DISEASES AND INSECTS 



CATALOGUE OF INSECTS, continued. 



TWO-LINED CHESTNUT BORER (Agrilus bilineatus). Slender, 

 flattened grubs, M inch long when mature, burrowing under 

 the bark and girdling the trees. 



Treatment. Cut and burn infested trees to prevent spread. 

 EUROPEAN FRUIT LECANIUM. See Plum. 



Chrysanthemum. GREEN APHIS (Aphis rufomaculata). Small, 

 green lice attacking the terminal shoots. 



Treatment. Fumigation. 



BLACK APHIS (Macrosiphum sanborni). Small, black lice attack- 

 ing the terminal shoots. 



Treatment. Fumigation. 

 TARNISHED PLANT-BUG. See Aster. 



CHRYSANTHEMUM LEAF-MINER (Oscinis sp.). Works in the 

 leaves. 



Treatment. Hand-picking. 

 Cineraria. LEAF-TYER. See Celery. 



Citrus. BARNACLE SCALE (Ceroplastes cirripediformis). A large, 



dark brown scale covered with a waxy secretion % inch in 



length. Surface of scale sculptured like a miniature barnacle. 



Control. Resin wash or kerosene emulsion before the waxy 



covering is secreted. 



BLACK CITRUS LOUSE (Toxoptera aurantiee). Small, dull black 

 lice, curling the leaves and killing the new growth. 

 Control. Contact sprays before the leaves curl. 

 BLACK SCALE (Saissetia olese). A black, oval scale % inch in 

 diameter with an "H"-shaped mark on the back of the female. 

 The young are light yellow to brown, unmarked. The scales 

 secrete honey dew in which a fungus grows smutting the fruit. 

 Treatment. Fumigation. On citrus, use a half to three- 

 fourths of regular dosage between September and January. 

 On deciduous fruits and olive, water distillate, caustic soda 

 mechanical mixtures or distillate emulsion may be used to 

 kill scales less than one-half grown. 



CITRUS RED -SPIDER (Tetranychus mytilaspidis). Bright red, 

 minute mite, frequently abundant on fruit and foliage. 



Treatment. Dusting with sulphur or commercial lime-sul- 

 fur solution diluted 1-35 or 50 of water. 



CITRUS THRIPS (Euthrips citri). Slender, minute, orange-yellow 

 insects, less than one-thirtieth inch in length, scarring the fruit 

 and injuring the foliage. 



Treatment. Lime-sulfur solution one part in eighty parts 

 water (likely to cause slight injury to foliage) or "Black Leaf 

 40" tobacco extract, one part in 1,800 parts water. Make four 

 applications: (1) As the last of petals are falling; (2) ten to 

 fifteen days later; (3) three to four weeks after the second; (4) 

 during the months of August or September (for California). In 

 greenhouses, fumigate with hydrocyanic acid gas. 

 COTTONY CUSHION SCALE (Icerya purchasi). Red or yellowish 

 scale insects with large, white, fluted, cottony masses which 

 cover the eggs from % to Y% inch in length. 



Control. Natural enemies, principally by the common 

 Vedalia. 



FLORIDA RED SCALE (Chrysomphalus aonidum). Circular flat, 

 brown scales, iV to j^ inch in diameter. 



Treatment. Fumigation with full dosage schedule. 

 FLORIDA WAX SCALE (Ceroplastes /Zortdensis). Oval convex, 

 white or pinkish, waxy scales with the upper surface evenly 

 lobed, 1-12 to % inch in diameter. 



Control. Resin wash or kerosene emulsion applied to the 

 young scales before the waxy covering is formed. 

 FULLER'S ROSE BEETLE. See Strawberry. 



GLOVER'S SCALE (Lepidosaphes gloverii). Closely resembles the 

 purple scale, but is longer and narrower. 



Control. Same as for Purple Scale, which see. 

 GREENHOUSE THRIPS (Heliothrips hxmorrhoidalis). A slender, 

 minute, yellowish brown insect destroying the blossoms and 

 russeting the fruit. 



Treatment. Same as for Citrus Thrips, which see. 

 HEMISPHERICAL SCALE (Saissetia hemisphserica). A smooth, 

 oval, convex soft scale without markings. Common in green- 

 houses. 



Treatment. Same as for Black Scale, which see. 

 MEALY-BUG (Pseudococcus citri'). Small, soft-bodied scale 

 insects, Yi to % inch long, covered with a white waxy secretion. 

 Control. A thorough application of carbolic acid emulsion; 

 spray under heavy pressure. 

 MELON APHIS. See Muskmelon. 



MEDITERRANEAN FRUIT FLY (Ceratilis capitata). Small white 

 maggots burrowing in a great variety of soft, juicy fruits. 

 The parent fly is about the size of the house fly, yellowish 

 marked with black, and with faintly banded wings. Widely 

 distributed in the tropical and subtropical regions of the world 

 and a most serious horticultural pest wherever it occurs. 

 Rigid quarantine regulations have prevented its introduction 

 into the United States. 



7Vea<men<.-^Sweetened arsenate of lead to kill the flies 

 before oviposition. 



ORANGE CHIONASPIS (Chionaspis citri). Elongate, blackish 

 brown scale with a gray margin and dark yellow exuviae. 



Treatment. Fumigation; kerosene emulsion, one part in 

 five parts of water; three applications at three-week intervals. 

 ORANGE MAGGOT (Trypeta ludens). Dirty white maggots, 

 about Yz inch in length when mature, burrowing in the pulp. 

 From four to twenty maggots may occur in a single orange. 

 The adult two-winged fly is straw-yellow in color with brown- 

 ish markings and bands on the wings. A serious pest to oranges 

 in Mexico. 



