Loss Of Setae Research Articles

Biological control of fall webworm larva (Hyphantria cunea Drury) and growth promotion of poplar seedlings (Populus × canadensis Moench) with Bacillus licheniformis PR2

The production of Populus × canadensis Moench seedling, as an important restoration resource has been constrained by the invasion of Hyphantria cunea Drury, a polyphagous pest that causes leaf feeding damage on nursery seedling production. This study investigated the larvicidal potential of cuticle degrading chitinase and protease enzymes secreted by the Bacillus licheniformis PR2 against H. cunea larvae. In addition, we investigated the growth promotion of P. canadensis seedling through the auxin belonging to plant growth hormones. Treatment of H. cunea larvae with either the bacterial crude enzymes or bacterial culture broth from B. licheniformis PR2 under laboratory conditions resulted in larvae mortality due to the severe degradation of the cuticle characterized by the loss of setae, swelling of sockets, and rupturing of the epicuticle and procuticle, and also caused a repellent effect from leaves, when the larvae suffered minor lacerations only in the epicuticle except the procuticle. Application of B. licheniformis PR2 culture broth on P. canadensis seedlings in the greenhouse experiment caused a mortality rate of 34.4 % and a repellency rate of 75.0 % against H. cunea larvae and reduced the leaf damage rate by 3.7-folds to only 25.9 % compared to 96.3 % in the control group. Accordingly, treatment with B. licheniformis PR2 improved seedling growth by reducing foliar damage caused by H. cunea larvae. In addition, B. licheniformis PR2 produced indole-3-acetic acid (IAA), which improves root hair growth and lateral root development to increase the surface area for nutrient uptake. Thus, inoculation of B. licheniformis PR2 improved the leaf chlorophyll content (photosynthetic rate) of the P. canadensis seedlings by 1.9-folds to 43.26 units compared to 23.26 units in the control group. Consequently, the application of B. licheniformis PR2 also improved the shoot, root, and leaf dry weights by 3.4-, 1.5- and 1.6-folds compared to the control group, respectively. Therefore, this study demonstrates the dual larvicidal and plant growth-promoting potential of B. licheniformis PR2, as an environmentally friendly alternative to chemical pesticides in the control of H. cunea larvae and production of healthy P. canadensis seedlings in the forest nursery.

Setal anomalies in the tropical earthworms Drawida willsi and Lampito mauritii exposed to elevated concentrations of certain agrochemicals: An electron micrographic and molecular docking approach

Abstract Setae are the functional organelle in the earthworms which act as anchors and thus are crucial for locomotion. Structural anomaly or loss of setae could result in significant functional loss in these animals. The present study reports novel observation on setal anomalies in two tropical earthworms, Drawida willsi and Lampito mauritii exposed to elevated concentrations of the agrochemicals, monocrotophos, glyphosate, urea, phosphogypsum (PG) and paper mill sludge (PMS) in soil. Three concentrations of monocrotophos (1.0, 2.0, 3.0 g/kg soil), glyphosate (0.1, 0.15, 0.2 g/kg soil), urea (0.5, 1.0, 1.5 g/kg soil), PG (50, 100, 150 g/kg soil) and PMS (5, 10, 15 g/kg soil) were used as per recommended agricultural doses and the animals were exposed for 24 h in treated soils to observe their effects on the setae. Scanning electron microscopic images revealed various setal structural deformities in both the worms. Urea had the maximum deleterious impact relative to other test chemicals. Computational analysis indicated that the high binding affinity of urea with the chitin of setae was responsible for the maximum conformational changes in the later. Setal anomalies could be used as early signal markers to evaluate soil toxicity.

Evaluasi Toksisitas Ekstrak Metanol Daun Jeruk Nipis (Citrus aurantifolia) terhadap Kematian Larva Nyamuk Aedes aegypti

The vector-borne diseases transmitted by the mosquito of Aedes aegypti are considered causes of serious health problems. Moreover, the used of chemical insecticides for Ae. aegypti control has resulted in resistance in mosquito populations and environmental problem. The aims of this study are to evaluate the toxicity of methanol extract (CH3OH) from key lime leaves against Ae. aegypti larvae after 24 hours exposure. This was experimental laboratory study, with six treatments and five replicates. Larvae mortality was observed after 24 hours exposure. Then, data were analyzed by descriptive analyze and probit. visualization of the damage that occurs in the body was observed through microscope. The result showed that mortality of larvae increased with an increase of the concentration of extract. LC50 and LC99 of the extract are 2,197 ppm and 4,266 ppm. The extract can cause morphological damages of larvae, such as head lost, neck elongation, exo-skeleton lost, abdomen transparent, digestive tract full of extract, and loss of setae on the side of the body. In conclusion, citrus aurantifolia leaves methanol extract cause mortality and morphological damages of larvae

Cu toxicity on growth and chlorophyll-a of Chaetoceros sp.

