coccus 



CACTI 



Cochineal 



Food of the 

 Insect. 



Herbarium 

 Specimens. 



Red and Yellow 

 Flowers. 



Life History 

 of Insect. 



Propagation. 



PLANTS OF THE INDIAN NOPALRY 



introduced by Dr. Anderson) ; also " Nopalry " (defined as " Garden for Cultiva- 

 tion of Cochineal Plant and Insect "), 13.] 



The favourite (and apparently the exclusive) food-plants of cochineal are 

 various forms of otmntin or .Voiml the prickly pear (see Opuntia, p. 822). The 

 grana fina feeds mostly on Otmntla foccintlllfera, Haw., whilst the grana syl- 

 vestris is reported to live on several species, including o. tnonacnutHa, Haw., and 

 the common Indian form O. miienii, Haw. Considering the prevalence of the 

 species of Opnntin, it may be said there are not many recently collected speci- 

 mens of the genus" from India in the Royal Herbarium, Ke\v. Five species are. 

 however, represented by the sets present, and these in alphabetical sequence are : 



O. decumana, O. Dllleult, O.jflett8-iitllci, O. monaca nttm and O. limit. There 



is no specimen of o. cocdnitufera , and which may also be regarded as some- 

 what significant there is only one sample of o. DUienii from Madras, and that 

 contributed in 1886, so that it would almost seem as if that plant had not been 

 known, or at all events little experimented with in South India, much before the 

 first decade of the 19th century. On the other hand, there are admirable samples 

 from Madras of the other species just named, which are stated to have been 

 collected from Dr. Anderson's garden on April 19, 1809. These are accordingly 

 historic specimens. Of o. -nionttcaiitint it is said that it was " the food of the 

 wild cochineal." That same species has on two subsequent occasions been sent 

 from Madras Presidency and once from the Panjab, so that it is probably widely 

 distributed in India, and completely acclimatised. Of o. /iciis-indicn another 

 Madras historic sheet bears on the label the following observation : " It is not eaten 

 by the wild cochineal." The specimen of o. aecumtimi was wrongly named 

 o. cocci nil lifera in the series from Dr. Anderson's garden, but there is no men- 

 tion of whether or not the true cochineal insect fed on this or any other species 

 grown in Madras. O. decumana has more recently, however, been sent from 

 Madras, so that it appears to have become acclimatised. Lastly there is only 

 one sheet of o. <, and it also came from Dr. Anderson's garden in Madras. 

 Most of the Indian specimens of Ojmntia preserved in the Herbarium, Kew, bear 

 a parasitic scale insect (possibly a species of /xj>i*), but no trace of cochineal. 

 It thus seems possible the sudden extermination of the Opuntias of certain 

 districts (such as that mentioned in Wilks, Hist. Mysore, iii., 89, in connection 

 with Tippu Sultan) might be accomplished by the parasite mentioned, without 

 supposing the sudden appearance and disappearance of a form of cochineal. 

 The fact, however, that certain Indian writers affirm that the cochineal will onh 

 feed on red-flowered Opuntia while others say that it prefers the yellow-flowered 

 plant, is perhaps best explained by the supposition that there are at least tw< 

 races or species of cochineal in India, though as yet not separately recognised 

 by entomologists. Dr. Bourne (Rept., July 26, 1897) obtained grana syi- 

 insects from Ganjam and found these on the yellow-flowered Opuntia ; the> 

 lived for a short time, and only a little longer on the red. He accordingly inferrei 

 that as a measure of extermination of Opuntia the rearing of any form of cochi 

 neal was attended with so much difficulty that it was a failure. But it ma\ 

 thus be asked, would similar failure necessarily result with all the other species 

 of Scale Insect seen on the Opuntias ? 



The cochineal insect at its birth is viviparous and the male and female larv.T 

 are not distinguishable even under the microscope. After a few days, however, 

 they fasten to the cactus-leaf, lose the power of locomotion, and become covered 

 the grana fina by a short white down, and the grana sylvestris by a much 

 longer cottony substance which conceals the insect. The creature destined t( 

 become the male is enveloped, along with the females, but in time becomes encased 

 within a separate pouch or purse open at the blottom. From this in due time it 

 emerges as a scarlet fly possessed of long transparent wings. It rarely flies. 

 hpwever, to any distance but jumps and flutters about while visiting the females. 

 and shortly after dies. The female, on the other hand, never emerges from her 

 case as a winged insect, in fact never moves again from the position she took 

 as a larva, but becomes absolutely torpid, round in shape, loses her eyes and 

 even all form of a head. She derives nourishment by means of a hollow pointed 

 tube, which she plunges into the fleshy texture of the cactus. She begins to 

 yield her offspring after about three months, and it is at this stage that the process 

 of " nesting " is begun. Some eight or ten females are picked off the cactus and 

 put into a little bag of cotton-gauze or other cellular tissue, which is fastened to the 

 underside of a fresh cactus-leaf by means of a thorn. The young larvae escape, seek 

 out good positions, and when fixed repeat their cycle of birth, growth and death. 



348 



