Chinch Bug Resistance Research Articles

Retention of Resistance by Mutants of ‘Floratam’ St. Augustinegrass to the Southern Chinch Bug and St. Augustine Decline1

St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze, a widely used turfgrass in the southern coastal states, has two major limiting pests, southern chinch bug, Blissus insularis Barbar, and St. Augustine decline strain of Panicum mosaic virus. Gamma‐rayderived mutants of ‘Floratam,’ a very coarse cultivar which is resistant to both pests, were evaluated for stability of resistance and turf characteristics. All mutants retained resistance to PMV‐SAD and all except #14 caused higher antibiosis to the confined bugs than the susceptible ‘Florida Common’ St. Augustinegrass (22%). Mutant #6 produced 76% mortality of the confined southern chinch bugs at 7 days which was significantly greater than the mortality produced by four of the other mutants. However, none of the mutants was significantly more resistant than Floratam (65% mortality). Egg deposition was significantly less on Floratam and all mutants (from 4 to 13 eggs/stolon) than on the Florida Common (average of 23 eggs/stolon). One of the mutants had a faster rate of establishment and all mutants had shorter internodes than Floratam, all were immune to PMV‐SAD, and only one had lost its southern chinch bug resistance.

Southern Chinch Bug Resistance in St. Augustine-grass12

Sixteen accessions of St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze, were evaluated for resistance to Blissus insularis Barber under heavy population densities in the laboratory. The grasses, FA-108, Floratam (FA-110), and FA-110, exhibited antibiosis and killed 57.66, 56.35, and 48.91%, respectively, of the adult population in 4 days. Antibiosis of 5th instars of 90.7, 89.8, and 71.1%, respectively, was exhibited by the same 3 accessions in 7 days. Of the remaining population of 5th instars, only 25–60% reached the imago in 7 days as compared to 98.2% for those confined on common St. Augustinegrass. Fecundity of adults was significantly reduced when they were confined on the resistant selections; 5 females produced an average of 9.75 eggs/stolon on Floratam whereas 42.75 eggs/stolon were produced when confined on common, which is very susceptible to chinch bug feeding and was used as a standard in these tests. Several other accessions, including Floratine, also showed considerable tolerance to southern chinch bug feeding.

The Effect of Fertilizers on Chinch Bug Resistance in Sorghums

The Effect of Fertilizers on Chinch Bug Resistance in Sorghums

Hybrid Vigor and Other Factors in Relation to Chinch Bug Resistance in Corn1

Hybrid Vigor and Other Factors in Relation to Chinch Bug Resistance in Corn1

Chinch Bug Resistance in Corn—an Inherited Character

Chinch Bug Resistance in Corn—an Inherited Character

Chinch-Bug Resistance shown by certain varieties of Corn

Chinch-Bug Resistance shown by certain varieties of Corn