Poinsettia: Main pests and strategy
Sciarid fly, commonly known as fungus gnats, can cause serious damage to the cuttings, to the extent of killing them. The larvae feed on the young roots of the plants, and can then progress into the stem, if not controlled adequately.
Control Strategy at Propagation (un-rooted cuttings)
Entonem (Steinernema feltiae)
- After the cuttings have been struck, protect the roots from sciarid fly attack by applying the entomopathogenic nematode Entonem, at 0.5 million nematodes per m2 of cultivated area
- Apply at 2, 5 and 8 days after planting; this is key to ensuring that cuttings can form roots without being damaged, and after 14 days the roots should be sufficiently mature to avoid damage
The glasshouse whitefly, Trialeurodes vaporariorum, and the tobacco whitefly, Bemisia tabaci, a non-native notifiable pest, are reported to be the main pest pressures.
However, over the last few years, the cabbage whitefly, Aleyrodes proletella, has become more prevalent. Although, fortunately, they usually cause little real damage, their scales and white waxy deposits are, unfortunately, highly visible on the undersides of the leaves, which can result in rejection and lost sales.
Yellow Horiver Traps
These are required for monitoring pest levels, and calculating the number of natural enemies required.
Use Enermix, a product mix of the parasitic wasps Eretmocerus eremicus and Encarsia formosa, at high introduction rates for the first 4-6 weeks of growing, prior to the first spacing.
After spacing, and based on the sticky trap counts of adult whitefly, this can be adjusted accordingly.
Introduction of the predatory mite Swirski-Mite, Amblyseius swirskii, is also very important for whitefly and thrips control strategies.
This natural enemy can be applied either as loose product and/or as slow release sachets (Ulti-Mite Swirski). They target the egg and crawler stages of the whitefly life-cycle, as well as the first larval stage of WFT.