An appraisal of butterfly species diversity study was conducted in four selected parts of Sirajganj District, Bangladesh, as a part of an ecological research.  The study was conducted from March 2015 to April 2016.  A total of 19,343 butterflies belonging to five families and 12 subfamilies was recorded.  A random sampling of forest, riverside rural, and urban areas in Sirajganj District revealed the presence of 65 butterfly species, dominated by Lycaenidae (37%) over Nymphalidae (33%) followed by Pieridae (19%), Hesperiidae (7%), and Papilionidae (4%).  Butterfly fauna in Bangabandhu Sheikh Mujib Jamuna Ecopark (BJEP), compared with the percentage of other study sites, was very high (Hs= 4.03) and the percentage of hedge species was relatively higher (45%) than that of improved grassland and forest interior species.  The relative abundance of the butterflies varied with the site, month, and family significantly. Considering the landscape of Sirajganj, steps to enhance riverside natural gardening should be adopted to maintain butterfly diversity and sustain the ecosystem services derived from them.

Tungsten and Niobium substituted αII-VOPO4 structure type solid solution (V1–x-yWxNby) OPO4 where x = 0.07 and y ≤ 0.05 was synthesized by solution combustion technique followed by heating in air at 700˚C for 3 days. Further incorporation of niobium (y > 0.05) leads to a mixture of αII-VOPO4 structure type solid solution and two very weak reflections of another unknown phase. The synthesized product was characterized by X-ray powder diffraction, SEM/EDX, FTIR, and magnetic property analysis. Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 31-37, 2019