The effect of short-term nutrient deprivation was studied in five populations of the mite Tyrophagus putrescentiae with different microbiomes. The fresh weight, nutrient status, respiration, and population growth of the mites were observed for the five mite population-scale samples. The starvation caused the larvae and nymphs to be eliminated, resulting in a significant increase in the fresh weight of starved adult specimens. Three populations were negatively influenced by starvation, and the starved specimens were characterized by a decrease in nutrient status, respiration, and population growth. One population was not influenced or was slightly influenced by starvation, which had no effect on population growth or nutrient contents but caused a significant decrease in respiration. One population was positively influenced by starvation; the population growth increased in starved specimens, and starvation had no effect on respiration. Although starvation altered the bacterial profiles of the microbiomes, these differences were much smaller than those between the populations. The bacterial profiles of Staphylococcus, Bacillus, Kocuria, Brevibacterium, and unidentified Micrococcaceae and Enterobacteriaceae increased in starved specimens, whereas those of Bartonella and Solitalea-like genera were reduced in the starved mite populations. The profiles of the intracellular symbiont Cardinium decreased in the starved specimens, and the Wolbachia profile changes were dependent on the mite population. In mite populations, when the symbionts were rare, their profiles varied stochastically. Correlations between changes in the profiles of the bacterial taxa and mite fitness parameters, including nutrient status (lipids, proteins, saccharides, and glycogen contents), mite population growth, and respiration, were observed. Although the microbiomes were resistant to the perturbations caused by nutrition deficiency, the responses of the mites differed in terms of their population growth, respiration, and nutrient status.
Mycophagy should not be considered as a single and homogeneous category of nutritional biology due to the specific symbiotic chitinolytic bacteria associated with mites and fungi. To test interaction among mites, fungi, and chitinolytic bacteria, experiments were conducted on the model species Tyrophagus putrescentiae (Schrank). Mucor sp, Alternaria alternata, Penicillium claviforme, P. griseofulvum, and Verticillium sp. were plated onto malt agar and offered to T. putrescentiae in the laboratory. Mites were evaluated utilizing microanatomical examination based on histology, excrement analysis using fluorescence microscopy, bacterial plating, impact of mite homogenate on fungi in Petri dishes, reproduction of mites feeding upon each fungus, and isolation of associated bacteria inside mites. There were clear differences regarding the digested spores of different fungi passing through the gut and subsequently in the feces. Abundances of bacterial cells in excrement also corresponded to the fungi offered. The extracts from mites had chitinolytic activity, and the plated bacteria are known to produce exochitinases. The various feeding patterns observed were caused by differences in the cell wall structures of the tested fungi. The study illustrates that mycophagy in saprophagous mites does not consist of a single pattern, but rather that it can be classified into several sub-patterns depending upon the digested fungal species and its parts. The results point to a nearly symbiotic relationship between chitinolytic bacteria and digested fungi in mycophagous microarthropods.
- MeSH
- Acaridae fyziologie MeSH
- fyziologie bakterií * MeSH
- fyziologie výživy zvířat * MeSH
- houby fyziologie MeSH
- potravní řetězec * MeSH
- stravovací zvyklosti * MeSH
- symbióza * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
From 2008 to 2014, stored product mites have been reported from prepackaged dried food on the market in the Czech Republic. The infestation was by Carpoglyphus lactis (L.) in dried fruits and Tyrophagus putrescentiae (Schrank) in dog feed. The infestation is presumably caused by poor protection of the packages. We compared various packaging methods for their resistance to mites using dried apricots and dog feed in laboratory experiments. The trial packages included nine different plastic films, monofilm, duplex and triplex, and one type of plastic cup (ten replicates per packaging type). All packaging materials are available on the Czech market for dried food products. The samples of dried food were professionally packed in a factory and packaged dried apricots were exposed to C. lactis and dog food to T. putrescentiae. After 3 months of exposure, the infestation and mite density of the prepackaged food was assessed. Mites were found to infest six types of packages. Of the packaging types with mites, 1-5 samples were infested and the maximum abundance was 1,900 mites g(-1) of dried food. Mites entered the prepackaged food by faulty sealing. Inadequate sealing is suggested to be the major cause of the emerged infestation of dried food.
- MeSH
- Acaridae fyziologie MeSH
- bezpečnost potravin MeSH
- kontaminace potravin MeSH
- obaly potravin * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
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 10 or 50 mites without preincubation on F. poae (Tp10 and Tp50); barley containing 10 or 50 mites after preincubation on F. poae (FTp10 and FTp50). The number of mites, successful transfer of F. 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 F. poae transfer. The preincubation of T. putrescentiae on F. poae increased DON level approximately to 800 and 300 μg/kg of grain for FTp10 and FTp50, respectively. T. putrescentiae population growth in FTp10 was lower than in Tp10, 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 of F. poae via mites. From the analyzed clones, only 13 cloned sequences clustered with F. poae in an OTU defined at distance level 0.07. The related clones originated from FTp10, Tp10, Tp50 and control treatments, but not from FTp50. However, the presence of F. 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 (FTp10) supported F. poae transfer.
