THE CUBA REVIEW. 



INSECTS AND DISEASES OF VEGETABLES. 



Pi-epared especially for 



The department of Vegetable Path- 

 ology has given considerable attention to 

 the troubles of the vegetable crops and 

 the following insects and diseases are 

 found to be specially worthy oi notice: 



Crickets. — Several species are trouble- 

 some, especially in new land or that 

 which has not been cultivated for some 

 time; the worst pest cuts twigs and leaves 

 from young plants and sometimes cuts 

 off a very young plant at the surface 

 of the ground. Continuous cultivation is 

 the best means of reducing their number, 

 or where they are very abundlant they 

 may be destroyed at considerable ex- 

 pense by pouring disulfid of carbon in 

 their burrows or, inexpensively but with 

 less certain results, by scattering poison 

 bait through the field in the late after- 

 noon. This is made by dissolving one 

 pound of paris green or white arsenic in 

 ten gallons of water, sweetening the 

 solution thoroughly and sprinkling it on 

 leaves of cabbage on other plants which 

 the crickets eat. 



Seedbeds may be considerably pro- 

 tected by raising them; on scaffoldings 

 three or four feet above the ground. 



Changa or Mole Cricket. — Rare in 

 Cuba. Same measures as above effective. 



Bibijagua. — Already discussed in pre- 

 vious issues. 



Aphis or Plant Lice. — Very abundant 

 on turnips, radishes, peas, beans, cab- 

 bage, cucumbers, etc., particularly during 

 the dry season. Spray with rose leaf 

 tobacco extract diluted at the rate of i 

 part to 60 parts water, or use an infusion 

 of tobacco made from boiling stems and 

 refuse tobacco, or use any of the stand- 

 ard sprays recommended for scale in- 

 sects, but should be used much weaker, 

 as plant lice are very easily killed and 

 tender vegetables might be injured by 

 sprays used at their full strength. Where 

 it is impossible to reach the aphis with 

 a spray, plants may be treated by putting 

 a tight box or bucket over them and put- 

 ting a spoonful of disulfid of carbon un- 

 der the bucket, pressing the bucket 

 down, drawing- earth up around it, and 

 leaving it for two hours. This is ex- 

 pensive and troublesome but in some 

 cases will pay. 



Thrips. — Injurious to onions and other 

 crops. Combatted with only partial suc- 

 cess by spraying with kerosene emulsion 

 diluted so as to contain from' 5 to 10% 

 of kerosene. On a commercial scale 

 where a '^ower sprayer could be used 

 the remedy would probably be much 

 more effective. Bulletin No. 40 of the 

 Florida Exneriment Station recoimmend's 

 either roseleaf tobacco extract, i pint to 

 4 gallons water; whaleoil soap (Anchor 

 brand), i pound to 4 gallons water; or 



The CUBA REVIEW. 



kerosene emulsion. The spraying must 

 be very thorough and must cover the 

 ground as well as the plants. 



Red Spiders or Mites (on eggplant, 

 tomatoes, etc.). — The standard treatment 

 IS a spray of sodium sulfid. This kills 

 the adults but not the eggs, sO' the treat- 

 ment must soon be repeated. Flowers of 

 sulphur dusted on plants is good, and 

 probablv the best treatment is spraying 

 with solution of sodium sulfid' to whicli 

 has been added flowers of sulfur mixed 

 into a flour paste. 



Cut- Worm (cachazudo of tobacco). — 

 Destructive to cabbage, tomatoes and 

 other plants, especially in the spring, at 

 the close of the tobaccO' season. They 

 can be greatly reduced by use of poison 

 baits. Before planting a field it should 

 be cleaned and thoroughly cultivated. 

 Then it should be treated twice if pos- 

 sible with poison bait made as follows: 



Molasses 2 quarts. 



Wheat bran or corn meal. 50^ lbs. 



Paris green or white arsenic i lb. 



Water enough to imoisten. 



Mix and distribute over the field i 

 tablespoonful in a place at distances of 

 not more than 10 feet, covering with a 

 leaf to nrevent drying. Many of the 

 worms eat this and are killed. After- 

 ward the field may be planted. 



Worim Attacking Rape and Cabbage 

 (Pieris monuste, Linn.) — This may be 

 checked by using paris green, but it must 

 be used in very small quantities, since 

 the plants are easily injured by it, and it 

 should not be used when the plants are 

 near maturity. It imay be applied with 

 a blower or by mixing in water in the 

 proportion of i pound paris green to 

 ICO gallons water. 



Eggplant Weevil. — This is a minute, 

 dark-colored' weevil which hides about 

 the leaf and flower buds of the eggplant, 

 injuring the leaves and causino^ the flower 

 buds to wither and fall off. It is due to 

 this insect that eggplants often cease to 

 bear while continuin- to grow with fair 

 vigor. The remedy is to spray with 

 bordeaux mixture to which paris green 

 has been added at the rate of i pound 

 per barrel of bordeaux. This insect is 

 also found on a common high-growing 

 Cuban weed with leaves resembling the 

 eggplant. This weed should be destroyed 

 wherever it is desired to grow eggplant. 



Bean Insects. — Beans are attacked by 

 several kinds of small insects. Soap, sul- 

 phur, paris green, and other insecticides, 

 even when used in very weak prepara- 

 tions, are injurious to the plants, but a 

 treatment with bordeaux mixture proved 

 to be effective, driving away the insects 

 and increasing the vigor of the plants. 



Tetuan or Sweet Potato Borer (Cycas 



