Middle Of September Research Articles

영남지방 지역 및 지대별 담배거세미나방과 파밤나방 성충의 발생소장

Seasonal occurrences of tobacco cutworm, Spodoptera litura and beet armyworm, Spodoptera exigua were observed using sex pheromone traps at different locations and climatic regions in Yeongnam district. In Gyeongnam province, S. litura male adults kept occur from mid or late March to mid or late November Whereas in Gyeongbuk province, S. litura occurred from mid or late April to early or mid November with exception at Uljin where it was late May to late October. According to the climatic regions, the peak occurrence of S. litura was middle September at the southern coast region, late August at the inland and the basin region, middle August at the inland mountainous region, and early September at the eastern middle coast region. The occurrence rate of S. litura was the highest at Jinju with 20.0% and the lowest at Changyeong with 8.6% in Cyeongnam province, while it was the highest at Sungju with 3.3% and the lowest at Uljin with 0.8% in Gyeongbuk province. In accordance with the climatic regions, the occurrence rate of S. litura was the highest at the inland region with 43.7%, and followed by the southern coast region (36.3%), the basin region (8.4%) and the inland mountainous region (7.0%), and was the lowest at the eastern middle coast legion with 4.6%. On the other hand, S. exigua occurred from early March to middle November with the exception of the eastern middle coast region including Pohang, Yeongdeog and U]ien in Cyeongbuk province where it occurred from mfd April to middle November. The peak occurrence of s. exigua was early August at the inland region, the basin region and the inland mountainous region, and was late of August at the southern coast region and the eastern middle coast region. The occurrence of S. exigua was the highest at Changyeong with 1.6% and the lowest at Busan with 0.4% in Gyeongnam province, while it was the highest at Sungju with 37.2% and the lowest at Uljin with 2.7% in Gyeongbuk province. The climatic regional occurrence rate of S. exigua was the highest at the basin region with 54.3%, and followed by the inland mountainous region (29.9%), the eastern middle coast region (9.3%) and the inland (3.9%), and was the lowest at the southern coast region with 2.6%. As a whole, S. litura occurred more in Gyeongnam province than Cyeongbuk province, while S. exigua occurred more in Gyeongbuk province than Gyeongnam province. According to the regions grouped by climatic differences, the occurrence of S. litura and S. exigua was the highest at the inland region in Gyeongnam province and at the basin region in Gyeongbuk province. The total number of S. litura captured by sex pheromone trap was 2.4 times higher than that of S. exigua. However, the first occurring time and the peak occurrence of S. exigua were slightly earlier than those of S. litura.

Physical factors influencing Muscidae and Pimelia sp. (Tenebrionidae) infestation of Loggerhead turtle (Caretta caretta) nests on Dalaman Beach, Turkey

The physical factors affecting the infestation of individual loggerhead turtle (Caretta caretta) nests by Muscidae and Pimelia sp. were determined in the 2002 and 2003 hatching seasons on Dalaman Beach, Turkey. The data were collected from the middle of July to the middle of September in both years. The most significant factor, by t‐test, for Pimelia sp., was the distance of the nest from vegetation (P<0.001), and the most significant factor for Muscidae was the depth from the surface to the egg chamber (P<0.001). The distances of nests from vegetation were found to be significant factors for both Pimelia sp. and Muscidae. For conservation, it should be noted that the relocation of nests from the water's edge to further inland or to a hatchery site closer to vegetation may increase insect infestation and reduce hatching success.

Produtividade de grãos e exportação de nutrientes de cultivares de arroz irrigadas por aspersão em conseqüência da época de semeadura

No sistema irrigado por aspersão, o uso de cultivares e épocas adequadas de semeadura podem possibilitar a obtenção de altos níveis de produtividade do arroz de terras altas. No entanto, são escassas as informações sobre a exportação de nutrientes pelos grãos dessa cultura nesse sistema de produção. Este trabalho objetivou avaliar o efeito da época de semeadura na produtividade e exportação de nutrientes pelos grãos de cultivares de arroz de terras altas (IAC 201, IAC 202, Carajás, CNA 7800 e CNA 7801), irrigados por aspersão. Os experimentos foram desenvolvidos nos anos agrícolas de 1995/1996 e 1996/1997, em Latossolo Vermelho distrófico, em Selvíria (MS). As semeaduras foram realizadas no início da segunda quinzena de setembro, outubro, novembro, dezembro, janeiro e fevereiro, de cada ano. Foi utilizado o delineamento de blocos ao acaso, em esquema de parcela subdividida, com quatro repetições. A época de semeadura influenciou a produtividade de grãos e exportação de nutrientes pelos grãos. A semeadura realizada em novembro proporcionou maior exportação de nutrientes por promover produtividades mais elevadas. Em épocas de semeadura antecipada (setembro), com a cultivar Carajás, a produtividade e a exportação de nutrientes foram superiores às demais; já nas semeaduras de outubro a dezembro, a cultivar CNA 7801 se destacou. No sistema irrigado por aspersão, é possível semeadura em fevereiro com produtividade acima 3.900 kg ha-1 utilizando as cultivares IAC 201 e Carajás.

