Fluoroacetate is a potent poison of animals. It is metabolized to fluorocitrate, which is a powerful inhibitor of mammalian aconitate hydratase [aconitase; citrate (isocitrate) hydrolyase] (Peters, 1952). Fluoroacetate and fluoroacetamide, as systemic insecticides for plants, are taken up by the roots or absorbed by the leaves and are then translocated to other parts of the plant. The plants sh...

Models of host-parasite coevolution predict pronounced genetic dynamics if resistance and infectivity are genotype-specific or associated with costs, and if selection is fueled by sufficient genetic variation. We addressed these assumptions in the black bean aphid, Aphis fabae, and its parasitoid Lysiphlebus fabarum. Parasitoid genotypes differed in infectivity and host clones exhibited huge va...

Transmission experiments of different isolates of Cucumber mosaic virus (CMV), Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV) were conducted using established colonies of Aphis gossypii Glover, Myzus persicae (Sulzer), A. fabae Scopoli and A. craccivora Koch as vectors. The transmission procedure used provided an estimate of the virus transmission efficiency for each aphi...

Cold storage is a valuable method for reducing the cost of producing large amounts of biological agents. Fluctuating thermal regimes (prolonged exposures at low temperatures combined with periodic short higher temperature) are reported to improve cold survival and fecundity in some parasitoid species. In this study, the pupal stage of the parasitoid wasp Lysiphlebus fabarum (Marshall) (Braconid...

Cucumber mosaic virus (CMV) is a major component of the virus complex that has become more pronounced in snap bean in the midwestern and northeastern United States since 2001. Multiple-vector-transfer tests were done to estimate the CMV transmission efficiencies (p) of the main aphid species identified in commercial snap bean fields in New York and Pennsylvania. The four most efficient vectors ...

1. Environmental cues associated with prey are known to increase predator foraging efficiency. Ladybird larvae are major predators of aphids. The sugary excretion of aphids (honeydew) has been proposed to serve as a prey-associated cue for ladybird larvae. 2. Ladybird larvae are regularly found on the ground moving between plants or after falling off plants. The use of prey-associated cues woul...

We compare the efficiencies of different stages of Hippodamia variegata (Coleoptera: Coccinellidae) preying on Aphis fabae (Scolpoli) (Hemiptera: Aphididae) by estimating the functional responses of all stages. The experiments were carried out on leaf disks in petri dishes with 15-20 replicates. Our results revealed that all larval instars and adult males and females of H. variegata exhibited t...