488 ORGANIC MATERIA MEDICA AND PHARMACOGNOSY 



be little opportunity for the sucking insects to injure the pharmacist's 

 stores. The insects may be divided according to this distinction as fol- 

 lows : The orders containing the beetles, the cockroaches, the dragon-flies, 

 etc., compose the group of biting insects; the orders containing the true 

 bugs, the butterflies and moths, and the flies, compose the group of suck- 

 ing insects; while the order of the ants, bees, and wasps, and the order of 

 mites (which are not true six-footed insects, but are closely related to 

 them) may be said to compose a third group, in which the mouth, parts 

 are arranged for both biting and sucking, or piercing and sucking. 



But we can not thus dismiss certain of the sucking insects from our 

 pharmaco-entomological consideration; for with wonderful adaptiveness, 

 nature has arranged that the young of certain sucking insects shall be 

 provided with jaws for biting. The common worm-like caterpillars, which 

 are the larval forms, or young, of butterflies and moths, are familiar to 

 all; most children know that the strong-jawed, foliage-eating "worm," 

 now feeding so voraciously on the green leaves of plant or tree, will in 

 time change into some beautiful four-winged butterfly or moth, incapable 

 of injuring a green leaf, and taking its food only in dainty sips, by means 

 of its sucking tubular mouth parts, from some bright flower. And most 

 housewives know that the dreaded clothes-moth little, brown, delicate 

 flutterer is, in its moth or winged stage, harmless to furs or woolens, but 

 that the dreaded little white grub, with its sharp jaws and voracious 

 appetite, which really does the damage, is only the young of the innocent- 

 looking moth, and that the moth, after all, is not so innocent. 



So, then, it behooves the pharmacist to keep an eye on not only those 

 insects which all their lives are truly biting insects, but also on those 

 insects, as the moths, which, while harmless as adults, yet in their young 

 stages, with strong biting mouth parts, appear as ravaging caterpillars. 



In setting out to fight an insect pest, the economic entomologist asks 

 first, "What is it? Is it a beetle, or a fly, or a moth?" This question 

 answered, he already knows much about it; whether, for example, it is a 

 biting or a sucking insect; he knows in a general way what sort of dam- 

 age it does and how it does it, and he knows, too, in a general way, what 

 remedies are most likely to be effective in fighting it. But it is always 

 better and usually necessary to know the exact life history of the particu- 

 lar pest he must fight; he must discover where and when its eggs are laid, 

 how long it remains in the larval or grub stage, what are its times and 

 places of feeding, and what are its favorite articles of diet. From this 

 life history he can decide on the character of the remedy to be applied, 

 and when and where the remedy can best be used. Therefore the phar- 

 macist may wisely turn to his jars and boxes, his store-rooms and labora- 

 tories, and try to discover what manner and number of insects he is to 

 array himself against. 



Referring to some of the more common and destructive pests attacking 

 stored drugs, the mites (order, Acarina) may first be noted. The mites, 