- MeSH
- Acaridae mikrobiologie fyziologie MeSH
- Fusarium metabolismus MeSH
- ječmen (rod) chemie mikrobiologie parazitologie MeSH
- kontaminace potravin MeSH
- mykotoxiny analýza metabolismus MeSH
- semena rostlinná chemie mikrobiologie parazitologie MeSH
- skladování potravin MeSH
- trichotheceny analýza metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The pH of the guts of mites strongly affects their digestive processes. This study was carried out to determine the pH in the guts of 12 species of stored product and house dust mites. Eighteen pH indicators were chosen and offered to the mites in the feeding biotest. Based on the color changes of the indicators, the gut contents of acaridid mites were determined to be within a pH range of 4 to neutral. The gut contents showed a gradient in pH from the anterior to the posterior part. The anterior midgut (ventriculus and caeca) of most species had a pH ranging from 4.5 to 5, or slightly more alkaline for most of the species, while the middle midgut (intercolon/colon) had a pH of 5 to 6. Finally, the pH of the posterior midgut (postcolon) was between 5.5 and 7. Except for Dermatophagoides spp., no remarkable differences in the pH of the gut were observed among the tested species. Dermatophagoides spp. had a more acidic anterior midgut (a pH of 4 to 5) and colon (a pH of 5) with postcolon (a pH of below 6). The results characterizing in vivo conditions in the mite gut offer useful information to study the activity of mite digestive enzymes including their inhibitors and gut microflora.
The study tested the effect of the chitin metabolic effectors, teflubenzuron, diflubenzuron, and calcofluor, and a combination of a chitinase and soybean trypsin inhibitor (STI) on the population growth of eight species of stored product mites under laboratory conditions. The compounds were incorporated into the diets of the mites in concentrations ranging from 0.01 to 50 mg g(-1). The final populations of mites were observed after 21 days of growth in controlled conditions. Diflubenzuron and calcofluor suppressed the growth of all the tested species more effectively than the other compounds. The doses required to suppress the mite populations to 50% (rc(50)) in comparison to the control ranged from 0.29 to 12.68 mg g(-1) for diflubenzuron and from 1.75 to 37.7 mg g(-1) for calcofluor, depending on the mite species. When tested at the highest concentration (10 mg g(-1)), teflubenzuron also suppressed all of the tested mite species in comparison to the control. The addition of chitinase/STI into the diet influenced population growth in several ways. When the highest concentration of chitinase in a cocktail of chitinase and STI (12.5 mg g(-1) of diet) was compared to the control, populations of Acarus siro, Aleuroglyphus ovatus and Aëroglyphus robustus decreased significantly, whereas populations of Tyroborus lini and Sancassania rodionovi increased significantly. The sensitivity of species to the tested compounds differed among species. The most tolerant species was S. rodionovi, the most sensitive was A. ovatus. The results confirmed that calcofluor and diflubenzuron have a toxic effect on stored product mites.
- MeSH
- Acaridae účinky léků růst a vývoj fyziologie MeSH
- akaricidy farmakologie MeSH
- benzamidy farmakologie MeSH
- benzensulfonáty farmakologie MeSH
- chitin metabolismus MeSH
- chitinasy farmakologie MeSH
- diflubenzuron farmakologie MeSH
- druhová specificita MeSH
- hustota populace MeSH
- inhibitory trypsinu farmakologie MeSH
- kontrola škůdců metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The pest potential of stored product mites depends on the reproduction rate that is affected by the environmental conditions. In this study we investigated the effect of temperature, ranging from 5 to 35 degrees C, on the population growth of three important mite species, Acarus siro, Tyrophagus putrescentiae and Auleroglyphus ovatus at 85% r.h. Starting with 10 individuals the population increase of mites was observed after 3 weeks of cultivation, or after 6 weeks for those kept at low temperatures (5, 10, 12.5, and 15 degrees C). The rate of increase was calculated for each temperature and species. The obtained data were fitted with polynomial models. The mite population growth rates increased with increasing moderate temperatures until 25 degrees C, when r ( m )-values were 0.179, 0.177 and 0.190 for A. siro, A. ovatus and T. putrescentiae, respectively. The lower development threshold was 10.2 degrees C in all three species. Estimated upper temperature threshold was higher in T. putrescentiae (49 degrees C) than in A. siro and A. ovatus (38 degrees C). Simulation of the rate of population increase under ideal conditions, using real temperature records obtained from Czech grain stores, showed that the pest mite populations increase only during 3.5 months within a typical 9-month storage season in Central Europe. These results indicate that control of mites, be it chemical, physical or biological, is recommended during the months when allergens and pests are produced, i.e. from September to mid November and in May.
- MeSH
- Acaridae růst a vývoj fyziologie MeSH
- jedlá semena parazitologie MeSH
- populační růst MeSH
- potravinářská parazitologie MeSH
- roční období MeSH
- teplota * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
