ANT (PHEIDOLE MEGACEPHALA F.) - MEALYBUG (DYSMICOCCUS BREVIPES CKLL.) RELATIONSHIPS IN PINEAPPLES IN SOUTH AFRICA

G.J. Petty, H. Tustin
The pineapple mealybug (Dysmicoccus brevipes Ckll.) has largely been controlled on pineapple (Ananas comosus (L.) Merr.) by controlling the big-headed ant. The relationship between these two species was studied in a Queen cv. pineapple plantation by regulating the ant population with hydramethylnon ant-bait (Amdro). Mealybug leaf infestation decreased to 10% of the original level 20 weeks after ants were eliminated. For the remainder of the 52 week-study, the mealybug population was significantly lower (P<0.05) than under ant-infested conditions. The mealybug infestation was lowest at week 32. Mealybug root infestation decreased to zero by week 12 after ants were eliminated and remained there, while under ant-infested conditions, root infestation was extremely high. When ants were controlled, correlations between both ant-infestation and ant-distribution and with mealybug infestation of both leaves and roots were high (P<0.01) and positive. However, when ant numbers were high, the correlation was close to zero, indicating that ants here were no longer a limiting factor to mealybug survival. Suppression of ant and mealybug numbers resulted in significantly (17%) greater plant growth.
Petty, G.J. and Tustin, H. (1993). ANT (PHEIDOLE MEGACEPHALA F.) - MEALYBUG (DYSMICOCCUS BREVIPES CKLL.) RELATIONSHIPS IN PINEAPPLES IN SOUTH AFRICA. Acta Hortic. 334, 387-396
DOI: 10.17660/ActaHortic.1993.334.41
https://doi.org/10.17660/ActaHortic.1993.334.41
big-headed ant, pink pineapple mealybug, Ananas comosus, mealybug wilt

Acta Horticulturae