A recently discovered biotype of the greenbug, Schizaphis graminum (Rondani), biotype E (GBE), was found to grow and reproduce at approximately twice the rate of biotype C (GBC) on a GBC-resistant variety of sorghum, IS 809. The probing behavior of both biotypes was electronically monitored on IS 809. Aphids of GBE established committed phloem ingestion (CPI) (i.e., ingestion from the phloem la...

The nutritive value of two cereal aphid species, Schizaphis graminum and Rhopalosiphum padi, for Hippodamia convergens development was compared as pureand mixed-species diets and as suboptimum and ad libitum quantities. Comparisons were based on the following daily aphid quantities and combinations: 4 mg R. padi, 4 mg S. graminum, 3:1 mg mixture of R. padi and S. graminum, 2:2 mg mixture of R. ...

A 1.0 kb region of the mitochondrial cytochrome oxidase subunit I gene from the greenbug aphid, Schizaphis graminum (Rondani), was sequenced for 24 field collected clones from non-cultivated and cultivated hosts. Maximum likelihood, maximum parsimony and neighbour-joining phylogenies were estimated for these clones, plus 12 previously sequenced clones. All three tests produced trees with identi...

Functional responses by Lysiphlebus testaceipes (Cresson), a common parasitoid of small grain aphids, on greenbug, Schizaphis graminum (Rondani), were measured at seven temperatures (14, 12, 10, 8, 6, 4, and 2 degrees C) during a 24-h period (12-h light: 12-h dark). Oviposition by L. testaceipes ceased at temperatures <4 degrees C. At all experimental temperatures, a type I, rather than a type ...

Interactions of the parasitoid Lysiphlebus testaceipes (Cresson) and the greenbug, Schizaphis graminum (Rondani), on greenbug-resistant 'Cargill 607E' (antibiosis), 'Cargill 797' (primarily tolerance), and -susceptible 'Golden Harvest 510B' sorghum, Sorghum bicolor (L.) Moench, were tested using three levels of biotype I greenbug infestation. The parasitoid infestation rate was 0.5 female and 1...

The increasing use of nanofertilizers in modern agriculture and their impact on crop yield pest management require further research. In this study, the effects nano-Fe, -Zn, -Cu (which are synthesized based nanochelating technology), urea (N) fertilizers antioxidant activities wheat plants (cv. Chamran), green aphid Schizaphis graminum (Rondani) investigated. authors observed highest levels phe...

Interactions among greenbug, Schizaphis graminum (Rondani), Russian wheat aphid, Diuraphis noxia (Mordvilko), and bird cherry-oat aphid Rhopalosiphum padi (L.) were examined on wheat plants (Triticum aestivum L., cultivar TAM 107). Nymphs were released on the plants as conspecific and heterospecific pairs of either first or fourth instars and evaluated for survival, developmental time, fecundit...

Chromosomal regions of sorghum, Sorghum bicolor (L.) Moench, conferring resistance to greenbug, Schizaphis graminum (Rondani), biotypes C, E, I, and K from four resistance sources were evaluated by restriction fragment-length polymorphism (RFLP) analysis. At least nine loci, dispersed on eight linkage groups, were implicated in affecting sorghum resistance to greenbug. The nine loci were named ...

The aim of this work was to analyze the clonal diversity variation in Schizaphis graminum during a complete phenological cycle of black oats (Avena strigosa). RAPD markers were used for detection of DNA polymorphisms of each clonal lineage, derived from a single clone collected weekly during a period of four months, in a crop field of black oats, Londrina, Paraná, Brazil. The monthly genotypic ...