scholarly journals Damage and spatiotemporal dynamics of the Ngaio flat mite, Brevipalpus ferraguti (Trombidiformes: Tenuipalpidae), with observations on the development of the female insemination system

2021 ◽  
Author(s):  
Hector Alonso Escobar-Garcia ◽  
Francisco Ferragut
Keyword(s):  
Developmental Stages ◽  
Leaf Surface ◽  
Population Level ◽  
Early Spring ◽  
Seasonal Abundance ◽  
Lower Leaf Surface ◽  
Abaxial Surface ◽  
Mite Density ◽  
Autumn And Winter ◽  
Considerable Damage

AbstractWe studied the Ngaio flat mite, Brevipalpus ferraguti Ochoa & Beard, on Myoporum laetum (Scrophulariaceae), a common introduced plant used as hedgerows in gardens and green areas of the Mediterranean, where the mite causes considerable damage. We first describe the damage, and then the patterns of mite seasonal abundance and spatial distribution. Finally, we address the development of the female insemination system at the population level. Damage occurs on both sides of the leaves, starting with a uniform stippling and bronzing and ending in the leaves drying out and extensive defoliation that coincides with summer. Mite population peaked between June and August, maintained moderate levels in autumn and winter and reached its lowest density in early spring. Active motile immatures and eggs were present throughout the year. Females and motile immature forms were more abundant on the abaxial (lower) leaf surface, but eggs were deposited on both surfaces indistinctly, suggesting that females actively move to the adaxial (upper) surface in summer to oviposit. All the developmental stages were aggregated on the leaves throughout the year regardless of their population density. Our study suggests that a binomial or presence-absence sampling, examining only the number of females on the abaxial surface, can accurately estimate the total mite density levels. Only 23.5% of females possessed a fully developed spermatheca, whereas in 76.5% of the cases the seminal receptacle was not present or not developed. Females with a complete spermatheca were less abundant in summer. Average temperatures and host plant species affected the occurrence of this reproductive structure.

Studies on Ergasilus labracis Krøyer (Cyclopidea: Ergasilidae) parasitic on striped bass, Morone saxatilis, from the lower Chesapeake Bay. I. Distribution, life cycle, and seasonal abundance

1976 ◽  
Vol 54 (4) ◽  
pp. 449-462 ◽  
Author(s):  
I. Paperna ◽  
D. E. Zwerner
Keyword(s):  
Life Cycle ◽  
Chesapeake Bay ◽  
Striped Bass ◽  
Egg Production ◽  
Developmental Stages ◽  
Morone Saxatilis ◽  
Early Spring ◽  
Seasonal Abundance ◽  
Free Living ◽  
Winter Peak

Information on the distribution, life cycle, and seasonal abundance of the copepod Ergasilus labracis Krøyer, parasitic on the gills of lower Chesapeake Bay striped bass, Morone saxatilis (Walbaum), is presented after a 12-month survey. The overall prevalence of E. labracis was 90% in all localities sampled and it was found to be as euryhaline as its host; it has been found in salinities from 0.l‰ to 32.0‰. E. labracis was present and reproductively active throughout the year, suffering only a temporary slowdown in egg production at the beginning of the winter. Peak invasion of striped bass gills by infective larvae occurred during April and May; minor peaks were also recorded during July and October. The free-living stage was estimated to last as long as 6 weeks during early spring. Duration of other developmental stages was also extrapolated. Attempts to rear larvae in the laboratory past the metanauplius stage failed. Larvae could be kept for a maximum of 23 days after hatching if fed nannoplankton and kept at 20 °C in river water of 16–18‰.

