192 F. W. DRY. 



the following averages : — shorter axis 0-87 mm., longer axis 1-125 mm., the longer 

 axis being at right angles to the point of attachment. As the embryo develops 

 within the egg a clear ring becomes distinct on the top, marking the place where 

 the cap will split off when the young nymph emerges. The cap is a complete arc 

 of the egg-shell and may be completely split off or left behind, hinged on, and 

 may shut down accurately. In some instances it fits down so tightly that only the 

 colour shows whether the nymphs have hatched. When the egg is from four days 

 to a week old, depending on the season, the eyes and tylus of the nymph can be 

 distinguished as darker spots shining through the cap. The eggs are usually found 

 in clumps of twelve, though ten and eleven are quite common. The clumps of eggs 

 are found on the under surfaces of the leaves, occasionally on the upper surface, 

 on the berries, on the pedicels of the berries, on the stem, on dry leaves, and even 

 on stones beneath the bushes." In the field 90 per cent, of the eggs collected were 

 found on the lower side of the leaves. 



III. Parasitised Eggs. 



The female parasites have been watched vigorously prodding the coffee bug eggs 

 with their ovipositors. The insect remains quiet for some time with the ovipositor 

 embedded in the egg, the whole operation lasting from two to five minutes. Eggs 

 that have been parasitised are distinguished by the fact that some time after being 

 attacked by the parasite, this time varying with the season, the colour of the egg 

 changes from the original dull white. Usually the eggs become bluish grey, but 

 occasionally parasites emerge from eggs which have only become pale grey. 



The parasite makes its way out of the egg through a hole with a ragged edge 

 bitten by the insect's mandibles ; the cap of a parasitised egg does not spHt off. 

 Many hundreds of eggs have been kept singly in tubes in the laboratory, but 

 never more than one parasite has been reared from one egg. 



In addition to the two named species of parasites other species have been reared, 

 but their numbers have been very few. 



In collections brought in from the field the eggs were kept under observation 

 so as to determine how many produced Antestia, how many had been parasitised, 

 and how many failed both to turn blue and to produce either bug or parasite. All 

 eggs which turned blue were recorded as parasitised, and were then kept in tubes 

 plugged with pads of cotton wool. The parasites hatching from them were preserved 

 and examined, and data for proportions of species and sexes are given below. Some 

 of the eggs which turned blue did not produce parasites. Any eggs about which 

 there was a doubt were kept until they produced parasites or until it was clear 

 that they were not going to produce anything. 



In making counts it was the practice to reject all eggs which had hatched — 

 whether Antestia or parasites — before being collected, and to reject as well all clumps 

 containing one or more eggs which had hatched before coming to hand. In this 

 way, for each collection of eggs examined, percentages were obtained of those hatching 

 Antestia, those parasitised, and those not going blue or hatching anything. The 

 figures so calculated may be taken to represent fairly well the parasite position 

 in the plantations where the collections were made, but the following sources of 

 inaccuracy must be noted : — 



(a) A parasitised egg remains unhatched longer than one which produces a coffee 

 bug. 



{b) If the eggs had not been brought into the laboratory some which hatched 

 Antestia would have been parasitised in the field ; this tends to counter- 

 balance {a). 



(r) Dead eggs, white or blue, remain on the trees a long time. 



