Suppression of leopard moth (Lepidoptera: Cossidae) populations in olive trees in Egypt through mating disruption.

The leopard moth, Zeuzera pyrina (L.) (Lepidoptera: Cossidae), is a damaging pest for many fruit trees (e.g., apple [Malus spp.], pear [Pyrus spp.] peach [Prunus spp.], and olive [Olea]). Recently, it caused serious yield losses in newly established olive orchards in Egypt, including the death of young trees. Chemical and biological control have shown limited efficiency against this pest. Field tests were conducted in 2005 and 2006 to evaluate mating disruption (MD) for the control of the leopard moth, on heavily infested, densely planted olive plots (336 trees per ha). The binary blend of the pheromone components (E,Z)-2,13-octadecenyl acetate and (E,Z)-3,13-octadecenyl acetate (95:5) was dispensed from polyethylene vials. Efficacy was measured considering reduction of catches in pheromone traps, reduction of active galleries of leopard moth per tree and fruit yield in the pheromone-treated plots (MD) compared with control plots (CO). Male captures in MD plots were reduced by 89.3% in 2005 and 82.9% in 2006, during a trapping period of 14 and 13 wk, respectively. Application of MD over two consecutive years progressively reduced the number of active galleries per tree in the third year where no sex pheromone was applied. In all years, larval galleries outnumbered moth captures. Fruit yield from trees where sex pheromone had been applied in 2005 and 2006 increased significantly in 2006 (98.8 +/- 2.9 kg per tree) and 2007 (23 +/- 1.3 kg per tree) compared with control ones (61.0 +/- 3.9 and 10.0 +/- 0.6 kg per tree, respectively). Mating disruption shows promising for suppressing leopard moth infestation in olives.

The calyx fluid of Microplitis rufiventris parasitoid and growth of its host Spodoptera littoralis larvae.

The morphology of the female reproductive system of pupal and adult stages of Microplitis rufiventris and the ultrastructure of the ovaries are described and illustrated. Two morphologically distinct types of particles of nuclear origin, i.e., polydnavirus (PDV) and a virus-like filamentous particle (VLFP) were detected in the ovarian calyx fluid of the female wasp. It is likely that these particles are injected into the host during oviposition. PDV initiated replication in the calyx of mid-aged pupae and in pharate adults and were present throughout adult life. VLFP were only seen in the calyx fluid of newly emerged adults, and therefore observed after the PDV. Feulgen and methyl-green pyronin staining revealed the presence of DNA in both types of particles. The effects of injection of Spodoptera littoralis larvae with a combination of parasitoid viruses and venom of M. rufiventris females (CxFV) were investigated and the results were compared with two control groups, i.e., larvae injected with Pringle's saline (PS) and naturally parasitized larvae. CxFV-larvae showed significant declines (P<0.05) in food consumption, weight of ejected faeces and weight gain when compared with PS-larvae. However, naturally parasitized larvae (parasitoid egg+CxFV+ovarian protein) displayed a high significance score (P<0.01) in comparison with those of PS-larvae. The approximate digestibility (AD) values of S. littoralis larvae were positively affected as early as day 2 post-treatment by either injection of CxFV or parasitization. However, a reduction in AD was observed in both PS- and CxFV-larvae on day 3-7 in comparison with naturally parasitized larvae. Other indices of food utilization were unchanged in CxFV-larvae when compared to saline treated or parasitized controls.

Carrion insects of the Egyptian western desert.

A general survey was made on the zoosaprophagous insects and their associates in a natural ecosystem in the Egyptian western desert (80 km west of Alexandria, 12 km from the Mediterranean Sea shore). Two types of traps were used, one for flying insects and the other for soil-burrowing insects. Two types of decaying media were used as baits: the common freshwater fish (Tilapia zilii Gerv.) and the desert snail (Eremina desertorum). More than 30 insect species were trapped. The following orders and families were represented: Diptera (Calliphoridae, Sarcophagidae, Muscidae); Coleoptera (Histeridae, Scarabaeidae, Dermestidae, Tenebrionidae); Hymenoptera (Chalcididae, Pteromalidae, Eulophidae, Formicidae). Monthly totals of numbers trapped in each of these groups are presented.

Estimation of crude oil grade using time-resolved fluorescence spectra.

