Antagonistic coevolution between hosts and parasites can result in negative frequency-dependent selection and may thus be an important mechanism maintaining genetic variation in populations. Negative frequency-dependence emerges readily if interactions between hosts and parasites are genotype-specific such that no host genotype is most resistant to all parasite genotypes, and no parasite genoty...

Many studies have paid particular attention to the role of either secondary plant compounds or amino acids as determinants of host-plant range in phytophagous insects. Here we examine the relative importance of both of these classes of compound in host acceptance by generalist and specialist morphs of the black bean aphid, Aphis fabae, that are morphologically similar and genetically identical....

Mutual interference involves direct interactions between individuals of the same species that may alter their foraging success. Larvae of aphidophagous coccinellids typically stay within a patch during their lifetime, displaying remarkable aggregation to their prey. Thus, as larvae are exposed to each other, frequent encounters may affect their foraging success. A study was initiated in order t...

Host defenses against parasites do not come for free. The evolution of increased resistance can be constrained by constitutive costs associated with possessing defense mechanisms, and by induced costs of deploying them. These two types of costs are typically considered with respect to resistance as a genetically determined trait, but they may also apply to resistance provided by 'helpers' such ...

The black bean aphid, Aphis craccivora was described by Koch in 1854 from Germany. Recently, the genus Aphis Linnaeus, 1758 is subdivided into 6 subgenera : Aphis (s.s.), Bursaphis Baker, 1934, Iowana Hottes, 1954, Maculaphis Zhang and Zhang, 2002, Pseudoprotaphis Kadyrbekov, 2001, Toxoptera Koch, 1856 and Zyxaphis Knowlton, 1947 (Favret, 2016). Aphis craccivora is kept under subgenus Aphis. In...

The crude seed extract of neem, black pepper, mahogani, and garlic bulb with three doses were evaluated against legume pod borer in the country bean field in two seasons kharif 2006 and rabi 2006-2007. The neem seed extract applied @150 and 100 g/l and mahogani seed extract @ 100 g/l of water 7 days intervals on the country bean showed better performance in the reduction of flower and pod damag...

Neuropeptide F (NPF) signaling systems are widespread and highly evolutionarily conserved from vertebrates to invertebrates. In fact, NPF has been identified in many insect species and plays regulatory roles in diverse physiological processes, such as feeding, learning, reproduction and stress responses. NPF operates by interacting with the NPF receptor (NPFR). Here, we characterized and determ...

A high-performance liquid chromatography-diode array detection (DAD) procedure separating and quantifying 16 phenolic acids was used for determination of phenolic acids content in dry beans (Phaseolus vulgaris L.). Dry beans from 10 market classes and 15 varieties that are commonly consumed in the United States were screened for phenolic acids content. Systematic sequential hydrolysis of a mode...