ISHS Acta Horticulturae 334: I International Pineapple Symposium
ANT (PHEIDOLE MEGACEPHALA F.) - MEALYBUG (DYSMICOCCUS BREVIPES CKLL.) RELATIONSHIPS IN PINEAPPLES IN SOUTH AFRICA |
| Authors: | G.J. Petty, H. Tustin |
| Keywords: | big-headed ant, pink pineapple mealybug, Ananas comosus, mealybug wilt |
| Abstract:
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. | |
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