Time-resolved fluorescence (TRF) spectra of six crude oils from the eastern province of Saudi Arabia were excited using a pulsed laser radiation at 250 nm and measured at specific time gates (TG) within the leading and trailing edges of the laser temporal pulse. The spectra showed the presence of a shoulder near 380 nm that systematically decreased in intensity from high-grade to low-grade crudes, and also from earlier to later TGs. The intensities of these shoulders are shown to be useful in estimating the grades of crude oils, particularly when the TRF spectra are measured at TGs within the leading edge of the laser temporal pulse. Contour diagrams depicting the shapes of the TRF spectra as function of TG (within the leading and trailing edges) are also presented to serve as true fingerprints of the crudes.

A possible mechanism for the physiological suppression of conspecific eggs and larvae following superparasitism by solitary endoparasitoids.

Competition for possession of a host by internal solitary parasitoids has been attributed to physical combat and physiological suppression, but the mechanisms that result in what has been referred to as physiological suppression is poorly understood. Some insights are provided by the studies reported here using the solitary endoparasitoid, Campoletis sonorensis (Cameron). Embryos of C. sonorensis less than ten hours old rarely hatch in various artificial media, while embryos twenty hours or older generally hatch. These results suggest that young embryos in which the embryonic membranes have not yet formed are only able to develop in a narrow range of environments represented by the nonparasited hemolymph. In contrast, embryos in which the embryonic membranes are formed are able to develop in a wide range of environments represented by parasitized hemolymph which has been shown by a number of studies to change. These ideas were given support by studies reported here, where young and older eggs were incubated singly or paired. We suggest the general changes in the hemolymph of a parasitized host become unfavorable for the development of newly oviposited eggs.

Effects of juvenile hormones and precocenes on the immune response of Spodoptera littoralis larvae to supernumerary larvae of the solitary parasitoid, Microplitis rufiventris Kok.

The study represents one of the first direct tests of juvenile hormones (JHs) on the cellular immune response of a lepidopteran insect, Spodoptera littoralis (Boisd.), superparasitized by a solitary parasitoid, Microplitis rufiventris Kok. JHII-treated S. littoralis larvae exhibited a significant reduction in encapsulation response to the supernumerary M. rufiventris larvae at different developmental ages (0-4, 10-14 and 24-26 h) of supernumerary M. rufiventris embryos within 48 or 144 h after parasitization than either JHI-treated or control hosts. The reduction in encapsulation response was significantly greater in hosts which received higher JHII dose (5 &mgr;g) than those treated with lower one (1 &mgr;g).The progression of the encapsulation, culminating in melanization in the capsules occurred more frequently in precocene-treated hosts than either JH-treatment or control ones. Application of the anti-juvenile hormones (PI or PII) caused stronger encapsulation reaction to the injured supernumerary parasitoid larvae than JHI or JHII. In PI-treatments, the reaction was rapid and dramatic by lower (25 &mgr;g) dose treatments than higher ones (70 &mgr;g).The capsules formed around the supernumerary larvae of M. rufiventris showed signs of melanization within 48 h in PI-treated hosts. Melanization was more pronounced in either PI- or PII-treated hosts prior emergence of successful parasitoid larvae. Generally, the injured supernumerary larvae were seen within melanin-rich capsules in PI- and PII-treated hosts. Melanization was not observed in most capsules of JHI- and JHII-treated hosts. Additional physiological effects were observed: (1) in some cases, application of JHI to parasitized S. littoralis larvae inhibited subsequent emergence of its wasp, M. rufiventris, and (2) teratocytes (cells of wasp origin) from PI or PII-treated hosts were smaller in size than those observed in the JH-treated or control hosts.Finally, the dramatic increase in encapsulation responses of precocene-treated S. littoralis larvae of the supernumerary of M. rufiventris and definitely opposite reactions in typical hosts but JHII-treated hosts suggested that the cellular defense reaction may be under inhibitory hormonal control.The results of the study have implications for medically important insects such as mosquitoes and their interactions with parasites, as well as having significance for biocontrol and mass rearing programs using parasitoids.

Efficacy of standard glucose-based and reduced-osmolarity maltodextrin-based oral rehydration solutions: effect of sugar malabsorption.

