194 



F. W. DRY. 



2. So far as the data go, the periods of ascendency of either species lasted for 

 from six to nine months. This time is .sufficient, as the life-history figures will show, 

 for from four to six successive generations of parasites. 



3. Ascendency of HadronoUis is associated with comparative abundance of 

 coffee bug eggs. Though an accurate index of the comparative abundance of eggs 

 was not obtained, it can be stated that they were most numerous from July to 

 October 1917, and the period of next greatest abundance was October 1918 to 

 March 1919. Ai the end of 1917 and for the first three months of 1918 they were 

 very scarce indeed. During the remainder of the time they were moderately plentiful, 

 though not very numerous. 



V. Collections from other Plantations. 



The data as yet obtained are far too few for us to be able to correlate the occurrence 

 and subsidence of outbreaks of Antestia with parasite conditions, but the following 

 points may be mentioned : — 



In collections of eggs made during outbreaks of Antestia the percentages of 

 normal eggs have sometimes been high and the percentages of parasitised eggs 

 low. The following are examples :— 



On the other hand, collections of eggs made during an outbreak of Antestia have 

 sometimes given a low percentage of normal eggs and a high one of parasitised eggs. 

 Such cases are : — 



The Kyambu case numbered (4) is an example of an outbreak of Antestia subsiding 

 without any control measures having been taken by the planter. At the time the 

 collection was made the bugs were extremely numerous in part of the plantation. 

 In such cases it is usual to have the bugs collected by hand, but here, although the}^ 

 were left undisturbed, the following April the planter reported that the outbreak 

 had completely subsided. This was probably due to the work of the parasites. 



The Kabete field in 1917 may also be cited. In June and July the bugs were 

 quite plentiful. In the months July to October 1917, as has already been stated 



