我国跗线螨科2新种和7种国内新记录种（蜱螨亚纲：跗线螨科）

近年来，在国内土壤、植物及螨瘿内，采到大量的螨类标本，经制片和鉴定后，发现有一批跗线螨科的螨类，其中有２新种和７种国内新记录种。本文就新种的形态特征及其与近似种之间的鉴别特征作了描述。模式标本保存于沈阳农业大学植保系。     

Genital sex pheromones of ixodid ticks: 1. Evidence of occurrence in anterior reproductive tract of American dog tick,Dermacentor variabilis (Say) (Acari: Ixodidae)

The occurrence of a genital sex pheromone in the anterior reproductive tract of partially fed femaleDermacentor variabilis was demonstrated by extraction and bioassay. A new type of bioassay, the neutered female assay, was developed to test the potency of extracts or chemically defined fractions to stimulate males to copulate. Electrophysiological tests confirmed the ability of males to detect the pheromone with sensilla on their cheliceral digits. Males of bothD. variabilis andD. andersoni exhibited neuronal excitation when stimulated with extracts of theD. variabilis reproductive tissues. The pheromone, which is soluble in methanol, was fractionated and found to contain at least two fractions that stimulated copulation by sexually excited males. Evidently, the pheromone is a mixture of two or more compounds. Histologic, ultrastructural, and histochemical studies suggest the vestibular vagina as the site of genital sex pheromone occurrence, presumably from secretions of the surrounding lobular accessory gland. The identity of the compounds that comprise the pheromone remains unknown.Supported by grants AI10986 and AI10987 from the National Institute of Allergy and Infectious Diseases, National Institute of Health, U.S. Public Health Service, Bethesda, Maryland 20205.     

2,6-Dichlorophenol in the tickRhipicephalus appendiculatus Neumann

Certain olfactory cells of maleRhipicephalus appendiculatus Neumann are known to be stimulated by 2,6-dichlorophenol.R. appendiculatus has been reexamined for the presence of 2,6-dichlorophenol, and it has been detected in both male and female adults. Unfed females contain 12 ng/ tick, declining to 2 ng/tick after six days of feeding, while unfed males contain 2 ng/tick, falling to 0 after feeding. Larval tick extracts which are also known to stimulate 2,6-dichlorophenol-sensitive cells were examined and found to contain this phenol, whereasR. appendiculatus eggs did not contain this compound.     

Quantitative and temporal analysis of effects of twospotted spider mite (acari: Tetranychidae) female sex pheromone on male guarding behavior

Responses of male twospotted spider mite,Tetranychus urticae (Koch), to female sex pheromone were described by a glass slide bioassay and computerized pathway digitizer. Pheromone was extracted from quiescent deutonymphs and fractionated by HPLC, and responses of guarding males to each fraction, all fractions combined, unfractionated extract, and a hexane control were bioassayed for 6 min. Mean angular velocities, linear velocities, percent time stationary, and distance from the 3-mm-diameter treatment circle were calculated for each mite at 20-sec intervals and these behavioral parameters regressed on time. Analysis of variance of regression-equation intercepts showed that no differences in initial male angular velocities were observed among treatments, but initial linear velocities were greater in response to all fractions combined and to extract than to individual fractions, and greater in response to individual fractions than to the control. Angular velocities decreased and linear velocities increased more rapidly in response to individual fractions than to all fractions combined and extract, while males turned preferentially in one direction and were stationary (no displacement) more often in response to all-fraction combinations than to individual fractions and the control. Significant differences were observed among the parameter values elicited by individual fractions, suggesting that active fractions differed qualitatively. The described changes in movement parameters show that maleT. urticae response to presence of pheromone occurs almost immediately, and that multiple pheromonal components are necessary to elicit maximum male response. The overall effect of pheromonal components was to decrease the rate at which males moved away from the treatment cycle, thereby causing male arrestment.     

