Control of the mango seed weevil, Sternochetus mangiferae (F.).
Joubert P. H., Pasques B. P.
Author Affiliation: Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200, South Africa.
Yearbook - South African Mango Growers' Association 14 : 69-71
Abstract : A study was undertaken to investigate certain behavioural characteristics of Sternochetus mangiferae (Coleoptera: Curculionidae), which might contribute towards a more effective control strategy, and to evaluate alternative, cost effective methods of control that are less damaging to the environment and correspond with European exports standards. Ripe 'aborted' mangoes were collected in an orchard known to be infested with S. mangiferae, and the seeds were stored in a gauze cage. The live weevils that emerged were marked with a fluorescent paint, and transferred to a cage erected over a mango tree. Movement of the weevils, as well as onset, rate and duration of egg production, were monitored. Alternative control measures, like stem barriers with pyrethroids and sticky polybutene gum, were compared with the standard fenthion treatment. The use of monocrotophos and imidacloprid stem treatments were also evaluated as alternative methods of control. The results indicated that 78% of weevils escaped from fruit before winter. The remaining 22% hibernated in the seed. The first eggs were observed during the first week of October 1993. Peak egg production was reached three weeks later (total egg laying period = 60 days). The effect of stem barriers and polybutene gum could not be assessed during 1993-94, as many weevils were already hibernating in the trees when these measures were first implemented. Initial results indicated that monocrotophos and imidacloprid were not effective in controlling S. mangiferae, suggesting that the existing chemical control strategy is probably inadequate.