Syrrhopodon gaudichaudii Mont. is lectotypified and its key features are discussed. A neotype is designated for Syrrhopodon hawaiicus Müll.Hal. and the taxon is placed in synonymy with S. gaudichaudii. A key to the species of Syrrhopodon occurring in the Hawaiian Islands is provided. 相似文献
Some lacewings occur in winter as larvae and may be efficient predators, either under Mediterranean and mild temperate climates, or in cold greenhouses. They can be used to help controlling aphids in winter. Among chrysopids,Dichochrysa spp. overwinter as second and/or third instars; they show a low preying rate, both a moderate cold hardiness and a minimal activity threshold.Nineta pallida overwinters as first instars which have a very low activity threshold and a high cold hardiness. In hemerobiids — namely various spp. ofHemerobius, Wesmaelius, Micromus — hibernating larvae manifest prey searching and feeding activity at low temperatures. Minimal thermal thresholds may be very low in embryos and in larvae. Adults often are insensitive to photoperiod and so do not exhibit any diapause under short daylength conditions; they have a low minimal activity threshold for preying and reproducing. 相似文献
In this study we evaluated (1) the combined effects of simulated defoliation and below-ground herbivory (BGH) on the biomass
and nitrogen content of tillers and roots of the bunchgrass Muhlenbergia quadridentata and (2) the effect of defoliation on the survival of third-instar root-feeder larvae of Phyllophaga sp. The experiment was performed in a pine forest area at an altitude of 3200 m above sea level. The grass and the root-feeder
species were native and dominant in the understory and in the macroarthropod root-feeder communities, respectively. Plants
were established in pots in the field and were subjected to the following treatments in a factorial design: simulated defoliation
(three levels) and BGH (with or without root-feeder larvae) with ten replicates per treatment. Plants were defoliated three
times at 2-month intervals. The interaction between defoliation and root herbivory was significant for all components of plant
biomass. In every case, light defoliation with BGH decreased live above-ground, root and total plant biomass, and the number
of live tillers by more than 50% with respect to the same defoliation level without root-feeders. Plants apparently did not
compensate for the carbon drain by root-feeders when a high proportion of older leaves were not removed by defoliation. Plants
under heavy defoliation were not affected by the presence of root-feeders and showed a greater live/dead above-ground biomass
ratio than lightly defoliated and control plants. Defoliation and BGH did not change tiller and root N concentrations but
root herbivores did decrease live-tiller N content in lightly defoliated plants. Root-feeders but not defoliation decreased
the root/shoot ratio by 40% and the live/dead above-ground biomass ratio by 45% through increased tiller mortality. Survivorship
and final biomass of Phyllophaga sp. larvae were not affected by defoliation treatments during the 6-month study period.
Received: 17 May 1996 / Accepted: 1 November 1996 相似文献
Indiscriminate use of synthetic pesticides to control the pests causes negative effects on non-target organisms. Some of the chemicals under B and C categories are carcinogenic to humans. The present study was aimed to assess the antifeedant, larvicidal and pupicidal activities of Hygrophila schulii (syn. H. auriculata) and Blumea mollis against Helicoverpa armigera. Maximum antifeedant activity of 70.01% was observed in ethyl acetate extract of H. schulii at 5.0% concentration with LC50 value of 2.0%. B. mollis ethyl acetate extract at 5.0% concentration showed antifeedant activity of 35.40% with LC50 value of 8.38%. The data for antifeedant activity showed homogeneity of variances in Levene Statistics and normality in Shapiro–Wilk test. Ethyl acetate extract of H. schulii at 5.0% concentration showed 68.66% larvicidal activity with LC50 value of 2.97%. It also showed 73.33% pupicidal activity and was statistically significant from other treatments. No pupicidal activity was observed in ethyl acetate extract of B. mollis. All concentrations of ethyl acetate extract of H. schulii showed promising biological activities which differed statistically from other treatments. Ethyl acetate extract of H. schulii could be used to develop new botanical formulations to manage agricultural pests. 相似文献
A strict consensus tree based on chloroplast and nuclear sequences (rbcL, matK, trnL, FLint2) from 46 Amorphophallus species, two Pseudodracontium species and six outgroups is used to develop a hypothesis for the evolution of ornamentation and ectexine ultrastructure in the pollen of Amorphophallus. There are four main clades: an exclusively African, largely psilate clade (‘African clade’), an Asian, largely psilate clade (‘Asian psilate clade’) and an Asian, largely striate clade consisting of a mainly continental SE Asian clade (‘continental SE Asian striate clade’) and one centred in Malesia (‘Malesian striate clade’). Ultrastructure provides a valuable contribution towards understanding pollen ornamentation in Amorphophallus. Pollen with a thin psilate ectexine without dark granules might be plesiomorphic in Amorphophallus. Then the diverse striate type would be derived. Within both striate clades, reversals to the psilate type occur. Striate pollen with psilate caps, which is nested in