Spider mites avoid caterpillar traces to prevent intraguild predation.

The phytophagous spider mites Tetranychus kanzawai and Tetranychus urticae can be as small as < 0.5 mm; thus, they are often incidentally consumed along with food plant leaves by voracious lepidopteran larvae (hereafter, 'caterpillars'). Therefore, the ability to avoid such intraguild predation should confer a selective advantage to mites. We experimentally demonstrated that adult females of both mite species avoided settling on food plant leaves with traces of all tested caterpillar species (Bombyx mori, Papilio xuthus, Spodoptera litura and Theretra oldenlandiae). We examined additional interactions using B. mori and T. kanzawai and found that B. mori trace avoidance by T. kanzawai lasted for more than 48 h. Tetranychus kanzawai also avoided B. mori traces on plant stems, along which mites access leaves. Moreover, T. kanzawai avoided acetone extracts of B. mori traces applied to filter paper, indicating that chemical substances of caterpillar traces are responsible for the avoidance. This study is the first demonstration of a repellent effect of herbivore trace chemicals on heterospecific herbivores. Although spider mites have developed resistance against many synthetic pesticides, these results predict that natural compounds simulating caterpillar traces may repel spider mites from agricultural crops.

Avoidance of ant chemical traces by spider mites and its interpretation.

Spider mites become easy prey for ants when they leave their protective webs; therefore, the ability to avoid traces of ongoing ant activity should confer a selective advantage to mites. We examined avoidance of ant traces by the spider mites Tetranychus kanzawai and Tetranychus urticae. Both mite species avoided host plant leaves with active traces of Pristomyrmex punctatus or Formica japonica ants. Pristomyrmex punctatus trace avoidance by T. kanzawai lasted for more than 1 h, but not more than 3 h. Tetranychus kanzawai also avoided P. punctatus traces on plant stems, along which the mites access leaves. Moreover, T. kanzawai avoided hexane extracts of P. punctatus or F. japonica applied to a filter paper pathway. This study represents the first demonstration of a repellent effect of ant chemical traces on spider mites. Considering the substantial abundance and global distribution of ants in nature, such repellent effects may help to answer the long-standing question of why only a small fraction of available plant resources is used by herbivores. Although spider mites have developed resistance against many synthetic pesticides, natural compounds that simulate ant chemical traces may repel spider mites from agricultural crops.

Oviposition-site shift in phytophagous mites reflects a trade-off between predator avoidance and rainstorm resistance.

Predators can reduce prey population densities by driving them to undertake costly defences. Here, we report on a remarkable example of induced antipredator defence in spider mites that enhances the risk to rainstorms. Spider mites live on the undersides of host plant leaves and usually oviposit on the leaf undersurface. When they are threatened by predatory mites, they oviposit on three-dimensional webs to avoid egg predation, although the cost of ovipositing on webs has not yet been clearly determined. We prepared bean plants harbouring spider mite (Tetranychus kanzawai) eggs on either leaf surfaces or webs and exposed them to rainstorms outdoors. We found that fewer eggs remained on webs than on leaf surfaces. We then examined the synergistic effect of wind and rain by simulating both in the laboratory. We conclude that ovipositing on webs comes at a cost, as eggs are washed off the host plants by wind and rain. This may explain why spider mite populations decrease drastically in the rainy season, although they inhibit leaf undersides where they are not directly exposed to rainfall.

Delayed mite hatching in response to mechanical stimuli simulating egg predation attempts.