Abundance of grey seals in Icelandic waters, based on trends of pup-counts from aerial surveys

Grey seals (Halichoerus grypus Fabricius, 1791) are distributed all around the Icelandic coast. The majority of the population breeds on the west- and northwest shores, with a second high density in the breeding distribution on the southeast coast of Iceland. During the last 5 decades the Icelandic grey seals have dispersed from the west- to the northwest-, the north- and the northeast-coast. The breeding period occurs from the middle of September to early November, with a maximum in mid October. The time of peak pupping shows some variation, beginning earlier along the west coast and later in the north and southeast. Seven aerial surveys to estimate pup production in Iceland were flown during October to November during the period from 1980 to 2004. Pup counts of the Icelandic grey seal, at all breeding sites combined, have been decreasing annually by about 3% (±1% s.e.), during the period 1982-2002. During the period 1990-2002, this downward trend doubled to about 6% annually. The abundance of the grey seal around Iceland in the year 2002 was estimated to be 4,100 to 5,900 animals. This is higher than estimates of around 2,000 animals during the 1960s, but much less than the estimated population of 8,000 to 11,500 in 1982.

The Analysis of the Content and Chemical Composition of Essential Oil in the Leaves of Sage (Salvia officinalis L.) cv. ‘Bona’ in the Second Year of Cultivation

The research was conducted in the years 1997–1999. The original material for the research was sage leaves (Salvia offcinalis L.) cv. ‘Bona’, which came from a two-year plantation. A three-year research study proved that the percentage amount of oil in the raw material of sage was related to the harvest time of the crop. It was higher in leaves coming from the second term of crop (middle of September) and ranged from 1.6% to 1.8%. The percentage amount of oil in sage leaves collected in May (frst crop) was lower and fluctuated between 0.8% and 1.4%. Qualitative and quantitative analyses of distilled oils were made using GC and GC/MS. The analyses demonstrated the presence of 31 components in the oil. We found that the oil components varied quantitatively, depending on the harvest time. The main components occurring in sage oil were α-thujone (18.4–27.9%), β-thujone (8.0–15.0%), 1,8-cineole (4.0–14.4%) and camphor (11.7–27.0%).

Population dynamics of Chaetocnema tibialis Illiger and Phyllotreta vittula (Redtenbacher) on the weed Amaranthus retroflexus L. and cultivated Amaranthus caudatus L.

In 1995–1997, the population dynamics of the flea beetles &lt;i&gt;Chaetocnema tibialis and &lt;i&gt;Phyllotreta vittula&lt;/i&gt;, associated with &lt;i&gt;Amaranthus retroflexus&lt;/i&gt; (wild species) and &lt;i&gt;Amaranthus caudatus&lt;/i&gt; (cultivated species), were studied at the locality Nitra-Malanta (48°19'N, 18°09'E) in south-western Slovakia. On both plant species, the number of &lt;i&gt;C. tibialis&lt;/i&gt; adults was usually very low until the beginning of July. During July the number of &lt;i&gt;C. tibialis&lt;/i&gt; increased, but sooner on cultivated amaranth. An increased number of &lt;i&gt;C. tibialis&lt;/i&gt; adults was observed on both amaranth species until the middle of September. The results showed that amaranth plants are a very important reservoir of &lt;i&gt;C. tibialis&lt;/i&gt; during summer. &lt;i&gt;P. vittula&lt;/i&gt; was a common flea beetle on amaranth during the whole summer, but its numbers never exceeded more than 10 adults per 25 plants. Low temperatures in winter had a negative effect on populations of &lt;i&gt;C. tibialis&lt;/i&gt; on both amaranth species and also on populations of &lt;i&gt;P. vittula&lt;/i&gt; on &lt;i&gt;A. retroflexus&lt;/i&gt;. The lower the precipitation was in July, the higher were the populations of &lt;i&gt;C. tibialis&lt;/i&gt; on both amaranth species and the populations of &lt;i&gt;P. vittula&lt;/i&gt; on &lt;i&gt;A. retroflexus&lt;/i&gt;.

