The nutritional ecology of Maruca vitrata Fabricius I. Development on flowers of wild and cultivated Vigna species

Abstract

Growth, development and fecundity of Maruca vitrata Fabricius (Lepidoptera: Crambidae) were studied on artificial diet and flowers of two accessions each of three wild Vigna species, namely V. vexillata (TVnu 594 and TVnu 72), V. oblongifolia (TVnu 957 and TVnu 42) and V. unguiculata ssp. dekindtiana (TVnu 979 and TVnu 863) and six accessions of cowpea, V. unguiculata ssp. unguiculata (Moussa Local, VICAM-1, TVu 13731, IT84S-2246, IT89KD-457 and IT91K-180). The percentage survival of the larvae, larval weights as well as growth and development indices were significantly higher on the artificial diet, flowers of cowpea cultivars and those of V. unguiculata ssp. dekindtiana compared to those of V. vexillata and V. oblongifolia. The fecundity of females from larvae reared on artificial diet and flowers of cowpea was also significantly higher than that of females from the wild Vigna genotypes. All variables were included in principal component analysis. Two components accounted for 81.79%. On the basis of this analysis, the diets appeared to fall into four categories based on their suitability for supporting development of M. vitrata: unsuitable (TVnu 42 and TVnu 957), fairly suitable (TVnu 72, TVnu 594, TVnu 979, Moussa Local and TVnu 863), suitable (IT89KD-457, IT91K-180, VICAM-1, TVu 13731 and IT84S-2246), and very suitable (artificial diet). The importance of these findings in the development of host plant resistance of cowpea to M. vitrata is discussed.