AbstractOviposition in Longidorus elongatus on strawberry crops (Fragaria X ananassa Duchesne) in Scotland began in April, increased rapidly to a peak in May and declined markedly or ceased in July/August; a secondary phase of oviposition terminated by October. This pattern of oviposition also occurred on perennial ryegrass (Lolium perenne L.) and appeared to coincide with the period of new root growth before and after flowering, a feature common to these favourable hosts. After peak oviposition the four larval and adult female stages reached maximum numbers at successive intervals of approximately two months, suggesting that most individuals have an annual life cycle. Total populations reached a peak in autumn or early winter and a nadir before spring in contrast with saprobic nematodes which were more numerous in spring or summer and least during late autumn or winter.
In Xiphinema diversicaudatum from a raspberry plantation (Rubus idaeus L.), most oviposition occurred about mid-summer, but comparable annual increases in the post-embryonic stages of development were less consistent; maximum total numbers were attained in November.