AND PROBLEMS OF SOUTHERN NIGERIA. 193 



were not found. This period coincides with the time of ripening and shedding of 

 the seed of the s ilk-cotton tree. 



The questions as to the number of broods in the year and the special local 

 plants upon which the insects feed, have not yet been settled. 



The eggs are of a cream-colour, translucent, about 1 mm. in length and 

 shaped somewhat like a fowl's egg (Plate XXIII, figs. 1, 2). They are laid in 

 clusters and the number in each cluster varies a great deal. The clusters depos- 

 ited by captive specimens were found to have eggs to the number of 20, 36, 36, 

 45, 50, 57, 70, 74, 77, 81, 83, 98 and 120 respectively, giving an average of 63. 

 It is probable that the average is really higher, as the conditions of the laboratory 

 experiments were not so natural as could be desired. 



Only once, after repeated searching, were the eggs found in a dry dead boll. 

 This suggested that they were laid on the ground, but the exact situation was not 

 readily found. Large numbers of very young stainers, only a few days hatched, 

 were observed under the shelter of weeds in the hollows between the rows of 

 cotton plants, and numbers of stainers in copulation were also noticed there. 

 After much and frequent searching the eggs were at last discovered. They were 

 deposited singly or, more usually, in clusters among the loose soil under weeds 

 and preferably in quite sheltered spots. In the laboratory the egg-stage in 

 various cases lasted for 3, 5, 6 and 7 days. 



Two experiments were tried to find the percentage of young hatched, but the 

 results cannot be considered conclusive. In one instance the result was 25 per 

 cent, and in the other 42 per cent. It is probable that the normal period of 

 incubation is about 4-5 days and that a far greater percentage hatches, as the 

 conditions of the experiments were not at all natural. 



The newly hatched young soon become active and, crawling up the cotton stalk, 

 swarm upon the opened bolls and suck the cotton seed. There are five moults 

 and after each moult changes in proportion, structure and colour are observable 

 (Plate XXIII, figs. 3-7). 



Foodstuffs are plentiful. The chief known are cotton, Hibiscus plants and the 

 silk-cotton tree, while other malvaceous bush plants are certainly frequented. 

 In the case of cotton, especially if the native planter, as he usually does, leaves 

 unpicked bolls on his plants, the stainers have food from September till after 

 December. In the case of the silk cotton tree, which is widely distributed and 

 scatters its seeds wide-spread, food is provided from March till April. Malva- 

 ceous plants ripen in the bush at all times. It has also been mentioned that the 

 young may be carnivorous. 



There may be natural enemies, but after much observation they have not 

 been discovered. 



Even should the following figures be modified in the future, they may serve to 

 give some idea as to the rate of development of the insect. 



Number of days from copulation to egg-laying .., ... 7 



„ „ in the egg stage .. . .. ... ... 5 



„ „ to 3rd moult, at least ... ... ... 28-32 



40-44 

 to 5th moult, say ... ... ... 28 



Total .. 68-72 



