Cranial morphology and taxonomic resolution of some dolphin taxa (Delphinidae) in Australian waters,with a focus on the genus Tursiops

Phylogenetic relationships in the family Delphinidae have been widely debated. We examined 347 skulls of Tursiops, Stenella, Delphinus, Steno, Lagenodelphis, and Sousa in order to resolve the phylogenetic position of Australian species of Tursiops. Five Tursiops type specimens were included. Cranial morphology was described using 2‐dimensional (2‐D) and 3‐dimensional geometric morphometrics (3‐GM), counts and categorical data. Analyses showed a clear morphological separation of Tursiops, including type specimens, from other genera. The three Stenella species did not cluster together. Stenella attenuata clustered with Delphinus delphis, and Stenella coeruleoalba with Lagenodelphis hosei. Length and width of the skull and rostrum were important discriminators in both methods. For 3‐D data, round vs. angular posterior skull shape distinguished some genera. Taxa that overlapped in the multivariate analyses had different mean tooth counts. Our study challenges genetic studies that identified Tursiops as polyphyletic, with T. aduncus closer to S. attenuata.     

Variation in cranial morphology of bottlenose dolphins (genus Tursiops) off South Africa

Taxonomy plays an important role in conservation biology. Despite the variety of methods used to differentiate units, some groups, such as Delphinidae within the Cetacea have proven difficult to untangle. This study aimed to shed light on morphological variation of the genus Tursiops in South African waters using geometric morphometrics and to distinguish morphological groups and variation in these groups. A total of 241 crania of Tursiops spp. were analyzed using a suite of 2‐dimensional landmarks defined on photographs of the specimens. Results revealed two distinct morphological groups, with the smaller cluster comprised mainly of specimens from the cold temperate region off the west coast and the larger cluster comprised of specimens mainly from the warm temperate and subtropical regions off the south and east coast, respectively. We suggest that these groups correspond to different species of Tursiops, but this result requires further support. These groups were treated as separate entities and sexual dimorphism and geographic variation were assessed within each group. While sexual dimorphism and geographic variation were not significant within Cluster D1 and V1, they were significant within Clusters D2 and V2. The few Cluster 1 specimens found in the warm temperate and subtropical regions, relative to the number of Cluster 2 specimens, could be an indication of an offshore distribution for this group in these regions. Alternatively, the smaller cluster may also be indicative of a potentially small population size.     

Comparative study of the corneal epithelium in some reptiles inhabiting different environments

El‐Bakry, A.M. 2011. Comparative study of the corneal epithelium in some reptiles inhabiting different environments. —Acta Zoologica (Stockholm) 92 : 54–61. The vertebrate cornea functions in either aquatic or aerial environments and in some cases in both. In terrestrial and aerial vertebrates, the cornea contributes most of the refractive powers of the eye because of the large variation in refractive index between the air and the cornea. The present study aimed to examine and compare the main features of the corneal epithelial surface of three reptilian species related to three different families (Caretta caretta, Varanus griseus and Mabuya quinquetaeniata) and inhabiting different environment, by light, scanning (SEM) and transmission electron microscopy. The mean epithelial cell densities of the species of the study were 8.670 ± 3.134, 5.945 ± 2.144 and 2.124 ± 713 respectively. The corneal epithelium of the three species observed by SEM showed a similarity to one another indicating that the apical cell surfaces possess regular polygonal cells with varieties of microprocesses. These microprocesses were represented by microplicae, numerous microvilli and some long microridges in C. caretta, microplicae and minute microholes in V. griseus and microplicae intermingled with short microvilli in M. quinquetaeniata. According to the densities of these microprocesses, three polymorphic cell types (light, medium and dark) appeared in C. caretta, light and medium cell types were observed in V. griseus and medium and dark cell types were noticed in M. quinquetaeniata. Different types of tight adhesions were observed by transmission electron microscopy between the cell borders of the epithelial cells which differ according to environment where the species occupy. In conclusion, variation in the structure of the corneal epithelial cells appears to be related to the living environment, such as aerial, terrestrial and aquatic ones, which is occupied by every species.     

