Studies on Certain Natural Enemies of Scale Insects Attacking Guava Trees at Kafr EI-Sheikh Governorate

Abstract

Guava trees are infested by several scale insects causing reduction

111 yield and fr!lit quality. Fortunately, scale insects are subject to be attacked by several parasitoids and predators. So, the role of these natural enem1es should be maximized and involved in integrated control programs at guava orchards.

The current study was conducted at guava orchard near to Kafr El­ Sheikh city from 1993 to 1995, aiming to survey scale insects, parasitoids and predators dominant at guava orchards. On the other hand, the relationships between these harmful insects and those beneficial were considered to find out the role of natural enemies in managing scale insects.

The obtained results could be summarized as follows:

1. Guava trees insects:

1.1. Guava trees are attacked by 18 insect species belonging to

Homoptera, in addition to one species from Diptera.

1.2.

Population fluctuations of major scale insects were studied:

* Pulvinaria

psidii Mask. becomes

activ

e in November-

December, and in July-August.

* Saissetia coffeae Walk has two durations of activity: The first from October to November, while the second from May up to August. lt is noteworthy that the adults (usually females) are absent from December to February. * Ceroplastes jloridensis Comst. occurs in a high population from September to January, then the numbers go down. The insect population relatively increases from .June up to August.