THE STATE ENTOMOLOGIST. 



21 



The fifth additional enemy of our Potato bug is the Nebraska Bee- 

 killer {Proinaclms Bastardii, Loew.) * This active and savage two-winged 

 fly was observed by Mr. A. R. "Whitney, of Franklin Grove, 111., to seize and 

 carry off the mature beetles, as we are informed by Dr. LeBaron. The Mis- 

 souri Bee-killer (Asilns Missouriensis, Eiley) would doubtless do likewise, 

 though the fact has not yet been observed; and neither of these flies would 

 be likely to kill Potato bugs enough to atone for their pernicious bee-killing 

 propensities. 



The sixth is the Kansas Bombardier beetle (BracJiinns Kansanvs, Lee) 

 — an insect bearing a general resemblance to the Great Lebia (3d Eep., Fig. 

 41) but being one-third larger and more lengthened, and with the wing-cov- 

 ers of a duller, less polished blue. The beetles of this genus all have the 

 power of discharging from the anus, when disturbed, an acrid fluid of so 

 volatile a nature, that upon coming in contact with the air, it tenuates with 

 an explosive noise and pungent smell, and hides the beetle in a bluish va- 

 por which enables the little artilleryman to effect his escape. The species 

 in question, was found attacking the Colorado Potato bug larvae, by Mr. 

 Thos. Wells, of Manhattan, Kansas, who furnished me with specimens for 

 identification. 



Lastly, we may add a species of Eove-beetle, belonging to the genus 

 Philonthus. An undescribed species of this genus was found by Dr. Shimer 

 maliciously killing the Doryphora larvae in one of his breeding cages. There 

 is no evidence yet, however, that it follows the same habit when free in the 

 field. The particular species noticed by Dr. Shimer was in the Walsh cabi- 

 net, which was destroyed in the great fire at Chicago, but to give the reader 

 a correct idea of this genus of insects I present a figure of PJrilonihus apicalis, 

 Sa}^ (Fig. 10). The larvae are active and voracious and bear considerable 

 resemblance to the perfect insects. Figure 11 is ta- [Fig. ii.] 

 ken from Westwood and shows that of Goerius olens. 

 The jjupte are quiescent and incapable of motion, all \^ 

 ■^ the parts being soldered together and encased almost 

 as firmly as in the chrysalis of a butterfly. The head 

 and pro-thorax are suddenly bent forwards, the former 

 touching the breast ; and the back is curiously flat- 

 tened. Figure 12 represents the pupa of an allied 

 insect* found in the ground and from Avhich I bred Quedius 

 [Fig. 12.] molochi7ius, Grav. The rove-beetles are, as a general rule, car- 

 rion feeders, preying voraciously on decaying animal and veg- 

 etable substances ; but some of them are true cannibals, while a 

 few are even parasitic. Indeed they are no doubt more carnivor- 

 ous than is generally supposed.^ 



Thus we have twenty-one enemies of its own Class, that have 



* See first Rep., p. 168, and second Rep. , p. 122. 



t This pupa is yellowish-brown in color. Dorsum perfectly flat with the sides compressed and 

 narrow-edged. First abdominal joint with a lateral spine; second with a larger, blunter, rounded 

 tubercle; each of the others with a stiff bristle: apical joint with two converging thorns. Abdomi- 

 nal joints 2, .3 and 4 with a tubercle each side of dorsum. 



t It is well known that these larvje are diflicult to rear to the perfect state, and one reason no 

 doubt is that they are often adephagous in habit, and are too generally treated as rypophagous 



[Fig. 10.] 