Patterns of ctenophore populations in the northeastern part of the Black Sea in 2005

Particular features of the distribution and the dynamics of populations of the ctenophores Mnemiopsis leidyi, Beroe ovata, and Pleurobrachia pileus in the Gelendzhik area in 2005 are studied and compared to their population structure in the previous years. The intensive evolution of the Rim Current, the suppression of the transversal eddy transfer, and other hydrological features of 2005 resulted in an unusually early mass appearance of Beroe in the plankton off the shores of the Caucasus, its prolonged and intensive breeding, and high biomass. This, in turn, caused the suppression of the population of Mnemiopsis, whose abundance and pressure on the mesoplankton in August–September turned out to be several times smaller than in the previous year, when Beroe appeared only in the middle of September.

Optimum Harvesting Time of Four Mentha Species in Northern Finland

The effect of harvesting time on the quality and quantity of mint oils produced from plants grown in short summer and long-day climatic conditions of northern Finland (64°40′N and 25°E) was examined to determine what growth stage is best for cutting to obtain the highest possible biomass (herb yield), oil content and suitable oil composition. In the field experiment, plants cut only once at the end of August were compared with those of two cuttings. The first cut was at the beginning of August and the second cut in the middle of September. The mint species were Mentha piperita L. “peppermint”, M. canadensis “cornmint”, M. canadensis “Sakhalin mint” and M. spicata L. “spearmint.”

Asama Eruption of 2004 : Field Investigations and Risk Communication through an Internet Forum

Asama Volcano repeatedly erupted in 2004. Six major eruptions were identified, each of which discharged more than 10, 000 tons of ash, lapilli, and bombs from the summit crater. Five were single Vulcanian explosions including the first eruption on 1 September. They are common in Asama, as thousands of Vulcanian explosions occurred in the last century. However, the series of eruptions from 14 to 18 September was unusual for Asama. It was an ash eruption. An eruption plume of a few kilometers high intermittently rose above the summit crater for the first two days. It was sustained by the morning of 16 September. From the plume, sand-sized micropumice and free-crystals continuously showered down at Karuizawa, 10 km SE from the source. It was observed for the first time since the notorious 1783 eruption that the juvenile was dominant among fallout. This makes a remarkable contrast to preexistent material by Vulcanian explosions. In the evening, a small amount of ash (1-0.1 g/m2) reached as far as Tokyo, 150 km from source. Incandescent bombs ejected from the summit crater were seen from the slopes until midnight. The maximum range traveled by the bombs in 2004 was 2.2 km. It was measured at the NW flank for the 1 September explosion and also at the W flank for the 23 September explosion. In total, 3.7 × 108 kg of ash, lapilli, and bombs were ejected from the crater in 2004. This is no more than 8 % of new lava, which was emplaced on the crater floor in the middle of September. An Internet forum is a useful tool for risk communication during a volcanic crisis. Thousands of messages were posted on three boards of a forum during the 2004 crisis. They described detonations, ash fallout, and other unrests of Asama. Some of them were posted ahead of not only television news but also official Volcano Information issued by Japan Meteorological Agency. Although Internet forums are very helpful for volcano risk communication, readers must use caution to distinguish the false from the true.

