266 



THE AGRICULTURAL NEWS. 



August 22, 1908. 



INSECT NOTES. 



Coleoptera. 



■{CoM-i.ahd from llii: Inat issin of '/" A'liiciiltiinil .Vr/^'s.) 

 Tlie long-h(.>rnt'd beetles cause a coiisideiable amount of 

 injury to the trees they attack, and they are always more 

 abundant on trees which are not in the most vigorous con- 

 dition of growth and have not the same powers of resistance 

 as ordinary trees. Trees sutiering from lack of drainage, or 

 from lack of fertility in the soil, or even from drought in 

 some cases, are sufficiently checked in their gmwth tii 

 he more readily attacked by this class of pest. 



The lime-tree bark borer (Li'jitosti/ltis jnitniiorsKs) and 

 the cacao beetle (Sttivaxtouin dcpro'-tiiiii) are well known. 



The lady-bird beetles (Coccinellidae) are very valuable 

 assistants in helping to control the attacks of certain insects 



Fic. 9. Cacao ISkkti.k and Ouuh. 

 injurious to plants, such as plant lice (Aphidae), M-ale insects 

 (Coccidae), and other small sucking insects. 



These lady-birds are predaceous in both the larval and 

 adult stages, and one or more kinds may be seen on almost 

 any plant infested with the insects on which they prey. The 

 most common form in the West Indies is the red lady-bird 

 {Cydont'dn .latu/idneri). The s|iottccl lady-bird (JIe;/i7/ii 

 ■in(inilatn) is also common, and tlii'ic are sexcral sp.'cies 



been very abundant during the past two oi- three seasons. 

 In the Leeward Lslands this insect is known as ' Jacob.s,' and 

 in Barbados as ' Scarabee.' .\lthough a very small insect, about 

 /.-inch in length, it is a great jicst, and when the attack on 

 a sweet potato field is general and severe, the entire crop is 

 lost. The larvae live in the potatos, tunnelling them through 

 and through as they are getting ripe, and animals refuse 

 to eat roots that are much tunnelled, in con.seipience of the 

 most di.sagreeable taste and odour that are imparted to them 

 by the weevils. 'I he sweet potato borer of .Jamaica and the 

 Southern States is another weevil {C'i//ns foniiiniriiix) which 

 is slightly larger and more elongate than the Scarabee. The 

 golden weevil {Didjitrjien .fyjcwf//*';/) occurs in St. Vincent and 

 is known as a pest o)i orange and other citrus trees in Porto 

 liico. The fiddler beetle {Fiiicpodex riffiifiis) is an active 

 enemy of orange trees at .Jamaica and has been reported as 

 attacking cacao. The rice weevil (Citutndid ori/uir) is of com- 

 mon occurrence, feeding on .stored rice, corn, ami grain of all 

 kin.ls. 



The remedies to be used in controlling beetles which 

 occur as pests nuist of necessity be varied according to the 

 habits of each species or grou]). Although they have mouth 

 parts suited for biting, they cannot in all cases be controlled 

 by the use of stomach poi.son.s. Sometimes this is because 

 the habits of the insects make it impossible to put poi.sou 

 within their reach, and in other cases because they do not 

 respond readily to the effect of i)oison. This is esi)ecially 

 true of many of the weevils which feed on the leaves of plants. 

 It has been fouiul that these iu.sects frequently continue to 

 feed on leaves that have been sprayed or dusted, and that 

 they are not killed (juickly enough by the poi.-^on to prevent 

 considerable injury being done to the plants. 



Kobt borers and other beetle larvae that live in the 

 ground can sometimes be checked by adopting a rotation 

 of crops, or by deep ploughing or forking. Horers in trees 

 may be dug out with a sharji kinfe, or they niay be killed by 

 proljing into their buriows with a w'ire. It is sonietime.s 

 pos.sible to prevent such in.sects from getting into the tree.* 

 by coating the trunks with a thick linu'-wasli. Root 

 borers, and other beetle lai'vae in the ground, bark and wood 

 bori'rs, grain beetles, pea weevils, etc., can be killed liy the use 





\ 





■CO 



Fn:. KJ LaoV lUKIis. (.i) Mi;/i//<i mni-idotd. (I,) ( 'tiilonnhi 



HiDKjuiiwi (c). l.ady-bii'd eggs. (.\ll enlarged), 

 vvh.ich though abundant and most u.seful are generally over- 

 looked on account of their small size ami plain colouring. 

 These small ladybirds {Si-i/miiiis sp|).) are freipiently not 

 more than -j'^ inch in length, and they are dark-brown, black 

 or steel-blue in colour. 



The weevils (l!hynchopliora) include in their nuinlier 

 some extremely troublesome pests to field crops, fruits and 

 .stored grains, etc. The weevil borer of the sugar-i-ane 

 (Sphc)iojihin-us sen'ceiix), and the root borer of the sugar 

 cane) Diti/tirpes ithltrcriatii-<) are well known in many sugar- 

 growing localities. The palm weevil (lihiinfhojihonix jiu/iiin- 

 riiiii), one of the very large weevils, occurs in Trinidad, 

 Dominica, and Orenada. 



The sweet potato weevil (/.^•///y^);7/ //»<■//«.< luitnl'i,) has 



Vv. 



Klo. 1"-'. W'kKVII. I'lOltKU OF 

 St (JAli-lANK. 



1 1 . IJoo'l' I'lOHKl; OK 

 Si i; M;-c \NK. 



of carbon liisulphide provideil there is a suitable op[iortunity of 

 applying it. The leaf-eating beetles may be controlled by the 

 use of Paris green and lime, or other ar.-^eiucal poison.s, a|)plied 

 as a dust or s[u'ay. Poison bait, made of bran and molasses 

 to which poison is added, is s(nnetimes u.seful in combating 

 beetle grubs in the soil. This poison bait is used in the same 

 way as already rec-ommended for the cut-worm. 



Clean agricultuial methods, esi>ecially the clearing up of 

 dead and decaying wood, which may contain the eggs or larvae 

 of boring insect.s, and the removal of weed.s, which may serve 

 as breeding places for insects, as well as prompt treatment 

 at the first ajipearance of any <jf the beetle pe.s'.s, will often 

 check a severe outbreak, and thus prevent damage to trees, 

 crol's, and stored product.9. 



