Control ofThrips tabaci [Thysanoptera: Thripidae] on glasshouse cucumber using large introductions of predatory mitesAmblyseius barkeri [Acarina: Phytoseiidae]

The phytoseiid miteAmblyseius barkeri (Hughes) (=Amblyseius mckenziei Sch. & Pr.) was used for biological control ofThrips tabaci Lind. in 7 commercial glasshouses with cucumber (a total of 5780 m²). Predatory mites were introduced 3–4 times in densities ranging from 40 to 300/m² at each release. In 6 of the 7 glasshouses, control of thrips was satisfactory throughout the growing season. Thrips densities were kept below 15 individuals per leaf. In 1 glasshouse, thrips damage was seen on the fruits at densities of 25 thrips per leaf, but the thrips population was quickly reduced and remained at low densities for the next 3 months.      

Predation ofOligonychus pratensis [Aca.: Tetranychidae] byPhytoseiulus persimilis andAmblyseius californicus [Aca.: Phytoseiidae] under controlled laboratory conditions

The predator efficacy ofPhytoseiulus persimilis Athias-Henriot andAmblyseius californicus (McGregor) (Acarina: Phytoseiidae) when feeding on the Banks grass mite (BGM),Oligonychus pratensis (Banks) (Tetranychidae), was compared under controlled laboratory conditions. Predation byP. persimilis andA. californicus reduced the BGM densities by 60% and 28%, respectively. In general, phytoseiids preferentially fed upon the more abundant instars. Ovipositional rates forP. persimilis while feeding on BGM approximated rates when feeding onTetranychus spp. The use of a trade name is not an endorsement by Texas A&M University.     

Biological studies including population growth parameters of the predatory miteAmblyseius barkeri [Acarina.: Phytoseiidae] at 25°C in the laboratory

Amblyseius barkeri (Hughes) fed onThrips tabaci (Lind.) at 25°C showed an average duration of 2.2, 0.8 and 3.2 days for the egg, larval and nymphal stages, with mortalities at 1.0, 1.0 and 3.1%, respectively. Females represented 63% of the population and required multiple matings for optimal fertility. The oviposition period was 20.3 days and the average oviposition rate 2.3 eggs per day. The intrinsic rate of increase was 0.22 per day. The expected life span was 29.6 days for ♀♀ and 27.4 days for ♂♂.A. barkeri ♂♂ and ♀♀ both consumed 3.3 nymphs of thrips per day (mean value for the feeding stages). The larva does not take up food. In the absence of thripsA. barkeri was able to consume two-spotted spider mites,Tetranychus urticae (Koch), and their eggs, adult broad mites,Polyphagotarsonemus latus (Banks), and pollen of various plants. Cannibalism was observed when food was lacking. Certain morphological features, egglaying, mating and predatory behaviour are described.      

Biological control of thrips [Thysanoptera: Thripidae] on greenhouse cucumber byAmblyseius cucumeris

The predatory miteAmblyseius cucumeris (Oudemans) [Acarina: Phytoseiidae] was evaluated as a biological control forThrips tabaci Lindeman andFrankliniella occidentalis (Pergande) [Thysanoptera: Thripidae] on greenhouse grown seedless cucumber.A. cucumeris spread throughout the greenhouses and provided control of both species of thrips.A. cucumeris adults persisted on plants for 7 weeks in the virtual absence of prey, and increased numerically in response to increases in prey population. On the basis of these resultsA. cucumeris is recommended as a useful biological control forT. tabaci andF. occidentalis on greenhouse cucumber. Publication No. 361, Agassiz Research Station, Agriculture Canada, Agassiz, B.C. Canada VOM 1AO.     

纽氏钝绥螨、尼氏钝绥螨及其猎物—桔全爪螨生态学特性的比较研究

本文从天敌与猎物的种群内禀增长力,天敌对猎物不同密度的功能反应及数值反应三个方面来评价和比较纽氏钝绥螨、尼氏钝绥螨时其猎物——枯全爪螨的控制作用。在五种温度下,两种捕食螨的种群内禀增长力都大于桔全爪螨。它们对猎物的功能反应属HollingⅡ型。尼氏钝绥螨的捕食量大于纽氏钝绥螨,在25℃时两种捕食螨捕食量最大,应用Rogers的模型能较好地对试验结果进行模拟。尼氏钝绥螨对桔全爪不同虫态的取食不存在选择效应,纽氏钝绥螨则嗜食若螨和幼螨。两种捕食螨对桔全爪螨的数值反应表明,仅供给桔全爪螨雌成螨作为食物,对两种捕食螨都不利,尤其对尼氏钝绥螨更为明显。综上所述,两种捕食螨能比较有效地控制桔全爪螨种群,当猎物密度较高时,尼氏钝绥螨控制效果优于纽氏钝绥螨,但纽氏钝绥螨控制效果优于纽氏钝绥螨,但纽氏钝绥螨田间种群数量比尼氏钝绥螨稳定。柑桔园中存在其它补充食物时对这两种捕食敌有利。     

