NO. 7 PROTECTIVE ADAPTATIONS McATEE 97 



dant, and well-defended ants." it should be apparent in some lessening 

 of predatory attacks upon them. However the very opposite is true 

 and the case aft'ords the best sort of proof of the thesis of this paper, 

 namely that the number of enemies, or perhaps better stated, the total 

 losses to enemies, is in direct proportion to abundance of the group 

 concerned. 



Selectionists regard bees as very highly protected insects, but taking 

 the honey bee as type of the group because more is known about the 

 species than any other, we find that bee-keepers complain bitterly of 

 the numerous enemies of the inmates of their hives. Wasps, velvet- 

 ants, robber tiies, Phymatid bugs, mantids. and dragonflies are serious 

 insect enemies of honey bees ; spiders, toads, lizards, rats, mice, and 

 skunks prey upon them; numerous wild birds join in the attack (32 

 nearctic species according to our tabulations), and domestic ducks are 

 said to be insatiable in devouring bees. A mite is the primary cause of 

 the so-called Isle-of-Wight disease among hive-bees ; ants and wax 

 moths destroy the comb ; and there are at least two serious infectious 

 diseases. At times bees rob other colonies, the rifling being accom- 

 plished however only after great slaughter. In the case of the honey 

 bee, much study has been devoted to the insect and we know consider- 

 able about its enemies, but the ruling principle is as clear in this case 

 as in that of the ants, namely, that common species have numerous 

 enemies. 



Since ants and the honey bee fairly exemplify two of the main 

 phases of protective adaptation in Hymenoptera, despite which these 

 species clearly have their full quota of enemies, we cannot doubt that 

 other species of the order, when they are as well known, will prove to 

 have predatory foes fully in proportion to their relative abundance. 



In fact the 27,000 records of Hymenoptera now available are suf- 

 ficient indication that the order contributes its due toll to the subsis- 

 tence of one of the chief groups of its enemies — the birds. 



Arachnida (Scorpions, Spidkks, Ticks, Etc.) 



Protective adaptations. — Most arachnids possess venom of suf- 

 ficient strength, and means of injecting it into other creatures, to 

 enable them to overcome the animals upon which they prey. Numbers 

 of them have chelicerae, which in a few cases are rather powerful. 

 The poisonous nature of many of the species has been greatly exag- 

 gerated especially by primitive races of man so that they are held 

 in extreme dread. 



