NORTH AMEKICAN ODONATA. 205 



virgo in the river Wieseck, near Giessen, to be infested with the 

 larvis of Folynema ovulormn L., a minute Hyraenopter of the family 

 Chalcididje. Minute Diptera and Acarina also oviposit in or devour 

 the eggs (Mrs. Aaron 54, p. 50). These and the young nymphs 

 provide food for fishes* and other aquatic animals ; added to this is 

 the cannibalism of the nymphs (see p. 178). The writer has found 

 a young spider, kindly identified by Dr. McCook as Dolomedes sex- 

 pundatus Hentz, feeding upon the soft parts of recently transformed 

 imagos of Ischnura verticalis and Nehalennia posita which were not 

 yet able to fly. The carnivorous habits of the Odonata naturally 

 expose them to the entrance of intestinal parasites, and de Selys has 

 recorded the finding of a Filaria in the abdomen of Dijylax flaveola, 

 inflating it to such an extent as to impede the insect's flight (Rev. 

 Odon. d'Eur. p. 36). Red Acarina (mites) frequently occur on the 

 thorax and abdomen of imagos, especially on the ventral side, and 

 have been mistaken for eggs ; a male of Mesothemis simplicicollis, 

 communicated by Mr. H. F. Moore, had upwards of 100 such mites 

 attached to the ventral surface of the sixth and seventh abdominal 

 segments. During oviposition the female dragonfly sometimes falls 

 a prey to fishes. Lastly, dragonflies are eaten by various kinds of 

 birds. 



Fisher (U. S. Dept. Agric. Div. Ornith. and Mam. Bull. No. 3, 1893) records the 

 following Falconida^ as feeding on the Odonata in the United States: Swallow- 

 tailed Kite (Elanoides forficahis), Sharp-shinned Hawk {Accipiter velox), Red- 

 shouldered Hawk {Btiteo lineatus), Broad-winged Hawk (Buteo latissimtis), Duck 

 Hawk (Faico peregrinns anatum). Pigeon Hawk (Falco columbarius) and Sparrow 

 Hawk (Falco sparverius); uoneof these live exclusively upon dragonflies. Miiller 

 (Proc. Ent. Soc. Loud. 1871, p. xlii) quotes Natterer, who found "Libelleu" in 

 the stomach of a South American Falcouid, Hypotriorchis rufigularis. In central 

 France, " from May to September, in the pond countries where Odonata are natu- 

 rally common, the Hobereau (Falco suhhuteo) lives almost exclusively on the 

 large Aeschnids, while the Hydrochelidons eat hardly anything but Agrions. 

 Certain other birds also attack the Libellulfe at times, but none of them, even 

 for a short season, make their exclusive diet thereon" (Bene Martin : Bull. Soc. 

 Ent. France, 1891, pp. clx'ix-xxi). Gould states that he has frequently seen 

 small birds, sparrows, etc., capture and eat the small species of Odonata frequent- 

 ing the sedgy banks of the Thames (Proc. Ent. Soc. Loud. 1871, p. xlvii). Both 

 Martin and Gould mention that the dragonflies were deprived of their wings 

 before being eaten by the birds. Hersey (Can. Ent. v, p. 160) found the King- 

 bird { Tyrannus carolinensis) feeding upon Odonata in New Hampshire. Starlings, 

 blackbirds and sparrows fed on a swarm of Odonata at Dresden, seen by Weid- 



» Forbes gives a list of fishes in whose alimentary canals nymphs were found 

 (Bull. 111. State Lab. Nat. Hist, ii, p. 524). 



TKANS. AM. ENT. SOC. XX. AUGUST. 1893. 



