Survivorship of the sexual and agamic generations of Andricus quercuscalicis on Quercus cerris and Q.robur

Abstract

1. Survivorship within the galls of the sexual and agamic generations of Andricus quercuscalicis (Burgsdorf) is estimated from field populations.2 . The sexual generation on Turkey oak suffers a 20% death rate through parasitism b y Mesopolobus spp. The emerging parasitoids are virtually all males.3. The agamic generation on the acorn cups of English oak is not attacked by any parasites or inquilines at our Berkshire site despite the fact that most of the species which parasitize the gall in continental Europe are on the British list.4. Agamic galls cause average losses of between 30% and 50% of the total acorn crop in different years. Individual trees differ greatly in their rates of loss, many losing over 90%, others losing virtually none.

Plant water stress and gall formation (Cecidomyiidae: Asphondylia spp.) on creosote bush

“…Limited availability of meristematic terminals as oviposition sites has been noted for other gallforming species (Collins et al, 1983). Limited availability of meristematic terminals as oviposition sites has been noted for other gallforming species (Collins et al, 1983).…”

Establishment of Acanthoscelides pallidipennis (Coleoptera: Bruchidae) feeding in seeds of the introduced legume Amorpha fruticosa, with a new record of its Eupelmus parasitoid in Japan.

“…Although it is hard to detect when the invasions occur because initial population sizes are often very small, a few long-term studies indicate that investigation of the development of a host-parasitoid complex over decades is a worthwhile approach to uncovering the process of parasitoid accumulation (e.g., Claridge, 1962;Collins et al, 1983;Godfray et al, 1995;Schonrogge et al, 1998).…”

Range expansion and enemy recruitment by eight alien gall wasp species in Britain

“…Both generations of all the Recent alien gall wasp species (with the exception of the undetected sexual generation of A. aries ) yielded parasitoid records, even if the sexual generation galls of A. lucidus yielded only one parasitoid species, S. biguttata . This contrasts with the early invasion history of the best‐studied species of the eight, A. quercuscalicis , whose asexual generation knopper galls were intensively reared since the 1970s and remained virtually free of parasitoids or inquilines through the 1980s (Collins et al. , 1983; Hails et al.…”