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661.
The effect of Tyrophagus putrescentiae on Fusarium poae transmission and fungal community composition was studied in nonsterile barley grain. The experiments included following treatments: control barley without mites; barley containing l0 or 50 mites without preincubation on E poae (Tpl0 and TpS0); barley containing 10 or 50 mites after preincubation on E poae (FTp 10 and FTp50). The number of mites, suc cessful transfer of E poae, and changes in the fungal communities were examined after 21 d of experiment. Increase of deoxynivalenol (DON) content in the barley was chosen as a criterion of successful Epoae transfer. The preincubation of T. putrescentiae on Epoae increased DON level approximately to 800 and 300μg/kg of grain for FTpl0 and FTpS0, respectively. T. putrescentiae population growth in FTpl0 was lower than in Tpl0, while no difference was found between FTp50 and Tp50. Fungal communities were compared by amplification, cloning and sequencing of ITS fragments, and operational taxonomic units (OTU) analysis. The OTU analysis did not support the transfer ofF. poae via mites. From the analyzed clones, only 13 cloned sequences clustered with E poae in an OTU defined at distance level 0.07. The related clones originated from FTpl0, Tpl 0, Tp50 and control treatments, but not from FTp50. However, the presence of E poae in FTp50 was confirmed by PCR amplification with specific primers. The observation may be explained by different effect of mite population density, that is, in the high density, (FTp50 treatment) the fungus was overgrazed, while the lower population density (FTp 10) supported E poae transfer. 相似文献
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The results of bioassay and colony evaluation demonstrated that British and Texas Buckfast honey bee stocks had one-third to one-half the mean prevalence and abundance of tracheal mites as Canadian standard stock, indicating that Buckfast stocks are less susceptible to tracheal mites than Canadian standard stock. Hybrid Canadian and Buckfast stocks exhibited resistance characteristics similar to only one of their parental stocks, suggesting the colony has an unknown effect on the expression of a bee's resistance to mites. A high correlation (r
s=0.66) between abundance values from the bioassay and colony evaluations indicates that the bioassay can be used to screen bees for mite resistance. 相似文献
665.
The damage of Oligonychus perseae Tuttle, Baker and Abbatiello on 'Hass' avocado trees occurs mainly on the underside of the leaves along the midrib, main veins and leaf depressions. The lower epidermal, spongy parenchyma and palisade parenchyma cells of the leaf tissues are destroyed. Large necrotic areas on the underside of the leaves result from feeding when high population levels occur. Feeding and reproduction takes place in 'nests' of silken webbing, which also provide protection from some predator mites and other natural enemies. Oligonychus perseae shows a modification of the earlier defined life-type web nest (WN-c). The greatest number of nests built by a female was 12.17 at 20°C and the greatest number of eggs per female per nest was 5.20 at 25°C. 相似文献
666.
Gerald T. Baker 《Experimental & applied acarology》1996,20(4):203-213
Silver nitrate staining of the solenidial and eupathidial sensilla on the palpi, tarsi and tibiae of legs I and II of Arrenurus acutus, Geayia ovata, Mideopsis reelfootensis and Albia caerulea, along with ultrastructural studies, showed that these setae have a porous shaft cuticle. These setae are hollow and contain dendrites in their lumens and more than one neuron is associated with each setae. Behavioural experiments supported the involvement of these sensilla in the perception of chemical cues from prey and sexual partners. 相似文献