Ecology and population dynamics of Erosomyia indica Grover.
Grover P.
Author Affiliation: Dep. Zool., Univ. Allahabad, India.
Cecidologia Internationale 8 : 71-82
Abstract : The biology of the cecidomyiid Erosomyia indica [E. mangiferae], a pest of mango, was studied in India in 1969-75. Individuals from the previous generation overwintered in the soil as larvae or pupae. Parasitism of overwintering pupae by Platygaster varied from 1.3 to 5.5%. Adult emergence coincided with the appearance of inflorescence buds. The mean sex ratio at emergence was 46:54 in favour of females. Oviposition occurred on the inflorescence bud, the axis of inflorescence panicles and on open flowers. On hatching, larvae entered the tissues to feed. Most damage was caused to the resulting fruits. An average of 6 larvae was found inside each fruit. Infested fruits became yellowish-green or yellow in colour, were often deformed and dropped easily. Fruit infestation varied from 41 to 97%. Four species of hymenopterous parasitoids, Platygaster sp., the pteromalid Systasis dasyneurae, Eupelmus sp. and Tetrastichus sp., were observed. With the exception of S. dasyneurae these appeared quite late in the season and were present in larvae dropping on the soil to enter diapause. Percentage parasitism reached 29.5 in the axis and 45.2 in the fruit. The most suitable conditions for the growth of the population of E. mangiferae was 26°C and 70-80% RH. High winds inhibited mating and oviposition.