Coleoptera: Cerambycidae: Cerambycinae)

Long-range sex pheromones have been demonstrated for several cerambycid beetle species. Our field study on the mating behavior of Zorion guttigerum, on the basis of its temporal and spatial distributions on mating and feeding sites (flowers), and longevity, however, suggests that such pheromones are not used by this species. Plant characteristics rather than long-range sex pheromones may play an important role in bringing both sexes together. Adult activities on flowers occur exclusively during the day with two peaks, one around midday and the other in the late afternoon. Overall operational sex ratio is male-biased (1 :1.5 ) but it becomes very highly male-biased (1 :9 ) when mating and feeding activities decrease to the minimum in mid-afternoon, suggesting that females leave flowers to oviposit during that period of time. For cerambycid species whose females oviposit alone, and in which mating and oviposition occur on different plants or different plant parts, the operational sex ratio appears to vary significantly over time on the mating sites. The number and duration of pair-bondings also vary over time for Z. guttigerum. Fewer and shorter pair-bondings in the morning may suggest a strong sexual selection process. After 2 h of selection, both sexes tend to engage in longer pair-bondings and mate more times before females leave the mating sites in mid-afternoon. Details of the mating behavior are described here.     

The citrus pyslla, Trioza erytreae (Del Guercio) (hemiptera: Triozidae): A review

The literature on the citrus psylla, Trioza erytreae, published since 1897, is reviewed. The citrus psylla is an important vector of the greening disease of citrus. The stages of development and life history are discussed. Of the factors that influence population size, flushing of the host plants and high saturation deficits are the most important. Methods of population monitoring and control are summarised. The main means of reducing vector numbers and therefore the spread of greening disease, are resistance of citrus trees to greening disease, restricting citrus growing to hot, low-lying regions of the country, and strict vector control in nurseries. Requirements for further research, are discussed.     

Developmental abnormalities in Glomeris marginata (Villers 1789) (Myriapoda: Diplopoda): implications for body axis determination in a myriapod

Abnormally developing embryos (ADEs) of the common pill millipede Glomeris marginata have been investigated by means of nuclear staining and mRNA in situ hybridization. It showed that all ADEs represent cases of Duplicitas posterior, which means that the posterior body pole is duplicated. The severity of the duplication ranges from duplicated posterior trunk segments in one specimen to an almost completely duplicated specimen that only shares the very anterior head region. Remarkably, none of the encountered ADEs represents a case of Duplicitas anterior (duplicated anterior pole) or a case of Duplicitas cruciata (cruciate duplication with two anterior and two posterior poles). This observation is discussed in the light of earlier reports on G. marginata ADEs that claim to have found these abnormalities. The lack of any other axial abnormality aside from D. posterior implies that early axis determination in G. marginata, and possibly myriapods in general, underlies the developmental mechanisms that prevent the formation of any other type of axial duplication. It is proposed that the formation of D. posterior-type embryos could be caused by the formation of two instead of only one posterior cumulus early during development.     

8:2氟调聚醇(8:2FTOH)厌氧生物降解特性

为了阐明厌氧环境下全氟羧酸（PFCAs）等全氟化合物的迁移归趋,研究了8：2氟调聚醇（8：2FTOH）的厌氧降解性能.结果表明,取自市政污水处理厂的污泥在厌氧条件下可还原降解8：2FTOH,并生成氟离子、全氟类和多氟类降解产物,且降解过程可采用双指数衰减模型拟合.在为期120d的培养中,8：2FTOH的摩尔降解率高达（93.2±0.9）%;摩尔回收率则随着培养时间的增加有下降的趋势,由培养初期（1d）的（97.5±5.1）%下降至末期（120d）的（68.9±4.0）%,这说明在培养后期可能产生了未知的降解产物或生成了未知的挥发性产物.8：2不饱和氟调聚酸（8：2FTUA）和全氟辛酸（PFOA）分别是摩尔产率最高的多氟类和全氟类降解产物,分别介于（6.94±0.10）%~（24.2±1.5）%和（2.67±0.22）%~（14.9±1.0）%的范围内.多氟类降解产物的摩尔产率随培养时间的增加先增加后降低,而全氟类降解产物的摩尔产率则随培养时间的增加持续增加,这说明其可能分别为中间降解产物和最终降解产物.     

Sr_(10)Bi_6O_(24-y)的制备及其光催化活性研究

以S(rNO3)2和Bi2O3为原料,采用高温固相法在900℃煅烧2h合成了纯度较高、钙钛矿型Sr10Bi6O24-y。使用X射线衍射、扫描电子显微镜和X射线光电子能谱对Sr10Bi6O24-y进行了表征。实验结果表明,Sr10Bi6O24-y光催化具有较强的光催化活性,其降解酸性红G的反应动力学符合一级反应。     

Food caching in orb-web spiders (Araneae: Araneoidea)

Caching or storing surplus prey may reduce the risk of starvation during periods of food deprivation. While this behaviour occurs in a variety of birds and mammals, it is infrequent among invertebrates. However, golden orb-web spiders, Nephila edulis, incorporate a prey cache in their relatively permanent web, which they feed on during periods of food shortage. Heavier spiders significantly reduced weight loss if they were able to access a cache, but lost weight if the cache was removed. The presence or absence of stored prey had no effect on the weight loss of lighter spiders. Furthermore, N. edulis always attacked new prey, irrespective of the number of unprocessed prey in the web. In contrast, females of Argiope keyserlingi, who build a new web every day and do not cache prey, attacked fewer new prey items if some had already been caught. Thus, a necessary preadaptation to the evolution of prey caching in orb-web spiders may be a durable or permanent web, such as that constructed by Nephila.     

Molecular phylogeny of metazoa (animals): Monophyletic origin

Dedicated to Prof. Dr. H. Risler and Prof. Dr. Dr. h. c. R. K Zahn