In vivo determination of young's modulus for the human cornea

The present paper describes a calculation technique to determine a value of Young's modulus for the cornea when the intraocular pressure, the shape of the cornea and the thickness variation along the cornea are known fromin vivo measurements. Twenty-eight persons were examined in both eyes and a mean value of Young's modulus for the cornea was calculated to 2.45×10⁴±0.57×10⁴ N/m² (S.D.).     

Microvascular patterns in the blubber of shallow and deep diving odontocetes

Blubber, a specialized form of subdermal adipose tissue, surrounds marine mammal bodies. Typically, adipose tissue is perfused by capillaries but information on blubber vascularization is lacking. This study's goals were to: 1) describe and compare the microvasculature (capillaries, microarterioles, and microvenules) of blubber across odontocete species; 2) compare microvasculature of blubber to adipose tissue; and 3) examine relationships between blubber's lipid composition and its microvasculature. Percent microvascularity, distribution, branching pattern, and diameter of microvessels were determined from images of histochemically stained blubber sections from shallow‐diving bottlenose dolphins (Tursiops truncatus), deeper‐diving pygmy sperm whales (Kogia breviceps), deep‐diving beaked whales (Mesoplodon densirostris; Ziphius cavirostris), and the subdermal adipose tissue of domestic pigs (Sus scrofa). Tursiops blubber showed significant stratification in percent microvascularity among the superficial, middle, and deep layers and had a significantly higher percent microvascularity than all other animals analyzed, in which the microvasculature was more uniformly distributed. The percent microvasculature of Kogia blubber was lower than that of Tursiops but higher than that of beaked whales and the subdermal adipose tissue of domestic pigs. Tursiops had the most microvascular branching. Microvessel diameter was relatively uniform in all species. There were no clear patterns associating microvascular and lipid characteristics. The microvascular characteristics of the superficial layer of blubber resembled the adipose tissue of terrestrial mammals, suggesting some conservation of microvascular patterns in mammalian adipose tissue. The middle and deep layers of blubber, particularly in Tursiops, showed the greatest departure from typical mammalian microvascular arrangement. Factors such as metabolics or thermoregulation may be influencing the microvasculature in these layers. © J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

Phylogenetic identification and population differentiation of bottlenose dolphins (Tursiops spp.) in Melanesia,as revealed by mitochondrial DNA

The taxonomic status of many dolphin populations remains uncertain in poorly studied regions of the world's ocean. Here we attempt to clarify the phylogenetic identity of two distinct forms of bottlenose dolphins (Tursiops spp.) described in the Melanesian region of the Pacific Ocean. Mitochondrial DNA control region sequences from samples collected in New Caledonia (n = 88) and the Solomon Islands (n = 19) were compared to previously published sequences of Tursiops spp., representing four phylogenetic units currently recognized within the genus. Phylogenetic reconstructions confirm that the smaller coastal form in Melanesia belongs to the same phylogenetic unit as T. aduncus populations in the Pacific, but differs from T. aduncus in Africa, and that the larger more oceanic form belongs to the species T. truncatus. Analyses of population diversity reveal high levels of regional population structuring among the two forms, with contrasting levels of diversity. From a conservation perspective, genetic isolation of T. aduncus in the Solomon Islands raises further concern about recent impacts of the commercial, live‐capture export industry. Furthermore, the low level of mtDNA diversity in T. aduncus of New Caledonia suggests a recent population bottleneck or founder effect and isolation. This raises concerns for the conservation status of these local populations.     

