72 



Fumigation for Scale-insects. 



A short time ago Fruit-pest Inspector Richardson, of Pasadena, and myself paid a 

 visit to Orange to learn more about fumigating trees with hydrocyanic-acid gas, and. 

 were shown around by President Hamilton, of the Orange County Board of Horti- 

 culture. About a dozen fruit-growers have fiimigators of their own, and several of 

 them fumigate for their neighbors at so much an acre, while some of them rent their 

 fumigating outfits to other growers. All I spoke to on the subject expressed them- 

 selves as being highly pleased with the results obtained by this process. It comes 

 the nearest to extermination when applied to the red scale of any process known to 

 me, and one of the largest orange growers at Tustin informed me that after ho had 

 sprayed his trees three times there were more living red scales on a single lemon than 

 could now be found in his entire orchard, the latter having recently been fumigated 

 with the hydrocyanic-acid gas. He also informs me that it costs but little more to 

 fumigate his largest trees than it did to spray them. Two different kinds of fumi- 

 gators have been patented, but I did not see one of them in use, the growers using 

 fumigators of their own devising, modeled after the one first constructed by Messrs. 

 Wolfskin and Craw, of this city.— [D. W. Coquillett, Los Angeles, Cal., July 1, 1890. 



A Parasite of the Vine Aspidiotus. 



I send some bottles containing larvis in alcohol, and a few more slides with speci- 

 mens for the microscope. An.oug the latter is an interesting parasite on Aspidiotus 

 uva', which seems to be doing good work in keeping this pernicious scale-insect in 

 check. More than a dozen of these little flies emerged from the scales on a bit of grape 

 cane not 5 inches long. 



In one of the bottles is a section of a Plusia larva found on Chrysanthemum, from 

 which thousands of the minute flies inclosed with it issued. I never saw a more ex- 

 treme case of parasitism. After spinning up the poor worm lost all semblance of 

 itself. A myriad of the parent flies must have attacked it at once. — [M. E. Murtfeldt, 

 Kirk wood, Mo., November 23, 1889. 



Reply. — The parasite on Aspidiotus m^ce is a species of Centrodora, while the Plusia 

 parasite is probably Copidosoma Irmicatellum Dalm. * * — [December 3, 1889.] 



Some Insects from Kansas. 



I inclose you two specimens of insects for identification. I have found four of the 

 smaller of the two crawling about the house during the last week. I should like to 

 know if it is the true curculio or not. The larger one with red markings is found 

 abundantly in the fall about box -elder trees, but as I have never seen it teed I thought 

 that perhaps it is a relation 1o the wheel bug pictured in Insect Life, and therefore 

 a predaceous insect and consequently beneficial. This last is seen all winter on sunny 

 days crawling about, especially getting into houses whenever it can. — [F. F. Creve- 

 Cffiur, Onaga, Kans., March 31, 1890. 



Reply. — Your letter of March 31 has been received together with the accompany- 

 ing specimens of insects for determination. The smaller one which you thought 

 might be the plum curculio is an entirely distinct insect, although it resembles that 

 species and belongs to the same family. It has no common name but bears the scien- 

 tific name of Dorytomus mucidus. It is a very common western beetle and breeds in 

 the catkins of Cottonwood. The larger specimen with red markings, which you 

 found abuudantly in the fall about box-elder trees and later in the winter about 

 houses, is the Box-elder Bug {Leptocoris irivittatus). This is also very abundant in the 

 west and is known to breed chiefly on the Box-elder. It also attacks other plants, 

 and in Bulletin 12 of this Division is recorded as seriously injuring apples. Ordi- 

 narily, however, it is not particularly injurious, but is frequently very annoying by 

 reason of its entering houses in the fall and winter. Its habit of congregating on 



