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The dielectric properties (dielectric constant and loss) for the system Cu x Fe 3-x O 4 with x = 1⋅ ⋅0, 0⋅ ⋅8, 0⋅ ⋅6, 0⋅ ⋅4 and 0⋅ ⋅2, were studied in the temperature range 300 ∼ ∼ 800 K and also in the frequency range 1 kHz ∼ ∼ 1 MHz. A.c. conductivity was derived from dielectric constant and loss tangent data. The conduction in this system is interpreted as due to small polaron hopping. The dielectric relaxation was observed for the compositions with tetragonal structure whereas normal behaviour was observed for cubic structure.

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Life cycle stages of butterflies parasitized by natural enemies. Many species of Chalcid wasps are parasites of the pupae of many insects, especially the Brachymeria genus. During field visits, it has been observed that pupae of butterfly Acarea terpsicore(Linnaeus, 1758) are parasitized by the chalcid wasp Brachymeria euploeae (Westwood, 1837). Pupae that become infested are blackish and their activity does not resemble that of normal pupae. The record of B. euploeae as a parasitoid is not only the first record on pupae of A. terpsicore but also for Maharashtra, India.