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tTHE TROPICAL AGRICULTURIST. 



August i, 1884- 



"Tupac Yupanqui" in the Tea Cyclopoedia is the 

 one which coincides most closely with what we our- 

 selves have observed in Ceylon of the habits of this 

 voracious little arachnidan: — 



The upper surface of the leaf attacked by red spider 

 is strewn with the cast-off skins of the mites — a few 

 entire, most broken and crumpled, — numbers of egg, and 

 deserted yolk-bags, firmly adhering excreinenta, and 

 filaments of the finest web stretched here and there, and 

 occasionally spun in little masses. The ova deposited on 

 the upper surface of the leaf, the favorite nest being 

 evidently along either side of the centre stalk. All this 

 space is" fully occupied, but eggs are also to be found 

 scattered without any order here and there over the 

 remaining surface of the leaf. Occasionally a few may 

 be seen on the underside, but rarely, and on none of 

 the leaves I examined more than half-a-dozen, evidently 

 stray ones. The little arachnoid indeed never seems 

 much at his ease amongst the rough fibres of the inferior 

 Bide of the leaf, as his tree motion aud progress over its 

 uneven, ciliated surface is rendered somewhat difficult. It 

 is clear that the little creatures are not evolved under the 

 leaf, though it hardly seems a hazardous conjecture to 

 suppose that they would, when free from the ovum and 

 possessed of activity of limb, naturally seek the shelter which 

 the underside would frequently afford theni against the 

 elements. When the ovum has recently been vacated, the 

 entire yolk-bag may be seen, but the upper hemisphere, 

 which at the exit of the larval spider is partially broken 

 off easily, afterwards becomes entirely detached, and is 

 blown away or otherwise shaken off the leaf, so that only 

 the inferior hemisphere remains still firmly adhering. 



The white mottles to be discerned on the superior surface 

 of the foliage are principally of two kinds ; the one in 

 dense coarser patches is a fungoid growth ; and the other, 

 in appearance like a floury dust to the naked eye, and 

 spread generally away from the divisory stalk more to- 

 wards the marginal superfice, consists chiefly of the moulted 

 skins of the little animals, intermingled also with dried 

 and broken yolk-bags. 



The Ovum is spherical pellucid, and very large as com- 

 pared with the size of animal which deposits it. At its 

 primary stage (I speak of the stage in which I was able 

 to observe it, but it is highly probable that when quite 

 recently deposited it may have a somewhat different as- 

 pect) through the transparent outer membrane, a traus- 

 lucent, reddish brown, germinal vesicle, occupying fully 

 one-third of the interior,- may be [discerned. It is poss- 

 ible though, that what I denominate the germinal vesicle 

 may already have attained the embryonic state. From the 

 upper exterior surface of the enveloping membrane a fine 

 1 dear white hyaline thread protrudes, generally of a length 

 about equal to the diameter of the egg. This thread is of 

 a structure as though consisting of the same viscous 

 secretion as the yolk-bag, of which it is in reality an ap- 

 pendaged continuation, doubtless drawn out, as it were, as 

 the egg leaves the ovipositor. Under a moderate magni- 

 fying power the dark reddish brown embryo may be 

 observed gradully to extend its volume, whilst it loses in- 

 tensity of colour, as it absorbs the food-yolk ; the vit- 

 ellus, which at first was clear and bright, becomes slightly 

 turbid, and at length the whole ovum presents an almost 

 uniform clouded fiery pink colour, more or less inten- 

 sified here and there. The yolk-bag maintains its grassy 

 aspect. Having reached this fiery pink stage, the egg is about 

 ready to bo hatched, and shortly the covering breaks 

 on one side, the upper hemisphere is lifted, and a 

 plump little creature ot true spider-like appearance makes 

 his exit, leaving the clear hyaline shell empty ; and, 

 after looking about a little aud laking a few slow turns 

 to test his translucent limbs, he makes oft" to survey 

 his territory. This is the red 6pider in his infancy ; 

 but, as he attains a very high development in the ovum 

 he is much like his later perfect state, only that now 

 he has not more than six legs, his color is much paler 

 and his body — veiy little smaller than the ovum from 

 which he emerged — is rounder. His legs are transparent 

 and almost colourless. 