Why become speckled? Ontogeny and function of speckling in Shark Bay bottlenose dolphins (Tursiops sp.)1

To date, color patterns have been used to assess cetacean age and taxonomic status, but few studies have determined precise correlates of coloration with known age or investigated its function. Here, we examine the ontogeny of speckling in 88 bottlenose dolphins (Tursiops sp.) in Shark Bay, Australia, of known age, tracked from birth to age 34. Ventral speckles first appear in the genital area at a mean age of 10.2 ± 0.35 yr (range = 7.6–12.7 yr). Throughout their life span, speckles increase in number and density, particularly along the ventral and lateral sides. The timing of speckle onset does not significantly differ by sex but is related to sexual maturity in females. The age of speckle onset in the genital area correlates with the age of first known parturition. In terms of speckle function, we discuss two hypotheses commonly proffered to explain color variation, concealment, and communication. Concealment from predators or prey is unlikely to explain speckle development in Shark Bay Tursiops because the onset occurs long after peak predation risk and initial hunting success (at 3 mo of age). We suggest that speckle patterns offer reliable cues on reproductive status and/or condition and could, thus, serve a communicative or some other function.     

Extensive Interspecific Gene Flow Shaped Complex Evolutionary History and Underestimated Species Diversity in Rapidly Radiated Dolphins

Recently diverged taxa are often characterized by high rates of hybridization, which can complicate phylogenetic reconstruction. For this reason, the phylogenetic relationships and evolutionary history of dolphins are still not very well resolved; the question of whether the genera Tursiops and Stenella are monophyletic is especially controversial. Here, we performed re-sequencing of six dolphin genomes and combined them with eight previously published dolphin SRA datasets and six whole-genome datasets to investigate the phylogenetic relationships of dolphins and test the monophyly hypothesis of Tursiops and Stenella. Phylogenetic reconstruction with the maximum likelihood and Bayesian methods of concatenated loci, as well as with coalescence analyses of sliding window trees, produced a concordant and well-supported tree. Our studies support the non-monophyletic status of Tursiops and Stenella because the species referred these genera do not form exclusive monophyletic clades. This suggests that the current taxonomy of both genera might not reflect their evolutionary history and may underestimate their diversity. A four-taxon D-statistic (ABBA-BABA) test, five-taxon D_FOIL test, and tree-based PhyloNet analyses all showed extensive gene flow across dolphin species, which could explain the instability in resolving phylogenetic relationship of oceanic dolphins with different and limited markers. This study could be a good case to demonstrate how genomic data can reveal complex speciation and phylogeny in rapidly radiating animal groups.

     

Effect of Orbital Decompression on Corneal Topography in Patients with Thyroid Ophthalmopathy

Objective

To evaluate changes in corneal astigmatism in patients undergoing orbital decompression surgery.

Methods

This retrospective, non randomized comparative study involved 42 eyes from 21 patients with thyroid ophthalmopathy who underwent orbital decompression surgery between September 2011 and September 2014. The 42 eyes were divided into three groups: control (9 eyes), two-wall decompression (25 eyes), and three-wall decompression (8 eyes). The control group was defined as the contralateral eyes of nine patients who underwent orbital decompression surgery in only one eye. Corneal topography (Orbscan II), Hertel exophthalmometry, and intraocular pressure were measured at 1 month before and 3 months after surgery. Corneal topographic parameters analyzed were total astigmatism (TA), steepest axis (SA), central corneal thickness (CCT), and anterior chamber depth (ACD).

Results

Exophthalmometry values and intraocular pressure decreased significantly after the decompression surgery. The change (absolute value (|x|) of the difference) in astigmatism at the 3 mm zone was significantly different between the decompression group and the controls (p = 0.025). There was also a significant change in the steepest axis at the 3 mm zone between the decompression group and the controls (p = 0.033). An analysis of relevant changes in astigmatism showed that there was a dominant tendency for incyclotorsion of the steepest axis in eyes that underwent decompression surgery. Using Astig PLOT, the mean surgically induced astigmatism (SIA) was 0.21±0.88 D with an axis of 46±22°, suggesting that decompression surgery did change the corneal shape and induced incyclotorsion of the steepest axis.

Conclusions

There was a significant change in corneal astigmatism after orbital decompression surgery and this change was sufficient to affect the optical function of the cornea. Surgeons and patients should be aware of these changes.     

