Chemical Usurpation of a Nest by Paper Wasp Parasites

The paper wasp Polistes atrimandibularis is an obligatory social parasite of another Polistes species, P. biglumis bimaculatus. To control the host nest, the parasite sequentially changes the composition of its chemical signature, the cuticular hydrocarbons, during the colonial cycle. Gas chromatography-mass spectrometry of the cuticular hydrocarbons at every stage of the cycle showed that the parasite can switch on and off an entire chemical family, namely, the unsaturated hydrocarbons. In this way the parasite can match the host signature at a critical moment of the colonial cycle.     

Isozyme variation in Passiflora subgenera Tacsonia and Manicata. Relationships between cultivated and wild species

Isozyme variation was studied in 87 plants from 32 cultivated and wild accessions of banana passion fruit (P. tripartita var. mollissima, P. tripartita var. tripartita, P. tarminiana, and P. mixta), rosy passion fruit (P. cumbalensis), tin-tin (P. pinnatistipula), gulián (P. ampullacea), P. antioquensis, P. bracteosa, and P. manicata, from the Andes of Venezuela, Colombia, and Ecuador. Six polymorphic enzyme systems (IDH, PGDH, PGM, DIA, PRX, and ACP) revealed 31 zymotypes characterized by the presence or absence of 31 electromorphs. Cluster analysis separated clearly the accessions of P. tarminiana, P. tripartita, P. mixta, and P. cumbalensis from the less typical species of subgenus Tacsonia, which is consistent with morphological evidence. P. mixta showed the highest intraspecific variation and the closest affinity with P. tripartita. The accessions of these two species formed two clusters, one dominated by Colombian genotypes and the other dominated by Ecuadorian genotypes. One of the P. tripartita var. mollissima accessions clustered close to P. tarminiana accessions. The affinity between these three species is particularly interesting for conservation and use of banana passion fruit genetic resources. All the other species formed monospecific clusters.     

The progamic phase in Cichorium intybus L. Pollen tube growth in the style,incompatibility reaction and gametophytic competition

Summary Pollen germination and tube growth were studied following compatible, incompatible and pseudo-compatible pollinations in chicory. Pollen germination begins 3 minutes after compatible pollinations. The earliest pollen tubes reach the ovary 17 minutes later. Many of the later germinating pollen tubes are arrested and burst at the stigma papillae. In the transmitting tissue inhibitional effects due to negative interactions between pollen tubes are frequently observed. Complete self-incompatibility results in total inhibition of germination. In case of pseudo-self-compatibility, some pollen germinate but germination and stigma penetration are delayed and often result in pollen bursting. There is no self-incompatibility reaction in the transmitting tract but if the pollen tubes reaching this tissue are relatively numerous, negative interactions between them occur as after compatible pollinations. An hypothesis is presented which attributes the negative interactions between pollen tubes to the diffusion of a substance from the growing pollen tubes. This substance would also provoke pollen bursting on the stigma.     

Equine post anaesthetic myositis: muscular post ischaemic hyperaemia measured by laser Doppler flowmetry

Measurements of muscular microcirculation in horses anaesthetised with halothane were performed by laser Doppler flowmetry. Variations of microcirculation in the compressed and uncompressed triceps brachii were measured when horses were positioned in dorsal recumbency after a prolonged period in lateral recumbency. A significant post ischaemic hyperaemia was recorded in horses which developed a post anaesthetic myositis.     

Comparative X-Ray and Neutron Diffraction Study of Bonding Effects in s-Triazine

X-ray and neutron-diffraction data were combined for study of deviations from spherical symmetry of the atomic charge distributions in the small organic molecule s-triazine. The results indicate that density has migrated from the atomic regions into the bonds and into the nitrogen lone-pair region. Refinement procedures for x-ray data, which do not take these bonding effects into account, give parameters containing small but measurable errors.     

