Depending on the species, the individual scales of butterfly wings have a longitudinal gradient in structure and reflectance properties, as shown by scanning electron microscopy and microspectrophotometry. White scales of the male Small White, Pieris rapae crucivora, show a strong gradient in both the density in pigment granules and the reflectance. After pigment extraction by aqueous ammonia, ...

In the present study, aqueous extract of eight plants, namely Azadirachta indica A. Juss, Melia azedarach Linn., Lantana camara L. Moldenke., Cannabis sativa Linn., Nerium indicum Mill., Eucalyptus sp., Ricinus communis Linn. and Solanum nigrum Linn. were tested for antifeedant and toxic effects against Pieris brassicae (Linn.). The ethanol extract of four potential plants were further tested f...

Genetic parameters for various backfat measurements (BF1FT, Backfat shoulder measured at the field test; BF2FT, Backfat mid-back measured at the field test; BF3FT, Backfat loin measured at the field test; BF1ST, Backfat shoulder measured at the station test; BF2ST, Backfat mid-back measured at the station test; BF3ST, Backfat loin measured at the station test) were estimated. The analysis was b...

To investigate endocrine mechanisms associated with the occasional occurrence of fertile oestrus during lactation in the high prolific Chinese Meishan (MS) breed, the incidence of oestrus and changes in plasma luteinizing hormone (LH) levels before and after oestradiol benzoate (OB, 15 micrograms/kg body weight) administration on day 22 was compared in 4 MS and 6 Large White (LW) sows. All sows...

The effect of breed [Creole (CR) vs. Large White (LW)] on performance and physiological responses during acclimation to high ambient temperature was studied in 2 experiments involving 24 (12/breed) growing pigs each. Pigs were exposed to 24 degrees C for 10 d (d -10 to -1) and thereafter to a constant temperature of 31 degrees C for 16 d (d 1 to d 16) in Exp. 1 and for 20 d (d 1 to d 20) in Exp...

Wounding in multicellular eukaryotes results in marked changes in gene expression that contribute to tissue defense and repair. Using a cDNA microarray technique, we analyzed the timing, dynamics, and regulation of the expression of 150 genes in mechanically wounded leaves of Arabidopsis. Temporal accumulation of a group of transcripts was correlated with the appearance of oxylipin signals of t...

Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunn...

Induced plant defence in response to phytophagous insects is a well described phenomenon. However, so far little is known about the effect of induced plant responses on subsequently colonizing herbivores in the field. Broccoli plants were induced in the belowground compartment using (i) infestation by the root-herbivore Delia radicum, (ii) root application of jasmonic acid (JA) or (iii) root ap...

The turnip sawfly, Athalia rosae Linnaeus, is a pest on cruciferous crops. Larvae sequester secondary plant compounds, namely glucosinolates, in their haemolymph. When attacked, their integument is easily disrupted and a droplet of haemolymph is exuded ('easy bleeding'). This has been shown to be an effective, chemical-based, defence against invertebrate predators. The efficiency of this propos...

Plants activate direct and indirect defences in response to insect egg deposition. However, whether eggs can manipulate plant defence is unknown. In Arabidopsis thaliana, oviposition by the butterfly Pieris brassicae triggers cellular and molecular changes that are similar to the changes caused by biotrophic pathogens. In the present study, we found that the plant defence signal salicylic acid ...