Characterization of Lygus hesperus (Hemiptera: Miridae) Feeding and Oviposition Injury on Celery Seedlings

2016 ◽  
Vol 17 (2) ◽  
pp. 101-105 ◽  
Author(s):  
Shimat V. Joseph ◽  
Ramon Ahedo ◽  
Maria de la Fuente
Keyword(s):  
Apium Graveolens ◽  
Adult Density ◽  
Lygus Hesperus ◽  
Central Coast ◽  
Tarnished Plant Bug ◽  
Crown Area ◽  
Diagnostic Symptoms ◽  
Coast Region ◽  
Dead Tissue

The western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), can be a serious pest of celery, Apium graveolens dulce (Mill.) Pers. in the Central Coast region of California. Little is known about injury symptoms caused by L. hesperus adults on celery. When celery seedlings were exposed to L. hesperus adults, their crown area was found destroyed with necrotic dead tissue. Destroyed crowns of dead seedlings were observed when seedlings were exposed to five or more L. hesperus adults for ≥24 h but was not observed on seedlings exposed ≤12 h. In addition, elongated lesions were noticed on the celery petiole and were significantly greater when exposed to five or more L. hesperus adults for as little as 4 h. Number of elongated lesion injuries and number of eggs recovered from elongated lesions was correlated (r = 0.66; P < 0.001). Data provide key diagnostic symptoms of L. hesperus feeding and ovipositional injury on celery seedlings. Also, this study expands our understandings on the effects of L. hesperus adult density and duration of exposure which reinforces the need for regular scouting, and immediate management decisions and action to reduce losses from L. hesperus injury in both celery seedlings and mature plants in greenhouse and field settings, respectively Accepted for publication 27 April 2016. Published 4 May 2016.

scholarly journals Impact of Lygus hesperus (Hemiptera: Miridae) Feeding and Oviposition on Lettuce

2019 ◽  
Vol 20 (4) ◽  
pp. 215-219
Author(s):  
Shimat V. Joseph
Keyword(s):  
Plant Height ◽  
Lactuca Sativa ◽  
Insect Pest ◽  
Lygus Hesperus ◽  
Tarnished Plant Bug ◽  
Feeding Sites ◽  
Lactuca Sativa L ◽  
Major Injury ◽  
Heavy Infestation ◽  
Coast Region

The western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae), is an important insect pest of lettuce, Lactuca sativa L. in the central coast region of California. However, little is documented on the injury symptoms relative to levels of L. hesperus infestation on lettuce. Experiments were conducted in which lettuce plants were exposed to 0, 1, 3, 5, and 10 L. hesperus adults for 2 and 7 days. The major injury symptom observed was lesions on the midrib of the leaves, and under low to moderate infestation (e.g., one to five adults per plant) after 2 days of exposure these lesions were not significantly different from the insect-free control. Under heavy infestation (e.g., 10 adults per plant), however, lesions developed rather quickly after 2 days of exposure. The number of lesions was positively associated with numbers of feeding sites and eggs. When heavy infestation lasted for a week, most of the plants died. At low to moderate infestation, more lesions developed compared with the insect-free control. After a weeklong exposure, an increase in number of lesions was negatively associated with plant height. The results emphasize the need for regular scouting to facilitate immediate management decisions and actions to reduce losses from L. hesperus feeding and oviposition injury in lettuce.

scholarly journals Molecular and Functional Characterization of Pyrokinin-like Peptides in the Western Tarnished Plant Bug Lygus hesperus (Hemiptera: Miridae)

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 914
Author(s):  
J. Joe Hull ◽  
Colin S. Brent ◽  
Man-Yeon Choi ◽  
Zsanett Mikó ◽  
József Fodor ◽  
...  
Keyword(s):  
Insect Cells ◽  
Functional Characterization ◽  
Biological Functions ◽  
Lygus Hesperus ◽  
Tarnished Plant Bug ◽  
Cerebral Ganglia ◽  
Peptide Expression

