345 



bring a swarm of mosquitoes ; occassionally some of them get into the house, but 

 cause us so little annoyance that we scarcely notice them. Before this ditch reaches 

 the Eucalypti it runs through a jungle of " fence bamboo " (^r«Mdo wi«cj'oj>%^^« )> where 

 the mosquitoes are so bad that we avoid working there except on the windiest days. 

 And, though the ditch has more currents there, the larvie of mosquitoes are plentiful 

 in the wjiter till it reaches the Eucalyptus trees, below which point none are found, 

 till it has become stagnant away below them. 



People who have camped among the willows of Kings River, only a few miles 

 away, have come here with faces so blotched and swollen from mosquito bites as to 

 be hardly recognizable, and have camped in the shade of "Sanders' Gum Trees," as 

 my grove is popularly called, for weeks, and declare that they never even heard a 

 mosquito sing during that time. — [W. A. Sanders, California. 



P. S. — To the non-botanical reader I may say this species of Eucalyptus is very 

 tender as to frost. The coldest weather ever known here, 19- F. above zero, killed 

 thousands of them. 



Another vegetarian Mosquito. 



Since writing to you last I have seen another vegetarian mosquito, possibly a de- 

 scendant of the one I saw last year, as it was in the same place. I think this may 

 be a new strain, or perhaps they belong to the total abstinence club. At all events 

 let us hope they will continue to inherit acquired characteristics; it may be they 

 will reform the race, as it were, and from mosquito bars and insect powder be com- 

 bated with rose nozzles and Bordeaux mixture. 



The mosquito in question settled on some apple sauce u^ion the table. She had a 

 better time of it than the other one I saw, as she soon drank her fill of the juice and 

 flew heavily away.— [A. A. Eaton, California. 



Insect Injury to Cactus Plants. 



I send you some bugs found on some Cactus plants. I have three species of Opun- 

 tia, which I am growing for ornament, namely, Opuntia rafinesqui ( ?), Opmitia engel- 

 manni, and O. leptocaulis (friitescens). I had a patch of O. rafinesqui and O. engel- 

 manni mixed, about twelve feet in diameter. It was a sight to look at when in bloom, 

 but to-day they are all dead. 



As a general thing the cactxis family is looked upon as an enemy of mankind, but 

 take away Opuntia enqelmanni from portions of Texas and the rest of the cactus kind 

 and there Avill be but little left to feed stock upon in case of protracted droughts. 

 If this insect works all over the State as it does here it will be a very short time 

 before all the Opuntias are exterminated. They are equally l)ad on the three named 

 species, and since I have seen what they are doing I am killing every one I can get 

 hold of. I do not know whether they attack such genera as Cereus, Echinocactus, 

 or Mamillaria, for I did not have any of the above-name genera. If you receive 

 these bugs in good condition you can experiment with them in your vivaria. Last 

 year was the first time I observed them. They are out again in full force this 

 year.— [F. W. Tliurow, Harris County, Tex.., March 17, 1893. 



Reply. — The bugs which you send as injuring Opuntias belong to the species 

 known as Chelinidea vittigera. Your account of their habits is of considerable inter- 

 est, as they have not before been found in such enormous numbers. You will find 

 them very difficult to destroy, and while I have no experimental knowledge of the 

 action of kerosene upon these cacti, I fear that an emulsion strong enough to kill 

 the bugs will also kill the plants. However, if you are willing to sacrifice those 

 plants which are most badly affected, you can certainly kill the insects at the same 

 time, either by the use of pure kerosene or a strong emulsion. Should you think it 

 worth while to conduct any experiments, I should be pleased to learn the result. 

 The specimens which you sent arrived before your letter, so that all had been killed 



