The nutritive value of mulberry leaves (Morus alba) as a feed supplement for sheep.

A study to determine the nutritive value of mulberry (Morus alba) leaves in sheep diets was conducted. Mulberry leaves contained (g kg(-1) on dry matter basis): 163 ash, 201 crude protein, 120 crude fibre, 37 ether extracts, 479 nitrogen-free extracts, 268 neutral detergent fibre, 148 acid detergent fibre, 41 acid detergent lignin, 121 cellulose and 107 hemicellulose, while the in vitro true digestibility of dry matter was 89.8%. The nitrogen (N) solubility, determined using: a) McDougall's buffer, b) 0.02 N sodium hydroxide (NaOH) and c) 0.15 N sodium chloride (NaCl) as solvents, ranged from 11.6 to 14.9% of total N. In addition, the soluble non-protein nitrogen contributed a substantial part of total N (26.1%), the total true protein was 14.4% and the protein fractions evaluated after classical protein fractionation, were: albumins 11.1, globulins 9.7, prolamins 44.1, glutelins 8.5 and insoluble (or structural) proteins 26.6% of total N. In a digestibility trial, where mulberry leaves partially replaced lucerne hay and concentrates in wether sheep diets, there were no significant differences in dry matter, crude protein or crude fibre digestibility of the total diet. It was concluded that mulberry leaves have an appreciable potential as a protein source in sheep feeding.

Solid-phase microextraction/gas-chromatographic/mass spectrometric analysis of p-dichlorobenzene and naphthalene in honey.

Protection of honeycombs from the Wax moth, Galleria mellonella, involves the use of physical, biological or chemical control methods. As chemical control may result in residues in the extracted honey, the presence of p-dichlorobenzene and naphthalene residues was investigated by solid-phase microextraction (SPME) coupled to gas-chromatographic/mass spectrometry (GC/MS). The method was linear between 5 and 200 microg kg(-1) honey for p-dichlorobenzene and 1 and 200 microg kg(-1) for naphthalene. Limits of detection were 1 and 0.1 microg kg(-1), respectively, for p-dichlorobenzene and naphthalene, while relative standard deviations were 2.6 and 7.9%, respectively. Application of the method to 90 unifloral Greek honeys revealed that, in 25.6% of the samples, the concentration of either one of the pesticides exceeded the maximum residue level (MRL). Maximum concentrations were 163.03 microg kg(-1) honey for p-dichlorobenzene and 193.74 microg kg(-1) honey for naphthalene. Naphthalene was found in traceable amounts in 78.9% of the samples, but only 5.6% of them contained concentrations above the MRL, which indicates the use of pre-contaminated honeycomb foundations or built combs. Nevertheless, because naphthalene is naturally present in some plant species growing in Greece, the contribution of nectar from such a floral source should not be overlooked.

Allozyme variability and phylogenetic relationships in honey bee (Hymenoptera: Apidae: Apis mellifera) populations from Greece and Cyprus.

Ten gene enzymic systems (alpha-GPDH, AO, MDH, ADH, LAP, SOD, ALP, ACPH, ME, and EST), corresponding to 12 genetic loci, were assayed from five Greek populations representing three subspecies of Apis mellifera, A. m. cecropia (Pthiotida, Kythira), A. m. macedonica (Macedonia), and the "Aegean race" of A. mellifera, which is supposed to be very similar to A. m. adami (Ikaria, Kasos), as well as a population from Cypus (A. m. cypria). ADH( *)-1, ADH( *)-2, and LAP( *) electrophoretic patterns discriminate the Cyprus population from the Greek populations. MDH( *)-1, EST( *)-3, SOD( *), ALP( *), and ME( *) loci were found to be polymorphic in almost all populations. The observed heterozygosity was found to range from 0.066 to 0.251. Allele frequencies of all loci were used to estimate Nei's genetic distance, which was found to range between 0.011 and 0.413 among the populations studied. UPGMA and neighbor-joining phylogenetic trees obtained by genetic distance matrix methods, as well as a Wagner tree based on the discrete character parsimony method, support the hypothesis that the most distant population is that from Cyprus. Our allozymic data support A. m. cypria as a distinct subspecies, but there was no allozymic support for the distinction of the other subspecies existing in Greece.

New method for pollen identification by FT-IR spectroscopy.

A new methodology for identification of pollen was developed based on FT-IR spectroscopy. Pollen samples of twenty different plant species were collected and the diffuse reflectance infrared Fourier transform (DRIFTS) and KBr pellet spectra were recorded. Libraries of spectra were created. Spectra of unknown plant origin pollen were recorded and compared with those of the corresponding pollen library and the match value was measured automatically using the appropriate software (OMINC ver. 3.1). From the same pollen samples, microscopic slides were prepared and the photographs of the pollen grains were used as a second comparison method. Using light microscopy, the pollen identification is usually limited to the family or generic name, while FT-IR spectroscopy can distinguish species belonging to the same genus. This method is simple and fast, and when the DRIFTS technique is used the sample is not destroyed.

Effects of applaud on the growth of silkworm (Lepidoptera: Bombycidae).

An experiment was carried out to evaluate the effect of the insecticide Applaud (buprofezin 25% WP) on the silkworm Bombyx mori (L.). This insecticide belongs to the class of insect growth regulators (IGR). The larvae were fed on leaves treated with 3 different concentrations (0.5, 1, 2 g/liter) of Applaud on the 1st d of each instar. Analysis of data with the Tukey-Kramer test at 1% significant level revealed that mortality and larval duration did not differ among the treatments. On the contrary, the larval weight, which was estimated just before mounting (procedure during which the mature larva climbing on a branch or other material to spin the cocoon), differed among the treatments. Also, cocoon weight, shell weight, and cocoon sericin and fibroin content were different among the treatments, except the shell cocoon ratio. Maximum weight was observed in the controls and minimum in the last instar treatments. Our data suggest that supplementation of Applaud through food to larvae does not affect their mortality rate. On the contrary, it affects larval growth and cocoon parameters.