Ectopic growth of the fungal symbiont (Chaetothyriales) on Ipomoea carnea

Botany ◽  
2021 ◽  
Author(s):  
Aziza Ibrahim Noor ◽  
Amy Nava ◽  
Marwa Neyaz ◽  
Peter Cooke ◽  
Rebecca Creamer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Storage Disease ◽  
Growth Habit ◽  
Leaf Surface ◽  
Livestock Grazing ◽  
Lysosomal Storage ◽  
Lower Leaf Surface ◽  
Ipomoea Carnea ◽  
Show Evidence ◽  
Glycoprotein Processing

Swainsonine, an indolizidine alkaloid, is an alpha-mannosidase and mannosidase II inhibitor that alters glycoprotein processing and causes lysosomal storage disease. Swainsonine is the toxic principle in several plant species worldwide and causes severe toxicosis in livestock grazing these plants. All swainsonine-containing plant taxa investigated to date are associated with fungal symbionts that produce swainsonine. Among the swainsonine-containing convolvulaceous species, Ipomoea carnea is associated with a seed transmitted symbiont belonging to the fungal order Chaetothyriales. The nature of this association was unclear therefore this association was investigated further using microscopy. Macroscopic and microscopic data reported here demonstrate that the Chaetothyriales symbiont associated with I. carnea grows ectopically on the adaxial (upper) surface of leaves as lacy mycelia in plants that contain swainsonine and was not present on plants lacking swainsonine that were derived from fungicide treated seeds. Hyphae were not observed on the surface of any other tissues including the abaxial (lower) leaf surface, petiole, and stem. Mycelia were not visible in internal tissues below the epidermis and there did not appear to be any hyphal extensions within the fibrovascular bundles or stomata. Longitudinal and/or cross sections of the stems or petioles did not show evidence of hyphae growing between cells. These results suggest an epibiotic growth habit of the Chaetothyriales symbiont in association with I. carnea.

Peronospora anemones. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
New Zealand ◽  
Botrytis Cinerea ◽  
Downy Mildew ◽  
Geographical Distribution ◽  
Primary Infection ◽  
Leaf Surface ◽  
Plant Debris ◽  
Lower Leaf Surface ◽  
Glass Slides ◽  
Secondary Infections

Abstract A description is provided for Peronospora anemones. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Anemone coronaria, A. globosa. DISEASE: Downy mildew of anemones. Infected leaves lose their natural bloom, appearing dull green, almost grey in colour and are often down curled giving the plant a rounded appearance. As the disease progresses, leaf colour may change to shades of pink or purple with necrotic areas appearing on the older leaves. Invasion by secondary organisms (e.g. Botrytis cinerea) is common, especially after frost or storm injury, and this accelerates plant death. In favourable conditions conidiophores develop forming a whitish-grey down on the lower leaf surface, on the bracts and, less frequently, on the petioles. It is not uncommon for affected plants to show little or no sporulation and in these cases the presence of extensive intercellular mycelium and, later in the season, oospores in petioles and peduncles helps diagnosis. GEOGRAPHICAL DISTRIBUTION: Australasia (New Zealand); Europe (England, Jersey, France, Italy, Netherlands). TRANSMISSION: Primary infection is caused by oospores in plant debris in the soil. Tramier (1963) was unable to germinate oospores and thus work out precise details of the conditions affecting their germination but he showed evidence that regular and prolonged rain encouraged germination. Conidia, which cause secondary infections, are dispersed by rain and during harvesting of the flowers. Wind is thought to be unimportant in their dissemination as shown by glass slides covered with vaseline and placed near an infected crop (Tramier, 1965).

New and noteworthy Melastomataceae from the Yanachaga-Chemillén National Park and surrounding areas in Oxapampa, Pasco, Peru

Phytotaxa ◽  
2018 ◽  
Vol 374 (3) ◽  
pp. 185 ◽  
Author(s):  
FABIÁN A. MICHELANGELI ◽  
RENATO GOLDENBERG
Keyword(s):  
National Park ◽  
Leaf Surface ◽  
Nodal Line ◽  
Abaxial Surface ◽  
North East ◽  
The North ◽  
The Andes ◽  
Abaxial Leaf Surface ◽  
Surrounding Areas ◽  
Sclerophyllous Forests

