Evaluation of buffelgrass genotypes for resistance to the spittlebug complex Aeneolamia albofasciata (Lallemand) and Prosapia simulans (Walker) of northeastern Mexico

Abstract

Seventy-seven genotypes of buffelgrass were screened for resistance to the spittlebug complex A. albofasciata (Lallemand) and. P. simulans (Walker) in Apodaca, N. L. Screening involved artificially infesting plants in caged pots and field plots, exposure of plots to natural infestations and preference evaluations, Nymphal and adult infestation levels did not positively correlate with degrees of damage. It was postulated that nymphal feeding affected only the appearance of the plants and not forage yield. The adult survey method followed was inappropriate to estimate adult population. Nymphs/stool were positively correlated to adults/stool. Severity of damage, mainly seen as streaked and dry foliage, correlated negatively to appearance rated by height, coverage, foliage density, turgidity, and color uniformity. Plant height and weight were negatively correlated to damage. Number of stems and leaves were both positively correlated with nymphs/stools and adults/stool but width of leaf and blooming period in early fall were negatively correlated with nymphs/stool. No clear evidence was found for preference, non-preference, or antibiosis, as responsible for the resistance shorn, but a characteristic tolerance was manifested by the rapid recovery of injured plants. Promising genotypes were separated into two groups: one was considered best for its more consistent combined response to all tests and factors of evaluation, while the other was considered second, best in the combined response to all tests and factors of evaluation. Artificial irrigation equivalent to 36 mm of rain distributed in two days incited hatching of diapausing eggs. Both species and sex of the spittlebug complex produced damage.