After a short period of activity, during which his 

 abdomen, doubtless from the food he imbibes, is always 

 becoming darker and darker in colour and somewhat 

 more elongated in form, he settles upon one spot — now 

 he is almost black, excepting his cephelo-thorax,and its 



appendages — his skin begins to dry and shrivel, and after 

 a period of semi torpor, he struggles and emerges from 

 his first moult a perfect eight-legged spider. At fir6t he 

 looks tender, semi-transparent and fresh, excepting, the 

 black abdomen upo n which the white bristles from a 

 striking feature, but little by little his whole being becomes 

 firmer and rougher and his colour more uniformly red the 

 male may he distinguished from the female by his 

 smaller sizo and more elongated abdomen. 



Various remedies have been proposed. The most 

 successful of which seem to be the plucking off and 

 burning of all affected leaves, and the pruning of 

 the bushes almost to the ground. 



"W. B. L." ON CACAO BLIGHT. 

 As my experience of cacao is limited to what I 

 have done myself on a single estate, aud the results 

 of such doings, I cannot claim to be an authority on 

 the subject, but in answer to the requisition made 

 for a contribution to the discussion originated in the 

 P. A. meeting, I now proceed to state what I know. 

 The land I had to deal with is hilly, and in the 

 higher purta rocky. The soil is of many qualities, 

 running from poor gravels into deep clayey and sandy 

 loams. Much rain falls iu the course of the year, but 

 chiefly in heavy thunder-storms, causing severe wash, 

 little alleviated by many drains. There is no part of 

 the land that is not exposeel to wind, either direct or 

 deflected. 



In clearing this land, a few large trees were left 

 dotted about the Held, olherwise it was thrown en- 

 tirely open, and planted with alternating cacao and 

 Liberian coffee. I pass over the tens of thousands of 

 cacao plants destroyed by white ants in the earlier 

 stages and the replantings that followed; but many 

 of those the white ants spared, after growing rapidly 

 1 ill they were from eighteen inches high, died off 

 without any cause that 1 could discover. Again, when 

 they began to branch, the tender leaves of the flushes 

 were to.-S' d about by the wind and dropped ; the ex- 

 tremities withered and fre?h shoots which originated 

 lower on the branches ran the same course. The 

 winds of the N. E. monsoon threw the plants back 

 ami the? recovered more or Ipbs during the prevalence 

 of the S.W. It was soon evident, however, that every 

 fresh effort at recovery was made with diminished 

 force, anil, as the past sasou has been the most trying 

 they have encoumered, the gieat bulk of the plants 

 that survived to meet it have succumbed. Where- 

 ever the toil was good and the shelter tolerable, the 

 plants throve vigorously, came early into hearing and 

 were very promising ; but this season, the whole of 

 those have suffered, not only to the loss of the crop, 

 but the loss of the tree itself. I have never been 

 able to trace to insect ravages Buy of the evils I 

 have experienced in my operations: insect work I have 

 seen as a consequence, but not as the cause. The 

 course of events has been the same on each occasion. 

 The winds blew off the tender leaves from the ex- 

 tremities of the shoots, the tender wood died back, 

 fresh shoots were thrown out to run the same course 

 and carry the dying-back deeper into the branches, 

 till the whole were affected down to the stein, aud, 

 when a sucker was allowed to run up, it ran precisely 

 the same course. 



In my opinion, the conditions of success are a deep, 

 tolerably rich loam and peifect shelter from wind, 

 and that either of those factors without the other will 

 lead to disappointment sooner or later. A gravtlly 

 soil, with a hard, stiff subsoil is to be avoided under 

 any other set of ciicumstance>; but on a suitable soil, 

 shelter may be got up in time to save the plants even 

 when no shelter has been provided to begin with. 



