THE SYRPHIDAE OF OHIO 51 



beneath, cuneiform spots on mesonotum, scutellum, post-scut ell 11 m, and band on 

 posterior tibiae white. Male — Differs only in having the face, scape beneath and a 

 stripe on pleura, yellowish white." — The Author, Ohio Nat. Vol. XH, No. 5, March, 

 1912. 



The first indication of the presence of the parasite is usually a failure 

 of the pupal envelope to inflate completely, remaining le.ss rounded up 

 donsalh' and often with the anterior segments but little retracted ventrally. 

 Very soon the pupa becomes darker in color than normal. 



"The following are the average dimensions of 15 puparia of SyrpJins 

 ante ricaii lis from which Bassus laetatorius had emerged: length 6 mm., 

 height 2.25 mm., wddth 2.45 mm. Compared with the dimensions of an 

 equal number of unparasitized individuals as given below, (p. 55) it will 

 be seen that the.se are .slightly smaller in all dimensions than the normal 

 ones, with a little more difference in height than in length or width. 

 The difference in shape is more conspicuous than these figures would indi- 

 cate (See Plate IV, Fig. 56 ) , and together with the difference in color makes 

 them rather easy to distinguish when once the characteristics are learned." 



(3) The very widespread misbelief that adult 5i77!)///V/<f7c' are stinging 

 insects is rather inimical to them. As mentioned in another place (p. 35) 

 the great majority of non-entomological people when shown Syrphidae 

 express the belief that they are bees. Many of the smaller species fre- 

 quently alight on the hands or face, and I have often seen them ruthlessly 

 killed under the impression that the\' are "sweat bees." 



Ashmead bred from the larvae oi Mesogramma polita "two parasites, 

 acynipid {Solenaspis hyalinus Ashm.) and a chalcidid {Eucvrtus nicsooyap- 

 /^r^-Ashm.)"— Ins. Life, VII, p. 326. 



Other enemies concerning which I have made no particular observa- 

 tions are as follows: 



Hubbard (1885) gives the following interesting note on Syrphus-fly 

 enemies: "Minute Chalcid parasites prey upon the Syrphus larva, {Baccha 

 babista) and issue from the puparium in numbers varying from six to 

 eighteen, thru a number of small holes which they gnaw in its top and sides. 

 They are from i mm., to 2 mm. in length, and have the dark bronze and 

 metallic colors with h3'aline and iridescent wings so common in this 

 f amil}- ( Chalcididae) . ' ' 



PRACTICAL MEASURES 

 Something might be done toward fostering and increasing the num- 

 bers of these vahtable insects, if people generally, and especiall}- those 

 engaged in agricultural purstiits, could be brought to .see that S\'?p/iidae 

 are not stinging insects; and that both as larvae and adults, they are 

 among our most valuable animal friends. 



