Abstract. The Heliothinae are a cosmopolitan subfamily of about 365 species that include some of the world's most injurious crop pests. This study re-assesses evolutionary relationships within heliothines, providing an improved phylogeny and classification to support ongoing intensive research on heliothine genomics, systematics, and biology. Our phylogeny estimate is based on two nuclear gene regions, namely elongation factor-1a (EF-1a; 1240 bp) and dopa decarboxylase (DDC; 687 bp), and on the barcoding region of mitochondrial cytochrome oxidase I (COI; 708 bp), providing a total of 2635 bp. These were sequenced for 71 heliothines, representing all major genera and nearly all recognized subgenera and species groups, and for 16 outgroups representing all major lineages of trifine Noctuidae. Analysis of the combined data by maximum likelihood, unweighted parsimony and Bayesian methods gave nearly identical topologies, and the individual gene trees showed only one case of potentially strong conflict. Relationships among genera and subgenera are resolved with strong bootstrap support. The earliest-diverging lineages (c. 200 species in total) consist almost entirely of host specialists, reflecting the inferred ancestral heliothine host range under parsimony. The remaining species form a clade -the Heliothis group -that includes most of the polyphages (30% of heliothines) and all of the major pests. Many other species in the Heliothis group, however, are host specialists. Our results extend previous efforts to subdivide this large clade, and show the most notorious pest groups, the corn earworm complex (Helicoverpa) and the tobacco budworm (Heliothis virescens) group, to be closely related, joining with a small oligophagous genus in what we term the major-pest lineage. Thus, genomic/ experimental results from one model pest may extrapolate well to other pest species. The frequency of evolutionary expansion and contraction in host range appears to increase dramatically at the base of the Heliothis group, in contrast to the case for earlier-diverging lineages. We ascribe this difference provisionally to differential evolutionary constraints arising from contrasting life-history syndromes. Host-specific behaviour and crypsis, coupled with low fecundity and vagility, may discourage host-range expansion in earlier-diverging lineages. By Systematic EntemologySystematic Entomology contrast, in the Heliothis group, the absence of host-specific traits, coupled with high vagility and fecundity, may more readily permit expansion or contraction of the host range in response to varying ecological pressures such as host species abundance or differential competition and predation.

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BackgroundMedical students are required to retain vast amounts of medical knowledge on the path to becoming physicians. To address this challenge, multimedia Web-based learning resources have been developed to supplement traditional text-based materials. The Picmonic® Learning System (PLS; Picmonic, Phoenix, AZ, USA) is a novel multimedia Web-based learning platform that delivers audiovisual mnemonics designed to improve memory retention of medical sciences.MethodsA single-center, randomized, subject-blinded, controlled study was conducted to compare the PLS with traditional text-based material for retention of medical science topics. Subjects were randomly assigned to use two different types of study materials covering several diseases. Subjects randomly assigned to the PLS group were given audiovisual mnemonics along with text-based materials, whereas subjects in the control group were given the same text-based materials with key terms highlighted. The primary endpoints were the differences in performance on immediate, 1 week, and 1 month delayed free-recall and paired-matching tests. The secondary endpoints were the difference in performance on a 1 week delayed multiple-choice test and self-reported satisfaction with the study materials. Differences were calculated using unpaired two-tailed t-tests.ResultsPLS group subjects demonstrated improvements of 65%, 161%, and 208% compared with control group subjects on free-recall tests conducted immediately, 1 week, and 1 month after study of materials, respectively. The results of performance on paired-matching tests showed an improvement of up to 331% for PLS group subjects. PLS group subjects also performed 55% greater than control group subjects on a 1 week delayed multiple choice test requiring higher-order thinking. The differences in test performance between the PLS group subjects and the control group subjects were statistically significant (P<0.001), and the PLS group subjects reported higher overall satisfaction with the material.ConclusionThe data of this pilot site demonstrate marked improvements in the retention of disease topics when using the PLS compared with traditional text-based materials. The use of the PLS in medical education is supported.