Biology and ecology of the Northern walkingstick,Diapheromera femorata (Say) (Phasmatodea: Diapheromerinae): A review

The northern walkingstick, Diapheromera femorata (Say), is the only stick insect of economic importance native to the United States. Young nymphs feed on various understory shrubs and trees whereas older nymphs and adults prefer oaks and cherries. Occasionally, field populations reach outbreak levels and cause complete tree defoliation. Widespread damage rarely occurs except those reported from Michigan (1930–1960), Wisconsin (1950–1960) and Arkansas and Oklahoma (1960–1975) where thousands to tens of thousands of hectares of trees were affected. The most recent infestations were detected in Arkansas, Maryland, and Pennsylvania with severe damage observed in localized areas. The morphology, life stages, host species, damage, biology, life history, natural enemies and management of this insect were reviewed. Host preference and insect predation were confirmed in Pennsylvania. Other notable stick insects in the United States and economically important species around the world are discussed to raise awareness about the ecological impacts of this understudied group of mostly nocturnal herbivores.     

Changes in cuticular transpiration rate and cuticular lipids of oat (Avena sativa) seedlings induced by water stress

Two cultivars of oat ( Avena sativa L. cvs Pendek and Stormogul II) were exposed to short periods of water-deficit stress on five consecutive days. The plants responded to the stress by decreasing their cuticular transpiration rate. After two stress periods the cuticular transpiration rate was reduced by 30% for Pendek and by 47% for Stormogul II, and after another three stress periods by 30% and 20%, respectively. These reductions were correlated neither to changes in the total amount of what is generally called epicuticular lipids, nor to changes in any of the major individual constituents of the epicuticular lipids (alkanes, free and esterified fatty acids or free primary alcohols). After removal of the epicuticular lipids the long chain free primary alcohols of the leaves were extracted and determined. The amount of these presumably intracuticular alcohols increased after stress and changed to shorter chain length. From these results it is concluded that the intra- as well as the epicuticular lipids must be taken into consideration when discussing leaf surface lipids as protecting agents against water loss.     

Chemotaxonomic investigations on the cuticular lipids of beetles

The cuticular lipids of nine species of beetles (Coleoptera) belonging to different superfamilies were analysed and found to consist of aliphatic hydrocarbons: n-alkanes, 2-, 3-, and other monomethylalkanes as well as dimethylalkanes and alkenes. The hydrocarbon pattern is qualitatively constant at the family level but varies from family to family and thus may be of use in the taxonomy of the insects.     

The cuticular scales of Lynx spiders (Araneae,Oxyopidae)

An examination of the cuticular scales of the lynx spiders Oxyopes aglossus, O. salticus, and Peucetia viridans using scanning electron microscopy revealed that scales in these spiders are morphologically distinct, yet similar to the scales of the jumping spiders Eris militaris and Hentzia mitrata. Like the cuticular scales of jumping spiders, the cuticular scales of lynx spiders exhibit morphological differentiation in regard to location of occurrence on the body, with scales near the eyes tending to have more numerous and larger spines on the superior surface than scales on other regions of the prosoma and opisthosoma. The functional significance of this differentiation in scale morphology is unknown. Sexual dimorphism and ontogenetic variation in scale morphology and color were observed in the genus Oxyopes,but not in Peucetia. In addition, the scales of P. viridans were distinguishable from the scales of Oxyopes spp. on the basis of the number of apical spines (1 in P. viridans instead of 3–7 in Oxyopesspp.) and on the presence of spines on the inferior surface (many in P. viridans and none in Oxyopesspp.). J. Morphol. 236:223-231, 1998. © 1998 Wiley-Liss, Inc.     

Composition of soluble cuticular lipids and water permeability of cuticular membranes from Citrus leaves

Water permeability and composition of soluble cuticular lipids of isolated cuticular membranes from leaves of Citrus aurantium L. were investigated for 3 successive years. The average water permeability coefficient determined using 169 cuticular membranes was 1.09·10^–7 cm s^–1 with a standard deviation of 0.78·10^–7 cm s^–1. There were no significant differences in water permeability between years. Cuticular membranes are characterized by a great variability in water permeability both within and between years. Both water permeability of individual membranes and variability between membranes are shown to be determined by soluble cuticular lipids contained within the cuticular membranes. The soluble cuticular lipids of Citrus leaves are composed of fatty acids, primary alcohols, esters, and hydrocarbons. They occur in amounts of 9.84 g cm^–2, which represents approx. 3% of the total mass of isolated cuticular membranes. The specific weight of cuticular membranes (365.4 g cm^–1) and total amount of soluble cuticular lipids did not vary significantly between years. Significant differences were observed for the amounts and composition of the constituent classes of lipids. Six homologues comprise 86% of the fatty acids (C₁₆; C₁₈; C₁₉; C₂₁; C₂₄; C₂₆), 83% of the primary alcohols (C₂₄; C₂₆; C₂₈; C₃₀; C₃₂; C₃₄) and 88% of the esters (C₃₆; C₃₈; C₄₀; C₄₁; C₄₂; C₄₄). Eleven major homologues amount only to 62% of the total hydrocarbons (C₁₆; C₁₇; C₁₈; C₂₀; C₂₆; C₂₇; C₂₉; C₃₀; C₃₁; C₃₂; C₃₃). Variability in the composition of soluble cuticular lipids between years was much smaller than variability of water permeability and, therefore, no relation between composition of soluble cuticular lipids and water permeability could be found. It is suggested that this may be due to the fact that the lipid composition observed represents the averages of 20 to 30 membranes analyzed so that differences between individual membranes may have been leveled out.Abbreviations CM cuticular membranes - MX polymer matrix - P_d permeability coefficient for diffusion of water - SCL soluble cuticular lipids - MES morpholinoethane sulphonic acid     