Selection for non-diapause inAmblyseius cucumeris andAmblyseius barkeri and exploration of the effectiveness of selected strains for thrips control

In Europe and North America the western flower thrips,Frankliniella occidentalis, is an important pest in various greenhouse crops, such as sweet pepper and cucumber. Two species of predatory mite are commercially applied for biological control of this pest:Amblyseius cucumeris andA. barkeri. Thrips control is generally successful from March onwards. During winter, however, thrips control by these predatory mites is less effective. An important reason for this is that the commercially applied strains of both mite species enter reproductive diapause under short-day photoperiods, whereas the western flower thrips does not enter diapause. In this paper we report on selection experiments for non-diapause in strains of both mite species, aimed at obtaining predators that do not enter diapause under light- and temperature conditions prevailing in winter. Additional experiments were done to estimate the potential of the selected lines as control agents ofF. occidentalis. Selection for non-diapause proved highly successful in both predatory mite species. In a New Zealand strain ofA. cucumeris diapause incidence decreased from 41% to 0% in about ten generations; in a Dutch strain ofA. barkeri diapause incidence decreased from 67% to 0% in about six generations. Furthermore, selection for non-diapause had no influence on predator performance, measured as predation rate and oviposition rate on a diet of first instar thirps larvae. Rates of predation and oviposition were the same for selected and unselected lines in both species; rates of predation and oviposition were higher forA. cucumeris than forA. barkeri. After 18 months under non-diapause conditions, no less than 92% of a sample of the selected non-diapause line ofA. cucumeris did not enter diapause when tested under diapause-inducing conditions. This indicates that ‘non-diapause’ is a stable trait in these predatory mites. Finally, a small-scale greenhouse experiment in a sweet pepper crop showed that the selected non-diapause line ofA. cucumeris established successfully under diapause-inducing short-day conditions.     

广西十万大山植绥螨三新种（蜱螨亚纲：植绥螨科）

本文记述了从广西十万大山采用的植绥螨科３新种：广西盲走螨,似沿海盲走螨和三角钝绥螨。本文描述中的测量长度单位为μｍ,模式标本保存于广东省昆虫研究所。     

青海甘肃植绥螨五新种（蜱螨亚纲：植绥螨科）

本文报道采自青海、甘肃植绥螨科5新种:青海钝绥螨Amblyseius qinghaiensis sp.nov.,长中毛钝绥螨A.longimedius sp.nov.,大通盲走螨Typhlodromus datongensis sp.nov.,张掖盲走螨T.zhangyensis sp.nov.,和冬盲走螨T.hibernus sp.nov.。全部标本保存在北京市农林科学院。     

Toxicity of a number of pesticides to strains ofTyphlodromus pyri andAmblyseius andersoni (Acari: Phytoseiidae)

Side effects of ten pesticides used in orchards and vineyards were tested with a laboratory method on several Dutch and Italian strains of the predatory mitesTyphlodromus pyri Scheuten andAmblyseius andersoni (Chant). Resistant and susceptible strains of both species were studied. Results showed that a test which evaluates mortality of various developmental stages and fecundity of adult females is better than one that measures only survival of adult females. A definite resistance to certain pesticides was found in ItalianT. pyri andA. andersoni. The level of resistance to parathion, azinphos-methyl and carbaryl was particularly high in some strains ofA. andersoni. The high level of resistance to certain pesticides was often associated with a marked reduction in fecundity.      

A reappraisal of Athoracophorus bitentaculatus,with comments on the validity of genus Reflectopallium (Gastropoda: Athoracophoridae)

Abstract

The slug Athoracophorus bitentaculatus (Quoy & Gaimard, 1832) is redescribed from material collected in the northern third of the North Island of New Zealand. Its anatomy is described and figured, local variation in the condition of the lateral grooves and mantle is figured, and supplementary information on its biology and distribution is given. Its identity and taxonomy are discussed in the context of earlier work on the species. Evidence is presented for the reduction of Reflectopallium Burton, 1963 to synonymy with Athoracophorus Gould, 1852. A revised key to New Zealand and subantarctic genera of Athoracophoridae is given.