Litter-associated bacteria and fungi – a comparison of biomass and communities across lakes and plant species

1. We investigated the importance of lake water chemistry and substrate properties in regulating microbial decomposer communities on macrophyte litter. Ten lakes of differing water chemistry, including such variables as nutrient concentration, pH and dissolved organic carbon, were sampled in October 2003. Water chemistry was analysed, and litter from the macrophytes Phragmites australis, Schoenoplectus lacustris and Nuphar lutea was collected from both above and below the water surface. 2. The three plant species differed widely in carbon and nitrogen content. The aerial parts of P. australis had highest C : N ratio (mean value 125), while the lowest values were found in leaves of N. lutea (19.8). 3. Fungal carbon ranged from 0.15 to 6.4 mg g^?1 dry weight (DW), and was higher on aerial than on submerged plant parts. Fungal biomass was highest on S. lacustris and lowest on N. lutea. Denaturing gradient gel electrophoresis revealed no differences in the number of fungal taxa between plant species or plant parts, with the limitation that no molecular analysis was possible for N. lutea. 4. In contrast, bacteria were most abundant on N. lutea, but showed no significant difference between leaf and stem parts. The number of bacterial taxa was highest on the submerged parts of P. australis. 5. The correlations between microbial variables and the properties of lakes and litter were analysed using multivariate statistics. In a principal component analysis, litter properties explained 78% of the variation in microbial variables. In contrast, redundancy analysis revealed that the explanatory power of lake water chemistry was only 20%, indicating that the properties of the growth substratum were more important than those of the lake water for the attached microbial communities.     

Distribution of Posterior Corneal Astigmatism According to Axis Orientation of Anterior Corneal Astigmatism

Purpose

To investigate the distribution of posterior corneal astigmatism in eyes with with-the-rule (WTR) and against-the-rule (ATR) anterior corneal astigmatism.

Methods

We retrospectively examined six hundred eight eyes of 608 healthy subjects (275 men and 333 women; mean age ± standard deviation, 55.3 ± 20.2 years). The magnitude and axis orientation of anterior and posterior corneal astigmatism were determined with a rotating Scheimpflug system (Pentacam HR, Oculus) when we divided the subjects into WTR and ATR anterior corneal astigmatism groups.

Results

The mean magnitudes of anterior and posterior corneal astigmatism were 1.14 ± 0.76 diopters (D), and 0.37 ± 0.19 D, respectively. We found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Pearson correlation coefficient r = 0.4739, P<0.001). In the WTR anterior astigmatism group, we found ATR astigmatism of the posterior corneal surface in 402 eyes (96.6%). In the ATR anterior astigmatism group, we found ATR posterior corneal astigmatism in 82 eyes (73.9%). Especially in eyes with ATR anterior corneal astigmatism of 1 D or more and 1.5 D or more, ATR posterior corneal astigmatism was found in 28 eyes (59.6%) and 9 eyes (42.9%), respectively.

Conclusions

WTR anterior astigmatism and ATR posterior astigmatism were found in approximately 68% and 91% of eyes, respectively. The magnitude and the axis orientation of posterior corneal astigmatism were not constant, especially in eyes having high ATR anterior corneal astigmatism, as is often the case in patients who have undergone toric IOL implantation.     

The effect of temperature on the egg incubation period and nymphal growth of two Nemoura species (Plecoptera) from subarctic fennoscandia

Field studies of Nemoura arctica and N. viki showed that the two species preferred different biotopes and indicated differences in their life‐cycles. N. arctica seemed to have a semivoltine life‐cycle, at least in some years, this was not the case for N. viki.