We describe six new species of Melastomataceae from the Yanachaga-Chemillén National Park and surrounding areas from the Department of Pasco, Province of Oxapampa in Central Peru. Macrocentrum andinum is the first species of the genus described from the Andes, found along creeks at 400–500 m elev. and characterized by its anysophyllous leaves, pubescent stems and four-merous flowers. Meriania rubriflora is found in forests above 2200 m elev. and it is characterized by stem nodes with stipular flaps, leaves with an acute base and four merous, deep red flowers. Miconia palcazuana is found along rivers and streams at 300–400 m on the eastern flank of the park, and it can be distinguished by its flowers with pink anthers with glands on the connective and narrowly oblanceolate to elliptic-lanceolate leaves. Miconia yanachagaensis grows in the dwarf-sclerophyllous forests at the top of ridges and grasslands over 2800 m elev. and it is characterized by its long dendritic-pedicellate trichomes on the abaxial leaf surface, the stems flattened to terete and the presence of a conspicuous annular nodal line. Triolena rojasae is found growing on rocks along the Palcazú River and its tributaries, and it is characterized by its lanceolate-crenate leaves. Triolena vasquezii grows on the northern end of the Huancabamba canyon and the North East portion of the park and can be distinguished by its pustulate leaves with purple abaxial surface and anthers with two ventral appendages. We also present the first report of the genus Wurdastom for Peru.

scholarly journals Effect of Fungicide Mobility and Application Timing on the Management of Grape Powdery Mildew

Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1167-1174 ◽  
Author(s):  
Brent Warneke ◽  
Lindsey D. Thiessen ◽  
Walter F. Mahaffee
Keyword(s):  
Powdery Mildew ◽  
Leaf Surface ◽  
Quality Standards ◽  
Pinot Noir ◽  
Abaxial Surface ◽  
Phenological Stages ◽  
Application Timing ◽  
Abaxial Leaf Surface ◽  
Detached Leaves ◽  
Grape Powdery Mildew

Grape powdery mildew (GPM) fungicide programs consist of 5 to 15 applications, depending on region or market, in an attempt to achieve the high fruit quality standards demanded by the market. Understanding how fungicides redistribute and targeting redistributing fungicide to critical crop phenological stages could improve fungicide protection of grape clusters. This study evaluated fungicide redistribution in grapevines from major fungicide groups labeled for GPM control. Translaminar and xylem redistribution was examined by placing fungicide-impregnated filter disks on the adaxial or abaxial leaf surface of detached leaves for 10 min and then incubating for 48 h before inoculating the abaxial surface with conidia. Vapor redistribution used Teflon disks sprayed with fungicides and placed on the abaxial leaf surface of detached leaves 48 h before inoculation. Disease development was rated 10 days later. Translaminar movement through calyptra was tested using flowering potted vines. All fungicides tested redistributed through at least one mechanism. Fungicide timing at critical phenological stages (early, mid, and late bloom) was assessed in small plots of cultivar Pinot noir vines. The application of trifloxystrobin, quinoxyfen, or fluopyram at different bloom stages showed that applications initiated at end of bloom resulted in the lowest berry infection probabilities of 0.073, 0.097, and 0.020, respectively. The results of this study suggest that integrating two carefully timed applications of redistributing fungicides initiated at end of bloom into a fungicide program may be an effective strategy for wine grape growers in western Oregon to produce fruit with low GPM infection.

Seasonal Abundance and Population Dynamics of a Bamboo Aphid, Takecallis arundinaria (Homoptera: Aphididae)

1990 ◽  
Vol 25 (4) ◽  
pp. 526-534 ◽  
Author(s):  
Mark A. Coffelt ◽  
Peter B. Schultz
Keyword(s):  
Population Dynamics ◽  
Life Cycle ◽  
Plant Species ◽  
Woody Plant ◽  
Early Spring ◽  
Climatic Conditions ◽  
Seasonal Abundance ◽  
Alternate Host ◽  
Woody Plant Species ◽  
Aphid Populations