辽宁省卡盾螨属1新种

在整理已采集的标本时,经观察鉴定发现有派伦螨科（Parholaspidae）卡盾螨属（Krantzholaspis）1新种．本文就新种的形态特征作了描述,模式标本保存在沈阳农业大学植保系。     

Volatile Stimuli Related to Feeding Activity of Nonprey Caterpillars, Spodoptera exigua, Affect Olfactory Response of the Predatory Mite Phytoseiulus persimilis

The effect of volatiles related to feeding activity of nonprey caterpillars, Spodoptera exigua, on the olfactory response of the predatory mites Phytoseiulus persimilis was examined in a Y-tube olfactometer. At a low caterpillar density (20 caterpillars on 10 Lima bean leaves), the predators were significantly more attracted to volatiles from infested leaves on which the caterpillars and their products were present or from infested leaves from which the caterpillars and their products had been removed when compared to volatiles from uninfested leaves. The predators, however, significantly avoided odors from 20 caterpillars and their products (mainly feces) removed from bean leaves. In contrast, at a higher caterpillar density (100 caterpillars on 10 Lima bean leaves), the predators avoided volatiles from caterpillar-infested bean leaves. Volatiles from infested leaves from which the caterpillars and their products had been removed were not preferred over volatiles from uninfested leaves. Volatiles from feces collected from 100 caterpillars were strongly avoided by the predators, while the behavior of the predatory mites was not affected by volatiles from 100 caterpillars removed from a plant. The data show that carnivorous arthropods may avoid nonprofitable herbivores. This avoidance seems to result from an interference of volatiles from herbivore products with the attraction to herbivore-induced plant volatiles.     

Absence of farnesol in strawberry and hop foliage

The farnesol content of foliage has been proposed as an indicator of susceptibility to the two-spotted spider mite in various crops. The use of this chemical marker was investigated for strawberry and hop varieties. No farnesol was detectable in any of the varieties tested. The techniques necessary for analysis and identification of farnesol from foliage are discussed.     

Importance of lichen secondary products in food choice of two oribatid mites (Acari) in an alpine meadow ecosystem

In an alpine meadow ecosystem in the Swiss National Park, the lichensCetraria islandica andCladonia symphycarpa occur in small vegetation patches dominated byCarexfirma (Cyperaceae) andSesleria coerulea (Gramineae). Laboratory food-choice experiments with two oribatid mitesFuscozetes setosus andCarabodes intermedius show that the thallus structure and secondary products ofC. islandica are repellent factors against herbivorous mites. In contrast, secondary products ofC. symphycarpa may be an attractant for the mites.     

Leaf age affects composition of herbivore-induced synomones and attraction of predatory mites

We investigated the olfactory response of the predatory mitePhytoseiulus persimilis to cucumber leaves infested with prey, the herbivorous spider miteTetranychus urticae. The predators responded to volatiles from young rather than old infested cucumber leaves. GC-MS analysis of the head-space of spider mite-infested, artificially damaged and undamaged cucumber plants showed that herbivore-induced plant volatiles were present among the volatiles of both old and young infested cucumber leaves. The major components of the herbivore-induced plant volatiles were (3E)-4,8-dimethyl-1,3,7-nonatriene and (E)--ocimene: these compounds are known to attract the predatory mites. In addition, we found three oximes (2-methylbutanalO-methyloxime, 3-methylbutanalO-methyloxime, and an unknown oxime) in the headspace of both old and young infested cucumber leaves. 3-MethylbutanalO-methyloxime and the unknown oxime were much more abundant in the headspace of infested old cucumber leaves. The potential adaptive value of differential attractiveness of cucumber plant leaves of different age is discussed.     

Influence of monoterpene vapors on spruce spider mite,Oligonychus ununguis,adult females

Adult female spruce spider mite,Oligonychus ununguis (Jacobi), were exposed to various concentrations of four host conifer monoterpene vapors (limonene,-pinene,-pinene, and ³-carene) for 24 hr to determine the lethal and sublethal effects. All four compounds were toxic to the mites. Further, at concentrations below the calculated LC₅₀s, all four compounds decreased oviposition by the mites and three of the compounds (limonene,-pinene, and-pinene) influenced movement. WhereasO. ununguis populations may not normally be exposed to high concentrations of host monoterpenes, trees continuously emit some monoterpene vapors, and when trees are damaged or under stress, oleoresin may accumulate at points on the external surface of tree tissues thereby exposing mites to the influence of monoterpene vapors.