INSECT PESTS IN MAURITIUS. 18vS 



Ambrevades (Cajanus indiais). 



This plant suffers a great deal from caterpillars, which live in the pods. In 

 certain regions 75 per cent, of the crop is lost. Control measures are difficult to 

 apply, for reasons mentioned further on. 



Adoretus vcrsidus, Har. This beetle, which has polyphagous habits, feeds on 

 the leaves of the pigeon-pea, but is not a serious pest. 



Lachnostermi [Phytalus) sniifhi, Arrow. Plants grown in the infested region are 

 usually visited by /-. smithi. The damage caused is insignilicant, as the plants in 

 the infested areas serve as trap plants, from which the beetles are hand-picked at 

 night. 



leery a seychellariim, Westw., is common enough on almost all the plants of the 

 island, and is only a minor pest of pigeon-pea. Various insecticides in the form 

 of emulsions have been tried against this pest, but the results have never been 

 successful. 



EucalyynnatHs tessellatus, Sign., is a minor pest of the twigs and attacks various 

 other Leguminosae. 



Chionaspis siibcorficalis, Green, is occasionally found on the branches of this 

 plant, more especially on the tender twigs, but does not do nuich harm. 



A species of Boiys is very common on the tender leaves. 



By far the worst pests of Cajanus indicus are certain Lycaenid butterflies, which 

 are exceedingly common when the plant begins to flower. 'The eggs are laid on the 

 flower-buds and young pods, and the newly-hatched caterpillar, after having fed 

 for a short time on the surface of the buds and pods, bores its way in. Advantage 

 was taken of this to try to control the insect by spraying the flower-buds and 

 pods with arsenate of lead. The results were not successful, for it was difficult to 

 make the spray adhere to the flower-buds, as these are covered with fine hairs, which 

 will not hold the spray. Moreover, at this time of the year the wind is usually very 

 strong, so that the sprayed material is shaken off the plant before it has time to dry, 

 in spite of its adhering power having been increased by the addition of mucilaginous 

 substances, such as a maceration of Opuntia in water. The following is a list of 

 the Lycaenids that feed in the flower-buds and pods : — Lampides boetica, L., Zizera 

 Ivsimon, Hb., Tarucus telicaniis, Lang, and Nacaduba mandersi, H.H.D. Of these 

 Lampides boetica is the worst pod pest, the others confining their attacks rather to 

 the fiower-buds. 



Chloridea cbsoleta, F., is an occasional pest of pods. 



Platyedra gossypiella, Snd., is also occasionally found in pods and is more common 

 than Chloridea. 



Bofys spp. Two species of Pyralidae are found in the flower-buds, and more 

 rarely in the pods. These are the most dangerous pests of flower-buds, and are 

 responsible for a great deal of damage. 



Pols Sabre [Canavalia ensiformis). 



Only a few pests are worth recording : — 



Thrips are often abundant in the flowers and cause many of these to fall off. 



Argyroploce rhynchias, Meyr. The caterpillar feeds in the pods, also attacking 

 the twigs, and may sometimes ruin the whole crop. 



Aspidiotus sp. This scale is a minor pest, and is found on the twigs. 

 Rhopalocampta forestall, Cram., is also a minor leaf pest. 

 (3442) o 



