92 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



to the larvae, Poulton says : " Numerous experiments have convinced 

 me that the latter are almost invariably distasteful." (Essays on 

 evolution, p. 238, 1908.) However, the present tabulations reveal more 

 than 3.D species of birds as predators upon sawfly larvae and no fewer 

 than 50 to 100 specimens of these larvae have been found in single 

 stomachs of the mockingbird and from 10 to 25 in those of other 

 species. Hewitt records seven species of British birds as feeding upon 

 larvae of the large larch sawfly (Nematus erichsonii) (Bull. 10, Div. 

 Ent. Dom. Can. Dep. Agr., p. 22, 1912), and attributes to them great 

 destruction of the larvae. The 380 records of Tenthredinoidea in 

 our table are distributed among 99 species of birds and such wasp- 

 suggesting forms as Cimhex, and the horntails of various kinds, with 

 24 records, seem to be proportionally represented. 



Most of the Ichneumonoidea are not credited with any special 

 defenses besides their resemblance to stinging hymenoptera, and the 

 more than 1,200 records of their being eaten would seem to indicate 

 that this means of protection is more imaginary than real. Some of 

 the more interesting records may be cited as indicating the extent to 

 which birds eat these insects: Prolapanteles: 50 specimens in the 

 stomach of an English sparrow (one of a series of 12 containing 10 or 

 more each), and 120 in one stomach each of a Brewer's blackbird and 

 an Aleutian sandpiper ; Ichneumonidae, further unidentified : 68 speci- 

 mens in a sanderling's stomach (19 birds have from 10 to 42 records 

 each) ; Ichneumon sp. : ■t^'j specimens in the stomach of a burrowing 

 owl ; Glypta tuhcrcidifrons: 44 individuals taken at a meal by a 

 yellow-throated vireo ; Ophion spp. : 54 records for these large 

 ichneumons which can sting. 



Most ants, their size considered, can bite severely ; their body fluids 

 contain formic acid and other pungent substances ; and many of them 

 also can sting. As further tribute to their prowess the reference of 

 Poulton may be quoted to the " numerous mimetic resemblances to the 

 aggressive, abundant, and well-defended ants." (Essays on evolution, 

 p. 252, 1908.) Badenoch says that ant-models " as a rule are exempt 

 from persecution." (Romance of the insect -world, p. 300, 1893). 

 The confidence of selectionists in the protective nature of ant mimicry 

 is further shown in the following statement by Dunisthorpe on Nabis 

 lativentris: " I consider this insect to be an ant mimic in its earlier 

 stages, when it is usually found in the company of ants. From this 

 mimicry it obtains protection from outside enemies, both as much 

 when away from ants as when with them." (Ent. Monthly Mag. 

 3rd ser., vol. 7, pp. 137-138, 1921.) 



