Electroantennogram and behavioral responses of Cotesia plutellae to plant volatiles.

Plant volatiles have been demonstrated to play an important role in regulating the behavior of Cotesia plutellae, a major larval parasitoid of the diamondback moth (DBM), Plutella xylostella, but little is currently known about the function of each volatile and their mixtures. We selected 13 volatiles of the DBM host plant, a cruciferous vegetable, to study the electroantennogram (EAG) and behavioral responses of C. plutellae. EAG responses to each of the compounds generally increased with concentration. Strong EAG responses were to 100 µL/mL of trans-2-hexenal, benzaldehyde, nonanal and cis-3-hexenol, and 10 µL/mL of trans-2-hexenal and benzaldehyde with the strongest response provoked by trans-2-hexenal at 100 µL/mL. In the Y-tube olfactometer, C. plutellae, was significantly attracted by 1 µL/mL of trans-2-hexenal and benzaldehyde. ß-caryophyllene, cis-3-hexenol or trans-2-hexenal significantly attracted C. plutellae at 10 µL/mL, while nonanal, benzyl alcohol, cis-3-hexenol or benzyl cyanide at 100 µL/mL significantly attracted C. plutellae. Trans-2-hexenal significantly repelled C. plutellae at 100 µL/mL. EAG of C. plutellae showed strong responses to all mixtures made of five various compounds with mixtures 3 (trans-2-hexenal, benzaldehyde, nonanal, cis-3-hexenol, benzyl cyanide, farnesene, eucalyptol) and 4 (trans-2-hexenal, benzaldehyde, benzyl alcohol, (R)-(+)-limonene, ß-ionone, farnesene, eucalyptol) significantly attracting C. plutellae. These findings demonstrate that the behavior of C. plutellae can be affected either by individual compounds or mixtures of plant volatiles, suggesting a potential of using plant volatiles to improve the efficiency of this parasitoid for biocontrol of P. xylostella.

A heterozygous moth genome provides insights into herbivory and detoxification.

How an insect evolves to become a successful herbivore is of profound biological and practical importance. Herbivores are often adapted to feed on a specific group of evolutionarily and biochemically related host plants, but the genetic and molecular bases for adaptation to plant defense compounds remain poorly understood. We report the first whole-genome sequence of a basal lepidopteran species, Plutella xylostella, which contains 18,071 protein-coding and 1,412 unique genes with an expansion of gene families associated with perception and the detoxification of plant defense compounds. A recent expansion of retrotransposons near detoxification-related genes and a wider system used in the metabolism of plant defense compounds are shown to also be involved in the development of insecticide resistance. This work shows the genetic and molecular bases for the evolutionary success of this worldwide herbivore and offers wider insights into insect adaptation to plant feeding, as well as opening avenues for more sustainable pest management.

The Incidence, Prevalence, and Mortality of Stroke in France, Germany, Italy, Spain, the UK, and the US: A Literature Review.

Background. Although the burden of stroke in terms of mortality and disability has been well documented in previous years, data after 2000 are limited. Therefore, the aim of this paper was to identify the epidemiology of stroke in the US and EU5 nations from data published in 2000 and later. Methods. Data from literature databases and online sources were collated to identify information relating to the incidence, prevalence, and mortality of stroke from the year 2000 onwards. Results and Conclusions. Twenty-three data sources were identified. The incidence of and mortality due to stroke both increase with age and are greater in males compared to females. Stroke is a common problem and likely to worsen in the US and EU5 as their populations age. However, pre-2000 trends of decreasing stroke mortality over time have continued after 2000, reflecting a consistent improvement in the treatment and care of patients with stroke.