146 FIRST ANNUAL REPORT OF THE STATE ENTOMOLOGIST. 



change, before the maturity and final development of the Tacliina 

 flies. In appearance these flies resemble several of our common species 

 of house-flies, having short and broad wings, stout and bristly bodies, 



and large eyes. Fig. 37 represents a species 

 of the family, NemorcBa levcam'm Kirkp., 

 which is of great benefit in checking the 

 ravages of the army-worm, Leucania uni- 

 puncta, for when the pest abounds it is 

 usually accompanied by its parasite, which 

 follows the hosts and deposits its eggs upon 

 ^1 J^P^IiSi^^ them neax the head, as shown in the figure. 



Fir, s7.-Nemor^a LEDCANi^; the and causing the death of the larger num- 



larva,fly and puparium; also its | . f ^j inyading army. 

 eggs placed upon the forepart or o J' 



an army-worm, on which it is The Tachiuid reared from the Crambus 



cocoons is one of the smallest that I have 

 seen, surpassing but little the common house-fly, Musca domesUca, in 

 size. Its eyes are large ; its thorax bluish, striped with black ; its ab- 

 domen quite bristly and presenting changeable patches of gray and 

 black as viewed in different lights. It has not been specifically deter- 

 mined. Many of the species are so similar in appearance, and there 

 appears to be so great a range of variation in a single species, that 

 their correct determination, in some of the genera, is a very diffieult 

 task, involving an amount of study which has not been given to them. 

 The above Tachina has given an illustration of secondary parasitism, 

 which is always interesting, although not infrequently met with among 

 the insects which prey upon one another. The Tachina fly, while 

 destroying the Crambus, has, in its turn, been attacked and destroyed 

 by a hymenopterous insect — one Of the Chalcididce. Of the three 

 Tachinid puparia found among the Crambus cocoons, one gave out the 

 fly noticed above, from another a Chalcid emerged, and the third 

 was discovered with a hole eaten in one end, through which the 

 head and front pair of legs of another example of the same species wag 

 projecting, evidently caught and fastened by some means in the act of 

 emerging, and dying in this position. 



Perilampus violaceous Dalm. — The Chalcid, as determined by 

 Mr. L.O.Howard, is Perilampus violaceovs Dalman. It is a beautiful 

 little insect in its brilliant deep violet color throughout, except its dusky 

 feet. Itsshortantennas, not so long as the transverse diameter of the head, 

 are closely jointed. The head is short and broad, with ovate eyes. The' 

 deeply punctured thorax is large, longer than the abdomen, protuber- 

 ant, and ending in a blunt point behind. The abdomen is smooth, 

 with short downy hairs, and is trigonate in form. The front wings 



