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We explore and expand on the morphological term digitule. The term was originally proposed for toe-like setae on a species of Phylloxera Boyer de Fonscolombe, 1834 (Hemiptera, Sternorrhyncha, Aphidomorpha) by Henry Shimer, an American naturalist. While it is standard terminology in scale systematics (Hemiptera, Sternorrhyncha, Coccidomorpha), the term digitule was ignored by aphid specialists despite being the original taxon for which the term was described. Similar setae occur on many arthropod groups, so the homology is poorly understood even within any superfamily of Hemiptera. We provide the etymology of the term, a proposed explanation for why it was used among scale taxonomists and not aphid taxonomists, and discuss briefly options to progress beyond the confusion between terminology for morphology and homology in Sternorrhyncha. [ABSTRACT FROM AUTHOR]

The taxonomic history of the genus Tenuipalpus Donnadieu is discussed and Tenuipalpus caudatus (Dugès) (=Tenuipalpuspalmatus Donnadieu) is redescribed based on specimens from Portugal intercepted at ports of entry in the United States, and references including photographic records of the neotype of T. caudatus. In addition, a proposed new species, Tenuipalpus erbeisp. nov. is described from Costa Rica. Our results show that T. caudatus, T. erbeisp. nov. and another 36 known species of Tenuipalpus share a pair of lateral body projections associated with setae c3, considered a synapomorphy for the newly defined group, Tenuipalpus sensu stricto. We also show that its members share other character states, although these features are found elsewhere in Tenuipalpus and also in Ultratenuipalpus, indicating their origins are within Tenuipalpus. A list of Tenuipalpus sensu stricto species is presented. [ABSTRACT FROM AUTHOR]

Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157:H7 by using peat moss-based soil-substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants (7 days postseeding) and in growth medium were examined. E. coli O157:H7 was shown to survive and proliferate significantly during microgreen growth in both production systems, with a higher level in the hydroponic production system. At the initial seed inoculation level of 3.7 log CFU/g, E. coli O157:H7 populations on the edible part of microgreen plants reached 2.3 and 2.1 log CFU/g (overhead irrigation and bottom irrigation, respectively) for microgreens from the soil-substitute production system and reached 5.7 log CFU/g for those hydroponically grown. At a higher initial inoculation of 5.6 log CFU/g seeds, the corresponding E. coli O157:H7 populations on the edible parts of microgreens grown in these production systems were 3.4, 3.6, and 5.3 log CFU/g, respectively. Examination of the spatial distribution of bacterial cells on different parts of microgreen plants showed that contaminated seeds led to systematic contamination of whole plants, including both edible and inedible parts, and seed coats remained the focal point of E. coli O157:H7 survival and growth throughout the period of microgreen production. [ABSTRACT FROM AUTHOR]

We discuss the taxonomic history of the genus Colopalpus Pritchard and Baker 1958, and redescribe the female, male and deutonymph of the type species, C. matthyssei (Pritchard and Baker). We provide previously unknown morphological data for C. matthyssei, in addition to complementary information on the morphology of C. nambii (Castro and Feres) obtained using low temperature scanning electron microscopy (LT-SEM). Our results show that both C. matthyssei and C. nambii share characters with the genera Tenuipalpus and Brevipalpus. Based on these findings, we propose that Colopalpus be reinstated as a valid genus. We discuss the characters shared by Colopalpus, Tenuipalpus and Brevipalpus, and also provide a list of species that are transferred to the genus Colopalpus. http://zoobank.org/urn:lsid:zoobank.org:pub:1A296CBB-4B02-41CD-86E6-1418F5A7F291 [ABSTRACT FROM AUTHOR]

The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus. [ABSTRACT FROM AUTHOR]