Delayed or induced hatching in response to predation risk has been reported mainly in aquatic systems, where waterborne cues from predators and injured neighbouring eggs are available. Newly emerged larvae of the terrestrial predatory mite Neoseiulus womersleyi are vulnerable to predation by con- and heterospecific predatory mites, whereas their eggs are not. We examined whether N. womersleyi embryos delay hatching in response to artificial mechanical stimuli that simulates egg predation attempts. When embryos near the hatching stage were artificially stimulated every 5 min for 60 min, most stopped hatching for the duration of the 60-min period, whereas unstimulated embryos did not. Stimulated embryos resumed hatching when the treatment was stopped, and the proportion of hatched stimulated embryos caught up with that of unstimulated embryos within 120 min after stimuli stopped. Since hatching did not stop in response to changes in gravity direction, the effect of direct mechanical stimuli on the eggs was considered a proximate factor in delayed hatching. These results suggest that N. womersleyi embryos recognise immediate predation risk via mechanical stimuli, and delay hatching until the predation risk is reduced.

Vines avoid coiling around neighbouring plants infested by polyphagous mites.

Vines that coil around plants heavily infested with ambulate polyphagous mites can be heavily damaged by the mites. To explore whether vines avoid mite-infested plants, we observed the coiling responses of morning glory (Ipomoea nil var. Heavenly Blue) vines and bush killer (Cayratia japonica (Thunb) Gagnep) tendrils around nearby kidney bean (Phaseolus vulgaris L.) plants that were either uninfested or heavily infested with the two-spotted spider mite (Tetranychus urticae Koch). The proportions of I. nil vines that coiled around spider mite-infested and uninfested bean plants did not differ significantly; however, no C. japonica tendril coiled around spider mite-infested plants. The proportion of such tendrils was thus significantly lower than that around uninfested plants. The ability of C. japonica tendrils to avoid spider mite-infested plants would prevent serious "contact infections" by mites. We further found that tendril avoidance seemed to be attributable to the mite webs that covered infested plants; neither spider mite-induced bean volatiles nor spider mite intrusion onto tendrils seemed to explain the avoidance.

Behavioural flexibility in spider mites: oviposition site shifts based on past and present stimuli from conspecifics and predators.

Predator-experienced individuals often change their predation avoidance response when they re-encounter the same predators or their cues. Recent reports show that behavioural change sometimes occurs even before the re-encounter. To function as an adaptive strategy in the wild, such prospective experience-induced behaviour should change flexibly in response to changing situations. We assessed flexibility of experience-induced oviposition site shift in two closely related species of spider mites, Tetranychus kanzawai and T. urticae, from the viewpoint of reducing future predation risk on their eggs. We found that: (i) individuals of T. kanzawai shifted oviposition site depending on the presence of conspecific eggs; (ii) after experiencing predation threat T. kanzawai females shifted oviposition site even in the absence of any current predation threat; (iii) this experience-induced shift of oviposition site was weakened in the presence of conspecific males; and (iv) experience-induced behaviour was retained for a shorter period in T. urticae than in T. kanzawai, possibly because the demand for learning may differ with regard to biological conditions encountered in the wild.

Ant-mediated indirect negative effects of aphids on spider mites living on the same plant.

Some aphid species are known to have mutualistic relationships with tending ants; that is, the aphids supply the ants with honeydew and are protected by the ants. Although spider mites and honeydew-producing aphids often live on the same host plant, it has not previously been determined whether the ants tending these aphids affect spider mite survival. Using replicated microcosms, each containing an artificial ant nest, we compared experimentally the survival of two-spotted spider mites on kidney bean plants with and without cowpea aphids. Our results showed significantly fewer spider mites on plants with aphids, indicating that spider mites were preyed upon by ants tending aphids. On the other hand, there was no detectable plant-mediated indirect effect of aphids on mite performance in the microcosms. Therefore, we conclude that aphids indirectly reduced the survival of spider mites living on the same host plant via their tending ants. Nonetheless, spider mites did not avoid settling on plant leaves infested with aphids.

[THE MINIMUM NUMBER OF SPUTUM SMEAR SAMPLES NEEDED FOR THE DIAGNOSIS OF TUBERCULOSIS].

