DEVELOPMENTAL STAGES OF FEMALE REPRODUCTIVE SYSTEM IN BANANA STEM WEEVIL (Odoiporus longicollis) (Coleoptera: Curculionidae)
ANUPRIYA SAMUEL
Department of Zoology, St. Johns College, Anchal, 691 306, Kerala, India.
NISHA THOMAS
*
Department of Zoology, St. Johns College, Anchal, 691 306, Kerala, India.
LEENAMMA JOSEPH
Department of Zoology, Mar Ivanios College, Thiruvananthapuram 695015, Kerala, India.
*Author to whom correspondence should be addressed.
Abstract
Odoiporus longicollis Olivier (Coleoptera: Curculionidae), also known as the banana pseudo stem weevil (BSW), is one of the main pests in Banana (Musa paradisiacal L.) plantations in South East Asia and all the banana-growing belts of India. The present study is on certain aspects of female reproductive system of Odoiporus longicollis in its different developmental stages. For this the morphometric and ontogenic studies were done in instars larvae, pre-pupa, one -day old pupa, five-days old pupa, pre-emergent adult and adults of varying ages such as newly- emerged, four- day old, ten -day old, fifteen -day old, seventeen- day old and a mature adult female. The development of female reproductive structures was not visible in any of the larval instars. But the onset of its development was indicated in one- day old pupa by the appearance of genital chamber (0.05mm) and rudimentary ovariole. The development was completed in twenty-day old adult who elicits maximum sex responses. Earlier studies on biological control of banana stem weevil are inadequate. Therefore, the present study has been made in order to fill up the gap as well as to help for controlling measures of the pest systematically by knowing the developmental stages in the reproductive system of female weevil. This will also contribute knowledge in comparative physiology of insect reproduction and its evolutionary success.
Keywords: Banana pseudostem weevil, Odoiporus longicollis, genital chamber, rudimentary ovariole, instar larvae, pre-pupa