The distribution and spread, interrelationship with other animals, and economic importance (mainly domestic) of Anoplolepis longipes (Jerd.) in Mah6, Seychelles, after its accidental introduction about 13 years ago, are described. Temporary control measures based on solid and liquid baits formulated largely from local materials were devised. Baits containing aldrin at 2 -5% a.i. and applied at 10 kg (solid) and 20 kg (liquid) /ha decreased the abundance of foragers for about 50 days after treatment. Other insecticides tested were less effective. Bendiocarb (004% a.i.) sprayed onto walls of houses and buildings provided protection for about a week outdoors, and for up to two months indoors. There are good prospects for the eventual decline and stability of populations of this ant on Mahe\

I n a field experiment on infested sandland from 1955 to 1967, numbers of Heterodera avenue increased only in 1957 and then decreased under both continuous and rotational spring oats and subsequently under spring barley ( I 963-67). Fluctuations in numbers of Pratylenclzus neglectus and Trichodorus primitivus were recorded from 1963 to 1967. Cereal grain yields were generally unsatisfactory, but were consistently higher for cereals grown in rotation rather than continuously. Extra nitrogen fertilizer gave slightly improved yields with higher post-cropping numbers of H . avenue.

One hundred and forty‐four samples of potato cyst‐nematodes, the majority chosen to contain G. pallida, from England, Wales and Scotland were identified to pathotype. Where G. rostochiensis was present it proved to be pathotype Rol, there being no indication of other pathotypes of this species. Of G. pallida, a minority of samples incorporated pathotype Pa 1; many were pathotype Pa3 but distinction between Pa2 and Pa3 was unsatisfactory in many more. It is concluded that recognition of these latter two pathotypes is of little value. The proposed pathotype New Leake could not be recognized.

No abstract

SUMMARYThe effect of a pre‐planting application of oxamyl on the yields of six potato cultivars was studied in co‐operative field trials in 1981. Two sites were ‘uninfested’ with potato cyst nematodes (PCN), two were lightly infested (<25 eggs/g soil) and six were moderately to heavily infested (three with Globodera rostochiensis and three with G. pallida). At the uninfested and lightly infested sites oxamyl had little effect on mid‐season haulm weights or on final tuber yields. At sites moderately to heavily infested with G. rostochiensis the haulm growth of all cultivars tended to be increased by a similar amount on plots treated with oxamyl, Pentland Dell being least responsive. Yield was increased by different amounts, the increases being least for cvs Cara and Maris Piper and most for Corsair and Pentland Dell. At the sites moderately to heavily infested with G. pallida Cara was again tolerant, its yield being increased little by oxamyl compared with the other cultivars. Maris Piper gave the largest yield increase.Final populations of PCN on non‐resistant cultivars were reduced by oxamyl at some sites but not at others. Resistant cultivars also decreased the final numbers of PCN at most sites. Two cultivars derived from Solanum vernei with different degrees of resistance, appeared to be almost equally effective in controlling G. rostochiensis and G. pallida.