Control measures of two soft scale insects (Hemiptera: Coccidae) infesting guava and mango trees in Egypt

At present the nigra scale, Parasaissetia nigra (Nietner) and the cottony camellia scale Pulvinaria floccifera (Westwood) (Hemiptera: Coccidae) are among the most important pests on guava and mango trees in Egypt. The present investigation was set up to study the effect of different compounds on P. floccifera and P. nigra on guava and mango trees, respectively. The results indicated that in the first season (2010), the treatment with different compounds (Biofly “Beauveria bassiana”, Neemazal “Azadirachta indica”, and Super Misrona oil) gave a moderate reduction of percent in the population of adult females and nymphs of P. nigra and P. floccifera respectively, as compared to Malathion and its mixture (“Super Misrona oil+Malathion”) which gave a higher reduction rate after the 1st, 2nd and 3rd weeks after spraying. Also, these compounds gave a moderate mortality to the parasitoids as compared to Malathion and its mixture (“Super Misrona oil+Malathion”) which gave higher toxicity after the 1st, 2nd and 3rd weeks after spraying. The data obtained in the second season (2011) were also similar to those obtained in the first season (2010). It can be concluded that treatment with Biofly, Neemazal and Super Misrona oil gave satisfactory control of different stages of P. nigra and P. floccifera and their parasitoids, Diversinervus elegans Silvestri, Metaphycus lounsburyi(Howard), Microterys flavus (Howard) and Coccophagus sp., Metaphycus zebratus Mercet, M. flavus , respectively, as compared to Malathion and its mixture “Super Misrona oil+Malathion”.