Al-Esawy,M.T مشتاق طالب كريم العيساوي

This study aimed to evaluate the nutritional behavior and some immunological criteria (encapsulation index and phenoloxidase – PO activity, the key enzyme for melanization) as well as to study the effect of protein to fat (P : F) diets on hypopharyngeal gland (HPG) protein content. Bees were restricted to consuming specific P : F diets varying in fat ratio under laboratory conditions. These diets included 25 : 1, 10 : 1, 5 : 1 (low-fat diet, LFD); 1 : 1 (equal-fat diet); 1 : 5, 1 : 10 (high-fat diet, HFD), and 1 : 0 (zero-fat diet) as a control. Bees preferred low-fat diets over high-fat diets, where it was 11.27 ± 0.68 μl · day–1 bee in 10 : 1 P : F, while it was 4.99 ± 0.67 μl · day–1 bee in 1 : 10 P : F. However, sucrose consumption was higher in high-fat diets where it was 25.83 ± 1.69 μl · day–1 bee in 10 : 1 P : F, while it was 30.66 ± 0.9 μl · day–1 bee in 1 : 10 P : F. The encapsulation index and phenoloxidase activity of bees were positively linked with the fat level they consumed during all 10 days. The maximum percentage of encapsulation index was 74.6 ± 7.2% in bees fed a high-fat diet, whereas the minimum percentage was 16.5 ± 3.6% in bees which consumed a lowfat diet. Similarly, phenoloxidase activity increased in the haemolymph with increasing fat consumed by bees (0.001 ± 0.0001 and 0.005 ± 0.0003 mM · min–1 · mg–1 at 25 : 1 and 1 : 10 P : F, respectively). The protein content of hypopharyngeal glands in bees which consumed HFD was double that of LFD. Overall results suggest a connection between a fat diet and bee health, indicating that colony losses in some cases can be reduced by providing a certain level of fat supplemental feeding along with sucrose and protein nutrition.

The sense of taste permits the recognition of valuable nutrients and the avoidance of potential toxins. Previously, we found that bumblebees have a specialized mechanism for sensing sugars whereby two gustatory receptor neurons (GRNs) within the galeal sensilla of the bees’ mouthparts exhibit bursts of spikes. Here, we show that the temporal firing patterns of these GRNs separate sugars into four distinct groups that correlate with sugar nutritional value and palatability. We also identified a third GRN that responded to stimulation with relatively high concentrations of fructose, sucrose, and maltose. Sugars that were nonmetabolizable or toxic suppressed the responses of bursting GRNs to sucrose. These abilities to encode information about sugar value are a refinement to the bumblebee’s sense of sweet taste that could be an adaptation that enables precise calculations of the nature and nutritional value of floral 

In this study, the insecticidal relative toxicity of carbon nanotubes (CNTs) synthesized from seeds of Iraqi date palm Phoenix dactylifera L. using a chemical vapor deposition (CVD) method was investigated. These Nanoparticles were evaluated against adult and larvae of the Khapra beetle, Trogoderma granarium . The results indicated that CNTs (25, 50 and 100 ppm) caused mortality of the Khapra beetle under laboratory conditions. Additionally, the germination percentage of wheat, Triticum aestivum L. grains, has not been affected by the carbon nanotube treatments at 25-100 ppm. This study demonstrates the potential of CNTs as a technology for population control of T. granarium because of their toxicity to larvae and adults

Abstract Deformed wing virus (DWV) is one of the most widespread viral infections of European honey bee Apis mellifera L. worldwide. So far, this is the first study which tested the effect of different ratios of synthetic protein to fat (P : F) diets on the health of broodless nurseaged honey bees in the laboratory. The aim of the current study was to determine the load of DWV in the whole body of A. mellifera that were fed different ratios of P : F diets (25 : 1, 10 : 1, 5 : 1, 1 : 1, 1 : 5, 1 : 10, 1 : 12.5 and 1 : 0 as a control). The methods involved feeding bees the tested diets for 10 days and then measuring the virus titre using qPCR technique. The results showed that DWV concentration decreased as the fat content of diets consumed increased. The copy number of viral genomes declined from 7.5 × 105 in the zero-fat diet (1 : 0) to 1.6 × 102 virus genomes in 1 : 12.5 (P : F). We can conclude that there is a positive relationship between fat diets and bee immunity and overall results suggest a connection between fat diet and bee health, indicating that colony losses can be reduced by providing a certain protein and fat supplemental feeding.

Essential macronutrients are critical to the fitness and survival of animals. Many studies have shown that animals regulate the amount of protein and carbohydrate they eat for optimal performance. Regulation of dietary fat is important but less often studied. Honeybees collect and consume floral pollen to obtain protein and fat but how they achieve the optimal balance of these two macronutrients is presently unknown. Here, using chemically defined diets composed of essential amino acids and lipids (lecithin), we show that adult worker honeybees actively regulate their intake of lipids around optimal values relative to the amount of protein in their diet. We found that broodless, nurse-age worker honeybees consume foods to achieve a ratio between 1:2 and 1:3 for essential amino acids to lipid or ∼1.25:1 protein to fat. Bees fed diets relatively high in fat gained abdominal fat and had enlarged hypopharyngeal glands. In most cases, eating diets high in fat did not result in increased mortality. Importantly, we also discovered that the total quantity of food the bees ate increased when they were given a choice of two diets relatively high in fat, implying that dietary fat influences bee nutritional state in a way that, in turn, influences behaviour. We speculate that dietary fat plays a critical role in maintaining workers in the nurse-like behavioural state independently of the influence of queen pheromone.

BACKGROUND Potassium ion channels play a critical role in the generation of electrical signals and thus provide potential targets for control of insect pests by RNA interference. RESULTS Genes encoding the small conductance calcium‐activated potassium channel (SK) and the voltage‐gated potassium channel (SH) were knocked down in Tribolium castaneum by injection and oral delivery of dsRNA (dsTcSK and dsTcSH, respectively). Irrespective of the delivery mechanism a dose‐dependent effect was observed for knockdown (KD) of gene expression and insect mortality for both genes. Larvae fed a 400 ng dsRNA mg–1 diet showed significant gene (P < 0.05) knockdown (98% and 83%) for SK and SH, respectively, with corresponding mortalities of 100% and 98% after 7 days. When injected (248.4 ng larva–1), gene KD was 99% and 98% for SK and SH, causing 100% and 73.4% mortality …