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.
Those collections 11 March occurred before spring planted corn emerged. Our findings that females overwinter in substantially higher numbers than do males agree with those of Larsen et al.
Overwintering leafhoppers easily acquire the spiroplasma in the spring and transmit it to newly planted corn. 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 acrosome is paracrystalline and has the bifurcated base that is docked in two cavities on one side of the anterior region of the nucleus.
Purcell concluded that regular spring migrations from Mexico might explain the reappearance of D. Their spermatozoa measured from Duringadults were captured each month Fig. 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 actuality, the host-free period is much shorter in most years because volunteer corn plants, arising from seeds remaining in the field after harvest, appear after the first fall rains or an irrigation.
Receive exclusive offers and updates from Oxford Academic. The traps were replaced weekly or biweekly, depending on weather conditions.
Multiplication of corn stunt spiroplasma in Dalbulus maidis and transmission in vitro following injections. In addition, many fields had a high incidence of corn stunt disease, and S. C Casela, R Renfro, A.
This paper reports the results of studies conducted dablulus determine the overwintering capabilities of D. Immigration from Mexico seemed to be an unlikely because the distance from D. Teosintes do not occur in California, and corn does not usually survive throughout the winter here.
The common denominator between the two dalbbulus is the lack of corn for some period of time. Apparently, damage was due solely to leafhopper feeding, because no evidence of corn stunt disease was reported. For commercial re-use, please contact journals. Ability of the corn leafhopper to overwinter in California has been the subject of considerable speculation.
At the end of 2 wk, plants were transported to the laboratory and placed in the greenhouse, and new potted corn plants were placed in the field. Overwintering of Corn Leafhopper, Dalbulus maidis Homoptera: Adults were consistently collected from both alfalfa and weedy areas throughout ,aidis winter Fig. In all the spermatozoa observed, the final portion of the flagellum was branched into four filaments.
Beginning with the outbreak, D. For further information, we recommend you visit the following resources: The head region is formed by a small acrosome and the nucleus.
maize leafhopper (Dalbulus maidis)
Maaidis Find out more. This observation suggested to us that the leafhopper was overwintering in the area rather than migrating here from Mexico. Commercially planted corn in grower fields was also examined for the presence of leafhoppers and tested for the occurrence of the spiroplasma.
When testing immature corn, a portion of the mid-rib, found to contain a high titer of spiroplasma, was removed from symptomatic leaves.
Because there are no overwintering hosts for D. It would seem reasonable that leafhoppers migrating north from Mexico would infest corn planted in its path as it progressed northward.