ABSTRACT
Cyamophiliopsis is a small genus restricted to the Palaearctic Region and associated with Spiraea spp. (Rosaceae). In the present work, following five species are recognized in China: C. pseudofasciata sp. nov., C. sarmatica, C. spinosa sp. nov., C. xinjiangana sp. nov. and C. zaisani. Cyamophiliopsis is diagnosed, redescribed in detail, and its phylogenetic relationships are discussed. All the species are described or redescribed, and the fifth instar immature of C. zaisani is described for the first time. Nomenclatorial problems are discussed concerning the Far East Russian Psylla spiraee which is transferred to Cyamophiliopsis as C. spiraee comb. nov.
Subject(s)
Hemiptera/classification , Spiraea/parasitology , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , China , Ecosystem , Female , Hemiptera/anatomy & histology , Hemiptera/genetics , Hemiptera/growth & development , Male , Organ Size , Phylogeny , Plant Diseases/parasitologyABSTRACT
BACKGROUND AND AIMS: Eversporting eudicots were sought to see if they behave like gymnosperms. Behaviour of eversporting gymnosperm chimeras indicates a single apical cell is present in SAM and it would be of interest to see if eudicot chimeras have the same behaviour. METHODS: Four eversporting spireas, the pineapple mint and the Silver King euonymus were inspected for the fate of the yellow (mutant)-green (wild type) chimeras. KEY RESULTS: As with gymnosperms, unstable eudicot chimeras in the four spireas, the pineapple mint and the Silver King euonymus became stable yellow about 80 % or more of the time and 20 % or less became stable green. CONCLUSIONS: The statistically significant preponderance of chimeric fates becoming all yellow suggests that a single apical cell resides in the yellow tunica. As with gymnosperms, descendent cells of the yellow replacement corpus cell eventually take over the corpus. Here is the first chimeric set of data to support the hypothesis of a one-celled meristem in eudicots rather than the traditional view of a muticellular meristem.
Subject(s)
Chimera/physiology , Euonymus/physiology , Mentha/physiology , Meristem/physiology , Spiraea/parasitology , Euonymus/cytology , Mentha/cytology , Meristem/cytology , Models, Biological , Spiraea/cytologyABSTRACT
Laboratory bioassays using leaf disks of apple dipped in test solutions of insecticides demonstrated that the apple aphid, Aphis pomi De Geer, and the spirea aphid, Aphis spiraecola Patch, differed significantly in susceptibility to a number of insecticides registered for control of aphids on apple (Malus spp.). Compared with A. pomi, A. spiraecola was approximately four- and three-fold less susceptible to pirimicarb and lambda-cyhalothrin, respectively, whereas there was little difference in response to dimethoate. Pymetrozine is thought to act on aphids primarily as a feeding inhibitor. Exposure of aphids to this material generated data that fit the probit model for only half the tested clones. However, the LC50 value for one clone of A. spiraecola was nearly 1,000 times higher than the value for one clone of A. pomi. Although the results from these trials did not indicate that either species had developed significant levels of resistance to the test materials, differences in LC50 levels of > 10-fold suggest insecticide tolerances and the possibility of control failures in the future. The demonstrated differences in susceptibility to insecticides between these two morphologically similar species also should be considered during the evaluation of new products for use on apple.