250 



THE AGRICULTUEAL NEWS. 



AucusT K, 190S. 



'"^SC^^ 



^: 





larvae art- boivrs in the bark aiiJ woml of livini; trees. The 



L'lick beetles and the fire-Hies 



uelong- to this grouj). 



INSECT NOTES. 



Coleoptera. 



The Coli'optera or beetles are distinguished fi-om 

 other insects by having the first pair of wings much 

 thickened or hardened, forming covers for the mem- 

 branous second pair, which are used for flight. The 

 thickened pair are known as elytra, or wing covers, 

 and they generally meet in a straight line down the 

 middle of the back, while the membranous pair, called 

 the true wings arc folded beneath. The mouth parts 

 of both larval and adult beetles are adapted for biting, 

 and many species are injurious in botii these stages. 



Tlie larvae of beetles are generally eallecl grubs. They 



Vu 



< iuri; ni 1 1 \i;iii; \iK. 



Ni>nietnnes have tln-ee pahs <,( welMexrIoped legsandsometinies 

 are without feet ami legs, lieetles vary greatly in their habits, 

 certain of them being among the most serious agricultural 

 and household pests, while others arc higldy lieneficial. 



The Coleoptera arc divided into luo principal groups, the 

 true beetles (Coleoptera genuina) and tlie weevils (Hhyncho- 

 phora). The essential difference between these two groups i.s 

 that the weevils have the front of the head iirolonged into 

 a bill or snout, i\t the extremity of which the mouth parts 

 are situated, wliile witli the true beetles this develop- 

 ment is absent. 'I'lie true beetles are further divided into 

 several groups, according to structure and habits, which for 

 convenience may be named a.s follows : earnivoroiis beetles, 

 club-horned beetles, sawhoriied beetles, bjailehorned beetles, 

 plant-eating beetles, and lady-lnrds. 'I'he carnivorous beetles 

 include the tiger beetles, the ground beelles, and the preda- 



ceous water beetles. () f the grottnil beetles (Cnlosoiiin 



ailidinii) has been reported from St. Vincent and Jiarbuda as 

 an actixe enemy of the cotton woiin. 



Ill the cliib-horned beetles the antennae are swollen to 

 from a ilub or knob at the end. This group includes the 

 large black water scavenger beetle {//i/<{r<>/i/u/iis uln-) which 

 occurs in pools of standing water in the West Indies. It is 

 the largest of the water beetles, and may be seen frequentlv 

 comi-ig to the surface of the water, and again diving to the 

 bottom. 



The saw-horned lieetles jMe .so named because the .seg- 

 ments of the antennae resemble in ap|)earance the teeth of 

 a .saw. Ill this grouji arc to be fotuid the metallic wfiod 

 borers, a few species of whiili occiu- in the West Indies. The 



The click beetles (Elateridae) are elongate insects having 

 a peculiar structure by means of which they are able, if [ilaced 

 on their backs, to throw themselves several inches into the air. 

 The larvae which are known as wire«orms, live in the ground, 

 feeding on roots and seeds, or in decaying wood. The most 

 noticeable West Indian memlier of this family is the laige 

 fire-fly ' La Belle ' {Pi/i(i/tliiiiii.< luirtilucitu), of Dominica, St. 

 Lucia, and other islands. Attemjits have been made to 

 introduce thi--, insect into islands in which it is not naturally 

 found, but it would be well to liear in mind in making such 

 attempts that the larvae are liable to become pests to agri- 

 culture if the species is established in any island in which 

 there is very little uncultivated or bush land. 



The fire-fly family (Lampyridae), to which the small fire- 

 flies belong is fairly well rcpi-esented in the West Indies. The 

 common fire-fly of the Lesser Antilles is Axjiidoxomuiii I'l/nifiiiit. 

 The larvae of this family generally feed on .soft-bodied insects, 

 slugs, etc., and the atlults of most species are said to be 

 carnivorous also. 



The blade-horned beetles {LainrUiconiia) are so called 

 because on the terminal segments of the antennae there are 

 flattciK'il p;ojections (lamelhu). This grou]! incktdes sfime of 

 the largest beetles known, and some which have most 

 l.-ccuiiar ap[)earances from the remarkable development of 

 mandibles or projections from the head or thorax. 



The Hercules beetles ( />////a.<A.< /irmi/rs) is remarkidile 

 iov its great size and for the enormous projecting horns, one 

 of which arises from the'iirothnrax, and the t)tlier from the 

 head. These insects are found in the mountainous and 

 wooded islands in the West Indies and in South America. 

 To this group also belongs the common hardliack (/./<///;•».< 

 fiimii/oxiis). which occurs .so freipiently in hou.ses at night, 

 being attracted by the lights. The larva of the hardback 

 is a white grub, and may be found in cultivated fields 

 and gardens. 



The larva of '/'ni/mni.-: Iiitiihiri-iilal us is ii borer of 

 bananas and p'lantains, and lias occasioneil some loss in St. 

 Lucia by attacking newly planted suckers. 



The plant-eating beetles may be dixidcd into three 

 principal hunilies: the leaf beetles (Chry.omelidae), the pea 

 and liean ^veevils ( bruchidae), and the long-horned beetles 

 (Cerambycidae). The leaf-beetles are represented in the 

 \\ est Indies by a considerable number of small insects, mostlj' 

 small in size, which eat holes in the leaves of plants. The 

 tobacco flea beetle (Kpttti.r parnila) occurs eonimonly on 

 tobacco and other plants, anil another flea beetle is often to be 

 seen on the sweet potato. The tortoi.se beetle (Vtiptoi-i/rla) 

 which also occurs on sweet potato leaves, 

 is a very beautiful insect, with its o|)ales- 

 cent colouring. The pea and bean weevils 

 are x)ell known in the West Indies, and 

 peas and lieans stored for food or for seed 

 are.crften found to be riifdled with small 

 round holes cau.sed by these in.seets. 



Fumigating with carbon bisulphide 

 or immersing for two minutes in water 

 heated to I III K. "ill kill tlic beetles. 

 I'liiirli IIS I'll nil iixix i\\u\ 11. iiiniilriniiiriiliil us are the 

 forms in the West Indies. ' Wecviled ' peas are 

 food, and should not be used for seed puriioses. 



The long horned beetles include a large mimV)er of tree 

 borers <a' bark borers which occur in the West Indies. 

 They are distinguished by the extreme length of their slender 

 antennae. 



Kn 



S. Tonr. 



r. KIVII.K. 



common 

 unfit for 



