202 



THE AGRICULTURAL NEWS. 



Jl-.ne 21. 1913. 



INSECT NOTES. 



INSECTS LIABLE TO DISSEMINATION 



IN SHIPMENTS OF SUGAR-CANE. 



The Bureau of Entomology of tbfe United States Depart- 

 7iient of Agriculture, in Circuiar Ko. 16.5, discusses, from 

 tlie poiut of view of the cane grower in America, the insects 

 tliat are liable to be transported in shipments of sugar cane, 

 particularly in those intended for purposes of plarnting. 



In the list of insects presented in the publication under 

 consideration, there appear references to several species with 

 which the West Indian planter is familiar; on the other hand, 

 many are mentioned which do not occur in these islands. 

 As regards classification, fhe pests of the sugar cane are 

 grouped under two heads in this list; (1) those which are 

 foreign to the United States, and (2) those which are native 

 to that country. 



The liability of insect pests to be transported in sugar- 

 cane intended for planting is a subject worthy of very 

 careful consideration There have been in the p^ist, instances 

 in which the dissemination of pests by shipment has occurred, 

 with the result that serious damage has been brouglit about. 

 In the present consideration of the subject, it will be advis- 

 able to deal chiefly with those insects which occur in the 

 ATest Indies, and to restrict our consideration of cane pests 

 in other parts of the world to those which might be intro- 

 duced willi imported sugar cane. 



MOTH r.LiiiEns. Perhaps the principal insect pest of sugar- 

 cane in the West Indies— it is certainly the most widely 

 distributed — is the motli borer {IJiatioeu sucr/iaralis). This 

 insect, probably a native of South America, is now known to 

 occur throughout the sugar growing areas of tropical and sub- 

 tropical America. The habit of the creature, in the larval 

 stage, of boring into those parts of fhe cane which are used 

 for planting, makes it especially liable to be transported in the 

 manner under consideration, and it seems probable that i-ts 

 pre.sent distribution is to be accounted for in this way rather 

 than a.s the result of migration 



The giant moth borer [Castnia lii-n^) is known as a pest 

 c.t .sugar cane in I'.ritish Ouiana, and in Trinidad. The insect 

 is a native of South Ameiica, its original food plants 

 apparently having been orchids and orchid-liki- plants. In 

 addition to sugar-cane, it is known to attack bananas. The 

 larvae of C'talnia ticus bore into the canes from the base, 

 extending their tunnels upward, for a ilistancc, sometimes, as 

 much as 2 feet, and also downwards into the underground 

 portiims of the plant. The tops are not affected, but they 

 and the cane trash might harbour the eggs. The greatest 

 care should be e.xeicised in order to prevent the introduction 

 of the giant moth borer into any new locality. 



wEE\iL r.oi:Li;s. The weevil borers, S/ihe-nophoras 

 sci-ire":-, and pi'ssibly other species of the genus are of general 

 occurrence tlu-oughout tropical America. There seems t* be 

 a strong opinion on the part of many planters that the 

 weevil borers rarely if ever attack sound healthy caues. 

 Any st€ms which have been injured by rats or by wind are 



liable to attack by these insects. It would seem, therefore^ 

 that perfectly healthy sound canes, .such us should be chosen 

 for planting, would not be likely to harlioiir the weevil borer. 

 THK KRo(;uoi'i'EU. Froghoppcrs occur as a serious pest 

 of canes only in Tiinidad. These insects are often known as 

 'spittle in-sects' on account of the mass of froth in which the 

 larvae live. Their natural food is one or another of 

 the species of coarse grass, and they have adapted them- 

 selves to canes only after they have increased to consid- 

 frable numbers on wild grasses near to the canes, when 

 insufficient natural food compels a parasitic attack on 

 the cultivated crop. Great care should be exercised to 

 prevent the introduction of froghoppers into a new locality. 

 They might not be able to establish themselves in all' 

 places as pests of sugar-cane, but the serious nature of their 

 attacks in Trinidad where they have become established 

 should be taken as a warning by all other sugar- 

 growing districts. Froghoppers would probably not be 

 transported with top cuttings since, for the most part, these 

 insects occur on the roots and at the base of the plants on 

 which they feed. 



SCALE INSECTS AND .M K.vLv-Dit.s. There are two 

 species of mealybugs and one scale insect of common occur- 

 rence in the West Indies, which may easily be transported 

 with sugar-cane cuttings. The mealy bugs are Faeudococua 

 ralceolariae and F sacc/ian . The scale insect is Aspidi'tua 

 sacchari. It is probable that if these insects were not intro- 

 duced into sugarcane fields along with the plants, they 

 would be of very rare occurrence, and it follows that the 

 more carefully the plants are selected with reference to their 

 freedom from the pests, the slighter will be ihe attack in 

 the fields. 



OTHER PESTS. Other insects related to those already 

 mentioned occur in different parts of the world — moth borers 

 and weevil borers, though not of the same species as our 

 West Indian ones, are liable to be disseminated with ship- 

 ments of sugar cane. In the Hawaiian Islands the leaf-hopper 

 (Ferldnuella saccharicida) has occurred as a very serious 

 pest. This insect wxs undoubtedly introduced into those 

 islands from Australia with shipments of sugar-cane. In 

 Australia, leaf-hoppers are lield in check by their natural 

 enemies and they do not often cause serious injury to 

 sugar cane. For a number of years the losses in Hawaii, as 

 a result of the attacks of leaf hoppers, amounted to very 

 large sums, but since the introduction of their natural 

 enemies these insects have caused much less injury. 



soiL-iNii.\BiTiNO BEETLK.S, In the \A'e«t Indies there 

 are several specifs of beetles which attack the underground 

 portion of the cane; some of these live in the soil and feed 

 on the smaller roots, whilst others tunnel into the under- 

 ground portions of the plant, eating out the interior, 

 and sometimes extending their tunnels into the stems cen- 

 siderably above the ground-level. These are not likeliy to 

 be transported with shipments of sugar-cane, but there is 

 a possibility of this happening under certain conditions, and 

 oare should always be taken to guard against it. These soil- 

 inhabiting beetles have been dealt with in receDt numbers of 

 the Agyifultiiial Sewn (see Vol. XIL Xos 285-90, March 

 29 to June 7, 1913) and they will be considered only briefly 

 on the present occasion. The most important o^' these beetles 

 is tlic brown hard back of Barbados {I'Ini/hilus sinitki). This 

 pest occurs only in Barbados and i^ Mauritius, as far as is 

 known at the present time. In I'.arbados it is of little 

 importance, lieing apparently well controlled by natural 

 enemies; in Mauriwus, on the other hand, it has been excess- 

 ively injurious. The genus Phytalus is a South American 

 genus, and Fliiitalussmithi has been known in Barbados for- 