Control. Pick up and destroy all infested fruit. 



67 



DISEASES AND INSECTS 1051 



CATALOGUE OF INSECTS, continued. 



ORANGE TORTRIX (Tortrix citrana). Greenish white to dark, 

 irregularly striped caterpillars, Yi inch long when mature 

 that burrow into the rind and induce decay. 



Control. Destroy all infested fruit. 



PURPLE SCALE (Lepidosaphea beckii). Reddish brown to rich 

 purple oyster-shell-shaped scales ^ to Y* inch in length. 



Control. Fumigate with full dosage schedule. 

 KED SCALE (Chrysomphalus aurantii). Circular, flat, reddish 

 scales, ft to % inch in diameter. 



Control Fumigation with full dosage schedule. On decidu- 

 ous trees lime-sulfur solution, one part in nine parts of water- 

 or distillate emulsion. 



SILVER MITE (Eriophyes oleivorus). A minute, elongate four- 

 legged yellow mite causing russeting of the orange and silver- 

 ing of the lemon. 



Control. Same as for Citrus Red Spider, which see. 

 SOFT BROWN SCALE (Coccus hesperidum). Oval, yellowish brown 

 pat, soft scale, sometimes with darker markings, V. inch in 

 length. 



Control. Same as for Black Scale, which see. 

 WHITE-FLY (Aleyrodes citri and A. nubifera). The immature 

 stages are found on the under side of the leaves and are scale- 

 like in form. The adults are minute white-winged flies. 



Treatment. Fumigation. Fungous parasites. 

 YELLOW SCALE (Chrysomphalus citrinus). Similar to the red 

 scale but yellowish in color. 



Control. Same as for Red Scale, which see. 

 Clematis. RED SPIDER. See Peach. 

 SOFT BROWN SCALE. See Citrus. 



Coconut. COCONUT SCALE (Aspidiotus destructor). Whitish to 

 creamy transparent scales often abundant on under side of 

 leaves and fruit. 



Treatment. When occurring on young trees spray with 

 whale-oil soap; on older trees it is advisable to remove and burn 

 badly infested leaves. 



COCONUT BEETLE (Strategus anachoreta). Large black beetles 

 attacking young trees near the "collar." One beetle will 

 destroy a tree if not removed in tune. 

 Treatment. Dig out and destroy. 



COCONUT WHITE-FLY (Aleyrodes cocois). Similar to the citrus 

 white fly. 



Control. Contact insecticides. Destroy wild food plants. 

 FLORIDA RED SCALE. See Citrus. 



PALM WEEVIL (Rhynchophorus palmarum). Shining black 

 snout beetles, the larvae of which live in young palm trees 

 reducing the interior tissues to a mass of pulp. 



Treatment. Dress all wounds with tar or similar prepara- 

 tions. Avoid all unnecessary pruning. Destroy all felled trees 

 and stumps not used as traps. The beetles may be attracted by 

 the use of injured palm cabbages and trapped under rubbish. 

 RHINOCEROS BEETLE (Oryctes rhinoceros). A large beetle about 

 \Yz inches long, attacking and burrowing through the crown 

 and stem. 



Treatment. Destroy all breeding-places, such as old coconut 

 trees, stump, and cocao pods. 

 Cocos. See Coconut. 



Codiaeum. GREENHOUSE THRIPS. See Citrus. 

 MEALY-BUGS. See Citrus. 

 PURPLE SCALE. See Citrus. 

 Coffee. BLACK CITRUS LousE.-^-See Citrus. 



COFFEE LEAF-MINER (Cemiostoma coffeella). A small cater- 



gillar about Y inch long, mines in the leaves producing small 

 rownish areas. Badly infested leaves drop. 



Treatment. No satisfactory treatment known. 

 HEMISPHERICAL SCALE. See Citrus. 

 MEALY-BUG. See Citrus. 

 Coleus. MEALY-BUG. See Citrus. 



Orthezia insignis. Ocherous to dark green scale insect covered 

 with a white waxy secretion extending posteriorly into a broad 

 plate. 



Treatment. Contact insecticides. 

 WHITE-FLY. See Tomato. 



Corn. ARMY-WORM (Leucania unipuncta). A cut-worm-like 

 caterpillar, which normally feeds on grass. When this food- 

 supply is exhausted, they migrate in numbers to other fields 

 and attack corn, wheat, and similar crops. 



Preventive. To stop the advance of the "army," plow deep 

 furrows so the dirt is thrown toward the colony; in the bot- 

 tom of the furrows dig post-holes into which the caterpillars 

 will fall and where they may be killed with kerosene. 

 CHINCH-BUG (Blissus leucopterus). A red or white and black 

 sucking bug, three-twentieths of an inch long. Attacks wheat 

 and corn in great numbers. 



Preventives. Clean farming to destroy suitable hibernating 

 shelter. Stop the migration of the bugs from the wheat-fields 

 into corn by maintaining along the field a dust strip 10 feet 

 wide in which a furrow and post-hole barrier has been con- 

 structed. This may be supplemented by a coal-tar barrier. 

 ANGOUMOIS GRAIN MOTH (Sitotroga cerealella). A small cater- 

 pillar living in the grains. The adult is a small grayish brown 

 moth. Most destructive in storage. 



Treatment. Fumigate with carbon bisulfid, five pounds to 

 1,000 cubic feet. Make bins perfectly tight and sprinkle over 

 grain, covering with gas-proof tarpaulin. Fumigate at least 

 twenty-four hours. This should be done when temperature is 

 not below 65 F. In steam-heated mills, the most practicable 

 method of destroying grain-infesting insects is by holding 

 temperature from 118 to 122 for several hours. 