Phytoplankton is a primary producer in marine aquatic ecosystem. Their sensitivity to metal makes them important to study to predict the environmental impact of pollution. Copper is an essential nutrient for aquatic life as micronutrients on an organism but toxic at high levels. The focus of this study was to assess the toxicity of copper to Chaetoceros sp. on growth and chlorophyll-a content. The result shows that inhibition concentration (IC50) of copper on the microalgae, Chaetoceros sp. was 30.25 μg L-1. Growth of Chaetoceros sp. decreased 16.84% in 16 μg L-1 and 81.97% in 44 μg L-1. Chlorophyll-a content decreased dramatically at 44 μg L-1 compared to control. Increase of the cell size, deformation of cell wall and loss of setae were observed at higher concentration of copper.

Does pleopod setation provide a measure of maturity in female southern rock lobsters <i>Jasus edwardsii</i>?

Processes affecting the estimation of the size at onset of maturity (SOM) using ovigerous setae were investigated in southern rock lobsters Jasus edwardsii. Comparison of estimates of SOM based on ovigerous setae in samples collected during summer months (December-March) with those based on the presence of external eggs from winter months (June-August) indicated that ovigerous setae provide an accurate classification of maturity. Females with partially developed setation on pleopods are frequently observed in research catch-sampling projects and their maturity status was unclear. Our results show that these females with partially developed setae are most appropriately classed as immature, based on comparison between estimates of SOM determined by presence of external eggs or setae. The seasonal timing of field sampling affected estimates of SOM based on ovigerous setae, though tag-recapture data indicated that this was not associated with a loss of setae during a second annual moult. Estimates of SOM for populations of Jasus edwardsii around Tasmania can be based on maturity classification using ovigerous setae but care should be taken to ensure that seasonal timing of sampling is consistent.

Phylogeny and character evolution of the marine mite genus Isobactrus (Acari: Halacaridae)

A morphology-based phylogenetic analysis of the 24 species of Isobactrus (Acari: Halacaridae) demonstrated three major monophyletic groups supported by synapomorphies. Each group is geographically distinct being tropical Pacific, North Atlantic and Holarctic. Character optimization indicates some evolutionary tendencies of character transformation. Reduction of idiosomal lateral setation, loss of setae on the genu and the addition of female subgenital setae are postulated synapomorphies congruent throughout the tropical lineage. Similarly, setal addition on the telofemur occurred in the North Atlantic lineage, while reduction of genital area sclerotization is recognized in a northern phyletic group.

Modelling Si-N-limited growth of diatoms

A mechanistic model for silicon (Si) physiology is developed, interfaced with a model of nitrogen IN) physiology, which is capable of simulating the major documented facets of Si-N physiology in diatoms. The model contains a cell cycle component that is involved in regulating the timing ol the synthesis of valves, girdles and setae. In addition to reproducing the timing of diatom cell division within a light- dark cycle, the model simulates the following features seen in real diatoms. Synthesis of valves only occurs during G 2 interphase and M, while the girdles and (if appropriate) setae are synthesized during G 1 Si stress alone results in a loss of setae, followed by a thinning of the valves in successive generations until a minimum Si cell quota is attained. After this point, the duration of G 2 increases and growth is Si limited. Concurrently, the carbon (C) cell quota increases, offering the capability to simulate the documented increase in sinking rates with Si stress. N stress alone results in an increase in the duration of G 1 and G 2 interphases, and high Si cell quotas, From this complex model which must be run for arrays of subpopulations to simulate non-synchronous growth, a simpler model is developed. This is capable of reproducing similar growth dynamics, although with no reference to component parts of the frustule. When allied to a photoacclimative submodel, a prediction of the model is that diatoms starved of Si will release increased amounts of dissolved organic C because cell growth is halted more rapidly than the photosystems can be degraded.

Naupliar development ofParastenhelia megarostrum(Copepoda: Harpacticoida), and its bearing on phylogenetic relationships

The six nauplius stages of Parastenhelia megarostrum are described in detail and significant autapomorphies are revealed, viz. loss of seta on the mandibular basis of NI and NII, the large size of the basis and exopod of the mandible, the simplification of the mandibular endopod seta and the armature of the antennal endopod claw. Larval, juvenile and adult characters confirm Lang's earlier positioning (1948) of the Parastenheliidae in close phyletic proximity to the Thalestridae.

