66 



Cleare (L. D.). a Butterfly injurious to Coconut Palms in British- 

 Guiana. — Bull. Entom. Research, London, vi, no. 3, December 1915, 

 pp. 273-278, 1 fig., 3 plates. 



During the year 1914, coconut palms in Georgetown were attacked 

 by the larvae of Brassolis sophorae, L. (coconut butterfly). From 

 previous records, it would appear that this insect occurs in injurious, 

 numbers at intervals of about five years. It is probably distributed 

 throughout the coast lands of British Guiana and has also been reported 

 from Dutch Guiana, Trinidad and southward to South Brazil. In 

 addition to coconut, Oreodoxa oleracea (cabbage palm) is also attacked. 

 The eggs are laid in masses of from 100 to 150 on the stem and under- 

 side of the leaves of the host. The larvae usually emerge simultaneousl3r 

 from the mass. They feed almost entirely at night on the green parts 

 of the leaves, resting by days in pockets formed by binding the leaves 

 together. Several hundred larvae collect in each such nest. The 

 duration of this stage is about four weeks. The pupal period lasts 14 

 days. From the apparent point of origin, south-west of Georgetown, 

 the attack spread to the north-east in opposition to the prevailing 

 winds. It was noticeable that blocks in the midst of afEected areas 

 remained untouched, as also did palms near the sea. A count of dead 

 trees made in September showed that 5 per cent, had succumbed. 

 The insect has several natural enemies, including a bird, Pitangus- 

 sulphuratus (kiskadee), which feeds on the adults, several egg-parasites, 

 and a parasite of the pupa, Chalcis annulata, F. The habit of the 

 larvae of living in nests during the day offers the best means of con- 

 trolling this pest, as the nest can be easily removed and destroyed. 



HowLETT (F. M.). Chemical Reactions of Fruit-flies.— .BmW. Entom, 

 Research, London, vi, no. 3, December 1915, pp. 297-305, 4 plates. 



Experiments carried out by the author at Pusa,Bengal, in 1912 showed 

 that certain essential oils were attractive to males of Dacus {Bactrocera) 

 zonatus, Saund., and D. diver sus, Coq. The flies perceived the smell of 

 small quantities of citronella mixed with almost any other substance. 

 In the absence of citronella no definite attraction was noted, except 

 in the following cases:' — (1) one sample of oil of eucalyptus; (2) a 

 mixture of clove oil, coconut oil and kerosene ; (3) a mixture of clove 

 oil and eucalyptol. Investigations were resumed in March 1913, 

 Three of the commoner species of fruit-flies, D. diversus, D.ferrugineus- 

 and D. zonatus, normally breed in (1) the anthers of Cucurbitaceae, 

 (2) the fruits of Solanaceae and mango, and (3) peach, guava, mango^ 

 and other fruits, respectively. Citronella contains methyl- eugenol 

 and probably eugenol and iso-eugenol ; bay oil contains methyl- 

 eugenol and eugenol, while clove oil consists of from 70 to 90 per cent, 

 of eugenol. It was found that D. diversus was most strongly attracted 

 by iso-eugenol, D. zonatus by methyl-eugenol, and D. ferrugineus by 

 methyl- and iso-eugenol. The odours of these substances have not 

 yet been identified with those of the plants which form the normal 

 breeding-places, but only the male flies have been found to be attracted 

 to mango, papaya, a Cycad, and Colocasia, plants with a very charac- 

 teristic scent similar to that of eugenol derivatives. The males give 

 the impression that they might visit these plants for food, since they 

 suck the surface of the flowers. One species, perhaps D. ferrugineus. 



