29S 



THE AGEICULTUKAL NEWS. 



September 22, 1917. 



INSECT NOTES. 



SOME INSECT PESTS IN JAMAICA. 



(ConclucUd ) 



In the last number of the Agricultural News some of 

 the more important insect pests in Jamaica were reviewed 

 under their host plants, as set forth by Mr. A. H. Ritchie, 

 the Government Entomologist. These notes are concluded 

 in this number. 



COKN. The leafhopper {Pereijrinus 7naidis) was respon- 

 sible for considerable daniiige to corn, rausing a withering of 

 the leaves and producing a general stunted appearance of 

 the plants The hopper is usually found associated with 

 a species of aphid or plant louse (Aphis iwiidis). Various 

 flies and beetles are attracted to the sweet excretions of 

 these pests. Among the natural enemies of this leafhopper 

 are two ladybird or coccinellid beetles, Scyiimus ochifxiertis 

 and Coccinella emarginala. A parasitic fungus known in 

 Hawaii as a 'sterile cordyceps' also attacks this hopper. 



SWEET POTATO. This crop is attacked by several 

 different kinds of beetles, the following being the most 

 important; (1) One of the so-called 'tlea-beetle' (C'haetoc- 

 nema aj^ricaria) which feeds on the upper epidermis of 

 the leaves, cutting serpentine channels but never eating 

 right through. (2) A species of 'tortoise-beetle' (Coptocyda 

 flavolineata) which eats out large portions of the leaves 

 both of the sweet potato anH of the related wild specie.s of 

 Ipomaea. (3) The scarabee (Euscepes hatatae), and (4) the 

 sweet potato weevil (Ci/lai- fortnicarius), the grubs of both 

 of which feed on the tubers and sometimes attack the vines. 

 These last two pests can be controlled by planting clean 

 slips from uninfested tubers, by rotation of crops, and by 

 a general clean up of refuse after the crop. 



It may be added that Cylas Jormicarius is not known to 

 occur in the Lesser Antilles, but is a pest in Jamaica, British 

 Guiana, Cuba, the Bahamas, and in some of the .Southern 

 United States, chiefly the Gulf .States. The (Quarterly 

 Bulletin of the State Plant Hoard of Florida. {\o\. I, No. 2, 

 January 1917) mentions that this weevil has recently been 

 found to occur in one of the northern as well as in two of the 

 southern counties of the State. Recent correspondence from 

 the Entomologist of the Mayaguez Experiment Station, Porto 

 Rico, mentions the fact that Cylas fort/iicarius occurs in that 

 island, but is apparently confined to the eastern portion. 



BEE keeping;. Mr. Ritchie states that so far as is known 

 neither the European nor the American foul brood disease 

 of bees exists in Jamaica, and strongly urges against the 

 importation of queens, and against the keeping of antiquated, 

 insanitary box-hives. This type of hive makes the detection 

 of the above bee disease very difficult if not impossible, and 

 at the same time is ideal for harbouring the wax moth 

 (Oalleria mellonella\ which is very prevalent in Jamaica. 



Ml8CELL.\NE0U.S InsECT.S. 



Tender this heading Mr. Ritchie mentions several insects, 

 the most important of which is the black weevil of bananas 

 [Cosmopolites sordidus). Experiments which are being 



suggested for the checking of this pest include deep planting 

 and the application of repellent substances around the base 

 of the plants. Attention is called to the presence of 

 a beneficial grub of Fyrophorus sp. in infested bulbs. Pyro- 

 phorus, it may be remembered, is one of the large luminous 

 beetles or 'fire flies' found in some of these islands, and one 

 species has been observed to be predaceous on hard back 

 grubs in Porto Rico. (Agricidtural News, Vol. XVI, No. C99, 

 Augu.st 11, 1917.) 



The introduction into Jamaica of two species of preda- 

 ceous histerid beetles is being considered. One of these ia 

 an enemy of Metamasius hemipterus in Trinidad, while the 

 other histerid, Plaesius javanus, helps to control the black 

 banana weevil in .lava. Within the last three years this 

 beetle has been introduced into Fiji from Java in the hope 

 that it will prey upon the banana weevil in those islands. 

 The subsequent re.sult of this experiment in Fiji is not known 

 at present. 



The lily caterpillar (Xanthopastis timais) sometimes 

 destroys plants belonging to the family Amaryllidaceae or 

 lily group. Observations were made on this species by 

 William Jones, a former naturalist of Jamaica, who lived 

 in the first half of the last century. He noticed that when 

 small the caterpillars 'arrange tlieniselves side by side like 

 detachments of hor.se soldiers.' Those who are familiar with 

 this caterpillar in these islands will probably have 

 observed that the older caterpillars no longer retaia 

 the habit of close formation, but scatter in all directions 

 over the plant. They usually end by devouring all of 

 the plant above ground and often burrow down and destroy 

 the bulb. The dusting of the plants with stomach poisons, 

 such as Paris green or arsenate of lead, or the collection of 

 the caterpillars while they still have the clustering habit, 

 can be recommended to control this garden pest. 

 Stock Pests. 



A rather serious outbreak of the horn fly (Lyperosia 

 irritans) occurred in one district in January 1917. There 

 are two classes of pasturage in this district, namely. Pimento 

 grass commons, and mixed Para and Guinea grass pastures. 

 The horn fly, it may be noted, breeds in manure, and 

 Mr. Ritchie considers that with a well distributed or even 

 rainfall, both types of pasturage would no doubt favour the 

 breeding of the horn fly, but that the manure dropped in the 

 Pimento grass would tend to dry out rapidly enough to 

 check or even prohibit the breeding of the horn fly. On the 

 other hand, the longer gra.ss in the mixed pastures would 

 shade and protect the manure from drying out by sun and 

 wind. Towards the end of 1916 this district had a Ion* 

 spell of continuous rains which no doubt contributed largely 

 to the sudden increase of the horn fly at the beginning of 

 1917. With the coming of warm and dry spells the numbers 

 of the horn fly are considerably checked. 



The scattering of the manure in the fields hastens the 

 drying out proce.ss. and it was noticed that a species of large 

 black dung beetle (Pfianae^is sulcatus) was of great assistance 

 in the drying out and deep burial of the manure in the fields. 

 Mr Ritchie suggests the exchange of such beneficial forms 

 with other entomological stations. 



The outbreak of the horn fly caused .serious wounds on 

 the shoulders and backs of the cattle which required 

 systematic dressing. The screw- worm fly {Paralucilia 

 macellaria), and other flesh flies were attracted, but the 

 careful supervision which is possible with the small herds in 

 Jamaica kept these pests down. 



The .systematic control of ticks on cattle by the adoption 

 of dipping vats is strongly urged, and this is especially impor- 

 tant since cattle kept free from ticks will be better able ta 



