162 THE MONTHLY BULLETIN. 



CALENDAR OF INSECT PESTS AND PLANT 



DISEASES. 



By E. J. VbsLERj 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 plants as nearly as possible just prior to or at 

 the time when the suggestions given should be carried into effect by the growers. The 

 material is, for the most part, compiled from the various state and Government pub- 

 lications.) 



CITRUS FRUIT INSECTS. 



The Orange Thrips. 



The minute active brownish or yellowish insects so common in the 

 orange or lemon blossoms and on the tender foliage of the trees are 

 known as thrips. Several species often attack the trees at the same time ; 

 one, the citrus thrips, causes a leathery distorted growth to the leaves 

 and marks the fruit, generally in the form of a ring around the stem 

 end or down in streaks. Another species attacks the leaves causing them 

 to turn a mottled pale color, and causing the surface of the fruit to turn 

 silvery. Others feed on the parts of the flowers. 



Spraying seems to be the most satisfactory method for combatting the 

 thrips, and the U. S. Bureau of Entomology recommends the following 

 spray : ■ Commercial lime-sulphur 33 degrees, 2^ gallons ; black-leaf 

 extract, 2 gallons of 2f per cent, or 14 fluid ounces of 40 per cent ; water, 

 200 gallons. Maintain a strong pressure of about 175 pounds. 



Fuller's Rose Beetle. 



The injury caused by the Fuller's rose beetle consists in the destruc- 

 tion of the foliage, particularly the new. The adult insect is of a greyish- 

 brown color, about a quarter of an inch in length and has the head 

 prolonged into a short snout. The beetles being unable to fly must 

 crawl up the tree trunks in order to attack the leaves. Barriers placed 

 around the trunks have been used by many growers. One type of barrier 

 is made of cotton, about four inches wide, and tied with a string on the 

 lower side of the band. The band is then pulled down over the string 

 so that it extends out a short distance from the trunk. Tree tanglefoot 

 is also used as a barrier. 



Diabrotica soror. 



Another beetle commonly found attacking the foliage of the citrus 

 tree is the Diabrotica. It is easily recognized by its green color and the 

 twelve black spots on the wing-covers. Two means of control are: by 

 jarring the beetles off the trees into a tarred or oil screen in the early 

 morning while they are sluggish, and by poisoning them by spraying the 

 tender growth with arsenate of lead, 2 pounds to 50 gallons of water. 



The Cottony Cushion Scale. 



The adult female scales are distinguished by the large white cottony 

 masses secreted by them. These sucking insects are in main pests of 

 citrus as well as the apple, peach, apricot, fig, walnut, acacia, etc., and 

 are usually held in check by the Australian ladybird beetle, Novius 

 cardinalis (Vedalia), supplied by the State Insectary. 