Previously we reported that standard oral rehydration salts (ORS) solution is not as effective as a reduced-osmolarity glucose-based ORS for the treatment of children with acute noncholera diarrhoea: with standard ORS the diarrhoea lasts longer, stool output is greater, serum sodium is higher, and there is more need for supplemental intravenous infusion. We studied a reduced-osmolarity maltodextrin (MD)-based ORS to determine whether it had similar benefits, and also the effect of sugar malabsorption on the efficacy of standard and MD-based ORS. A total of 90 boys aged 3-24 months with acute noncholera diarrhoea and moderate dehydration were randomly assigned to either standard ORS (glucose 20 g/l, osmolarity 311 mmol/l) or MD-ORS (MD 50 g/l, osmolarity 227 mmol/l). There were no differences in treatment results. Some 46% of subjects had a high total stool output (> 300 g/kg), which was unrelated to the type of ORS given. High stool output was significantly associated with a longer duration of diarrhoea (33 vs. 15 hours; P < 0.001), a persistently elevated serum sodium (149 vs. 144 mmol/l at 24 h; P < 0.02), the need for intravenous infusion (11/41 vs. 0/48; P < 0.002), and an increase in faecal reducing substances (10.8 vs. 3.4 g/l at 24 h; P < 0.001). We conclude that some children given standard ORS develop osmotic diarrhoea owing to the combined effect of transient sugar malabsorption and slight hypertonicity of the ORS. Earlier studies show that this adverse outcome can largely be avoided when extra water is given in reduced-osmolarity glucose-based ORS. Reduced osmolarity has no benefit, however, when glucose is replaced by maltodextrin, probably because the sugars released by hydrolysis of MD, when malabsorbed, raise the intraluminal osmolarity to equal or exceed that of standard ORS. Thus, reduced-osmolarity glucose-based ORS is superior to both standard ORS and reduced-osmolarity solutions based on maltodextrin and probably other complex carbohydrates. Studies are in progress to define the optimal formulation of reduced-osmolarity glucose-based ORS.

PIP: At the Diarrhoeal Disease Research and Rehydration Centre of Bab El-Sha'reya Hospital in Cairo, Egypt, clinical researchers randomly assigned 90 fully weaned boys aged 3-24 months with non-cholera diarrhea and signs of moderate dehydration to either the treatment group receiving the standard glucose-based oral rehydration solution (ORS) or the group receiving a reduced-osmolarity ORS with minimally hydrolyzed maltodextrins (MD) (50 g/l) in place of glucose (20 g/l). They wanted to determine whether the reduced-osmolarity, MD-based ORS yielded similar benefits as the glucose-based ORS and to examine the effect of sugar malabsorption on the efficacy of both solutions. The osmolarity of the MD-based ORS was 227 mmol/l compared to 311 mmol/l for the standard ORS. There were no significant differences in the clinical outcomes (duration of diarrhea, stool output, ORS intake, serum sodium level, and weight gain at discharge) for each treatment group. High stool output had a significant positive association with longer duration of diarrhea (33 vs. 15 hours for low stool output; p 0.01), a persistently elevated serum sodium concentration (149 vs. 144 mmol/l for low stool output; p 0.02), the need for intravenous infusion (11/41 vs. 0/48 for low stool output; p 0.002), and an increase in substances that reduce feces (10.8 vs. 3.4 g/l for low stool output; p 0.001). Based on these findings, the researchers hypothesized that, like the standard ORS, the reduced osmolarity ORS, in which glucose is replaced with MD, also caused sugar malabsorption. The sugar malabsorption, in turn, increased the effective intraluminal osmolarity to equal or exceed that of the standard ORS. Both sugar malabsorption and intraluminal hypertonicity were responsible for a net flow of water from extracellular fluid into the gut, an increased serum sodium concentration, increased thirst leading to greater intake of ORS, ORS treatment failure, an increase in stool output, and an increase in duration of diarrhea. In conclusion, reduced-osmolarity, glucose-based ORS is superior to the standard glucose-based ORS and reduced-osmolarity, MD-based ORS.

Controlled clinical trial on the efficacy of rice powder-based oral rehydration solution on the outcome of acute diarrhea in infants.

We report a controlled clinical trial of rice powder-based oral rehydration solution (ORS) versus glucose ORS on the outcome of acute diarrhea in infants. The rice ORS group (n = 30) received ORS containing 50 g rice powder instead of standard WHO solution (20 g glucose, n = 30). Formula-fed male infants were enrolled to enable calculation of milk intake and excretion of urine. Patient allocation to either group depended on the method of random permuted blocks. Both groups were comparable regarding age (4-18 months), duration of diarrhea, number of bowel movements or vomiting per 24 h, rectal temperature, dehydration score, and nutritional status. Results revealed that the rice ORS group had a shorter duration of diarrhea (28.4 +/- 5.1 vs 34.3 +/- 2.3 h) and greater mean weight gain in the first 24 h as percentage of recovery weight (5.7 +/- 0.5% vs 4.1 +/- 0.6%). Furthermore, the mean amount of ORS intake, mean stool output, and mean number of episodes of vomiting were lower in the rice-ORS group as compared with the glucose ORS group. All differences were statistically significant. Due to its observed superiority and low cost, the widespread use of rice ORS should be considered for treatment of acute diarrhea.