1566 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



water and agitate thoroughly. This 

 strength will kill a large percentage of 

 the hibernating females, without injury 

 to the trees. 



If a good naphtha soap can he obtained 

 the preparation of the emulsion will be 

 simplijQed. It will be unnecessary to 

 heat the solution, since the kerosene will 

 combine readily with the naphtha and 

 soap and form a perfect, cold, milky- 

 white emulsion when the mixture is 

 thoroughly agitated. If naphtha soap is 

 used, double the amount called for by 

 the formula, and emulsify in soft (rain) 

 water. 



Buieau of Entomology Circular 88 



Peacli and Plum Slug 

 Peach Saw Ply 



GaUroa (Eriocampotdes) amygdahna 

 Rohwer 



The adult saw flies are very active 

 little insects, running back and forth 

 across the leaf on the upper side and 

 occasionally stopping to sip the nectar 

 at the nectaries at the base of the leaf. 

 This seems to be its chief food. The 

 adults appear first in early spring and 

 may be found until cold weather in the 

 fall. There are about seven generations 

 each year, the last one hibernating over 

 winter. 



The larva is of a peculiar slug-like 

 appearance, swollen in front and cov- 

 ered with the slimy secretion which 

 hides the segmentation of its body. The 

 head is pale brown and the eye spots 

 darker. Its body is translucent and the 

 course of the alimentary canal can be 

 traced by the green food within. The 

 slug feeds upon the green leaves of the 

 trees to such a degree that trees are 

 sometimes completely defoliated in 

 August. 



Remedies 



Without doubt an arsenical spray, such 

 as arsenate of lead, would very effectively 

 destroy these insects, and this poison is 

 advised when the insects occur in suffi- 

 cient numbers to warrant treatment. The 

 rapid increase in the spraying of peaches 

 and plums with arsenate of lead tn self- 

 boiled lime-sulphur wash for the control 



of the plum curculio and fungus diseases 

 of the fruit will unquestionably result 

 in keeping the peach and plum slug well 

 reduced m orchards. Its occurrence m 

 injurious numbers is to be looked for 

 largely in small unsprayed home or- 

 chards. 



Peacli Tree Bark Beetle 



PJilaeotribus Ummaris Harr 

 The peach tree bark beetle is native of 

 this country and until cultivated trees 

 were introduced must have held to for- 

 est trees for food and breeding places. 

 The work of the beetle is similar to that 

 of the fruit tree bark beetle (Scolytus 

 rugulosus, Ratz), and there exists a 

 marked similarity m the beetles them- 

 selves by which the two species may be 

 easily confused. 



Distribution 



From Ohio eastward. 



Extent and Character of Injury 



When the beetles are present in large 

 numbers their injury to the trees is 

 quickly brought to the attention of the 

 orchardist by the large amount of sap 

 exuding from the trees through the many 

 small borings made both in the trunk 

 and limbs of the tree. In some instances 

 from one to three or more gallons of sap 

 will flow from a single tree during a 

 season. 



The adults or beetles produce the pri- 

 mary injury to healthy trees, the work 

 of the larvae being secondary. The 

 healthy trees, by repeated attacks of the 

 adults, are reduced to a condition favor- 

 able to the formation of egg burrows. 

 When the beetles are ready to hibernate 

 in the fall they fly to the healthy trees 

 and form their hibernation cells. These 

 latter are injurious to the trees, for 

 through each cell there will be a tiny flow 

 of sap during the following season. 



Methods of Control 



Pending further investigation the fol- 

 lowing treatments are suggested as being 

 practicable and to a certain degree favor- 

 able: For trees seriously injured — Se- 

 verely trim back the trees and apply 

 barnyard manure or commercial fertili- 

 zers; then apply a thick coat of white- 