[Objective] To determine whether three sputum examinations with fluorescent staining are necessary to diag- nose tuberculosis (TB) in our hospital. [Patients] From April 2005 to December 2012, 379 TB patients were admitted and received anti-TB therapy in our hospital. [Methods] A retrospective study was conducted to assess the positivity rates of sputum smears based on three exami- nations. The positivity rate of first sputum smear and the cumulative smear-positive rates in the second and third were determined. Then, we also determined difference of positivity rates in sputum properties, sampling procedures and cavity formation. [Results] Of the 379 patients who met the screening criteria, 300 tested positive based on the first sputum smear (79.2%). The positivity rate of the first sputum smears was higher in the purulent sputum group than in the mucous sputum group (91.2% vs. 72.3%). Cavity formation, and sputum extraction procedures were not related to the positivity rate of the first sputum smears. In the mucous sputum group, the cumulative smear-positive rate in the second test significantly rose, but did not rise in the third test. [Conclusions] Three sputum smear examinations were necessary in patients who submitted mucous sputum samples. It is important to get purulent sputum.

[AN OUTBREAK OF PULMONARY TUBERCULOSIS DUE TO DEFINITE EXOGENOUS REINFECTION AMONG ELDERLY INDIVIDUALS IN WELFARE FACILITIES].

PURPOSE: We report an outbreak of 64 cases of tuberculosis (TB) that spread in a welfare facility for elderly individuals. OBJECTIVE AND METHODS: First, 64 TB patients who had contact with the source patient were screened at our hospital. We examined the time course up to the discovery of symptoms and analyzed the results for variable numbers of tandem repeats (VNTR) and the drug susceptibility tests. Second, we performed chest computed tomography to examine lesions due to a previous TB infection. RESULT: The source patient had recurrent aspiration pneumonia. The delay in doctor consultation was considered day 0, and the delay of diagnosis was 267 days. On examining the contacts, we found that 29 patients had TB while 35 had a latent TB infection. Results of the VNTR and the drug susceptibility tests showed that all the patients who developed TB had the same pattern as that of the source patient. Chest computed tomography showed lesions due to a previous TB infection in 8 patients. CONCLUSION: Based on the results of the VNTR and drug susceptibility tests, we concluded that the outbreak was due to an exogenous infection from the same source. All 8 patients who showed lesions due to a previous TB infection were aged > 81 years, and TB in these patients was found to be due to exogenous re-infection.

Low-intensity noninvasive ventilation: Lower pressure, more exacerbations of chronic respiratory failure.

BACKGROUND: For patients with chronic respiratory failure (CRF) who are treated with noninvasive positive pressure ventilation (NPPV), a little is known regarding the effects of low-intensity NPPV (LI-NPPV) on the clinical course of CRF and the frequency of adjustments in these patients. OBJECTIVES: This study investigated the effects of LI-NPPV on the clinical course of patients with CRF as compared with patients who were treated with conventional NPPV (C-NPPV) and determined how frequently NPPV was adjusted during therapy. METHODS: Clinical data from 21 patients who received long-term NPPV were retrospectively analyzed. Patients were categorized into two groups based on the level of initial pressure support (PS): C-NPPV group (PS ≥ 10 cm H2O) and LI-NPPV group (PS < 10 cm H2O). RESULTS: Patients in the LI-NPPV group had significantly more exacerbations of CRF (P < 0.05). There was no significant difference in the number of patients who required adjustments of NPPV settings between the two groups. There was no significant difference in PaCO2 levels 1 month after the start of NPPV between the two groups; however, PaCO2 levels were significantly lower after 1 year in the C-group (P < 0.001). Seventy-one percent of LI-NPPV patients and 43% of C-NPPV patients needed NPPV adjustments. CONCLUSIONS: Attention should be paid to CRF patients who are initially administered LI-NPPV; they should be carefully observed because they can develop more exacerbations of CRF than patients undergoing C-NPPV. If possible, higher initial PS should be administered to prevent CRF exacerbations.

[[CASE OF TUBERCULOSIS COMPLICATIONS DURING PREGNANCY LEADING TO AN INFECTION OUTBREAK].]

