90 



THE AGRICULTURAL NEWS. 



March 12, 1904. 



INSECT NOTES. 



Lady-birds in the West Indies. 



A note appeared in the A(jri<ii/fii ml Keiv.^i, WA. 

 II, p. 410, stating that inve.stigation.s were about to be 

 undertaken by the Entomologist of this Department 

 with a view to obtaining information with reference to 

 the habits and life-histories of the hidy-birds in these 

 islands. We make the following extracts from a pro- 

 gress report recently presented to the Impei'ial 

 Commissioner of Agricidture : — ■ 



Specimens have been receixed from several of the other 

 island.s, and some Iiave been collected in Rarljados. Most of 

 those forwarded from the other islands liave arrived alive ami 

 in good condition, but they have not laid eggs after their 

 arrival, though some of them have lived for some time. In 

 all, five species of ladybird have l>een under observation. 



The red lady-bird (Ci/cloiieJa sam/iiiiiea), the most 

 common of the West Indian lady-birds, is about } inch in 

 length, nearly as wide and very convex above. The wing 

 covers are a dark, blood-red colour, the thorax black with 

 white markings at the lateral edges, the head very inconspic- 

 uous and brownish in colour. The markings of the thorax 

 give it the apjiearance of a head with white eyes. This 

 species feeds mostly on the plant lice, only one individual 

 having been seen to fee<l upon scale insects. 



The .spotted lady-bird (Mei/illa macnlaia, var. DeGeer) is 

 more elongate than the preceding, the ground colour is more 

 pinkish or pale-red, and there are twelve black spots on the 

 wing covers. When these are closed together there .seem to 

 be only ten spots, because two spots on each side are exactly 

 opposite the two corresponding ones on the other side, and 

 they touch and run together when the wing covers are closed. 

 The head and thorax are lilackish with light uiarkings. 

 Length, about ] inch. This species feeds entirel)' upon the 

 plant lice so far as is known at inesent. 



Scpmvii.t sp., taken in Barbados, is a very .small lady- 

 bird likely to be over-looked and to escape, so small is it and 

 so quick to take flight. It, however, is a valuable .species 

 feeding on the white fly [Ahyrodea), which is so common on 

 guava trees. Species of this genus are known to occur in 

 several other i.slands. Length, about ^^ inch. 



E.rocho?iuis nitididiis is a beautiful steel-blue insect with 

 two orange-yellow spots on the thorax, a very little smaller 

 than the red lady-I>ird, and very useful, feeding ujion scale 

 insects. Attempts have been made to establish it in .several of 

 tlie islands, the supply in each case coming from St. Lucia. It 

 is not certain that any of these atteniiits have been successful. 

 In St. Lucia this species is found most commonly feeding on 

 the Bamboo scale. Length, -j-^ inch. 



There has recently been received from Jamaica another 

 species of lady -bird. This is a small black insect, ^'^ inch long, 

 very convex above, with six large oiange-coloured spots on the 

 wing covers and two on the thorax. Head, yellowish with 

 green eyes. It feeds upon scale in.sects and will jirobably 

 prove a very valuable aid in keeping in check scale insect 

 pests. 



The following notes oi\ life-history refer to the red 

 lady-bird. In each case only one insect was brought to 

 maturity from the egg clusters. 



The following table .shows the time spent in each 

 stage : — 



The life-cycle of No. 1 is complete except that no time 

 is given for the laying of the eggs, which would probably 

 occujiy only a few days. As far as observed, twenty-three 

 days are occupied in passing through the changes from egg 

 to perfect insect. 



Comparison n\ay, however, be made between Nos. 1 

 and 2 in the larval stage, where No. 1 spent seventeen days 

 and No. 2, fifteen days. Also we may compare all these 

 in the pupal stage, in which No. 1 spent four days ; No. 2, 

 four days, and No. 3, six days. 



Several of the lady-birds under observation in the 

 laljoratory have been oliserved to feed uj>oii scale insects, 

 others feed greedily upon the plant lice and some feed 

 u[>on both scales and plaiit lice. The cotton plant louse 

 (Aji/iix (/(>s>:i/2'ii) has been most frequently fed to them, 

 although one adult fed U()on the jilaut louse on the grape. 

 I may mention that while in ilontserrat recently I found 

 individuals of the red lady-bird feeding on the young of the 

 cotton stainer {Dffidociis andreae). 



Thrips on Cacao in Grenada. 



Mention was made in the Agricultural Ifeivs 

 (Vol. Ill, p. 10) of the increasing severity of the 

 attacks of the cacao thrips and of the necessity for 

 vigorous action on the part of the planters. The 

 following recommendations are made by the Entomolo- 

 gist on the staff of the Imperial Department of 

 Agriculture : — 



I would suggest two washes which might give good 

 results and which seem at least worthy of fair trial. The 

 first is Lounsl>ury's Lime and Sulphur fornuda used at the 

 Capeof (lood Hope. This is made by boiling 10 Ih. lime 

 with 20 11). sulphur in a large kettle, in sufficient water to 

 dissolve them. Good quicklime should be u.sed and any 

 additional water .should he added gradually. This is sufficient 

 for from 100 to 300 gallons of wash. I would recommend 

 a trial of this on a very few trees to see whether it would 

 give gooil results with the thrips and whether it would injure 

 the foliage, fruit, or branches of the cacao. 



The second wa.sh that might be worth trial is Lefroy's 

 mixture — whale oil soap, 10 lb.; crude Barbados oil, 5.1 pints ; 

 naphthalene, 4 oz. This .should be dissolved in water at the 

 rate of 1 It), to 4 gallons water and 1 lb. to 2 gallons water. 

 Care must be taken to get it thoroughly dissolved. 



