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Native starch was isolated from two corn landraces (blue and white) and a hybrid variety and then characterized for its physicochemical, thermal and rheological properties. The hybrid variety showed the highest starch yield, with its starch showing the highest fat, moisture and protein content but the lowest onset temperature of gelatinization. The hybrid corn starch also showed the highest G' and G" values. The tested starches showed similar T p , T c , and ΔH values. The amylose contents ranged from 21.5 to 22.4%, with starch from blue corn showing the highest amylose content. All starches were white, with L values ranging from 93.6 to 99.5. The light absorbance of the starch gels increased with storage time. The obtained results demonstrated that the physicochemical, thermal and rheological properties of corn starch are highly dependent on the corn type.

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Temperature, relative humidity (RH) and accumulated precipitation were obtained from the weather stations of Unifrut and INIFAP. The highest percentage (48 %) of mycosed larvae by M. rileyi was obtained during the sample performed in August, where temperature and RH average were 16.76 °C and 80.1 %, respectively, and an accumulated precipitation of 218 mm. These results suggest that the climatic conditions were optimal for the development of the fungal epizootic on field.

The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), is the most important pest of maize in many countries. Entomopathogenic viruses mainly Baculoviruses family are excellent biological control agents and therefore a viable alternative for managing this pest. The aim of this study was to determine the biological activity of eight native nucleopolyhedrovirus (NPVs) against FAW larvae.Additionally, two of the most virulent isolates (SfCH32 and SfCH15) were characterized biologically by bioassays to estimate their median lethal dose (LD 50 ) and median lethal time (LT 50 ), morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and molecularly by restriction enzymes.Three (SfCH15, SfCH18 and SfCH32) of the eight tested native nucleopolyhedrovirus isolates caused mortalities ˃98% at 168-hr post-inoculation (hpi) with a dose of 9.2 × 10 4 OBs/larva. SfCH15 and SfCH32 isolates showed occlusion bodies (OBs) of irregular shape and size (1.02-2.24 μm). The SfCH15 and SfCH32 isolates showed similar median lethal dose (5.6 × 10 2 -6.4 × 10 2 OBs/larva). The lowest median lethal time (114.5 hpi) was observed with the SfCH15 isolate at the highest concentration (2.5 × 10 6 OBs/larva). The DNA restriction profiles for SfCH15 and SfCH32 were different, with their genome size being ~128,000 bp and 132,000 bp, respectively. SfCH15 and SfCH32 isolates showed similar morphological characteristics and the highest virulence against fall armyworm. This study showed that native isolates were highly virulent against S. frugiperda larvae, being similar to other reported strains; however, field studies are required to confirm their insecticidal effect. K E Y W O R D Sbaculovirus, biological control, fall armyworm, genetic variability, morphology, virulence