The pyrokinin (PK) family of insect neuropeptides, characterized by C termini consisting of either WFGPRLamide (i.e., PK1) or FXPRLamide (i.e., PK2), are encoded on the capa and pk genes. Although implicated in diverse biological functions, characterization of PKs in hemipteran pests has been largely limited to genomic, transcriptomic, and/or peptidomic datasets. The Lygus hesperus (western tarnished plant bug) PK transcript encodes a prepropeptide predicted to yield three PK2 FXPRLamide-like peptides with C-terminal sequences characterized by FQPRSamide (LyghePKa), FAPRLamide (LyghePKb), and a non-amidated YSPRF. The transcript is expressed throughout L. hesperus development with greatest abundance in adult heads. PRXamide-like immunoreactivity, which recognizes both pk- and capa-derived peptides, is localized to cells in the cerebral ganglia, gnathal ganglia/suboesophageal ganglion, thoracic ganglia, and abdominal ganglia. Immunoreactivity in the abdominal ganglia is largely consistent with capa-derived peptide expression, whereas the atypical fourth pair of immunoreactive cells may reflect pk-based expression. In vitro activation of a PK receptor heterologously expressed in cultured insect cells was only observed in response to LyghePKb, while no effects were observed with LyghePKa. Similarly, in vivo pheromonotropic effects were only observed following LyghePKb injections. Comparison of PK2 prepropeptides from multiple hemipterans suggests mirid-specific diversification of the pk gene.

Characterization of microsatellite loci in the western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae)

2007 ◽  
Vol 7 (6) ◽  
pp. 1342-1344 ◽  
Author(s):  
R. B. SHRESTHA ◽  
M. N. PARAJULEE ◽  
O. P. PERERA ◽  
B. E. SCHEFFLER ◽  
L. D. DENSMORE
Keyword(s):  
Microsatellite Loci ◽  
Lygus Hesperus ◽  
Tarnished Plant Bug

Fauna habitat modelling and mapping: A review and case study in the Lower Hunter Central Coast region of NSW

2005 ◽  
Vol 30 (7) ◽  
pp. 719-738 ◽  
Author(s):  
BRENDAN A. WINTLE ◽  
JANE ELITH ◽  
JOANNE M. POTTS
Keyword(s):  
Habitat Modelling ◽  
Central Coast ◽  
Coast Region

scholarly journals Sorbitol Transporter Expression in Apple Sink Tissues: Implications for Fruit Sugar Accumulation and Watercore Development

2005 ◽  
Vol 130 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Zhifang Gao ◽  
Sastry Jayanty ◽  
Randolph Beaudry ◽  
Wayne Loescher
Keyword(s):  
Membrane Transport ◽  
Sour Cherry ◽  
Apium Graveolens ◽  
Sugar Accumulation ◽  
Isolation And Characterization ◽  
Photosynthetic Product ◽  
Highly Hydrophobic ◽  
Major Facilitator ◽  
Transporter Expression

In apple (Malus ×domestica Borkh.), where sorbitol is a primary photosynthetic product that is translocated throughout the plant, accumulation of sorbitol in sink cells appears to require an active carrier-mediated membrane transport step. Recent progress in isolation and characterization of genes for sorbitol transporters in sour cherry (Prunus cerasus L.) and mannitol transporters in celery (Apium graveolens L.) suggested that similar transporters may be present in apple tissues. A defect in these transporters could also explain the occurrence of the fruit disorder watercore, characterized by the accumulation of fluids and sorbitol in the apoplasmic free space. Our objectives therefore included isolation and characterization of genes for sorbitol transporters in apple tissues and comparisons of expression of transporter genes, especially in various sink tissues including watercored and non-watercored fruit tissues. We have isolated and characterized two sorbitol transporter genes, MdSOT1 and MdSOT2. Sequence analyses indicated that these are members of the major facilitator transporter superfamily that gives rise to highly hydrophobic integral membrane proteins. Heterologous expression and measurement of sorbitol uptake in yeast indicated that these are specific and with high affinities for sorbitol, with Kms for sorbitol of 1.0 and 7.8 mm for MdSOT1 and MdSOT2, respectively. Sorbitol transporter expression was evident in all sink tissues tested with the exception of watercore-affected fruit tissues. Sorbitol accumulation in apple sink tissues thus involves an apoplasmic active membrane transport step and watercore results from a defect in that process.

scholarly journals Characterization of Verticillium dahliae Isolates and Wilt Epidemics of Pepper