Laboratory studies showed that the temperature tolerance of the eggs of N. arctica was wider than for those of N. viki. The length of the egg incubation period of both species was influenced by the ambient temperature, but no significant interspecific difference existed between the regression lines of the relationship between the temperature (T°C) and egg incubation period (Y days), as given by the regression equation Y = aT^?b for the log values. Reared at constant food supply, nymphal growth occurred in two periods. Firstly a rapid growth to about 4 mm, followed by a period of slow growth until emergence. During the first period growth (G)at (D) days was linear, according to the simple linear regression equation G = a+bD . The temperature tolerance of the nymphs of N. arctica was wider than for those of N. viki and significant interspecific differences between the species in growth were recorded at relatively high rearing temperatures, such as 12° and 16°C, but not at low temperatures. At constant food supply, nymphal growth was greatly influenced by the rearing temperature. At a mean temperature of 16°C N. arctica nymphs grew rapidly and emerged after 120 days; whereas at a mean temperature of 4°C growt h was slow and the nymphs did not even manage to reach the emergence stage after 700 days.     

Factors That Influence Food Amount Ratings by White,Hispanic, and Asian Samples

Objective: Two studies explored in nonclinical samples variables that may influence meal size assessments. Research Methods and Procedures: In Study 1, the contribution of dietary restraint, weight, depressive symptoms, and gender to ratings on the Food Amount Rating Scale was examined in 153 white women and 121 white men; in Study 2, the contribution of dietary restraint, weight, ethnicity, and ethnic group identification to Food Amount Rating Scale ratings was examined in 67 Asian, 81 Hispanic, and 107 white women. Results: Study 1 indicated that food amounts were rated as larger when rated by male rather than female raters (male rater, mean = 62.37, SD = 1.14; female rater, mean = 59.28, SD = 0.89), for female rather than male targets (male target, mean = 56.16, SD = 0.97; female target, mean = 64.87, SD = 1.02), and by restrained rather than unrestrained eaters (restrained, mean = 63.14, SD = 1.11; unrestrained, mean = 58.69, SD = 0.91). Study 2 indicated that food amounts were rated as larger when rated by restrained eaters (restrained, mean = 67.53, SD = 1.21; unrestrained, mean = 64.99, SD = 1.09), Hispanic women (Asian, mean = 64.59, SD = 1.61; Hispanic, mean = 68.71, SD = 1.30; white, mean = 65.41, SD = 1.34), and underweight women (underweight, mean = 70.38, SD = 1.68; normal weight, mean = 64.52, SD = 0.93; overweight: mean = 64.23, SD = 1.64). Discussion: Food amount judgments may be influenced by personal characteristics. Future research should examine whether variation in food amount judgments is related to dieting behavior, disordered eating, or obesity.     

The development of the refractive state in the newborn Thomson gazelle

Changes in refractive error during the first 3 months of life were studied retinoscopically in six Thomson gazelles (Gazella thomsoni). Animals were hand-raised to allow repeat testing over time without chemical restraint. Refraction results were correlated with ultrasound measurements of intraocular dimensions, and with values in adult gazelles. Gazelles are born hyperopic with a mean refractive error of 3.44±0.31 D. By day 50, the animals are virtually emmetropic (0.13±0.21 D) and remain so in adulthood (0.03±0.09 D). The refractive error is highly correlated with the axial length (r²=0.96) and with the vitreous chamber depth (r²=0.83), but not with anterior chamber depth. Significant with-the-rule astigmatism was recorded (P<0.001).     

Differences in mechanical efficiency between power- and endurance-trained athletes while jumping

Mechanical efficiency (ME) of jumping exercises was compared between power-trained (n = 11) and endurance-trained athletes (n = 10) using both a biomechanical and a physiological approach. In drop jumps and in stretch-shortening cycle exercise on a special sledge (sledge jumps), the subjects performed 60 muscle actions from a dropping height of optimum minus 40 cm (O – 40), as well as from dropping heights of optimum (O) and optimum plus 40 cm (O + 40). Thus, they were tested in six different tests which lasted for a total of 3 min for each. The mean ME values in the drop jumps from the lowest dropping height upwards were as follows: 23.8 (SD 5.3)%, 35.5 (SD 10.8)% and 39.2 (SD 6.6)% for the power group, and 30.8 (SD 6.5)%, 37.5 (SD 8.7)% and 41.4 (SD 7.0)% for the endurance group. In the sledge jumps the ME values were 37.0 (SD 5.6)%,48.4 (SD 4.0)% and 54.9 (SD 8.5)% for the power group, and 40.2 (SD 5.9)%, 46.9 (SD 5.7)% and 58.5 (SD 5.5)% for the endurance group. As can be seen, the ME values increased with increasing stretch load. However, the groups did not differ from each other except in the drop jump condition of O – 40 (P < 0.05). The higher power (P < 0.001) among the power athletes in every measured condition was associated with a faster rate of electromyogram development during the pre-activity, and smoother muscle activity patterns in the ground contact. On the other hand, the endurance athletes had a lower blood lactate concentration after every test, and in addition a lower heart rate and ventilation during the sledge jumps than their power counterparts. Therefore, it would seem that the similar mean ME values between the subject groups could be explained by improved function of the neuromuscular system among the power group and improved metabolism among the endurance group.     

