'Die Food of Birds. 101 



dant as before and make about a fourth of the food. Arc- 

 tiidae and Phalaenidae (measuring- worms) appear in some 

 quantity, but of unrecognized species. The larvie of Bibio 

 fall to eight per cent, and do not again appear in the food 

 during the year. 



A strong upward jump in the ratios of Coleoptera, which 

 rise in this month to forty- two per cent., is doubtless due 

 to the greater activity of beetles during this season of their 

 amours. The effect is clearly seen by running along the 

 line of averages for Ooleoi)tera from February to October, 

 viz. : 4, 18, 42, 44, 15, 9, 7, 6, 3. The upward swell which 

 commences in March and dies away in June, corresponds 

 to the time when the procreative impulse overcomes the 

 usual discretion of these insects, and draws them out more 

 freely into the open air. It is in this month that the bird 

 makes its principal attack on the predaceous beetles, which 

 are represented by an average of seventeen per cent., eaten 

 by eleven of the birds. Thirteen heads of Harpalns her- 

 ilvagus, for example, were taken from the stomach of a 

 single robin. Other species of Harpalus, Brachylohus 

 lit/iop/iilus, Anisodactylus haltimoretisis^ Oeopinus Incras- 

 satus, Pterostichus and Amara were observed. Scarabaei- 

 dae also occur in unusual abundance at this time (fifteen 

 per cent.), as might be anticipated by one who recalls the 

 numbers in which they are now seen flying in the air. 

 May-beetles (Lachnosterna) make about half of these, and 

 Aphodii the other half. A single bird had happened upon 

 an interesting store of water-beetles (Hydrophilidcie) whicli 

 included a specimen of HydTocTiaris ohtusatus., several of 

 Philhydi'us cinctus., and a number of Helophori unknown 

 to me. Rhyncoj)hora amount to about three per cent, of 

 the food. Only Centrinus and Graphorhinus vadosus weve 

 recognized. Minor items were the traces noticed of Ela- 

 teridse, Lampyrida^ and Ohrysomelidae. 



Hemiptera stand at about the ordinary average (three 

 per cent.), as usvial chiefly Pentatomidce. Coriscus ferns, 

 some indeterminable Reduvid, Podisus modestus and Hy- 

 tnenarcys nervosa were the principal forms. The Orthop- 

 tera (five per cent.) call for no especial remark; neither 

 do the Arachnida (one per cent.). One bird had eaten a 



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