Comparative mouthpart morphology and evolution of the carnivorous heptageniidae (Ephemeroptera)1

Mouthparts of the carnivorous mayfly larvae in the family Heptageniidae are detailed and compared to each otheras well as to generalized, non‐carnivorous heptageniid mouthparts. The three carnivorous forms are presently classified in the genera Anepeorus, Spinadis, and Pseudiron, although proper application of these names to larval stages is tentative. Autapomorphies in each of the carnivores are numerous. General loss of setae and development of impaling structures are not used as phyletic data since they are subject to convergence in carnivores in general; however, synapomorphies involving maxillary crown spinal plates, the superlinguae, and labial palpi suggest a common carnivorous ancestor for the group and strongly suggest that Spinadis and Pseudiron are sister groups. General facies support this. Behavioral studies indicate that, contrary to previous reports and drawings, the legs of live Pseudiron larvae orient forward and the femoral setal row is posterior, just as in other heptageniids.

The genus Symploce Hebard. III. Species from Borneo, Flores, India and the Philippines. (Dictyoptera: Blattaria, Blattellidae)

[Chaetotaxy of thorax and abdomen in a number of genera of the subfamilies Pseudachorutinae and Neanurinae is analysed. The most complete (primitive) chaetotaxy is found in members of Pseudachorutes/Pseudachorutella. The genus Anurida displays several reductional stages demonstrating a postero-anterior sequence in loss of setae on the tergites. Reduction in number of axial setae shows apparent parallelism between distant groups. Nearly all genera of the Neanura complex have a rather advanced chaetotaxy characterised by loss of seta P1 on Abd. 1-4. The same chaetotaxy is found in Paranura which is clearly linked to the hammerae group of Anurida. The two species Anurida vulcanica sp. n. (Washington) and A. luciae sp. n. (NE Siberia) are described., Eight species of Symploce are described, of which the following 5 are new: busuangensis (Philippines),juxtafalcifera (Kalimantan, Sabah, Sarawak, Philippines, Singapore), talinasensis (Philippines), tibangensis (Sarawak), and torrevillasi (Philippines), Symploce falcifera (Hanitsch) (Sarawak), telephoroides (Walker) (India), and dispar Princis (West Flores) are redescribed. A key is provided for determining males.]

The Genus Drepanaphis Del Guercio (Homoptera: Aphididae)12

The genus Drepanaphis Del Guercio is known only from North America. The usual host is Acer; however, 1 species occurs on Aesculus. The 17 described species, 4 of which are new, can be grouped into 5 homogeneous groups of 3 species each. The remaining 2 species seem to be more closely related to the monelli-group than any other. The utahensis -group includes utahensis Knowlton and Smith, granovskyi Smith and Knowlton, and simpsoni Smith. These are the only species which have pleural setae on the sixth abdominal segment of the nymphs and 2 pairs of frontal setae in the adults. The monelli-group includes monelli (Davis), spicata Smith, and knowltoni, new species, which are very similar morphologically in both nymphal and adult stages, but are distinctly separated from one another by locality and host. A fourth species, keshenae Granovsky, does not fit the monelli group very well but is probably more closely related to it than to any other group. The acerifoliae-group contains acerifoliae (Thomas), carolinensis Smith, and sabrinae Miller. They differ from other species in bearing 4 pairs of conspicuous dorsal abdominal tubercles, but only 1 pair of frontal setae in the adults. The species in the parva -group, consisting of idaboensis, new species, saccbarini, new species, and parva Smith, are very similar morphologically as adults and nymphs but have distinct hosts. The most specialized group is the nigricans -group, which contains nigricans Smith, tissoti Smith, and choanotricha, new species. The nymphs in this group show a strong tendency toward loss of setae. All 3 species look quite alike when alive, and are small with relatively long antennae. The dorsal abdominal setae are distinctly expanded distally. D. kanzensis Smith is difficult to place with any certainty. It shares characteristics with the monelli -group as well as the parva -group. It is probably most closely related to the monelli -group. Keys and descriptions are given for all species. A closely related genus, Shenahweum Hottes and Frison, is similar to Drepanaphis but the siphunculi are truncate rather than swollen at the base as in Drepanaphis. Also, in Shenahweum the flange is weak and inconspicuous, and the sensorial pattern of a.s. VI is different. S. minutum Davis has the same habits as Drepanaphis species, and the nymphs have the same basic chaetotaxy.