Communication by substratum vibration in the New Zealand tree weta, Hemideina femorata (Stenopelmatidae: Orthoptera)

The propagation of vibrations along the trunk and branches of a manuka tree, generated in response to the impact of a steel ball-bearing on the trunk, was measured with an accelerometer. The impact generated bending waves which travelled along the trunk and into the branches. Close to the point of impact the waveform was dominated by a damped oscillation at 518 Hz; as the bending wave progressed away from the point of impact the frequency of the dominant waveform increased. Beyond 200 cm the waveform became increasingly complex and a smallamplitude, high-frequency component progressively preceded the main wave. Branching points also induced complex waveforms, particularly where branches lay at a large angle to the trunk. Stridulating wetas also generated bending waves in the tree at a frequency close to that generated by the ball-bearing, as well as at a higher frequency of 7.5 kHz. The acoustic frequency of stridulation peaked at 0.8 and 3.4 kHz. Records from nerves serving the vibration-sensitive subgenual organs showed that wetas can detect oscillations at 1 kHz at 0.015ms^-2. A stridulating weta placed on the same log as a preparation in which the nerve from the subgenual organ was monitored generated oscillatins well above the threshold for detection.     

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。     

Critical temperature and changes in cuticular lipids in the rabbit tick, Haemaphysalis leporispalustris

The epicuticle in the rabbit tick, Haemaphysalis leporispalustris, appeared to be continuously changing, with deposition and removal of lipids during and after engorgement. These changes were accompanied by corresponding changes in critical temperature. The correlation between changes in critical temperature and composition of cuticular lipids (i.e. changes in the number, types, and relative concentration of lipid classes) suggested that changes in lipid composition could be responsible for changes in critical temperature.A hypothesis, alternative to those of Beament and Locke, is proposed to explain the phenomenon of critical temperature. At critical temperature, certain lipids probably change phase from crystal to liquid crystal, with hydrocarbon chains in a highly mobile condition. The hypothesis is not based on the presence of a water-proofing monolayer, and is supported by transition phenomena known in many lipids.     

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.     

The physical mechanism of cuticular color in Phelotrupes auratus (Coleoptera,Geotrupidae)

The physical mechanism of cuticular color in Phelotrupes auratus was investigated by polarized inspection, spectrophotometry and transmission electron microscopy (TEM). No color change was observed when viewed through either a right‐ or left‐handed circular polarizer. Further, under the incidence of linearly polarized light, the reflected intensity was markedly reduced when observed through a linear polarizer set with its optical axis perpendicular to that of the incident light. These results indicate that P. auratus does not possess any circularly polarizing reflectors. TEM observations revealed a total of ten or twelve thin layers (about 60–120 nm in thickness) of two types of material (electron‐dense and electron‐lucent) alternately stacked in the epicuticle. The thickness of the layers in the different color forms of the beetle corresponded to the peak wavelengths in the reflectance spectra, λmax(α), with thicker layers found in beetles exhibiting reflectance peaks at longer wavelengths and vice versa. Based on these findings, we concluded that all the cuticular color forms of P. auratus were not produced by a circularly polarizing reflector but by a simple multilayer reflector.     

Armored cuticular membranes in Brachycera (Insecta,Diptera)

