<p>The extinction of insect populations or species is a significant issue. Ex situ conservation is often the only way to prevent the extinction of declining populations. A cryopreservation technique developed for the larval ovaries of the silkworm <i>Bombyx mori</i>, has the potential to contribute to the ex-situ conservation of endangered insects. In this technique, the ovaries removed from the donor larvae are cryopreserved and transplanted into the recipient larvae. However, this method needs to be modified to target other taxa or species because of variations in the larval body size and physiological differences among species. In the present study, this technique was applied to a pierid butterfly, <i>Eurema mandarina</i>, with the ultimate aim of achieving ex-situ of endangered butterflies. When the mature egg production performance using several other modified methods was compared, the cryopreserved ovaries of <i>E. mandarina</i> were shown to produce mature eggs. In addition, the recipient adults in which a single ovary was exchanged developed an extremely small number of transplanted ovaries, suggesting that the physiological response of this species differs from <i>B. mori</i>. These results elucidate the physiological responses of butterflies to the cryopreservation of ovaries and the potential application of this technique to their ex-situ conservations.</p>