Dissection of Complex, Fitness-Related Traits in Multiple Mapping Populations Offers Insight into the Genetic Control of Stress Resistance.

We leverage two complementary mapping panels to genetically dissect starvation resistance-an important fitness trait. Using >1600 genotypes from the multiparental Synthetic Population Resource (DSPR), we map numerous starvation stress QTL that collectively explain a substantial fraction of trait heritability. Mapped QTL effects allowed us to estimate DSPR founder phenotypes, predictions that were correlated with the actual phenotypes of these lines.

Mortality of Sugarcane Aphid, Melanaphis sacchari (Zehntner, Hemiptera: Aphididae), at Low Temperatures.

We conditioned colonies of Melanaphis sacchari (Zehntner, Hemiptera: Aphididae) to three different temperature regimes over a period of 2 mo: 30°C, 25°C, and a cycle of 18/8°C (L:D), all under a diurnal photoperiod of 12:12 (L:D). Plants of susceptible sorghum, 85Y40, were grown to the five-leaf stage in 4-liter pots, 2 per pot, and then infested with mixtures of second-fourth instar M. sacchari nymphs, either 50 (18/8°C treatment) or 100 (25 and 30°C treatments) aphids per plant.

Toxicity of three aphicides to the generalist predators Chrysoperla carnea (Neuroptera: Chrysopidae) and Orius insidiosus (Hemiptera: Anthocoridae).

Recent widespread infestations of the invasive sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), in sorghum fields in the southern USA have created demand for insecticides that will provide effective control of sugarcane aphid, while conserving those beneficial species that contribute to biological control of the pest. We tested the susceptibility of both adult and immature stages of two aphid predators, the green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and the insidious flower bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), to three aphicides, flonicamid, sulfoxaflor and flupyradifurone. Flonicamid was innocuous to both species regardless of life stage or route of exposure.

Feeding by Melanaphis sacchari (Hemiptera: Aphididae) Facilitates Use of Sorghum by Rhopalosiphum padi (Hemiptera: Aphididae), but Reciprocal Effects Are Negative.

In the process of feeding, aphids modify the physiology of their host plants in species-specific ways, and plant responses to these aggressions are often genotype- or cultivar-specific. Thus, different aphid species sharing a host can influence each other's fitness via plant-mediated interactions, usually with negative and asymmetric impacts. Here, we show that feeding by the sugarcane aphid, Melanaphis sacchari Zehntner, can improve the suitability of sorghum as a host plant for the bird cherry-oat aphid, Rhopalosiphum padi L.

Relative Toxicity of Two Aphicides to Hippodamia convergens (Coleoptera: Coccinellidae): Implications for Integrated Management of Sugarcane Aphid, Melanaphis sacchari (Hemiptera: Aphididae).

Flupyradifurone and sulfoxaflor present novel insecticide chemistries with particular efficacy against aphids, and the recent emergence of sugarcane aphid, Melanaphis sacchari (Zehntner), as a pest of sorghum in the United States has resulted in their widespread use. We examined their toxicity to Hippodamia convergens Guerin-Meneville, an important aphid biocontrol agent. We exposed beetles to topical applications of the field rate (FR) of these insecticides, fed them contaminated food (eggs of Ephestia kuehniella Zeller), and gave first-instar larvae 24-h exposures to leaf residues.

Extending the "Ecology of Fear" Beyond Prey: Reciprocal Nonconsumptive Effects Among Competing Aphid Predators.

Nonconsumptive effects of predators on prey are well known, but similar effects among competing predators are not. Aphidophagous insect larvae are notorious for cannibalism and intraguild predation, as they compete for aggregated but ephemeral prey. We tested for indirect effects of competitors on the development of Coleomegilla maculata DeGeer and Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae), and a green lacewing, Chrysoperla carnea Stephens (Neuroptera: Chrysopidae), with all larvae reared on eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae).

Indigenous Aphid Predators Show High Levels of Preadaptation to a Novel Prey, Melanaphis sacchari (Hemiptera: Aphididae).

The performance of four aphid predators, Hippodamia convergens Guerin-Meneville, Coleomegilla maculata DeGeer, Chrysoperla carnea Stephens and Orius insidiosus Say was compared on three prey species: Schizaphis graminum Rondani, Melanaphis sacchari (Zehntner), and Ephestia kuehniella Zeller eggs. Species predatory in both life stages (all except Ch. carnea) were reared on E.

Multiple Quantitative Trait Loci Influence the Shape of a Male-Specific Genital Structure in Drosophila melanogaster.

The observation that male genitalia diverge more rapidly than other morphological traits during evolution is taxonomically widespread and likely due to some form of sexual selection. One way to elucidate the evolutionary forces acting on these traits is to detail the genetic architecture of variation both within and between species, a program of research that is considerably more tractable in a model system. Drosophila melanogaster and its sibling species, D.