The anholocyclic life cycle of the aphid Takecallis arundinaria (Essig) on golden stem bamboo, Phyllostachys aurea (Carrie're) was investigated in 1987 – 1988. Aphid populations peaked from March – May, declined from June – October, and peaked again in December. Aphid population dynamics were strongly influenced by climatic conditions. When aphid populations were at constant or rising levels, significantly more nymphs were found in the southern and eastern quadrants, than in the northern and western quadrants. This directionality may have allowed T. arundinaria populations to be exposed to increased sunlight and decreased winds during the winter and early spring periods. Alate viviparae had a mean fecundity of 147 nymphs and a longevity of 46.5 days. Predators were few and no parasites were found. An alternate host study revealed no aphids on yellow sticky traps placed on nine woody plant species.

The drift of Trichoptera larvae in a river with a disturbed hydrological regime

Zoosymposia ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 481-496
Author(s):  
MARIUSZ TSZYDEL ◽  
ELIZA SZCZERKOWSKA-MAJCHRZAK
Keyword(s):  
Current Velocity ◽  
Developmental Stages ◽  
Hydrological Regime ◽  
Head Capsule ◽  
Control Site ◽  
Running Water ◽  
Flow Fluctuations ◽  
U Value ◽  
Study Sites ◽  
Autumn And Winter

The aim of the study, carried out in a section of the Drzewiczka River downstream of a dam reservoir and a white-water canoeing track, was to estimate seasonal changes in the number of drifting invertebrates, especially Trichoptera and their body size and weight as compared with individuals living in benthos. It was also important to determine environmental factors which have the most significant influence on transported invertebrate fauna.      The abundance of Trichoptera in benthos and drift was estimated for stonegravel habitats at 2 study sites; one just downstream of a canoeing track, which underwent flow fluctuations, marked as disturbed (D), and the other, control site (N), 10 km farther downstream, where no changes caused by 2 hydro-constructions were noticed.      The percentage of dominant Trichoptera in drift [U coefficient, %] ranged from 0.0001 (Hydropsyche contubernalis McLachlan) to 0.06 (Halesus sp.). The U value for Trichoptera was 0.0005 and 0.012 at the 2 study sites, respectively, which indicates that when there was no correlation with the flow/current velocity, drifting preferences of Trichoptera were random or dependent on seasons, seasonal reservoir management, and larval concentration in the benthos, and at the same time independent of canoeist training. The highest number of drifting individuals was observed between March/April and August/September. This might be connected with a release of a larger amount of water from the impoundment after spring thaw and autumn rain, especially because sudden increases in water level and current velocity were noticed at that time.      The increase in abundance of early developmental stages (juvenile) of caddis larvae in drift took place mainly in autumn and winter, whereas larvae at more advanced developmental stages were more frequently noticed in late spring. The differences in Trichopteran sizes at their 3th, 4th and 5th larval instars representing benthos and drift were observed by comparing the width of the head capsule [mm] and body mass [mg] of the examined individuals. Organisms transported in running water were definitely smaller than benthic ones, with the exception of the most developed larvae of H. pellucidula (Curtis).

scholarly journals Botryosphaeriaceae Species Spore-Trapping Studies in California Vineyards

Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 717-724 ◽  
Author(s):  
J. R. Úrbez-Torres ◽  
M. Battany ◽  
L. J. Bettiga ◽  
C. Gispert ◽  
G. McGourty ◽  
...  
Keyword(s):  
Strong Relationship ◽  
Early Spring ◽  
Seasonal Abundance ◽  
Petroleum Jelly ◽  
Riverside County ◽  
Spore Release ◽  
Spore Trapping ◽  
Rain Events ◽  
Microscope Slides ◽  
Glass Microscope