両側網膜芽細胞腫既往を伴った鼻腔原発平滑筋肉腫例

We report a case of leiomyosarcoma in the nasal cavity of a patient with a history of bilateral retinoblastoma.Leiomyosarcomas account for 7% of all soft tissue sarcomas, and they usually develop in smooth-muscle-rich organs such as the uterus, urinary bladder, and gastrointestinal tract, but they also occur at other sites, including the extremities, retroperitoneal space, mesenteries, kidneys, liver, orbits, pancreas, spleen, femoral veins, and heart. Most malignant tumors of the nose and the paranasal sinuses are carcinomas, and the incidence of sarcoma is low; leiomyosarcoma is even rare among the sarcomas in these regions. To the best of our knowledge, only 27 cases, including our own, have been reported in Japan.The patient was a 51-year-old male with a chief complaint of nasal obstruction. He had experienced nasal obstruction on the left side since about May 2004, and was told of the presence of a tumor filling the nasal cavity when he consulted a local otorhinolaryngologist. A CT scan showed a homogeneous tumor filling the inferior nasal meatus on the left, and the tumor was endoscopically removed towards the end of August. Because leiomyosarcoma was diagnosed as a result of istological examination, extirpation of the tumor was performed via the maxilla in the middle of September. Two cycles of a CYVADIC protocol were given postoperatively as adjuvant chemotherapy. There is no evidence of recurrence or metastasis at present.Retinoblastoma occurs when the Rb1 region is deleted in one of the responsible alleles and point mutation occurs in responsible alleles or when point mutation occurs in both of the responsible alleles. Patients with a history of retinoblastoma are known to manifest other primary tumors secondarily. These tumors are thought to develop because of a mutation in the Rb1 gene caused by irradiation, a genetic mutation or other factors that reduce the tumor suppressing function of the body. Osteosarcoma accounts for as much as 50% of sarcomas in patients with both a retinoblastoma and soft tissue sarcoma, but the incidence of leiomyosarcoma is very low. As far as we have been able to determine in a search of the literature in Japan and abroad, this condition has only been reported in the liver in one case and in the urinary bladder in two cases. Thus, this is the first report of a case in which primary leiomyosarcoma developed in the nasal cavity of a patient with a history of retinoblastoma. Because radiation therapy had previously been used in our case, we suspected that the leiomyosarcoma had developed secondarily to a gene-related abnormality such as that of the Rb gene.

A simple method to visualize the mechanism why Alnus glutinosa remains green during autumn colouration of Sorbus aucuparia

The autumn colouration of two deciduous trees (Sorbus aucuparia and Alnus glutinosa) from northern Finland (65°N) was studied during leaf senescence in autumn 2003. Their leaves were harvested from the end of August until leaf abscission in Sorbus trees at the end of September. The leaves were extracted in ethanol and measured with a spectrophotometer at 663 nm (chlorophyll a), 644 nm (chlorophyll b), 536 (anthocyanins) and 470 nm (carotenoids). The ratios A663/644, A663/470 and A663/536 were calculated to demonstrate the degradation of chlorophyll a in relation to the other studied pigments. The most important results of the present study were as follows: (1) Rapid (within 4 days) visually observed change in Sorbus colour from green to red. (2) Simultaneously occurred significant change in the calculated absorbance ratios in the same species. (3) The distinct difference between the tree species in both variables: Alnus remained green and maintained its absorbance ratios above the threshold ratios of Sorbus throughout the experiment. Sorbus exhibited the reddish colour in a ratio of 0.4 for A663/470 and 4 for A663/536 around the middle of September. The lowest ratios for Alnus remained 0.5 and 6 for A663/470 and for A663/536 (respectively), i.e. the ratios in Alnus never reached the level in Sorbus. Alnus maintained its green colour throughout the studied period, but the Sorbus trees started to turn red in mid-September. Alnus remained green for two reasons: It maintained higher chlorophyll concentrations, and higher ratios of chlorophyll to other pigments.

Biochemical composition of &lt;I&gt;Sorbus&lt;/I&gt; fruits and its change during ripening

Biochemical composition of fruits of Sorbus species and cultivars was determined. It was ascertained that the mean content of sugar in fruits in the years of investigation reached 5.5-7.4%, dry solubles - 18.0-24.2%, titrable organic acids – 1.5-3.8%, ascorbic acid – 22.3-98.3 mg%, carotenoids – 4.0-22.2 mg%. The content of investigated compounds changed during fruit ripening which was high for carotenoids, dry solubles and total sugar in the middle of September. However the content of ascorbic acid and titrable organic acids was highest in the middle of August and later decreased. Differences between genotypes were established. Meteorological conditions influenced the amount of the chemical compounds in fruits. Some genotypes distinguished by stability of investigated properties: the same or almost the same amount of sugars in different years of investigation was determinate for “Granatnaya”, dry solubes – for Elite Nr. 10, “Granatnaya”, titrable organic acids – for S. aucuparia SA-26 and S. aucuparia SAG-36, ascorbic acid for S. aucuparia SAG- 36 and “Krasavitsa”, carotenoids – for “ Coral Beuty”. The most valuable Sorbus species and cultivars according to the biochemical composition were selected. Fruits of Elita No 10 had highest sugar content, dry soluble and carotenoids. The highest content of ascorbic acid was found in “Coral Beauty”, S. asserteauiana and S. aucuparia SA-26 fruits. Key Words: Sorbus; carotenoids; ascorbic acid; sugar, titrable acids; dry solubles Moor J. Agric. Res. Vol.4(1) 2003:90-93

