772 THE MONTHLY BULLETIN. 



CALENDAR OF INSECT PESTS AND PLANT 



DISEASES. 



By E. J. VosLER, Assistant Superintendent of the State Insectary. 



[Under the above heading the author aims to give brief, popular descriptions and 

 methods of controlling insect pests and plant diseases as near as possible just prior to 

 or at the time when the suggestions given should be carried into effect by the growers.] 



INSECTS INJURIOUS TO FRUIT TREES. 



The Red-humped Caterpillar. 



The red-humped caterpillar, ScJiizvra concinna S. & A., spends the 

 winter as a pupa in cocoons which are located several inches under the 

 surface of the ground, or among the thickly fallen leaves and other 

 matter under the trees. Hoeing or cultivating close to the trees in 

 the winter time will kill many pupae of this insect as well as the hiber- 

 nating stages of other destructive pests. The description of this 

 insect's appearance and work was given in a previous issue. 



Scale Insects on Deciduous Trees. 



If the fruit trees are infested with scale insects don't let another 

 year lapse before remedial measures are undertaken. The man who 

 g-rows the best fruit is the man who makes it his business to see that 

 the trees are free from all pests. If the San Jose scale, black scale, 

 brown apricot scale, Italian pear scale and others which might be 

 mentioned are destroying the vitality of your trees, a little time and 

 money spent in spraying will do wonders. What to use for a spray 

 material is another question. Crude oil emulsion, 10 per cent (home- 

 made) ; crude oil emulsion (prepared), 8 per cent; distillate emulsion, 

 5 per cent; Yel-ros, 1 to 40. and lime-snlphur. 4.5 degrees Baume, arc 

 all good eradicators. If you are in doubt as to what pest is troubling 

 your trees, send a sample to the office of the State Commissioner of 

 Horticulture, and it will be identified. 



Apple Tree Tent Caterpillars. 



The two apple tree tent caterpillars, commonly known as the eastern 

 apple tree tent caterpillar and the forest tent caterpillar, both occur 

 in California. The former has a very limited distribution in this State. 

 and the latter is confined to the central and northern portions. Both 

 attack the foliage and the young fruit of the apple. The general 

 appearance of the larvis of the two species is practically the same. 

 They are hairy caterpillars, about If inches long when full grown ; 

 black in color with distinct yellow and white stripes along the back 

 and with blue and white spots along the sides. The larva? of the 

 former species spin a web or tent on which they congregate when 

 not feeding; while the latter congregate in ma.sses on the trunks 

 and limbs of the trees. (Fie. 405.) The winter is spent in the em:^ 

 stage, the egg masses being attached in cylindrical formation to the 

 smaller twigs. Destroying these egg masses during the winter time 

 is one method of controlling these two pests. 



