Diurnal periodicity and dispersal of Coconut mite, Aceria guerreronis Keifer

Abstract

Investigation on biology and behaviour of the coconut mite, Aceria guerreronis, in situ revealed mass migration of the individuals from concealed meristematic zone of the infested nuts under the perianth to open surface. Regular monitoring of infested nuts at an interval of 3 hrs. for 3 consecutive days showed the existence of diurnal periodicity in migration of the individuals to open surface of the nuts. Maximum mite population on surface the nuts coincided with bright hours of the day ranging from 10th to 15th hr. This activity of the mite starts at II phase of the infestation and continues till IV phase extending over a period of about 4 to 5 months. As wind has been identified as the major factor in transmission of the mite, surface population of the mite represents the fraction directly involved in the process. Nuts of phase II to phase IV of infestation act as the source of the pest for fresh infestation.