632 Report of Entomologists of the 



On Long Island, land on which beets or spinach have been raised 

 should be plowed at least six inches deep any time between the 

 middle of Kovember and the 15th or 30th of March, depending on 

 the forwardness of the season. Spinach sown for spring cutting if 

 sown late is not liable to harbor many of the maggots. 



The plowing should be thoroughly done and the ground rolled, if 

 possible, as the object of the plowing is to bury the puparia so deep 

 that the delicate flies, when they issue, will be unable to get to the 

 surface. 



True, many of the gardeners and farmers on Long Island as well 

 as elsewhere practice late fall and early spring plowing, and are still 

 troubled with the " Spinach maggot." 



Undoubtedly they destroy a goodly number of the pests but it is 

 the same with cultural methods of treatment as with other remedies, 

 it must be thoroughly done and at the right time. Furthermore, 

 care must be taken not to allow some corner to grow two or three 

 crops of weeds which furnish a good breeding ground for the flies, 

 and plenty of food for the maggots. 



Possibly some farmer who reads the above recommended measures 

 will decide that it is useless for him to take all this trouble to keep 

 his fields clean unless all his neighbors keep their fields clean. I 

 have noticed a decided diiierence in the amount of damage done in 

 fields of thrifty farmers and in the fields of those who simply exert 

 themselves enough to get a crop to grow. This fact would indicate 

 that the migration of the flies from one field to another is slow. Pos- 

 sibly cornfields or other crops act as barriers. 



It is also quite evident that if roadsides and fence corners were 

 kept in grass and clover that it would add 50 per cent, to the 

 appearance of many farms, besides yielding some return in hay and 

 a better crop of beets and spinach. 



Conclusion. — The " Spinach maggot" is known to feed within 

 the leaves of beets and lamb's quarters {Chenopodium album) as 

 well as within spinach leaves. 



As far as known these are the only food plants that this species 

 feed upon in this country. 



It can not be destroyed by any insecticide without injury to the 

 plant. 