the continental SE Asian striate clade, is a synapomorphy of Pseudodracontium. The fossulate type is also diverse, and its distribution in the tree indicates a polyphyletic origin. Areolate, echinate and verrucate ornamentation, occur in single species in the tree, but are found also in species not included in the molecular analysis. All three are heterogeneous and probably polyphyletic too. Reticulate, scabrate and striate/scabrate ornamentation are autapomorphies, of which the reticulate type and the striate/scabrate type may derive from psilate and striate ornamentation, respectively. Of the four main clades, the Asian psilate and African clade seem to be basal, while both striate clades might have evolved from the Asian psilate clade via a species like A. rhizomatosus. Dark granules evolved more than once, which might explain their diverse size, shape and distribution. 相似文献
The tiny echinoid Echinocyamus pusillus (O. F. Müller) is equipped with specialized external structures that suit it for a wide variety of environments. Special features include the ability to burrow in sediments of fine sand to shell gravel and to climb vertically.Specimens dredged off the west coast of Scotland were observed in aquaria and with the SEM. E. pusillus is characterized by three kinds of spines, and by two of pedicellariae. In contrast to sand dollars, the spines play a passive rôle in the feeding and burrowing operation, probably retaining a defensive nature as in the regular urchins. It is the podia that are chiefly involved in climbing, burrowing, righting, and probably feeding. Surface ciliary currents transport particles, but not to the mouth; they may have a respiratory or cleansing function. Experimental animals did not burrow in either very fine or very coarse sand, probably because a certain relationship exists between particle weight and podia size.E. pusillus shares behavioural and structural characteristics with regular and irregular urchins. It is not a true sand dollar, but may illustrate an evolutionary stage towards such a form. 相似文献
The compound Cu(Bromazepam) SO4 having been synthesized, its crystal structure shows distorted octahedral environment for the Copper(II) ion. Because of the long Cu-O(4) length (2.90 Å), we can consider that there is a semicoordinative interaction with the sulfate group acting as tridentate bridging ligand. The structure is a polymeric chain where dimeric units are linked by the oxygen (C-O(5)) atom of the Bromazepam carbonyl group. The drug consequently acts as a tridentate ligand in this compound. The magnetic results show a very weak antiferromagnetic interaction. 相似文献
Journal of Plant Growth Regulation - Among the different olive cultivars, ‘Shengeh’ olive trees have a poor yield, due to the incomplete flower bud development and increment of... 相似文献
The alginates extracted from ‘leaf’, ‘stem’ and entire thallus of Turbinaria conoides (J.Ag.) Kütz. were investigated for their viscosity and biochemical constituents namely, β-D-mannuronic acid (M-block}), α-L-guluronic acid (G-Block) and alternating sequences of β–D-mannuronic acid and α-L-guluronic acid (MG-block). Substantial seasonal variation was recorded with high yield of alginate during premonsoon. The yield of alginate was maximum in ‘leaf’ region. In contrast to this, viscosity and G-block were maximum in the ‘stem’ region. A significant positive correlation was observed between viscosity and G-block}. The ratio of guluronic: mannuronic acid was also assessed. Low levels of M/G ratio were recorded in the ‘stem’ region followed by ‘leaf’ and entire thallus. 相似文献
The complexes [Cu(samen)Cu(L)] and [Cu(samen)Ni(L)2] (Lbpy, phen) have been synthesized by the reaction of sodium N,N′-ethylenedisalicylamidatocuprate(II) pentahydrate (Na2- [Cu(samen)]·5H2O), a divalent metal ion, and 2,2′- dipyridyl or 1,10-phenanthroline. Cryomagnetic data for the CuCu complexes did not fit the Bleaney- Bowers equation; but the data did fit a modified Bleaney-Bowers equation with a large negative J and a significant negative θ, suggesting that a considerable magnetic interaction operates between essentially planar [Cu(samen)Cu(L)] molecules. The magnetisms of the CuNi complexes were well interpreted in terms of the susceptibility equation based on the Heisenberg model. An antiferromagnetic spin-exchange interaction (J= −13∼−14 cm−1) was suggested between the metal ions. 相似文献
Plot 82 is one of a hundred permanent plots that have been set up in Croatia for the purpose of long-term and continual investigations of ecosystems and their successions. It is located in the area of Karleuine Plase within the Plitvice Lakes National Park. Vegetation on the plot belongs to association Bromo-Plantaginetum mediae. The association develops in mountainous regions of continental Croatia within a wide altitude range, from 180–1300 m a.s.l. on shallow soil over pervious carbonate rocks. The floristic composition and phytocoenological characteristics of the association have been analyzed using the common methods of the phytocoenological school Zürich-Montpellier, on the basis of 17 phytocoenological records. In addition to floristic composition, some site characteristics have been analysed: soil moisture, calcium carbonate, phosphates, pH value, humus, cation exchange capacity and nitrogen mineralization on the site and in the laboratory. The results obtained are comparable with the data presented in the available phytocoenological and ecological literature. 相似文献