Peach Evaluation Website

The evaluation of peach and nectarine cultivars and advanced selections for suitability of production in the southeastern U.S. has been conducted at Clemson Univ. since 2000. Currently, there are 240+ cultivars and advanced selections being tested at the university's Musser Fruit Farm in Seneca, S.C. The harvest season begins in early May and ends in the middle of September. Additionally, two on-farm grower trials were planted in the primary peach growing regions of the Piedmont (Cowpens, S.C.) and the Ridge (Monetta, S.C.). At the grower locations, advanced selections are compared with industry standard cultivars. Evaluation data collected includes bloom and ripe date, fruit set, shape, color, size, firmness, taste and disease susceptibility. Digital photos are taken to scale at commercial maturity. Evaluation information, photos, plus chill hours, variety descriptions and other valuable information are on the website. In 2004, substantial improvements were made to the site utilizing a database, search and compare tools. The website has been well received by the southeastern commercial peach growers and is utilized to assist them in cultivar selection and to learn more about peach culture in general.

EFFECT OF NO-TILLAGE AND RYE MULCH ON OCCURRENCE OF WEEDS AND APHIDS AND ON YIELDS OF CABBAGE, CARROT AND RED BEET

EFFECT OF NO-TILLAGE AND RYE MULCH ON OCCURRENCE OF WEEDS AND APHIDS AND ON YIELDS OF CABBAGE, CARROT AND RED BEET

Intra-seasonal changes in directional preferences of Robins (Erithacus rubecula) caught on autumn migration at Bukowo-Kopań ringing Station (N Poland) in 1996

Intra-seasonal changes in directional preferences of Robins (Erithacus rubecula) caught on autumn migration at Bukowo-Kopań ringing Station (N Poland) in 1996 Data were collected in 1996 at Bukowo-Kopań ringing station situated on the southern Baltic coast. During the whole autumn migration period 2380 Robins were caught, and 445 of them were tested with Busse's method for directional behaviour. Birds' headings were grouped in four main axes: ENE-WSW, NNE-SSW, NNW-SSE and WNW-ESE. The seasonal dynamics of birds caught was divided into periods reflecting waves of migration. For each period the percentage shares of these four main axes were extrapolated into the daily numbers of birds caught. The obtained pattern consisted of four migration dynamics characterising differently heading birds. The total migration dynamics of the Robin at the station is interpreted as follows. In 1996, the intensive migration started around the middle of September with a numerous wave consisting of at least three populations. The peaks of those population waves were shifted in relation to each other in just 1-2 days, and occurred in following order: birds heading to the Apennine winter-quarter, birds heading to the most eastern wintering grounds, and birds heading to the southern parts of Western winter-quarter. The second, numerous wave consisting at least of birds heading to Mediterranean winter-quarter occurred with a peak on 26 September. In two most numerous October waves around 10 and 18 October, birds heading to the northern parts of Western migration route dominated. However, also birds heading to the Balkan (earlier) or even more eastern (later) wintering grounds formed numerous waves around those dates. The model of Robin migration is proposed, in which the wavy character of migration is generally explained by large-scale factors (like macrosynoptic weather situations, or changes in length of day). Their influence results in the most pronounced waves consisting of populations of different origin. However, the final pattern of dynamics is affected strongly by many other factors: e.g. localisation and characteristics of those populations.

