756 



De Charmoy (D. D'E.). Report of the Division of Entomology. — 



Summary of Investigations made during the period January 1st 

 to June 30th 1915, Dept. Agric. Mauritius, pp. 3-7. [Received 

 27th October 1915.] 



The life-histories of Diatraea striatalis (spotted borer), Sesamia vuteria 

 {nonagrioides) (pink borer) and Argyropiloce schistaceana (white borer) 

 have been completely worked out and a special bulletin is being pre- 

 pared. The planting of maize as a trap for S. vuteria continued to be 

 successful. The evolution of the parasite, Prophanurus {Ceraphrott) 

 heneficiens, was found to be completed within a fortnight. The adult 

 is ready to infect fresh moth eggs as soon as it hatches out. Eggs 

 collected from affected maize should be placed in large glass jars. 

 After a few days those that have turned black should be placed 

 separately in test tubes stoppered with cotton wool and covered 

 with a piece of muslin. When the parasites hatch out, 10 to 15 batches 

 of eggs should be placed in each tube containing the parasites. Twelve 

 days afterwards, a single batch of eggs is left in the test tube, the others 

 being removed and brought to the fields in a Avooden box or glass jar 

 covered on one side with a piece of wire gauze for the liberation of the 

 parasite. A census of the area infested by Phytalus smithi made in 

 January showed a slight extension of the pest on the northern borders. 

 A census made in May and June showed that at the Mount and Mon 

 Rocher estates the infestation was considerably reduced when com- 

 pared with that of 1914, but at Beau Plan and on small planters' lands 

 there has been a noticeable increase. A further effort is being made to 

 introduce its parasite, Tiphia parallela, from Barbados and enquiries 

 are being made in Madagascar where two species of Tiphia have been 

 reported to exist. The careful removal of all the infected fruits 

 combined with periodical spraying with arsenate of lead considerably 

 reduced the numbers of the curcubit flies, Dacus curcurbifae and 

 D. ferrugineus. The insecticide was composed of : sugar, 2 lb. ; 

 glycerine, 2 oz. ; arsenate of lead, 2 oz. ; water, 17| pts. This 

 quantity was found to be sufficient for 3,000 square feet. A test 

 showed that 69 out of 120 fruits remained sound and reached their 

 normal size, while 52 were attacked by the flies and dropped. 



Fuller (C). Termite Economy. ^ — South African Jl. Sci., Cape Town, 

 xii, no. 2, September 1915, pp. 60-64. 



The conditions under which the nests of certain termites are 

 associated with trees and shrubs, has led the author to the conclusion 

 that the so-called " park-formation " in South Africa is entirely due 

 to these insects. That certain termites derive some direct advantage 

 from the presence of trees and shrubs upon their mounds is evidenced 

 by the fact that while they do not permit grass to grow upon the 

 mound, they do not interfere with deep rooting and stronger grovnng 

 plants. The species of Hodotermes (harvesting termites) are well- 

 known to injure lucerne, oat and wheat crops. The common African 

 species, Eutermes trinervius, seriously reduces the feeding value of any 

 ground it occupies and in time of drought its depredations are of great 

 importance. Generally speaking, grass is the normal food ; this is 

 cut in the green condition and allowed to dry. The destruction of 

 living trees is restricted to a few species and occurs only when the 



