Parasitism rate of Plutella xylostella (Lepidoptera: Plutellidae) larvae in greenhouse by Tetrastichus howardi (Hymenoptera: Eulophidae) females at different densities.

Parasitoids control insect pests, but their number per host affects their efficiency. The objective of this work was to evaluate the best density of Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) individuals parasitizing fourth instar Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae) larvae in greenhouse conditions. These larvae were exposed to parasitism by T. howardi females with 1:1, 3:1, 6:1, 9:1, 12:1, 15:1 and 18:1 parasitoid/host ratios with 10 replications during 96 hours. After this period the larvae were kept on host plants (Brassica oleracea) until pupa formation. Tetrastichus howardi parasitized and reproduced in P. xylostella larvae at all its densities tested, but with higher values, 84% and 10 ± 2.4 individuals, respectively, with 9:1 parasitoids/host. Nine T. howardi females per P. xylostella larvae are the adequate number to manage this insect pest.

Skeletogenesis of the pectoral girdle and forelimbs in embryos of Caiman yacare (Daudin, 1802) (Crocodylia, Alligatoridae)

Embryos of Caiman yacare were collected and subjected to the bone clearing and staining protocol in orderto analyze the ontogenetic patterns of ossification of the pectoral girdle and forelimb skeleton. The osseousstructure of the girdle and forelimbs of C. yacare begins to ossify starting at 30 days of incubation, withthe presence of dye retention in the scapula, coracoids, humerus, radius and ulna bones. During embryonicdevelopment, the autopodio of C. yacare has four bones in the carpus, the radial, ulnar, pisiform and carpaldistal 4+5 bone. Their ossification begins at 39 days of incubation with the radial, followed by the ulnar, and at54 days, the pisiform and the distal carpal 4 + 5. Each mesopodio has 5 metacarpi and are present 15 phalanges,two in digits I and V, three in digits II and IV, and four in digit III (phalangeal formula 2:3:4:3:2). Ossificationof the metacarpi starts at 27 days of incubation, following the sequence MCII=MCIII=MCIV>MCI>MCV.The first phalanges begin the process of ossification on day 36, continuing up to the last day of incubation.The sequence of ossification of the proximal phalanges is PPI=PPII=PPIII>PPIV=PPV, that of the medialphalanges is MPII>MPpIII>MPdIII>MPIV, and that of the distal phalanges is DPI>DPII>DPIII>DPV>DPIV.The ontogenetic pattern of the bones of the forepaw of C. yacare generally differs from that of other reptiles,although there are some similarities.

Ocular manifestations in fetal alcohol syndrome.

PURPOSE: To report the prevalence of ocular abnormalities in a group of Portuguese children with a complete fetal alcohol syndrome (FAS). METHODS: Complete ophthalmologic examination in a sample of consecutive children with FAS. Ocular fundus photography was carried out on the cooperative FAS children and on 25 reference children. Ocular fundus anomalies were recorded by the observation of ocular fundus photography. The ratio between the distance of the center of the disc to the fovea and optic disc diameter (DM/DD) was determined. Small optic disc was defined as a DM/DD ratio above mean control group +1 SD. RESULTS: The authors studied 32 children with FAS (mean age: 9 +/- 5 years; 72% boys). The mean corrected visual acuity (VA) was 0.8 +/- 0.2. Refraction ranged from -23.00 to +6.50 spherical equivalent. Ocular findings included short horizontal palpebral fissure (81% of children), strabismus (28% of children), epicanthus (27% of eyes), blepharoptosis (16% of eyes), telecanthus (13% of children), nystagmus (1 child), and cataract (1 eye). Ocular fundus photography analysis showed retinal vessel tortuosity in 30% of the eyes and optic disc hypoplasia in 25%. The mean DM/DD for the control and FAS groups was 2.72 +/- 0.20 and 2.89 +/- 0.25 (p=0.001). Forty percent of the eyes of FAS children had small optic discs. CONCLUSIONS: The most common ocular findings were anomalies of retinal fundus and minor changes in the outer region of the eyes. The authors noted better VA and less severity of disease than others, which might be due to a different selection of patients, different pattern of alcohol consumption, or genetic differences.

Food production and population growth.

PIP: Governments have frequently ignored the issue of population consumption exceeding the rates of renewal of natural resources. At the UN Conference on the Environment and Development in Rio de Janeiro, the issue of population growth was ignored in the agenda and action plan. In 1974, the UN World Population Conference suggested population stability would be possible if standards of living were raised. Industrialized nations spent half a century of active interference with the stability of global populations and failed to slow growth. 27 countries, mainly in tropical and subtropical zones, have an average cereal yield of under 1 ton per hectare, when improved seed and basic minimum fertilizer could yield 2 tons per hectare. Efforts to increase yields by the Consultative Group for International Agricultural research in 13 international centers resulted in global annual increases of about 50 million tons of grain (wheat and rice). Rainfed agriculture did not benefit as much because of climatic conditions. Where varieties of triticale, sorghum, millet, groundnuts, chick peas, cowpeas, beans, and cassava have helped increase food production, population growth has outstripped the gains. Agricultural fertilizers have been unfairly blamed for soil nutrient losses. Because of the age structure of population, the expected population growth can only be addressed through development of higher yields, new strains resistant to disease, and fertilizers. Slow release phosphates for tropical soils are needed. Shortages of domestic fuel divert much needed farmyard manure and composted crop residues. About 400 million tons of dung are thus wasted annually; food grain harvests are thus reduced by 14 million tons. About 50% of the 1133 million poorest people will live in Asia and another 25% will live in Sub-Saharan Africa, living on a total degraded area of 1219 million hectares. Imbalance between food supply and population need to be addressed on an effective international scale.^ieng