Say it with flowers

Amongst Chelsea Flower Show's champion blooms last month, a range of diseased specimens helped flag up key plant research goals.     

悬铃木方翅网蝽

<正>悬铃木方翅网蝽是半翅目（Hemiptera）网蝽科（Tingidae）昆虫,原产北美洲,20世纪60年代开始分别入侵欧洲,目前在欧洲、南美洲、澳洲和亚洲都有该虫危害,也是我国的重要入侵害虫。悬铃木方翅网蝽以成虫和若虫刺吸悬铃木（Platanus spp.）的叶片吸食汁液,致使叶片褪色,严重时叶片枯黄或提前脱落,影响光合作用导致树木生长衰弱并影响景观效果。本期封面照片于2015年9月30日拍摄于北京市朝阳区中国科学院奥运园区。     

Say hello to our little friends

A review of Invertebrate Zoology, edited by Donald T. Anderson. New York, Oxford University Press, 1999, 467 pp, $55.00 paperback.     

Leptinotarsa decemlineata Say sensitivity to ionizing radiation and pesticides

The effects of acute gamma-irradiation on the Colorado potato beetle (Leptinotarsa decemlineata Say) and sensitivity of insects, long time exposed on radioactively contaminated territories, to pesticides were studied. LD50 values of insects to ionizing radiation during the ontogenesis process was shown to increase (from 8 to 48 Gy). Differences were noted in the development rates of the natural population of beetles collected on agricultural lands with 137Cs contamination density of 0.05-1.2 MBq/m2, with the sensitivity to various pesticide groups being the same.     

The B-chromosome system of Tettigidea lateralis (Say)

Additional samples from a discrete population of the pygmy grasshopper Tettigidea lateralis, at the periphery of the species range, have shown that the frequency of the B-chromosomes has remained stable over a two year period (30-35%), and that there is not significant difference for this metric in the two sexes. The intensity of the preferential movement of the B with the X at male first meiotic division has also remained constant in time and homogenous in different individuals. Hence it is possible that this distortional effect plays a role in the equilibrium frequency of the B in the population. The B's may possess special adaptive properties under ecologically marginal conditions, since in a number of more 'central' demes they occur at much lowere frequencies (7-9%). -Unique morphological and/or behavioral variants of the standard B were encountered in addition to distinct cases of spontaneous fragmentation of A elements. The meiotic behavior and chromatic expression of these centric fragments provide evidence on the possible origin and evolution of supernumeraries. A modified. Giemsa staining technique has been used to identify regions of centromeric (C-) hererochromatin in mitotic and meiotic chromosomes. The C-banding pattern of the X and the allocyclically similar B is compared. It suggested that the B may have originated from the X by deletion of centromeric heterochromatin. This may have affected the centromere "strength" of the nascent B leading to its preferential movement with the X at anaphase I.