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Objective: To analyze the race diversity and geographic distribution of the native maize landraces currently cropped at southern Nuevo León, México. Design/Methodology/Approach: Data was obtained from 41 accessions which represent the commercial production in the dry land area, where fertilization and pest control are scarcely used. Landraces were classified according to the CONABIO guidelines for ear traits. Results: The measured accessions correspond to seven maize races and to seven interracial crosses. The two most frequent maize races were Ratón and Cónico Norteño, mainly located in the dry areas with less rain. Study Limitations/Implications: Three races, Celaya, Tablilla de Ocho and Elotes Cónicos, had not been previously reported; while two formerly reported races Tabloncillo and Olotillo, were no longer found. This study did not include the grain-colored accessions. Findings/Conclusions: Three collections stood out for producing large cobs with large kernels, thus showing a high yield potential. The maize landraces harvested in dryland areas might offer advantages to be grown under harsh environments or be used as gene donors for drought tolerance. [ABSTRACT FROM AUTHOR]

Melanaphis sacchari Zehntner (Hemiptera: Aphididae) is an important destructive pest in forage sorghum in Nuevo León, Mexico. This study was conducted to identify predatory and parasitoid insect species associated with this pest in Nuevo León, and their impact on its biocontrol. During the monitoring period, identified insects indicated the coexistence of 8 coccinellid species, 2 syrphid species, and 1 chrysopid species. In addition, 2 hymenopteran species were identified. After the insecticide applications, sugarcane aphid population was reduced by about 20.6% (about 14 nymphs per cm2); when the sampling ended, population was reduced by about 70.6% (about 5 nymphs per cm2), thus indicating predator and parasitoid biocontrol. Collected data allowed us to conclude that the biological controllers were responsible for the principal pest population reduction. Overall, results showed that yellow sugarcane aphid predatory and parasitoid species may play an important role in the pest management in sorghum crops in Nuevo León, Mexico. [ABSTRACT FROM AUTHOR]