The seasonal abundance of Botryosphaeriaceae spp. spores was studied in California vineyards by using glass microscope slides covered with petroleum jelly placed on grapevine cordons and Burkard volumetric spore traps at seven and two different locations, respectively. Correlation analysis was used to determine which meteorological variables (precipitation, relative humidity, temperature, and wind speed) influenced Botryosphaeriaceae spp. spore release. Among all variables, regression analysis resulted in a strong relationship between spore release and precipitation. Additionally, a positive relationship between irrigation and spore release was also observed in the Riverside County vineyard. During the study period, spore discharge of Botryosphaeriaceae spp. occurred from the first fall rain through the last spring rains, coinciding with September to April. However, based on the results obtained from the spore traps, most spores (over 60%) were trapped following rain events during the winter months of December, January, and February, which coincides with the grapevine pruning season. Botryosphaeriaceae spp. spore release was much lower in fall and early spring (22%) and very few or no spores were trapped in late spring and summer (3%). This work suggests that a delay of pruning time in California may be warranted to reduce grapevine infection because the current timing coincides with the greatest period of spore discharge.

Reproduction of paua, Haliotis iris Gmelin 1791 (Mollusca:Gastropoda), in north-eastern New Zealand

1995 ◽  
Vol 46 (3) ◽  
pp. 617 ◽  
Author(s):  
SH Hooker ◽  
RG Creese
Keyword(s):  
New Zealand ◽  
Gonad Index ◽  
Sharp Decrease ◽  
Late Summer ◽  
Early Spring ◽  
Reproductive Pattern ◽  
Marine Gastropods ◽  
North Eastern ◽  
Males And Females ◽  
Autumn And Winter

An examination of the reproductive condition of a population of paua, H. iris, at Leigh in north-eastern New Zealand during 1986-87 revealed a long breeding season extending from late summer through autumn and winter and into early spring. Within this period, a sharp decrease of over 60% in the gonad index for both males and females indicated major spawning events in July and October. A smaller decrease in the gonad index in March suggested a third, minor spawning. These spawning events were confirmed by regular examination of histological sections of gonadal material. This breeding pattern is different from that previously described for southern localities in New Zealand, where spawning activity is limited to a four-month period from late summer into autumn. Paua in this northern population had a sex ratio slightly biased towards males (1 female to every 1.3 males) and achieved reproductive maturity between the sizes of 48 and 60 mm shell length. These features are also different from those described for southern populations of H. iris. These findings highlight the need to take regional differences in reproductive pattern into account when describing the population dynamics of marine gastropods.

scholarly journals Distribution pattern of developmental stages of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) on the surface of citrus leaves

2020 ◽  
Vol 1 (89) ◽  
pp. 1-6
Author(s):  
Meriem Dahmane ◽  
Gahdab Chakali
Keyword(s):  
Developmental Stages ◽  
Leaf Surface ◽  
Leaf Age ◽  
Pupal Stage ◽  
Phyllocnistis Citrella ◽  
Citrus Leafminer ◽  
Leaf Surfaces ◽  
Young Leaves ◽  
Citrus Orchards ◽  
Citrus Leaves

The leafminer Phyllocnistis citrella (Stainton, 1856) (Lepidoptera: Gracillariidae), is considered a potential serious pest of citrus in Algeria. The aim of this work was to investigate the relationship between the ecophases of the citrus leafminer and the leaf surface of the Washington navel citrus variety. Practically all the examined leaves of the young shoots were occupied by at least a developmental stage of this insect. More than 80% of the leafminer ecophases were distributed on the lower surfaces of the leaves. A relationship is highlighted between the leaf surfaces and the stages evolution of citrus leafminer. The choice of area laying by females is decisive for the survival and evolution of stages of development of the insect in relationship with leaf age. The analysis of the eggs distribution revealed that young leaves, with leaf surface smaller than 2 cm², were significantly preferred by females for oviposition. However, the larvae were abundant on leaf surfaces smaller than 6 cm² which provide a favorable environment for the development of larvae in order to realize their respective gallery. The pupal stage was observed almost uniformly on all the analyzed area classes. These results could contribute to the guidelines for pest risk assessment highlighting the intervention for the protection of citrus orchards against heavy infestations of Phyllocnistis citrella.

Sign in / Sign up

Export Citation Format

Share Document