This study describes and quantifies the ultrastructural design of some cuticular protuberances in the Diptera-Brachycera that appear to have a specialized mechanical function. The microsculpture of membranes in the transitional areas of prothorax-neck, neck-head, head-mouthparts, and in the articulations thorax-coxa and coxa-trochanter was investigated in eight species from six families (Tabanidae, Stratiomyidae, Calliphoridae, Syrphidae, Muscidae and Drosophilidae) by means of scanning electron microscopy. The membrane armatures are single or grouped microtrichia, often located on microplates in the flexible membrane. The different membranes were compared using the following details: microtrichia length, microplate length and width, the shortest distance between microplates, and the number of microtrichia per microplate. Five different types of microstructure were observed: (1) single short papilla-like microtrichia directly arising from the flexible membrane, (2) single elongated microtrichia directly arising from the flexible membrane, (3) single microtrichia located on small areas of the inflexible cuticle, here called microplates, (4) microtrichia groups located on the microplates, and (5) microplates without microtrichia in the flexible membrane. The study reveals the differences in the surface ultrastructure of membranes between different parts of body and between different taxa of flies. The prothorax-neck transition is less specialized in membrane armature as compared with the head-neck articulation, and especially with that of the head-proboscis. The head-proboscis transition has the most complex membrane armature of those species studied. The membrane of the basal joints of the legs has larger plates and a higher number of microtrichia per plate than that of the more distal joints. The complexity of the membrane armature depends on the dimensions of the animal: the smallest species have short ungrouped microtrichia or micropapillae, whereas large species have the highest degree of grouping, the longest microtrichia, and the largest microplates. Three main mechanical functions served by the different armored membranes are suggested, based on the specific characteristics of the microsculptural design: (1) fixation of the folds, (2) prevention of folding, and (3) determination of direction of folding. J. Morphol. 234:213–222, 1997. © 1997 Wiley-Liss, Inc.     

Epi- and intracuticular lipids and cuticular transpiration rates of primary leaves of eight barley (Hordeum vulgare) cultivars

The major constituents of the epi- and intracuticular lipids of primary leaves of 8 cultivars of barley ( Hordeum vulgare L.) have been studied together with cuticular transpiration rates. The total amount of analysed cuticular lipids ranged from 9.6 to 13.4 μg cm⁻² and was dominated by the epicuticular fraction, which made up 73–84% of the total. There were variations in the percentages of the analysed lipid classes, alkanes, esters, aldehydes, β-diketones and alcohols, between epi- and intracuticular lipids among individual cultivars, but no clear tendency in these variations, except for the aldehydes, was found. The epicuticular lipids were richer in aldehydes than the intracuticular lipids. The cuticular transpiration rates were poorly correlated with the levels or composition of epi-, intra- or total cuticular lipids. The cuticular transpiration rates were considerably altered as a response to a water stress treatment, but these changes could not be correlated with any changes in amount or composition of the cuticular lipids. From these results it is concluded that some property other than amount or composition of cuticular lipids is the most important in regulation of water diffusion through the cuticle.     

Evolution of the female cuticular organ in the asellota (crustacea,isopoda)

In an effort to understand the variation and probable origin of a female copulatory organ found in isopods of the asellote superfamily Janiroidea, the morphology of female reproductive structures among the Asellota was surveyed. Examples of four asellote superfamilies were studied using whole mount staining after potassium-hydroxide maceration or clearing with lactic acid. In contradiction to previous conclusions, the cuticular organ is shown to occur in the more primitive Asellota, although the position of its opening varies considerably. In the genera Asellus, and Stenetrium, Munna, and Santia, the cuticular organ originates adjacent to the oopore, and in the remaining janiroidean isopods, it is placed dorsally and usually anteriorly. This information permits a simple hypothesis explaining the origin of the cuticular organ: it was present in the proximate ancestor of the Asellota and evolved to the janiroidean condition by anterodorsal migration.     

The food-finding orientation mechanism of Biomphalaria glabrata (Say)

An experimental procedure involving the use of time-lapse cinematography for accurately recording pathways was used to investigate the responses of Biomphalaria glabrata (Say) to a stimulus source of plant chemicals. This allows a more detailed analysis of the orientation mechanism than is the case with the Y-maze method. Snails of this species, which are essentially herbivorous, respond either by klinotaxis or tropotaxis or both to a source of plant chemicals. It was not possible to demonstrate the involvement of kinesis in the orientation mechanism.     

Sex- and age-related changes in the biophysical properties of cuticular lipids of the housefly,Musca domestica

We examined the biophysical properties of cuticular lipids isolated from the housefly, Musca domestica. Melting temperatures (T_m) of surface lipids isolated from female houseflies decreased from 39.3 °C to 35.3 °C as the females attained sexual maturity and produced sex pheromone, whereas those prepared from males did not change with age. Lipids melted over a 10–25 °C temperature range, and their physical properties were a complex function of the properties of the component lipids. The T_m of total cuticular lipids was slightly below that of cuticular hydrocarbons (HC), the predominant lipid fraction. Hydrocarbons were further fractionated into saturated, unsaturated, and methyl-branched components. The order of decreasing T_m was total alkanes > total HCs > methyl-branched alkanes > alkenes. For 1-day-old flies, measured T_ms of hydrocarbons were 1.3–5.5 °C lower than T_ms calculated from a weighted average of T_ms for saturated and unsaturated components. For 4-day-old flies, calculated T_ms underestimated T_m by 11–14 °C. © 1995 Wiley-Liss, Inc.