OF WASHINGTON. 221 



to verdigris are the following : All Adephagous families, 

 Hydrophilidae, Coccinellidae, Byrrhidae, Parnidse, Hetero- 

 ceridae, Dascyllidae, Lampyridae, Malachiidae, Melolonthinae, 

 Chrysomelidae (excepting Donacia}, Tenebrionidae (excepting 

 Platydema and other fungus-inhabiting genera), Lagriidae, 

 Anthicidae, Meloidae, Rhipiphoridae, Rhynchitidae, Attelabidae, 

 Otiorhynchidae, Curculionidae. The families consisting exclu 

 sively of small-sized species (Pselaphidae, Scydmaenidae, etc.), 

 which no one would think of pinning, are omitted from this 

 list, and thus the number of those families where precautionary 

 measures should be adopted is in reality not so very large. 



A few generalizations which I have drawn from my expe 

 rience with verdigris in insects may perhaps be of some interest 

 to our younger entomologists : 



1. Coleoptera, which, in the larva state, live in the interior 

 of woody and other plants, including fungi, or those which de 

 posit their eggs within such plants, are liable to verdigris. On 

 the other hand, all phytophagous Coleoptera, the larvae of 

 which live openly on the plants, do not verdigris. So far as 

 my experience goes this rule holds good also for the other 

 orders. Thus the Rhopalocera do not verdigris, excepting the 

 genus Megathymus and those Hesperids which are ' ' inside- 

 feeders." The Sphingidae are free from verdigris, the Sesiidae 

 badly subject thereto. The Bombycidae do not verdigris, ex 

 cepting Cossus, Hepialus and allied genera. In Noctuidae only 

 Nonagria, Arzama, etc. , verdigris. In Hymenoptera the wood- 

 boring Uroceridae are badly subject to verdigris, and the same 

 holds true in the Tenthredinidae, the eggs of which are inserted 

 within plants, although most larvae live free. In Neuroptera 

 (taken in the old sense) the only inside-feeding families are the 

 Termitidae and Kmbidae, which, when pinned, are speedily 

 ruined by verdigris. In Orthoptera all families are either not 

 or only slightly subject to verdigris, excepting those Gryllidae, 

 the eggs of which are laid in the wood. In Diptera such 

 families as Trypetidae and Xylophagidae are more subject to 

 verdigris than most other families, and the same may be said 

 of the Aradidae and Cicadidae among the Hemiptera. 



2. All aquatic families of Coleoptera are free from verdigris. 

 In the Dytiscidae I do not know a single exception from this 

 rule ; in Gyrinidae, Hydrophilidae and Parnidae a slightly ver- 

 digrised specimen will occasionally be found in collections, but 

 probably only on account of an exceptionally poor pin. If the 

 Chrysomelid genus Donacia (including Macroplcea) be counted 

 among the aquatic Coleoptera it forms a striking exception to 

 this rule, for these beetles are among the worst to verdigris. 

 There are no other truly aquatic (i. e., aquatic in all stages) 

 families in the other Orders except in Heteroptera, and, so far 