A 31-year-old woman developed a constant cough during the 8th week of pregnancy and was diagnosed with bronchial asthma. She was prescribed prednisolone and inhaled corticosteroids. At 28 weeks of pregnancy, she showed worsening weight loss, fever, night sweats, hoarseness, and coughs. At 31 weeks of pregnancy, a scatter shadow and cavitary lesions were detected on the chest radiograph. Acid- fast bacilli smear test and tuberculosis (TB) polymerase chain reaction tests yielded positive results (G-8), and she was diagnosed with TB. Contact tracing and screening indicated 3 patients with TB onset and 18 patients with latent TB infec- tion attributed to the initial patient, who infected a total of 36 people. In the present case, physicians were reluctant to order a chest radiograph for fear of harming the fetus and did not order sputum or interferon gamma release (IGRA) assay tests either. The diagnosis was delayed by 152 days, which was considered as a factor that caused the outbreak. The diag- nosis of TB in a pregnant patient may be very challenging because symptoms may initially be ascribed to the pregnan- cy, and delayed diagnosis and treatment of military TB can lead to the death of the mother and fetus. Consequently, to ensure early diagnosis and treatment, chest radiography and sputum and IGRA tests are recommended for pregnant women who have TB symptoms or are at high risk for TB.

An analysis of etiology, causal pathogens, imaging patterns, and treatment of Japanese patients with bronchiectasis.

BACKGROUND: Bronchiectasis (BE), a syndrome that presents with persistent or recurrent bronchial sepsis related to irreversibly damaged and dilated bronchi, has not been well-characterized in Asians. This study aims to review the etiology, causal pathogens, imaging patterns, and treatment of BE and to define the prognostic factors for acute exacerbation in a Japanese population. METHODS: We performed a retrospective cohort study of 147 patients (104 women; median age, 73 years; range, 30-95 years) with BE at our institution using high-resolution computed tomography to identify imaging patterns and the area of pulmonary involvement. RESULTS: Common BE etiologies were idiopathic (N=50 [34%]), sinobronchial syndrome (N=37 [25%]), non-tuberculous mycobacteriosis (NTM; N=26 [18%]), and previous respiratory infection (N=21[14%]). Pseudomonas aeruginosa was the most common causal pathogen (24%). Common imaging patterns were cylindrical (66%) and mixed including cylindrical pattern (47%). The median number of involved lobes was 2; 49% of the patients had ≥ 3 involved lobes, and 49% had middle lobe and left lingula dominant BE. Patients with predominantly lower lobe BE comprised 4% of the NTM group and 48% of the non-NTM group (P<0.001). In multivariate analysis, cystic BE was a predictor for frequent exacerbations in non-NTM patients (OR=7.947; P=0.004) which led to increased hospital admissions (OR=4.691; P=0.004). CONCLUSIONS: Idiopathic and sinobronchial syndrome were common causes of BE. Etiology did not contribute to imaging pattern or predictors of exacerbations. Cystic BE was a predictor for frequent exacerbations in the non-NTM BE patients.

Potential lethal and non-lethal effects of predators on dispersal of spider mites.

Predators can affect prey dispersal lethally by direct consumption or non-lethally by making prey hesitate to disperse. These lethal and non-lethal effects are detectable only in systems where prey can disperse between multiple patches. However, most studies have drawn their conclusions concerning the ability of predatory mites to suppress spider mites based on observations of their interactions on a single patch or on heavily infested host plants where spider mites could hardly disperse toward intact patches. In these systems, specialist predatory mites that penetrate protective webs produced by spider mites quickly suppress the spider mites, whereas generalist predators that cannot penetrate the webs were ineffective. By using a connected patch system, we revealed that a generalist ant, Pristomyrmex punctatus Mayr (Hymenoptera: Formicidae), effectively prevented dispersal of spider mites, Tetranychus kanzawai Kishida (Acari: Tetranychidae), by directly consuming dispersing individuals. We also revealed that a generalist predatory mite, Euseius sojaensis Ehara (Acari: Phytoseiidae), prevented between-patch dispersal of T. kanzawai by making them hesitate to disperse. In contrast, a specialist phytoseiid predatory mite, Neoseiulus womersleyi Schicha, allowed spider mites to escape an initial patch, increasing the number of colonized patches within the system. Our results suggest that ants and generalist predatory mites can effectively suppress Tetranychus species under some conditions, and should receive more attention as agents for conservation biological control in agroecosystems.