QUANTITATIVE VARIATION OF LIFE HISTORY TRAITS IN AMPHICARPIC PEANUTGRASS (AMPHICARPUM PURSHII) AND ITS EVOLUTIONARY SIGNIFICANCE

Peanutgrass, Amphicarpum purshii, is a predominantly selling annual that exhibits an amphicarpic reproductive strategy, producing spikelets (and seeds) both above and below the soil surface. Both aerial and subterranean spikelets are self-fertile, but only the aerial spikelets are chasmogamous and capable of cross-pollination. This species mostly grows in disturbed areas of the New Jersey Pine Barrens. To examine life history variation, 60 quantitative characters were measured on twelve families raised from seeds collected from the aerial panicles of twelve parents grown in the greenhouse. Only 19 (= 31.7%) of the traits showed significant between-family phenotypic variation, and the mean percentage of the total variation due to family was 14.9 (N = 60 characters). Percentage biomass allocation and vegetative characters showed the highest narrow-sense heritabilities. Traits directly relevant to fitness such as subterranean seed set and seed weight of both seed types showed the least genetic variation. This low variation could reflect genetic fixation and/or developmental canalization of those fitness components important to survival in disturbed, early-successional habitats.     

Sequence of the regulatory region of omp T, the gene specifying major outer membrane protein a (3b) of Escherichia coli K-12: implications for regulation and processing

Summary The DNA of the promoter region of ompT, including the putative start for the pro-OmpT protein (proprotein a), has been sequenced. Previous studies showed that trypsin inhibitors prevent the processing of pro-OmpT to OmpT protein which led to the prediction that the processing site would be a lysine or an arginine. The deduced amino acid sequence contains a lysine at amino acid 12 and an arginine at amino acid 17 from the N terminus. Chou-Fassman analysis would predict processing at the lysine (but not the arginine) to remove a 1389 dalton peptide, consistent with the fact that the estimated molecular masses of pro-OmpT and OmpT are 42 kd and 40 kd respectively. In addition, the predicted mRNA of the promoter region can form a stable secondary structure (-17.1 kcal) that sequesters the Shine-Dalgarno (SD) sequence as well as the initiator AUG codon. There is evidence that the perA (tpo, envZ) gene product is required for synthesis of OmpT protein (as well as several outer membrane and periplasmic proteins). The perA gene product could be activating translation of OmpT protein by disrupting the mRNA secondary structure that sequesters the SD sequence. OmpT protein synthesis is reduced at temperatures below 32°C and this may also be related to the greater stability of the sequestered SD sequence of the mRNA at low temperature.     

