other stages. Work hand in hand with the insectaries and scientists. It is true 

 they are destroying and in time will utterly exterminate entire families of butterflies 

 and moths, it is true that nearly all cocoons found in the vicinity of insectaries will 

 be worthless because of enemies which have been bred and liberated by these 

 institutions, but your highest duty is to assist in this work. I hold that the butterfly 

 farmer can be of incalculable service to agriculture, horticulture and viticulture. It 

 is very disappointing to find that cocoons which you have gathered are worthless 

 because of parasitic flies, but if it chance that you discover a new parasite you 

 may score a victory by giving to science a remedy that may save the crops of an 

 entire state from devastation. Never breed and liberate species which can become 

 pests. Most species of moths and butterflies are known to be harmless, and none 

 others should be allowed to escape from your breeding cages. When you lose a 

 batch of eggs, a brood of larvae, or a lot of cocoons, try and discover the cause. 

 The cause of your loss may reveal a secret for which scientists are vainly searching, 

 a secret which may ward off poverty, ruin and even famine from prosperous 

 regions. 



HOW TO TELL LIVE PUPAE. 



Cocoons which are naked will usually squirm and wriggle if held gently in 

 the warm hand for a few moments. If dead, they will be hard and brittle and 

 light. The usual test for a cocoon covered with a silken web or covering is to 

 invert it suddenly close to the ear. Don't shake it for that may cause injury and 

 a quick turn of the wrist is sufficient. If sound and healthy there generally will be 

 a distinct, solid, rather heavy thud, as the pupa drops from one end of its hollow 

 enclosure to the other. If parasites are present there will be a rattling sound as if 

 the interior contained small shot. When the pupa is dead it will be of Tight weight 

 and there will be no sound at all. Sometimes these tests fail and I have cut open 

 cocoons which were healthy but which gave no response when inverted. The 

 appearance and flexibility of naked cocoons indicate their condition. Empty 

 pupa-cases should not be destroyed. Label and preserve them to illustrate life- 

 histories. 



MULTITUDES OF ENEMIES. 



Some Ichneumon flies deposit their eggs in larvae to develop after the pupa has 

 formed, and other deposit their eggs in the chrysalis itself. 1 est your pupae fre- 

 quently and separate those which seem infested. When you discover flies of any 

 size,, even though they be very small, among your cocoons, capture them at once. 

 You must constantly guard your cocoons against mice, ants, beetles and spiders. 

 Unless the earth and sand in the breeding cages was baked an army of microscopi- 

 cal enemies may threaten the pupae. Filth, mold, fungus and the decomposition of 

 larvae which died while endeavoring to transform to pupae, cause disease and 

 death to riot among stores of cocoons. Artificially heated rooms parch the life 

 out of pupae, freezing kills them, shaking or dropping them breaks the chitine or 

 outer covering, and any unnecessary handling or rough usage may prove fatal. In 

 nature "countless horrors lurk unseen" about the pupal stage. Birds, bats, snakes, 

 squirrels, roaches, vermin and other enemies devour them by the thousands. Toads 

 have such greedy, insatiable appetites for every form and stage of insect life that 

 I cannot understand why they are not propagated in ponds and swampy places 

 for the purpose of being transported to districts which are threatened by grass- 

 hoppers, army worms or other pests. 



61 