Plant Disease ◽  
2003 ◽  
Vol 87 (7) ◽  
pp. 789-797 ◽  
Author(s):  
R. G. Bhat ◽  
R. F. Smith ◽  
S. T. Koike ◽  
B. M. Wu ◽  
K. V. Subbarao
Keyword(s):  
Verticillium Wilt ◽  
Verticillium Dahliae ◽  
Random Amplified Polymorphic Dna ◽  
Disease Incidence ◽  
Bell Pepper ◽  
Central Coast ◽  
Minor Variation ◽  
Bell Peppers ◽  
Compatibility Group

Epidemics of Verticillium wilt in pepper fields of the central coast of California and isolates of Verticillium dahliae associated with these epidemics were characterized. The mean incidence of wilted plants per field ranged from 6.3 to 97.8% in fields with Anaheim, jalapeno, paprika, or bell peppers. In general, incidence of wilt in jalapeno and bell pepper crops was lower than in crops of other types of pepper. Inoculum density of V. dahliae in the surveyed pepper fields ranged from 2.7 to 66.6 microsclerotia g-1 dry soil, and the correlation between disease incidence and density of microsclerotia was high (r = 0.81, P < 0.01). Distribution of Verticillium wilt was aggregated in a majority of the pepper fields surveyed, but the degree of aggregation varied. Vegetative compatibility group (VCG) characterization of 67 isolates of V. dahliae indicated that 67% belonged to VCG 2, 22% to VCG 4, and 11% to a new group, designated VCG 6. The pathogenicity of isolates of V. dahliae from bell pepper and tomato plants was tested by inoculating 1-month-old bell pepper (cv. Cal Wonder) and tomato (cv. EP 7) seedlings and incubating the inoculated plants in the greenhouse. Seedlings of bell pepper were susceptible only to the isolates of V. dahliae from pepper, whereas seedlings of tomato were susceptible to both pepper and tomato isolates. Pepper isolates belonging to VCG 2, VCG 4, and VCG 6 were highly pathogenic to bell pepper and chili pepper. Temperatures between 15 and 25°C were optimal for mycelial growth of a majority of isolates of V. dahliae. Molecular characterization of pepper isolates of V. dahliae using a polymerase chain reaction (PCR)-based random amplified polymorphic DNA (RAPD) technique revealed minor variation among these isolates, but unique polymorphic banding patterns were observed for isolates belonging to VCG 6. Verticillium wilt of pepper is a major production constraint in the central coast of California. More aggressive isolates of V. dahliae may have been selected in this region as a result of intensive cropping practices.

scholarly journals Comanaging fresh produce for nature conservation and food safety

2015 ◽  
Vol 112 (35) ◽  
pp. 11126-11131 ◽  
Author(s):  
Daniel S. Karp ◽  
Sasha Gennet ◽  
Christopher Kilonzo ◽  
Melissa Partyka ◽  
Nicolas Chaumont ◽  
...  
Keyword(s):  
Food Safety ◽  
Fresh Produce ◽  
Foodborne Pathogen ◽  
The United States ◽  
Livestock Grazing ◽  
Central Coast ◽  
E Coli ◽  
Vegetation Removal ◽  
Pathogen Prevalence ◽  
Coast Region

In 2006, a deadly Escherichia coli O157:H7 outbreak in bagged spinach was traced to California’s Central Coast region, where >70% of the salad vegetables sold in the United States are produced. Although no definitive cause for the outbreak could be determined, wildlife was implicated as a disease vector. Growers were subsequently pressured to minimize the intrusion of wildlife onto their farm fields by removing surrounding noncrop vegetation. How vegetation removal actually affects foodborne pathogens remains unknown, however. We combined a fine-scale land use map with three datasets comprising ∼250,000 enterohemorrhagic E. coli (EHEC), generic E. coli, and Salmonella tests in produce, irrigation water, and rodents to quantify whether seminatural vegetation surrounding farmland is associated with foodborne pathogen prevalence in California’s Central Coast region. We found that EHEC in fresh produce increased by more than an order of magnitude from 2007 to 2013, despite extensive vegetation clearing at farm field margins. Furthermore, although EHEC prevalence in produce was highest on farms near areas suitable for livestock grazing, we found no evidence of increased EHEC, generic E. coli, or Salmonella near nongrazed, seminatural areas. Rather, pathogen prevalence increased the most on farms where noncrop vegetation was removed, calling into question reforms that promote vegetation removal to improve food safety. These results suggest a path forward for comanaging fresh produce farms for food safety and environmental quality, as federal food safety reforms spread across ∼4.5 M acres of US farmland.

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