130 F. C. WILLCOCKS — A MEALY BUG 



foliage of the crown did not expand fully but remained more or less bunched, 

 so that the tree appeared as if suffering from the attacks of some fungus, 

 allied to " witch-broom '^ disease. 



Later in the year, if the insects invade the seed pods, these latter also 

 become malformed ; but such instances are unusual. 



In July and August, one of the sooty mould fungi (Meliola sp.) is common 

 on the honey-dew^ secretion, producing a blackish covering over the twigs 

 and leaves of infested trees, and to some extent on the ovisacs of the 

 females. 



Methods of dispersal. 



It has frequently been asked in what manner these insects spread 

 from tree to tree, since in their active (larval) stages they are minute, 

 fragile and destitute of organs of flight. In many cases there can be no 

 doubt that the young larvae migrate or spread from tree to tree by means of 

 the interlacing twigs and branches of the crowns. The trees are frequently 

 planted so close as to touch those on either side, and sometimes they even 

 meet across the road. However, when the trees are not in contact but are 

 separated from each other by considerable distances, we mast seek other 

 ways by which the pest extends its field of operations. Reasoning on what 

 is known concerning the dissemination of the CocciD^ as a group, we may 

 safely assume that birds, insects and wind each play a part in the dispersal 

 oi. I), perniciosus. The grey crows (Corvus corni.v) and sparrows (Passer 

 domesticus indicus) are frequent visitors to the lebbeks, and it is more than 

 likely that they sometimes carry from tree to tree parts of the egg-bearing 

 ovisacs of the female mealy bugs, and also the young active larvae, on their 

 feet or bodies. The same may be said of some of the predaceous enemies of 

 this pest. Infested twigs and leaves may also be blown from place to place 

 and thus fresh colonies of the pest may be established. 



The Infested Area. 



The area in which the lebbek mealy bug increased to injurious proportions was 

 approximately one square kilometre in extent. This area was bounded on the 

 North by Chareh Boulak ; on the East by Chareh Kamil and Chareh Abdin; on 

 the South by Chareh Koubri Kasr el Nil ; and on the West by Chareh Kochlak 

 (Meidan Mariette Pasha) and Chareh Abbas. The pest was not equally 

 injurious to all the lebbek trees contained in this portion of the city. The 

 streets in which most damage occurred are as follows : — Chareh el Manakh, 

 Chareh Kasr el Nil, Chareh Soliman Pasha^ Chareh Emad el Din, Chareh 

 Boulak, Chareh Kamil, Chareh Abdin, Chareh el Maghraby, Chareh el Mada- 

 begh, Chareh Gameh Charkasse, Chareh Mazloum Pasha. Of these streets, the 

 first four suffered most noticeably. Chareh Taher, which lies just beyond the 

 Eastern boundary mentioned, and Chareh Tewfik, outside of the Northern 



