Due to the high content of nutrient, sieve tubes are a primary target for pests, e.g., most phytophagous hemipteran. To protect the integrity of the sieve tubes as well as their content, plants possess diverse chemical and physical defense mechanisms. The latter mechanisms are important because they can potentially interfere with the food source accession of phloem-feeding insects. Physical def...

BACKGROUND Bemisia tabaci MEAM1 (Middle East-Asia Minor 1) feeding alters antioxidative enzyme activity in some plant species. Infestation of B. tabaci nymphs decreases Myzus persicae performance on systemic, but not local leaves of tobacco plants. However, it is unclear if B. tabaci nymphs induced antioxidant activities contributing to the aphid resistance. METHODOLOGY/PRINCIPAL FINDINGS We ...

The tripartite interactions in a pathosystem involving wheat (Triticum aestivum L.), the Barley yellow dwarf virus (BYDV), and the BYDV vector aphid Sitobion avenae were studied under field conditions to determine the impact of these interactions on aphid populations, virus pathology and grain yield. Wheat varietal resistance to BYDV and aphids varied among the three wheat varieties studied ove...

during a two-year (2004-2005) survey of alfalfa aphids and their natural enemies in isfahan, a total of four aphid species and 58 species of their natural enemies comprised of 45 predatory species, 11 parasitoid species and two species of parasitic mites were collected and identified. moreover, five hyperparasitoid species were collected. on each sampling date, six 20-sweep samples were taken u...

The within-plant distribution of soybean aphid, Aphis glycines Matsumura has been attributed to various causes, yet it is unclear which factor or combination of factors most influence aphid within-plant distribution. Understanding soybean aphid distribution within the soybean canopy is important both in developing sampling programs and in evaluating injury. Because natural enemies have the pote...

Aphidius transcaspicus Telenga, a mealy plum aphid (Hyalopterus pruni Geoffroy) parasitoid from the Mediterranean, was recently introduced into Hawaii for control of invasive aphids. Under laboratory conditions the parasitoid successfully attacked several important aphid pests in Hawaii, including the melon aphid Aphis gossypii Glover, the banana aphid Pentalonia nigronervosa (Coquerel), the gr...

In the north central United States, populations of the exotic soybean aphid, Aphis glycinesMatsumura (Hemiptera: Aphididae), are highly variable across space, complicating effective aphid management. In this study we examined relationships of plant nutrients, landscape structure, andnatural enemieswith soybeanaphid abundance across Iowa,Michigan,Minnesota, andWisconsin, representing the range o...