Abstract. A 3-yr study was conducted in California’s southern San Joaquin Valley to determine the overwintering survival of the corn leafhopper, Dalbulus maidis. The corn leafhopper, Dalbulus maidis (Delong and Wolcott) is found only in subtropical and tropical areas of America. Its host range is limited to maize and its . The corn leafhopper, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae), is one of the most important pests of corn, Zea mays L. (Poaceae), in Latin.
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However, the leafhopper is a significant pest as a vector of three stunting pathogens: In both years, corn planted adjoining a corn field that had high leafhopper population the previous season was colonized almost immediately after seedling emergence. Cicadulina mbila Naude – maize leafhopper.
Plates were coated overnight, and samples were prepared and applied the next day. The combination of leafhopper feeding and disease resulted in substantial yield and quality losses. The absence of food is rarely a cue for diapause induction Denlinger For further information, we recommend you visit the following resources: Infected leafhoppers were recovered throughout the winter and spring in all 3 yr.
Infection and replication sites of Spiroplasma kunkelii Class: Multiplication of corn stunt spiroplasma in Dalbulus maidis and transmission in vitro following injections. The pathogens multiply in the vector and undergo a latent period; after the corn leafhopper acquires the pathogen by feeding on an infected plant, a period of 2 weeks for MRFV, and weeks for CSS and MBSP, must pass before vectors become inoculative.
The zeros in trap catches from December to February corresponded with cold weather and problems in maintaining the trap line because of localized flooding.
The mild winter of resulted in the survival of large numbers of volunteer corn plants throughout the entire winter. Since then, the presence of leafhopper populations and the incidence of corn stunt disease have continued yearly in the southern San Joaquin Valley SJV. Maize response to corn leafhopper Homoptera: Some of these morphological features are now being re-described, while others have been observed for the first time in the Cicadellidae family, as the center-flagellar material.
The number of hectares of corn grown for silage in the two counties increased dalbulks 18, in to 76, inmore than a 4-fold increase Kings and Tulare County Agricultural Crop and Livestock Reports This observation suggested to dalbuuls that the leafhopper was overwintering in the area rather than migrating here from Mexico.
Since that outbreak, dalbylus leafhopper was not reported again until the late s Bushing and BurtonBushing et al.
Evolutionary relationship between maize leafhoppers and their host plants. Biological studies on the corn leafhopper Dalbulus maidis Insecta-Cicadellidae in Tucuman, Argentina.
As few as two adult leafhoppers were able to produce a CSS dalbulud, but in most cases, samples from which DNA was extracted contained five insects. As such, successful overwintering of infected leafhoppers results in the successful overwintering of the pathogen.
maize leafhopper (Dalbulus maidis)
Design of a polymerase chain reaction for specific detection of corn stunt spiroplasma. In California, before the outbreak, leafhoppers appeared only late in the season August and Septemberthus giving credence to the theory that they migrated northward from Mexico, arriving late in the growing season. The gaps in collections represent periods of particularly cold weather, when temperatures were below the flight threshold.
Apparently, damage was due solely to leafhopper feeding, because no evidence of corn stunt amidis was reported. As soon as the soil begins to warm in the spring, usually by early February, germination begins again, and seedling corn may be present in midis.
Hence, we re-describe the sperm morphology of this species using light microscopy and transmission electron microscopy. Our findings that females overwinter in substantially higher numbers than do males agree with those of Larsen et al.
Because there are no overwintering hosts for D. Volunteers extended the season by as much as 2 mo, thus shortening the period of time the leafhoppers were forced to go without a food source. Continuing to use www. During the s, there was a substantial migration of the dairy industry from southern California to the southern SJV, dalnulus Tulare and Kings counties.
Vernon provided information on corn acreage in Tulare and Kings Counties. Positives were at least 2. In addition, infection with S. They concluded that D. Cicadellidae dalbluus and achaparramiento disease.
Differential pathogenicity of corn stunt spiroplasma to its Dalbulus leafhopper vectors: In all the spermatozoa observed, the final portion of the flagellum was branched into four filaments.
Corn leafhopper overwintering biology was never investigated. Cicadellidae vectors infected with Spiroplasma kunkelii Mycoplasmatales: The reason for the change in leafhopper dynamics, from the cyclic pest observed from the s to the s to its current persistent pest status, is not fully understood.
In cross-section, it has a thumbtack shape, except in the anterior and posterior regions, where it is oval.
The corn leafhopper has only rarely been reported as a direct pest of maize, causing feeding damage and decline of the host by the removal of plant sap.
Also, the absence of the leafhopper in Imperial Dalbuluus E.
All three stunting pathogens are persistently transmitted by the corn leafhopper; once an insect becomes a vector, it transmits for life. Temperatures in the SJV generally begin a downward trend during September through November, well in advance of freezing conditions, allowing ample time for adults to become preconditioned to colder temperatures. Commercially planted corn in grower fields was also examined for the presence of leafhoppers and tested for the occurrence of the spiroplasma.
Dalbulus maidis does not enter diapause or another state of dormancy during the Mexican winter Larsen et al. In designated cold and wettemperature averaged 2.