A microcapsule in which a liquid droplet is coated with a resin, wherein in the droplet, a pesticidally active solid ingredient is suspended in a compound of formula (I), wherein R represents a C1-C5 alkyl group, is useful as a formulation of a pesticidally active solid ingredient.一種作為具殺蟲活性之固態成分的調製劑之微膠囊,其中液滴係經樹脂塗覆,且於該液滴中具殺蟲活性之固態成分係懸浮於式(I)之化合物(其中R代表C1-C5烷基)中。