The in vitro antimicrobial effect of cinnamaldehyde and Sporan in combination with acetic acid against Escherichia coli O157: H7 and Salmonella was investigated in Luria-Bertani broth (7 log cfu/mL) containing cinnamaldehyde or Sporan (800 and 1,000 ppm) alone or in combination with 200 ppm acetic acid, and incubated at 37C for up to 6 h. Surviving populations of test pathogens were determined by spiral plating on selective media. E. coli O157: H7 and Salmonella were undetectable after 1 h in the presence of 800 ppm cinnamaldehyde. A 1,000 ppm Sporan significantly reduced Salmonella and E. coli O157: H7 populations by 1.83 and 3.02 log cfu/mL within 2 and 4 h, respectively. Scanning and transmission electron microscopy of oil-treated bacterial cells revealed cell structural damage and leakage of cellular content. Cinnamaldehyde was highly effective against both E. coli O157: H7 and Salmonella whereas the effect of Sporan was dependent on its concentration, exposure time and pathogen. Practical Applications Consumers' preference for fewer chemicals in food has led to research on potential use of natural antimicrobials in food for controlling spoilage and pathogenic microorganisms. The antimicrobial effect of essential oils has been studied earlier. This is the first report on the antimicrobial activity of Sporan, and the combined effect of acetic acid. The results of the present study indicate that the antimicrobial activity of cinnamaldehyde and Sporan against enteric pathogens could be useful in food processing and preservation. [ABSTRACT FROM AUTHOR]

The localisation, chemical composition, and morphology of calcium (Ca) oxalate crystals in the leaves and stems of Abelia mosanensis and of A. X grandiflora were analysed using a variable pressure-scanning electron microscope (VP-SEM) equipped with an X-ray diffraction system, a low temperature SEM (LT-SEM), and a transmission electron microscope (TEM). Foliar analyses of macro- and micro-elements were performed on the leaves and stems of A. mosanensis. A greater number of Ca oxalate crystals were observed in A. mosanensis than in A. X grandiflora. Three morphologically distinguishable types of crystals were observed: the prismatic crystals found inside the chloroplast, multifaceted star-like spherical and bladed aggregate crystals (druses) inside the vacuoles of the mesophyll cells, and small angular crystals (sand crystals) inside the cuticle. Semi-solid crystals that may drip and accumulate to become a solid Ca oxalate crystal were observed by LT-SEM, which indicated the growth of druses of Ca oxalate crystals. The growth of prismatic crystals and of druses were evident through the formation of crystalline lamellae. Micro-analysis indicated that the crystals were Ca oxalate and contained magnesium in A, mosanensis, or silicon in A. X grandiflora. Abelia stems with low foliar calcium concentrations showed no Ca oxalate crystal formation. This is the first report, to our knowledge, on the presence and possible growth of crystals of different morphologies and chemical compositions in Abelia. [ABSTRACT FROM AUTHOR]

Similar to phytopathogens, human bacterial pathogens have been shown to colonize the plant phylloplane. In addition to environmental factors, such as temperature, UV, relative humidity, etc., the plant cultivar and, specifically, the leaf blade morphological characteristics may affect the persistence of enteropathogens on leafy greens. This study was conducted to evaluate the effect of cultivar-dependent leaf topography and the role of strain phenotypic characteristics on Escherichia coli O157:H7 persistence on organic spinach. Spinach cultivars Emilia, Lazio, Space, and Waitiki were experimentally inoculated with the foodborne E. coli O157:H7 isolate EDL933 and its isogenic mutants deficient in cellulose, curli, or both curli and cellulose production. Leaves of 6-week-old plants were inoculated with 6.5 log CFU per leaf in a biosafety level 2 growth chamber. At 0, 1, 7, and 14 days, E. coli O157:H7 populations were determined by plating on selective medium and verified by laser scanning confocal microscopy. Leaf morphology (blade roughness and stoma density) was evaluated by low-temperature and variable-pressure scanning electron microscopy. E. coli O157:H7 persistence on spinach was significantly affected by cultivar and strain phenotypic characteristics, specifically, the expression of curli. Leaf blade roughness and stoma density influenced the persistence of E. coli O157:H7 on spinach. Cultivar Waitiki, which had the greatest leaf roughness, supported significantly higher E. coli O157:H7 populations than the other cultivars. These two morphological characteristics of spinach cultivars should be taken into consideration in developing intervention strategies to enhance the microbial safety of leafy greens. [ABSTRACT FROM AUTHOR]