^^^Tc?y:7T«r»i "^Ji,*!;^ 



1862. 



THE ILLmOIS FAEMER. 



367 



vuced. Occasionally aa individul was noticed, 

 varying tomcwhat i'rara the others, and which I 

 have tUerefoie suspected might be made ; but, 

 on imprisoning such specimens in vials over 

 night, I have invariably found young lice with 

 tiiem next morning. 



When, and under what circumstances males 

 occur, if they do occur, is yet remaining to be 

 discovered. At present it seems as though these 

 insects might go on forever, producing young, 

 without any intercourse of the sexes. 



Finally, with regard to the fecundity of these 

 insects, I would state that those which have no 

 wings, and which lemain on the stalks of grain 

 on which tbey are boru, are much more prolific 

 than tliose which have wings and wander abroad. 

 By enclosiug them separately in vials, I found 

 the winged females quite uniformly gave birth to 

 two young lice in a single night, whilst the wing- 

 less ones produced four in the same time. We 

 frequently see young lice produced in the day 

 time, but fewer appear to be born then than dur- 

 ing the night. The winged ones are also much 

 slower in coming to maturity. I placed several 

 young lice the mornirg after they were bora upon 

 grain growing in a flower pot, and en the third 

 morning afterwards I found four little ones 

 around each of them, showing that the wingless 

 ones come to maturity in three days. It will 

 thus be seen with what prodigious rapidity these 

 creatures multiply. Thej' almost duuble their 

 numbers daily. A single one producing four 

 young daily, and these becoming equally prolific 

 when they arc three days old, her descendants, 

 in twenty days, if all live, will number upwards 

 of two millions. Tliis will serve to explain to us 

 how it is that this insect becomes so excessively 

 numerous upon the grain at harvest time, as we 

 nave seen it. 



As they multiply so rapidly, it is evident no 

 vegetation which they infest would escape de- 

 struction from fliese plant lice, if nature had not 

 iierself provided most efficient means for check- 

 ing and subduing them Vv'e accordingly find 

 that these insects are preyed upon and consumed 

 by other insects, to a greater extent tiian are 

 any other kinds of injurious insects wherewith 

 we are molested. Tliere are whole groups and 

 tribes of prcdaceous insects which subsist ex- 

 clusively upon the plant lice of different kinds. 



A tribe of very small Ichneumon flies, named 

 Aphidius, are parasitic destroyers of these in- 

 sects — puncturing and thrusting an egg into the 

 body of the aphis, from which hatches a minute 

 worm which feeds within the aphis till it kills it. 

 I have found two species of these parasites de- 

 stroying the grain aphis. 



Another most efficient destroyer is the Lady 

 Bug or Coccinella, of which there are numerous 

 species, a'l of which are continually searching 

 plantlice tofeed upon, these being the sole nour- 

 ishment of the lady bu^ , both in its larvae and its 

 perfect state. 



In addition to these are the Synphus flies, 

 the golden-eyed flies, and the la^e-wing flies, all 

 mortal enemies to the different kind of Aphis. 



By such meansisit that these plant licelive upon 

 the grain as on other vegetation, are usually but 

 a transitory evil — these their foes and destroyers, 



always gathering around them wherever they 

 Lecome numerous, and multiplying until they 

 overbalance and subdue them. 



Some one asked for a description of the Lady 

 Bug. Dr. Fitch described it as follows: — It is 

 about the size and shape of half of a small pea, 

 of a yellowish red color, with round black spots 

 upon it. 



Question. — Is it poisonous to animals? 



Dr. Fitch kn^w a single instance when swine 

 had been pastured in a field where the lady bug 

 was numerous All of the herd were taken sick 

 and some of them died. The swine were re- 

 moved from that field to another, and such as 

 were so removed recovered. Dr. F. said that it 

 was possible that the swine were poisoned by 

 eating large quantities of the lady bug; for if it 

 is taken in the fingers and crushed, an acrid 

 j lice is emitted, which is doubtless poisonous, 

 inasmuch as it is the insect's only means of de- 

 fen -e. lie had thought it pos.sible that this par- 

 ticular herd of swine might have been poisoned 

 by it. 



Question. — Is there any prcppect of the Aphis 

 becoming a permanent pest in the country ? 



Answrr. — I think not. Its enemies are too nu- 

 merous for that. Not more than a single year 

 at a time, will they be likely to ravage in a tin- 

 gle locality. As before said, they seem to be mi- 

 grating Westward. 



Q— Is the midge a permanent pest ; is it plenty 

 here at all seasons ? 



A — There is no doubt that the midge is plenty 

 in all parts of the country. The character of 

 the season governs its ravages. If the latter 

 part of June is wet, look out for the midge; if 

 dry, there is no danger. In dry weather it can- 

 not subsist on the uplands ; it i-eturns to the low- 

 lands. 



T. C. Peters — We are fast reaching the maxi- 

 mum of former years, in the amount of wheat 

 sown in Western New York, and it is an impor- 

 tant matter to us to know how to avoid the rav- 

 ages of the m.idge. Do you recommend f horou-rh 

 culture ? 



Dr. FiTCii — Strong growing wheat will pro- 

 duce de.-pite the midge. Yes, I do recommend 

 thorough culture as one of the preventives of the 

 ravages of the midge ; also of the Hessian fly and 

 other insects. 



Q — What is the effect of the work of the Aphis 

 upon the grain — upon the kernel? 



A — The insect extracts the juices from the 

 plant, which aid in developing and maturing the 



kernel. This diminishes the size of the grain 



sometimes virtually destroying it, for the sub- 

 stance is almost gone. 



Mr. Geddes, of Onondaga, does not agree with 

 the existence ot the midge. lie doubts if the 

 midge exists in as great numbers one year as 

 another, or if they are present at all; for prior 

 to the past six years he had failed to get a crcp 

 of wheat for some years on their account ; while 

 the past six years he had grown it successfully. 

 His success, he thinks, is not due to dry Junes 

 but to the fact that the midge had disappeared. 

 He doubts, too, if success is due to superior cul- 

 ture ; for he used to summer fallow all his land • 



