INJURIOUS INSECTS OF luo,?. 



153 



Europe years ago, may cause serious damage, and it is evident 

 that we are quite at the mercy of the weather and the comparative 

 abundance of its parasites, both plant and animal, in the matter 

 of immunity from loss. It may not be present one year, may 

 be exceedingly abundant another season ; may be taken care 

 of by parasites one time and at another cause very serious in- 

 jury. As far as our knowledge extends at the present time, man 

 can do absolutely nothing against it. 



The Entomologist received many letters during last July, 

 asking for help in connection with this insect. To these letters 

 we had to reply substantially as above. This season the insect's 

 parasites apparently helped us out, and no serious loss was occa- 



Fig. 95.— A Grain Plant Louse. N. ccrcalis: a, winged migrant; b, nymph of 

 winged migrant; c. wingless parthenogeiietic female; d, wingless female, show- 

 ing e.xit hole of parasite, all enlarged. Marlatt, Division of Entomology, U. S. 

 Department of .\grictiltvne. 



sioned by them, as far as we can ascertain. The actual scientiiic 

 name was not ascertained, many of the specimens reaching the 

 office in a crushed condition, and others, received in better shape, 

 were, in the press of work at the time, laid one side "for a few 

 hours'' until the Entomologist had leisure to identify them, and, 

 as frequently happens in such cases, the "leisure hour" never 

 came until the specimen had died and shriveled or had crawled 

 away, and the end of the season found us without the scientific 

 name. Correspondence with Theo. Pergande, a specialist in 

 this group, leads us to believe that without doubt this particular 