Predation risk increases dispersal distance in prey.

Understanding the ecological factors that affect dispersal distances allows us to predict the consequences of dispersal. Although predator avoidance is an important cause of prey dispersal, its effects on dispersal distance have not been investigated. We used simple experimental setups to test dispersal distances of the ambulatory dispersing spider mite (Tetranychus kanzawai) in the presence or absence of a predator (Neoseiulus womersleyi). In the absence of predators, most spider mites settled in adjacent patches, whereas the majority of those dispersing in the presence of predators passed through adjacent patches and settled in distant ones. This is the first study to experimentally demonstrate that predators induce greater dispersal distance in prey.

Metastatic bone lesion due to methotrexate and etanercept 24 years after breast cancer treatment.

A 72-year-old woman with rheumatoid arthritis presented with lumbar vertebral bone metastasis 24 years after mammectomy and radiotherapy for breast cancer. She was treated with prednisolone and methotrexate (MTX) for 11 months to which 10 mg of etanercept twice a week was added for a further 8 months. On the basis of this result, the possibility of a metastatic bone lesion appearing many years after cancer treatment should be considered when planning MTX and etanercept therapy.

Chemical investigation of aggregation behaviour in the two-spotted spider mite Tetranychus urticae.

The silk produced by the group-living mite Tetranychus urticae provides group protection and is used as an informative material during habitat settlement, egg laying, mating, and dispersal events. In this context, cues contained in the silk and other materials produced by mites [eggs, black faeces (BF) and white faeces + silk (WFS)] were investigated. Chemical compounds were extracted by hexane or methanol, and choice tests were used to determine the individual attractiveness of each extract. For both solvents, individuals did not respond to the extract from eggs and WFS. BF extracts were attractive for both solvents. After separating the BF methanol extract into four different chemical components using thin layer chromatography, no component was determined to be responsible for mite attraction. This work supports the evidence that the faeces of T. urticae do contain substances that promote behavioural changes. Not particular chemical compounds but combinations of them seem to induce the mites' preference. Moreover, the response of mites to chemicals seemed to be context dependent as mites belonging to populations with different densities differed in their attraction to BF extracts.

Factors determining species displacement of related predatory mite species (Acari: Phytoseiidae).

Neoseiulus womersleyi (Acari: Phytoseiidae) used to be the dominant species in fruit-tree orchards throughout Japan, but starting in the 1990s, N. womersleyi began to be displaced by Neoseiulus californicus in central and southwestern Japan. The present study was conducted to examine factors explaining the displacement of N. womersleyi by N. californicus. First, we confirmed under laboratory conditions that N. californicus could exclude N. womersleyi if they initially coexisted in a 1:1 ratio. During a 2-h continuous observation period, none of the heterospecific pairs had copulated and after 5 days together with heterospecific males, none of the females had laid eggs. When these females were placed with conspecific males, normal numbers of offspring were produced. Moreover, conspecific matings were not substantially disturbed in the presence of heterospecific males or females. Total fecundity was significantly lower in N. womersleyi than in N. californicus, but their r m values did not differ from each other. On the other hand, the frequency of intraguild predation by N. californicus on N. womersleyi was significantly higher than vice versa. From these results, we concluded that not reproductive interference nor differential female fecundity but asymmetrical intraguild predation seemed to explain the competitive exclusion of N. womersleyi by N. californicus.