EXPERIMENT STATION EEPOET. 587 



number of such larvae sometimes found it seems surprising that the 

 insect is no more widespread than it is, and Mr. Bird explains it thus : 



"Happily, nature has the matter pretty well in hand. With no 

 other species [of Ilydroecia] does parasitism exist so severely as it 

 does with nitela [another name for this insect]. Two hymenopterous 

 and two dipterous parasites play the very miscliief with the species, 

 and while others also suffer, it falls to niicla to l)ear the brunt. It 

 seems enough for the female 1/ i/mciio/ilcr to nxTcly find a. huiTow 

 and thrust therein an ovum — the young maggot appears to be equal 

 to keeping up his end of tlu' contract. It seems able to live for some 

 time in the moistiwe and t'rass of the hni'i'ow and trust to a chance 

 contact with the host. The small JJijder, howc^ver, I believe, enters 

 the burrow and places her eggs on the larva to the number of twenty 

 or more. I have yet to get the name of this fly, ])ut wo know the 

 larva's name from this time on is Dennis." 



The pupa also seems sul)ject to numerous perils, and, on the whole, 

 only a small proportion of the insects reaches the adult stage. As 

 adults they are occasionally attracted to light, l)ut are liardly ranked 

 as common in collections anywhere. 



Remedial Measures. 



No satisfactory melbod of i-eacliing borers in herbaceous plants lias 

 yet been proposed, and it is usually best, when an infested plant is 

 found, to take it out and destroy it, borer and all. But in this 

 instance it appears tbat the cultivated plants are not the normal 

 food of the insect, and that attacks are exceptional rather than the 

 rule. It appears, also, that the real food plants are some of the 

 common, large weeds, without which the borers would not occur, at all. 



The suggestion is obvious — keep down all such weeds in and around 

 your fields and gardens, and in no event allow them to overrun the 

 ground late in. the season. A we(>dy field in September is an invita- 

 tion to the moths to lay eggs, and ihcre is always a chance tbat in 

 preparing the ground for next year's crop some of these eggs may 

 survive. Abolish the ragweed, burdock, pigweed and the like, and no 

 further trouble need be appreliended. The danger period is Septem- 

 ber, when eggs are being laid and dirty fences and roadsides offer 

 points of survival from which there may be an invasion of the neigb- 

 boring fields during the June following. 



