168 



Harland (S. C). Report of the Assistant Superintendent of Agriculture 

 on the Entomological and Mycological Work carried out during the 

 Season under Review. — Rept. Dept. Agric, St. Vincent, 1915-1916, 

 Barbados, 1916, pp. 7-34. [Received 20th February 1917.] 



Some of the investigations dealt with in this report have already 

 been recorded [see this Review, Ser. A, iv, pp. 42, 321, 416]. 



Insect pests noted during the year included : — 



On cotton, Alabama argillacea (cotton worm) and Eriophyes gossypii, 

 Bks. (leaf -blister mite). Investigations were carried out to determine 

 the resistance of budded cottons and cotton hybrids to the latter pest 

 and the results are embodied in a separate paper [see this Review, Ser. 

 A, V, p. 109]. Saissetia nigra (black scale) and Colaspis fastidiosa 

 (bronze beetle) were minor pests. Corythuca sp. feeds on the leaves. 

 Two new pests have been observed at the Experiment Station ; 

 cotton plants blown to the ground by high winds were tunnelled by 

 a beetle larva, the adult of which has not been reared. A species of 

 thrips has been found attacking the bolls and leaves ; nothing is 

 known of its life-history and no natural enemies have been discovered. 



Pests of cassava included : — Cryptorrhynchus sp. (cassava borer), 

 of which no natural enemies are known ; this pest will be an important 

 one if the cultivation of cassava is extended. Dactylopius sp. (mealy- 

 bug) is parasitised by the larva of an unidentified Syrphid fly and 

 of a LepidopterOn, neither of which is sufficient for its control. For 

 both this pest and Cryptorrhynchus a close season for cassava is 

 recommended. Diaprepes spcngleri, L., in some cases almost 

 defoliated the plants ; no control measures have been attempted. 

 Eggs of Erinnyis ello, L. (cassava hawk-moth) were abundant, but 

 are parasitised by a small Hymenopteron. Two cassava thrips, 

 Corynothrips stenoptera and Franldiniella melanmmnatais , again caused 

 considerable damage ; the growth of young cassava near old infested 

 fields encourages this pest. Cecidomyia manihot, Felt (cassava gall 

 maggot) does very little damage and is extensively parasitised by 

 minute Hymenoptera. A small mite was found to cause premature 

 leaf-shedding at the Experiment Station. 



Maize pests included the mole-cricket [Scapteriscus didactylus), 

 which severely damages the young plants, and for which no adequate 

 control has yet been undertaken. A fungus which has been found 

 attacking the insect does not seem to be an important check. 

 Laphygma frugiperda, the larva of which is a serious pest, can be 

 controlled by a mixture of lead arsenate and low-grade arrowroot 

 or cassava starch in the ratio of 1 part to 30, which is dropped into 

 the heart of the young plant by means of a pen-nib. This pest is 

 able to complete its life-history on a large number of plants. No 

 larval or pupal parasites have been found. Diatraea saccharalis, 

 F. (moth borer of sugar-cane) is the most serious maize pest in St. 

 Vincent. Eggs are continually collected and these are also controlled 

 by the parasites Projohanurus alecto, Crawfd., and Trichogramma 

 minutum. As this moth prefers to oviposit on maize rather than 

 on sugar-cane, old maize stalks should be cleared from fields to 

 prevent the completion of its life-history. Heliothis obsoleta, F. 

 (boll worm) attacks maize, but is largely controlled by egg-parasites. 

 Agromyza sp. (leaf-miner) is extensively parasitised by Chalcids. 



