The floral biology of cacao, 2: Observations on foraging activity of Forcipomyia midges

The daily pattern of foraging activiy of midges under field conditions was determined and their activity as related to environmental conditions was interpreted. Foraging was assessed by observing the midges in the flowers in successive 2-hour periods of the day and night. Temperature and other meteorological variables were measured by a Fuess hygrothermograph and other standard meteorological equipment. Day length was determined by consulting standard meteorological tables. The times of foraging activity were found to coincide with those preceding and following sunrise and sunset. Therefore, day length seemed to have an important role in triggering the initial activity and its decline under field conditions. On the other hand, when air temperatures rose, foraging activity declined and flight activity to the upper canopy seemed to be encouraged. Thus, activity habits were considered to be diurnal. The midges rested during the night. The results also indicated that Forcipomyia midges were considerably more prevalent under deeply shaded conditions on calm, sunny mornings (7:00 - 9:00 h, 22 grade centigrade). They were less active during the breeziest (3.5 or more km/h) and hottest (29 grade centigrade) hours of the day from 11:00 to 17:00 h, and although few midges were collected at night (19:00 to 21:00 h), they were never observed to pollinate flowers after dark.

Bibliographic Details

Main Authors:	120629 Soria, S. de J., 56579 Chapman, R.K.
Format:	biblioteca
Published:	1984
Subjects:	THEOBROMA CACAO, FORCIPOMYIA, COMPORTAMIENTO, POLINIZADORES,
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