RESEARCH ON THE INTRODUCTION AND TRANSPLANTING OF AROMATIC PLANTS FROM THE MEDITERRANEAN REGION TO HESHUO XINJIANG AND SHANGHAI CHINA

RESEARCH ON THE INTRODUCTION AND TRANSPLANTING OF AROMATIC PLANTS FROM THE MEDITERRANEAN REGION TO HESHUO XINJIANG AND SHANGHAI CHINA

Fluxes of carbon dioxide and methane from swamp and impact factors in Sanjiang Plain, China

The fluxes of CO2 and CH4 emission of the two types of primary swamp were measured in Sanjiang Plain using the opaque chamber and gas chromatogram technique. The mean value of ecosystem respiration flux in continuously inundated swamp ecosystem is 548.04 mg · m−2 · h−1, lower than that of the seasonal inundated swamp (713.08 mg · m−2 · h−1). The peaks concentrated on July and August which are the growing period of the vegetation. CH4 emission was different from the respiration flux of ecosystem. The CH4 flux of continuously inundated swamp was 12.80 mg · m−2 · h−1, larger than that of the seasonal inundated swamp (8.56 mg · m−2 · h−1), and they were varied at different periods, the continuously inundated swamp emitted CH4 mainly from July to September, whereas from last August to middle September in the seasonal inundated swamp. The ecosystem respiration flux of the swamp has the significantly positive correlation with the soil temperature (0–10 cm depth) and the water temperature, but CH4 emission was associated with the soil temperature in a certain degree. The CH4 emission from swamp depends on the integral function of water table and soil temperature.

Inflorescence and Flower Development in Chinese Ixora

Experiments were conducted on 6-month-old chinese ixora (Ixora chinensis Lam.) from February 1999 to April 2000. Floral development was studied with scanning electron microscopy (SEM) to determine the flowering sequences. Morphological characters were used to clarify the stages of flowering processes. The time of organogenesis and flowering arrangement was established through field observations. Floral evocation occurred in early September, floral initiation occurred in the middle of September and floral differentiation began in late September. A distinctly convex apex with bracts around the shoulder indicated the beginning of reproductive development. Subsequently, primary inflorescence axes were observed and differentiated into secondary, tertiary, and quaternary inflorescence axes consecutively in about one and a half months. Once the terminal apex reached the inflorescence bud stage, it would flower without abortion, and this may be assessed as no return. The sepals, petals, stamens, and pistil were well developed thereafter and anthesis was achieved in January through March in the following year. The observation of floral differentiation sequences and investigation of floret arrangement made it certain that chinese ixora had cymose inflorescence (cyme), but not corymb. A quadratic equation was established to predict floret number from the differentiation level (a quantitative description of differentiation stage) of a developed inflorescence.

CHARACTERISTICS OF A NEW JAPANESE PEAR CULTIVAR, 'FUKUSUI'

‘Fukusui’ is a new Japanese pear cultivar, selected from the seedlings of ‘Chikusui’ by Mr. Fujii, Tsu city, Mie prefecture. The fruit ripens during early to middle September at the original site, Hisai city. Anthesis is earlier, about the same as ‘Housui’ and ‘Choujuurou’. Low cross compatibility with ‘Kousui’ but high with other major cultivars. The amount of net pollen grains is 0.125g per 100 flowers which is less than that of ‘Chikusui’ and similar to that of ‘Housui’. Fruit is large and abundant, 467g in wt., skin color is reddish brown, redder than ‘Housui’ and ‘Choujuurou’. Fruit hardness is 5.4 lb, somewhat harder than ‘Housui’ but softer than ‘Choujuurou’. Brix is 12.7, higher than ‘Housui’, and it contains more fructose and so sweeter. pH is 4.65, similar to ‘Housui’ and somewhat tart. This cultivar is balanced with acidity and has fine texture, thus palatability is excellent. Bagging culture results in lowering of Brix by 0.5, poor development of cork tissue in dot, and spreading of thinner cork development between dots. It is resistant to many pests and diseases and there is few occurrence of spray injury. Growing of the new cv. ‘Fukusui’ will gradually increase as it matures early- to mid-September, in the zones where russet type cultivars of Japanese pear have been grown.

Heat tolerance of strawberry tarsonemid mite Phytonemus pallidus

SummaryThe heat tolerance of the strawberry tarsonemid mite Phytonemus pallidus ssp. fragariae was studied in northern Sweden by treating adult mites in hot water at temperatures 44°C, 46°C and 48°C. During the summer, the shortest exposure times required to kill all adult mites at these temperatures were 6, 2.5 and 1.25 min, respectively. It is concluded that hot‐water treatment of strawberry runners for 6.5 min at 46°C would suffice to kill all tarsonemid mites on infested runners. This exposure time includes the time needed to raise the temperature of the plant material to that of the water bath. In the autumn, from the middle of September and later, the mites became successively much more heat tolerant as they prepared for hibernation. It is expected that longer exposure periods are needed to kill mites on frigoplants.