Biological control in Proteaceae - An effort to solve some problems

Since the establishment, in 1999, of the Europrotea's plantation, work has been done on the identification and quantification of insect populations in the region towards the definition of an Integrated Pest Management program. As a result of a survey during the seasons of 2000 and 2001 key pests were identified, namely the Lepidoptera Helicoverpa armigera, Cacoecimorpha pronubana and Sesamia nonagrioides as well as a species from the genus Paracoccus (Hemiptera: Sternorryncha). The importance of beneficial insects was also highlighted through the survey. Quantification of the key-pest populations present in the fields begun in 2002 and it continued in 2003. In this study an economic threshold is proposed for the Lepidoptera. In the first research stage only chemical control was applied. However, all care was taken in the choice of the active ingredients to reduce the effect on the natural enemies already present in the fields. Indeed a percentage of the caterpillars collected was parasitized and some generalist predators of mealybugs were also captured. Along the establishment of the plants mealybugs became a serious problem, very difficult to control, in particular on the species Protea cynaroides, using the available chemicals. As a consequence, the use of biological control methods was adopted for this pest. In the spring of 2003 releases of the mealybug predator Cryptolaemus montrouzieri were done with interesting results in all varieties except for P. cynaroides. In the spring of 2004, a massive introduction of this predator will be performed and the parasitoids Leptomastix dactylopii and Anagyrus pseudococci will be laboratory tested for the control of Paracoccus spp. on P. cynaroides. The release of Trichogramma spp. for H. armigera is also planned, namely on Leucadendron spp.