Nutrient Limitation to Primary Productivity in a Secondary Savanna in Venezuela1

We examined nutrient limitation to primary productivity in a secondary savanna in the interior branch of the Coastal Range of Venezuela, which was converted from forest to savanna more than 100 years ago. We manipulated soil nutrients by adding nitrogen (+N), phosphorus and potassium (+PK), and nitrogen, phosphorus, and potassium (+NPK) to intact savanna. Eleven months after fertilization, we measured aboveground biomass and belowground biomass as live fine roots in the top 20 cm of soil, and species and functional group composition in response to nutrient additions. Aboveground biomass was highest in the NPK treatment ([mean g/m2]; control = 402, +N = 718, +PK = 490, +NPK = 949). Aboveground production, however, appeared to be limited primarily by N. Aboveground biomass increased 78 percent when N was added alone but did not significantly respond to PK additions when compared to controls. In contrast to aboveground biomass, belowground biomass increased with PK additions but showed no significant increase with N (depth 0–20 cm; [mean g/m2]; control = 685, +N = 443, +PK = 827, +NPK = 832). There was also a 36 percent increase in root length with PK additions when compared to controls. Whole savanna shoot:root ratios were similar for control and +PK (0.6), while those for +N or +NPK fertilization were significantly higher (1.7 and 1.2, respectively). Total biomass response (above + belowground) to nutrient additions showed a strong N and PK co‐limitation ([mean g/m2]; control = 1073, +N = 1111, +PK = 1258, +NPK = 1713). Aboveground biomass of all monocots increased with N additions, whereas dicots showed no response to nutrient additions. Trachypogon spp. (T. plumosus+T. vestitus) and Axonopus canescens, the two dominant grasses, made up more than 89 percent of the total aboveground biomass in these sites. Trachypogon spp. responded to NPK, whereas A. canescens, sedges, and the remaining monocots only responded to N. Even though nutrient additions resulted in higher aboveground biomass in N and NPK fertilized plots, this had little effect on plant community composition. With the exception of sedges, which responded positively to N additions and increased from 4 to 8 percent of die plant community, no changes were observed in plant community composition after 11 months.     

Susceptibility of Nontarget Hosts to Nosema furnacalis (Microsporida: Nosematidae), a Potential Biological Control Agent of the European Corn Borer, Ostrinia nubilalis (Lepidoptera: Pyralidae)

Nosema furnacalis Wenn whose normal host is the Asian corn borer, Ostrinia furnacalis (Guenee), is also pathogenic to the European corn borer, Ostrinia nubilaus (Hübner), making N. furnacalis a candidate biological control agent for O. nubilalis. Before N. furnacalis can be used in classical biological control, its effect on natural enemies of O. nubilalis needs to be assessed. We fed nine predator species and one parasitoid of O. nubilalis either purified N. furnacalis spores or N. furnacalis-infected larvae. Using microscopic examination and a species-specific serological assay within these natural enemies, we determined whether N. furnacalis spores were present and whether the spores had germinated. Of the 424 adult predators fed N. furnacalis spores or N. furnacalis-infected corn horers, only 2 tested weakly positive with the enzyme-linked immunosorbent assay (ELISA), indicating that ingested spores did not germinate in the adult predators. Fifteen of 130 immature predators tested weakly positive with the ELISA, but because relatively few spores were found upon microscopic examination, we concluded there was no evidence of an active N. furnacalis infection in any of the nine predator species tested. In contrast, the parasitoid Macrocentrus grandii Goidanich always tested strongly positive in the ELISA (mean O.D._{405 nm} = 1.36), indicating that sporoplasm antigens were present. Microscopic examination of this parasitoid showed that a high number of spores were present (mean spore number/larvae 1.4 × 10⁷). From these data, M. grandii might become infected with N. furnacalis.     

Bacteria associated with the roots of epiphytic orchids

This work is the first to report the isolation and identification of bacteria colonizing the roots of the tropical epiphytic orchids Acampe papillosa (Lindl.) Lindl. and Dendrobium moschatum (Buch.-Ham.) Swartz. and bacteria inhabiting inner layers of the aerial and substrate roots of A. papillosa. We showed by the example of this epiphyte that associative bacteria are present in large amounts on the aerial but not the substrate roots. We isolated and identified bacteria from the substrate roots of D. Moschatum and from its growth substrate (pine bark). The structure of the intercellular matrix of the associative bacteria was studied.Translated from Mikrobiologiya, Vol. 73, No. 6, 2004, pp. 825–831.Original Russian Text Copyright © 2004 by Tsavkelova, Cherdyntseva, Netrusov.