164 



Lamborn (W. a.)- The Agricultural Pests of the Southern Provinces, 

 Nigeria. — Bull. Enfom. Research, London, v, pt. 3, December 1914, 

 pp. 197-214, 4 figs., 9 plates. 



An account is given of the insect pests and methods for their control, 

 observed in the Southern Provinces, Nigeria, between May 1913 and 

 May 1914. Cotton pests included : — The Tineid, Acrocercops bifasciata, 

 Wlsm., which mined the young leaves, and Aphis gossypii, Glov., which 

 was abundant in August, but was checked by natural enemies, especially 

 Chilomenes limata, F., C. vicina, Muls., and Hyperaspis pmnila, Muls., 

 also to a less extent by Syrphits nasiitus, Wied., Paragiis horhomcus, 

 Macq., P. longiventris, Bezzi, and Micromus timidus, Hagen. Zonocerus 

 variegatus, L., the worst cotton-leaf pest, occurred suddenly in 

 November and entirely defoliated many plants. This locust was prac- 

 tically omnivorous, and also attacked young maize. Para rubber, 

 cassava, bananas, and occasionally cacao. The leaf -roller, Sylepta 

 derogata, ¥ ., was abundant about November on certain imported 

 varieties, notably American Upland, but was less numerous on the 

 native ones ; Tachinid parasites, possibly of two species, the 

 Ichneumonid, Xanthopimpla punctata, F., and some Braconidae, 

 were bred from the pupae, but were not numerous enough to be 

 effective checks ; insecticidal sprays failed owing to the difficulty 

 of getting the poison on to the rolled-up part of the leaf, so hand-picking 

 by native boys was resorted to, the various cotton-stainers being 

 collected at the same time. Parasa infuscata, Wichg., was not un- 

 common ; green half-looper Noctuid larvae were prevented from 

 causing any serious damage by a wasp, Eumenes maxillosa, de Geer, 

 which stored them in its mud cells. Lagria villosa, F., Syagrus 

 calcaratus, F., and other beetles cause some leaf damage. The 

 scale-insects, Hemichionaspis minor. Mask., and Pulvinaria jacJcsoni, 

 Newst., occur in small numbers ; the former was checked late in the 

 season by the larvae and imagines of Chilocorus schiddtei, Muls. A Bu- 

 prestid beetle, Pseudagrilus sojihorae, L., caused considerable damage by 

 boring the stems ; destruction of the affected plants seemed to be the 

 only remedy. A number of plants were destroyed by the decortication of 

 their roots by the larvae of a Lamellicorn beetle ; the application of 

 a 1 in 200 aqueous solution of carbon bisulphide to the roots, by means 

 of the Gastine apparatus [see this Review, Ser. A. ii, p. 256], gave 

 promising results. Diparopsis castanea, Hmp., was abundant, and in 

 some instances the pupae of this moth lay dormant in the ground for 

 many months instead of the usual 8 or 10 days. Earias biplaga. Walk., 

 was found in flower-buds as well as in bolls, and was also observed 

 feeding on the leaves and in seed-pods of the fibre plant, Sida carpini- 

 folia, L., and on leaves of several bush plants ; Rhynchium ventrale, 

 Sauss., a Eumenid wasp, was an important check on the larvae of 

 this moth. Pyroderces simpilex, Wlsm., and Mometa zemiodes, 

 Durrant, were found abundantly in June, in late bolls on plants 

 of the previous season, but were not seen again until the cotton season 

 was well advanced ; these moths are not so injurious as the former 

 pests, confining themselves to the seeds in opened bolls, though their 

 activities continue in stored cotton, larvae being found ahve in the 

 seed even after ginning. The larvae of both species are parasitised 

 by Chalcis olethrius, Waterston. Collecting and destroying affected 

 bolls seems to be the only suitable method of control, though the 



