THE MONTHLY BULLETIN. 715 



Very few natural enemies have lieen recorded on this caterpilhir. An 

 undetermined species of a tachinid fly has been reared from Maniestra 

 picta. A species of Canipoplex of the family Ichneumonidce was reared 

 from the young larva of Maniestra picta, at Salt Lake, Utah. The 

 Campoplex oviposits in the very young larva and emerges from the host 

 at about the third stage, spinning its cocoon below the host remains. 

 Fig. 383 shows the cocoons of this parasite and the remains of the host. 



INJURY AND PROTECTION OF FRUIT FROM FREEZING. 



By Geo. P. Wbldon, Chief Deputy State Commissioner of Horticulture. 



One of the chief limiting factors in the production of fruit through- 

 out the various states of the Union is frost. It is true that there are 

 certain sections of the country where such have seldom or never occurred 

 to the detriment of the fruit crop. Experience of orchardists in Cali- 

 fornia and elsewhere has led to the conclusion that no section, no matter 

 how free it has been from killing frosts during the danger period of 

 trees in the past, can be said to possess immunity, and there may come 

 a time when the temperature will drop so low that buds, blossoms and 

 fruit, if not trees, must succumb. There are, of course, many places 

 where fine fruit is grown during favorable seasons that are visited by 

 killing frosts periodically, and the chances for and against raising a 

 crop are about even. Such sections do not offer the best advantages for 

 commercial orcharding unless some practical means of protecting the 

 crop during the danger period may be employed. 



Period of Greatest Danger from Killing Frosts. 



In the case of deciduous fruits, the injury is usually done either to 

 the buds, l)lossoms or small fruit in the early spring, about blossoming 

 time, although a severe freeze during the winter season may kill the 

 buds. In the case of citrus trees, freezing temperatures any time during 

 the winter or spring season may result in the destruction of the fruit, 

 while the buds of well-ripened, perfectly dormant deciduous trees will 

 often stand temperatures ranging from 10° to 30" or more below zero. 

 The period of greatest danger, as far as deciduous fruits are concerned, 

 corresponds pretty closely to the time from when the buds begin to swell 

 in the spring until the fruit (apples or peaches) has reached a diameter 

 of a half inch. This time is, of course, subject to variations in climate, 

 due to altitude or local conditions. 



Bud Injury. 



Winter or early spring injury to buds may be detected by a discolored 

 area seen in the center upon cutting them open. The pistil or central 

 organ of the blossom is usually the first part to freeze and once frozen 

 fertilization is rendered impossible. Blossoms so injured will sometimes 

 develop, and the trees will come out in blossom and be just as beautiful 

 as if nothing had happened. An examination of such blossoms will show 

 the blackened pistil in the center, and if any fruit develops, it must be 

 from blossoms which escaped this injury or which developed later. A 

 peculiar form of freezing of apple blossoms which has come to my notice 

 in another state destroys the petals entirely. The rest of the parts of 

 the blossom develop normally ; fertilization takes place as usual, and a 

 good crop of fruit may set on the trees. 



