US 



KNOWLEDGE 



[July 2, 1894. 



On removing the creature from the plant to which it is 

 attached, the under scale often remains behind and appears 

 as a thin film on the leaf. When the insect dies, its upper 

 scale after a time falls ofi', but the under film still remains 

 attached, to attest the former presence of the insect ; and 

 in this way relics of two or three generations, which have 

 succeeded one another, may be found on the same area. 



The life of a female Conns is about as uneventful as one 

 can well imagine ; and in this respect it is a fitting accom- 

 paniment of a degree of degradation in structure which is 

 almost without parallel amongst insects. If one felt 

 inclined to moralize on the subject, one might well adopt 

 the quaint words of an old naturalist writing a century ago 

 about one of these scale-insects that is to be found on rose 

 trees. He closes his paper with the words : "This is the 

 biography of a creature whose world consists of two inches 

 of a little branch of a rose bush, and it accomplishes what 

 most men do : being born, multiplying itself, and — dying." 

 The sluggish habits and semi-vegetative life of these 

 degraded female Cucci render them peculiarly liable to the 

 attacks of parasites of various kinds, and, amongst others, 

 parasitic fungi have been discovered upon them. Some of 

 these appear to attack them during life, but others locate 

 themselves on their dead bodies, deriving their -nourish- 

 ment from the carcase. Of course all such fungi are 

 exceedingly minute, but still some very beautiful forms are 

 sometimes to be met with. In his " Vegetable Wasps and 

 Plant Worms," Dr. M. C. Cooke figures one, of which we 

 reproduce a sketch (Fig. 6 1, showing three pretty little 

 clubs rising up from the surface of the convex scale. 



Two other genera of this 

 remarkable group of insects 

 may be referred to as form- 

 ing their waxy or silky secre- 

 tions into dift'erent shapes 

 from those mentioned above. 

 The first oitheseis Kiinpt'ltis. 

 This forms little compact 

 oval tufts, like pieces of cot- 

 ton wool (Fig. 7) attached to 

 the stems and blades of 

 certain grasses, and there is 

 certainly nothing whatever in their external appearance to 

 suggest any connection with bisects, unless, indeed, they 

 might be cocoons of small ichneumon flies. But a close 

 examination, revealing a number of separate threads 

 standing out in all directions, would soon dispel this idea, 

 and would leave their real nature as problematical as ever. 

 Though apparently not uncommon, they have not long 

 been generally known in this country, having previously, 

 no doubt, been overlooked, partly because of the little 

 attention that was until recently paid to the Con-iiUe, and 

 partly because of the completeness of 

 their disguise. They seem to have been 

 first noticed in this country in 18.56, 

 when there is a reference to them in 

 " The Proceedings of the Entomological 

 Society of London " ; but that was soon 

 forgotten, and they passed out of know- 

 ledge till 18H5,when Mr. G. C. Bignell 

 again called attention to them. 



The other genus is called Onhaia, 

 at least one species of which is a com- 

 mon and widely distributed insect 

 (Fig. 8), though, as it is of retiring 

 habits, it is not likely to be fre- 

 quently seen except by those who specially look for it. 

 The whole body is invested in the waxy secretion, and 

 no parts of the real insect are visible except the legs 



Fig. G. — Scale-insect, with 

 parasitic fungi. Much magnified. 

 (Aft ~ ■ 



• Cooke 



Fio. 7. — Eriopeltis 

 festncfF, on l)lacle of 

 grass. 



Fig. 8. — Adult female 

 of Orthezia urticte. 

 Magnified eight 

 diameters. 



be alive ; and 

 idea of an im- 



and antenn*. which project from the waxen coat which 

 envelopes the whole. There is also the further peculiarity 

 that the exuilation is not irregularly disposed in the form 

 of loose threads, but is perfectly symmetrically arranged in 

 the form of fluted columns and rosettes, so rigid and so 

 exquisitely chiselled as to give the in- 

 sect the appearance of being a little 

 marble statuette. On the fore part 

 the white secretion is arranged in a 

 sort of rosette, and behind in parallel 

 longitudinal lines, reminding one of 

 stiflly arranged folds of drapery. Un- 

 derneath, the surface is strongly convex 

 and smooth, forming the outer boun- 

 dary of a kind of pouch in which the 

 eggs are carried. On seeing the in- 

 sect from above, it appears simply to 

 be an exquisitely neat cast in plaster 

 of Paris, and there is nothing sugges- 

 tive of a living being at all. On 

 turning it over on its back, one is 

 much astonished to find that the 

 supposed mineral is provided with 

 six little brownish legs, which by 

 their movements show the thing to 

 there is then irresistibly suggested the 

 prisoned being enclosed in a perfectly rigid shell of plaster 

 of Paris, with minute holes for the legs to come through, 

 and one is apt to think that some misfortune must have 

 happened to the creature to bring it into such a condition. 

 The condition, however, is a perfectly natural one. and the 

 insect may be found thus covered in all its stages amongst 

 dead leaves and other rubbish. While it is young, little 

 more than the rosette is developed, and the egg pouch is 

 not added till the insect becomes fully grown. It is only 

 the female insect that appears in this curious form ; the 

 male is a small winged creature, with a single pair of 

 wings and a number of tufts from its tail, like spun glass. 

 The aphides are closely allied to the Coccida, and 

 amongst them too we find instances of the secretion of 

 masses of protective matter, which are employed to shelter 

 both old and young insects. Perhaps the best known 

 example of this is to be found in the "American blight," 

 or " woolly aphis," that sometimes infests apple trees. A 

 badly infested tree will look as if its branches had had 

 masses of cotton wool scattered about in all directions 

 over them. The cottony substance will be found specially 

 thick round crevices in the bark, or on places whence 

 boughs have been removed in pruning or accidentally 

 broken off, and occasionally it hangs down from the 

 branches to the depth of several inches as loose masses, 

 which wave about in the wind and are sometimes blown 

 away on to the neighbouring trees. A cursory glance will 

 probably fail to detect the insects, so completely are they 

 concealed by the masses of down they secrete, and the 

 white threads will very likely be set down as a sort of 

 fungus. On turning it aside, however, the insects will be 

 discovered in the midst of the mass as yellowish or reddish, 

 wingless, fat-bodied, six-legged beings, of various sizes 

 according to age. They differ from the majority of aphides 

 in not possessing the two tubes which visually project from 

 the hinder part of the body for the secretion of the honey- 

 like liquid of which ants are so fond. Being deprived, 

 however, of that secretion, they have all the more fully 

 developed the power of exuding the protective cottony 

 mass. In speaking of this secretion as " cottony," it will 

 of course be understood that its appearance only, and not 

 its constitution, is referred to. If its real nature were to 

 be indicated by a name, the epithet "silky" would be 



