Aposematic insects use warning colours to deter predators, but many also produce odours or sounds when attacked by a predator. One possible role for these additional components is that they promote the association between the warning colour and the non-profitability it signals, thus reducing the chance of future attacks from visually hunting predators. This experiment explicitly tests this idea...

Cuscuta spp. (i.e., dodders) are stem parasites that naturally graft to their host plants to extract water and nutrients; multiple adjacent hosts are often parasitized by one or more Cuscuta plants simultaneously, forming connected plant clusters. Metabolites, proteins, and mRNAs are known to be transferred from hosts to Cuscuta, and Cuscuta bridges even facilitate host-to-host virus movement. ...

Action Rules are currently only implemented by B-Prolog. One reason is that it is difficult to extract their exact semantics from the manual or the implementation. This issue is attacked by describing a transformation from Action Rules to almost plain Prolog. The transformation captures most of the B-Prolog semantics, and shows clearly how it could be extended. It also allows for an easy to und...

In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha tree plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 species were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic species. Five species [Dryoxylon onoharaensum (Murayama), Euwallacea valid...

False positives cause many promising detection technologies to be unworkable in practice. Attackers, we show, face this problem too. In deciding who to attack true positives are targets successfully attacked, while false positives are those that are attacked but yield nothing. This allows us to view the attacker’s problem as a binary classification. The most profitable strategy requires accurat...

*Correspondence: Geoffrey E. Hill, Department of Biological Sciences, Auburn University, 331 Funchess Hall, Auburn, AL 36849-5414, USA e-mail: [email protected] Male eastern bluebirds (Sialia sialis) have feathers with either structurally based blue coloration or melanin-based chestnut coloration, and they hold territories during the breeding season that they defend vigorously. We tested whether...

Plants attacked by leaf herbivores release volatile organic compounds (VOCs) both locally from the wounded site and systemically from non-attacked tissues. These volatiles serve as attractants for predators and parasitoids. This phenomenon is well described for plant leaves, but systemic induction of VOCs in the roots has remained unstudied. We assessed the spatial and temporal activation of th...

H(2)O(2) production and changes in glutathione, catalase, and peroxidase were followed in whole-leaf extracts from the susceptible (AlgS [Algerian/4* (F14) Man.(S)]; ml-a1 allele) and resistant (AlgR [Algerian/4* (F14) Man.(R)]; Ml-a1 allele) barley (Hordeum vulgare) isolines between 12 and 24 h after inoculation with powdery mildew (Blumeria graminis [DC]. Speer [syn. Erysiphe graminis DC] f.s...

Efficacy of Compound 1080 LP Collars was studied under pen and field conditions. Coyotes poisoned themselves by attacking collared sheep and biting the collars. In 54 pen tests where 1 or 2 captive coyotes had opportunity to attack 1 collared lamb, 41 lambs were attacked and 26 collars were punctured. Of 25 different coyotes offered lambs with collars containing 5 or 10 mg sodium fluoroacetate ...

While plants are invariably attacked by numerous insects and pathogens, the consequences of multiple enemies for plant performance are poorly understood. In particular, a predictive framework is lacking for when to expect enemies to have independent versus non-independent effects on their host plant. This is problematic for weed biological control programmes where multiple enemies are frequentl...