252 ENTOMOLOGICAL NEWS [XXXI, '20 



Male genitalia extended lateral view. 



Male genitalia extended posterior view. 



Tip of ovipositor. X8. 



Anterior leg. X2. 



Egg. Xi5. 



Stalk of sea oats showing characteristic egg punctures. X^- 



Stalk of sea oats cut longitudinally to show arrangement of 



egg punctures. Xi}4- 

 Single egg puncture. X15. 

 Single egg puncture. X15. 

 Recently hatched nymph. X20. 

 Antenna of recently hatched nymph. X120. 

 Anterior leg of recently hatched nymph. X3S. 



The Occurence of Mallophaga on a Dragonfly (Odon.)> 



Mr. E. B. Williamson has recently sent me specimens of Ma//o/>/taga, 

 several of a small species of Gyropus, and one Trichodectes, which he found 

 at Quebrada La Camelia, Colombia (Feb. 18, 19 1 7) attached to a dragonfly 

 (Ischnogomphus jessei Williamson). The only recorded case of a Mallo- 

 phagous insect found on another insect is that noted by Sharp (Proc. Zool. 

 Soc. Lond. 1980, p. xxx) who found several attached, apparently by the 

 mandibles, to a Hippoboscid fly, Ornithomyia avicularia. As this is also a 

 bird parasite it is not surprising that the smaller Mallophaga should at 

 times crawl upon it, but the occurrence of the Colombian specimens on 

 the dragonfly seemed at first inexplicable, especially as the genus Gyropus 

 lives exclusively on small terrestrial rodents. However Williamson, in his 

 description of the dragonfly (Occ. Papers, Mus. Zool. Univ. Mich. No. 

 52, 1918, p. 44) shows that it is in the habit of alighting on the ground or 

 on leaves near the ground, and one may reasonably suppose that the drag- 

 onfly had recently perched upon some dead agouti or simlliar rodent and 

 that the insects had then attached themselves to it. So while this case 

 is very interesting, it is not an example of phoresy, but more properly 

 belongs with other cases of insects being found in unusual situations, 

 best explained by our genial E. A. Schwarz in words which formulate a 

 simple yet indubitable biological law: "They must sit somewhere." 

 Wm. M. Mann, U. S. Bureau of Entomology, Washington, D. C. 



