702 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



stems of the cacti, the male in the meanwhile being able to fly about; 

 then the female attaches herself to the tissues of the Nopal plants, 

 her body becoming a membranous cradle for the larvae of the next 

 generation, and after which she dies. From three to five generations 

 of the cochineal insect may be produced in a single year. The first 

 generation usually is richer in coloring matter and is considered 

 the most valuable. It is estimated that from an area of about 

 an acre of Nopal plants approximately 100 kilos of cochineal may 

 be gathered; this would represent about 14,000,000 of the dried 

 insects of commerce. The cochineal of commerce consists of the 

 membranous cradle of the female which is removed by the 

 planters from the Nopal plants. They are then subjected to 

 steam or hot water and dried, or they may be dried by direct 

 heat. 



Description. The commercial article consists of small concavo- 

 convex fragments about 5 mm. in length, and of a dark garnet color. 

 When cleared 1 it shows the insect to be a hollow vesicle of an ovoid 

 or plano-convex shape having in the upper portion some of the ~emains 

 of the mother insect (Fig. 308). The mouth part with a more or 

 less developed beak or rostrum is always present, the beak sometimes 

 being extended and recurved in a narrow elliptical form in the direc- 

 tion of the abdomen. One or both of the antennae are frequently 

 present, showing 5 to 7 parts. The joints of the legs are usually 

 more or less detached, the point of insertion usually only being 

 indicated by large yelloxvish-brown elliptical scars. In between each 

 of the legs on both sides are situated 2 distinct pores, resembling 

 in form and color the point of attachment of the legs, and which 

 are tracheae or respiration canals. In the abdominal region, which 



1 The following method is useful in destroying the coloring matter, rendering 

 it possible to study the cochineal insect. A convenient quantity, as 10 gm., of 

 commercial cochineal is macerated with 100 c.c. of water containing 2 or 3 per 

 cent of an alkali. The mixture is allowed to stand for an hour or so, the contents 

 being poured over a piece of wire gauze. The insects remain on the gauze and 

 are then washed with a few litres of water. The insects, from which the coloring 

 matter has been partly removed, are then transferred to 150 c.c. of hydrogen 

 peroxide solution and allowed to stand for a few hours with occasional gentle 

 stirring. The mixture is again transferred to the gauze, the excess of hydrogen 

 peroxide being washed off and the insects transferred to a weak alkali solution in 

 which they are macerated for six or eight hours. The mixture is poured upon the 

 wire gauze and washed ..ith water until the filtrate runs practically colorless. 

 The insects on the gauze are then transferred to dilute alcohol to which a few drops 

 of hydrochloric acid have been added. This now renders them translucent and 

 ready for microscopical study. They may be mounted in chloral solution or a 

 solution of chloral and glycerin and examined. 