An isolation of Leptospira serotype Pomona from a domestic cat

Extract

Between November 1971 and July 1972, the gastro-intestinal tracts of 51 dogs and 47 cats of various age were examined for helminth parasites. The animals examined were unselected and had been submitted for autopsy following death from causes unrelated to parasitism. Most of the animals were pets, but included in the survey were some working dogs. All came either from the city of Palmerston North or its surrounding rural areas.     

An in situ single-pass perfusion model for assessing absorption across the intestinal mucosa of the brushtail possum

AIM: To develop an in situ animal model for assessing absorption of molecules across the intestinal mucosa of possums.

METHODS: A surgical preparation was used to perfuse known concentrations of reference compounds (fluorescein and luteinising hormone-releasing hormone; LHRH) through measured sections of selected regions (jejunum, caecum, proximal colon) of the intestinal tract of 19 possums, over a 2-h period. Plasma concentrations of the compounds, which were perfused either with or without co-administration of a permeation enhancer (sodium deoxycholic acid; SDA), were determined in the perfusion effluent, peripheral and in some instances in the pre-hepatic circulation by spectrofluorometry (fluorescein) or radio-immunoassay (LHRH). Pharmacokinetic parameters of both compounds in the possum were determined over a period of up to 4 h in a further 30 animals (fluorescein, n=6; LHRH n=24), from their plasma profiles following intravenous (I/V) administration of a bolus dose.

RESULTS: In animals perfused with 25 mg/ml fluorescein (Perfusion Experiment (PE) 1), the mean plasma concentration was 2.8 (SE 0.12) µg/ml in post-hepatic blood samples. When possums were perfused with 2.5 mg/ml fluorescein and 7 µg/ml LHRH (PE 2), mean plasma concentrations were 0.3 (SE 0.01) and 7.8 (SE 1.64) µg/ml fluorescein and 0.1 (SE 0.02) and 6.3 (SE 0.45) ng/ml LHRH, in the absence and presence of permeation enhancer, respectively. There was a poor correlation between pre-hepatic and post-hepatic concentrations.

CONCLUSIONS: The single-pass in situ perfusion technique provided a useful model for investigating basic information on the absorption of biocontrol agents across the intestinal tract of possums, but had limitations that must be recognised.     

Emergence,Mating and Oviposition Behavior of the Chinese Population in Pink Bollworm,Pectinophora gossypiella (Lepidoptera: Gelechiidae)

The pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae) is one of the most serious lepidopteran pests of cotton in the world. This pest invaded China at the onset of the 20th century, possibly through repeated introductions from several different locations worldwide. In this paper, we describe different behavioral parameters of this Hubei P. gossypiella strain under laboratory and field conditions. Using an infra-red video recorder, we observed (nocturnal) emergence, flight and mating activities, and oviposition patterns. Moth emergence started from 13:00 and continued up till 23:00. Under laboratory and field conditions, 2-7-d-old moths initiated flight around sunset, peaked 50 min later and gradually declined until 04:00. Although mating started immediately after darkness (i.e., 20:00), mating behavior was most intense from 23:00 to 03:40. Oviposition also showed distinct time-related patterns, with approx. 70% eggs laid between 20:00 and 22:00. In the studies of the relationship between flight and oviposition, the duration of flight had an effect on oviposition. The 1-d-old moths flown for 6 and 12 h began oviposition earlier than the unflown ones, and the 6-h flight had no effect on the egg production. However, the longevity of the flown moths was shortened after flight. In addition, the peaks of oviposition for the flown moths were advanced 2–3 d. The age when the moths flied affected the oviposition of adult moths. The earlier the moths started to fly after emergence, the greater the fecundity they had. The average egg production of moths flown for 24 h was less than that of non-flown moths which were of the same age. Both flight and delay in mating could advance the oviposition peak. Our study provides detailed insights in nocturnal activities and the reproductive biology of local P. gossypiella populations, which could be employed to fine-tune current pest management programs in China.