The use of fungicidal paints and gels to treat existing apple cankers

Four paints containing mercuric oxide, octhilinone, thiophanate-methyl or triad-imefon and five gel formulations (carbendazim/triadimefon in sodium alginate or xanthan gum, carbendazim/triadimefon/hypophosphorous acid and thiophanate-methyl/oxycarboxin in xanthan or PP969/alginate) were tested on natural cankers caused by Nectria galligena on apple trees. Scraping cankers decreased their size 7–9 months later due to stimulation of callus formation, even where no fungicide was applied, and decreased perithecial, but not conidial production. Only the paints were applied to scraped cankers and that containing mercuric oxide was the most effective in decreasing canker size and restricting new canker growth. All formulations except the octhilinone paint were applied to unscraped cankers. Only mercuric oxide paint and acidic carbendazim/triadimefon/xanthan gel stimulated callus formation and only the former caused a decrease in canker size. Every treatment, except triadimefon paint and PP969/alginate, reduced conidial production. Bioassay with TV. galligena showed that the carbendazim and thiophanate-methyl gels achieved some movement of fungitoxicant into plant tissue.     

OXYNOE AZUROPUNCTATA, N. SP., A NEW SACOGLOSSAN FROM THE FLORIDA KEYS (MOLLUSCA: OPISTHOBRANCHIA)

A new species of Oxynoe from the Florida Keys is described.It differs from the other Caribbean Oxynoe, O. antillarum Mörch,1863, in color, number and size of papillae, size increase ofradular teeth, diet, and type of development. The type of developmentis extended lecithotrophic. The larvae hatch about 4 weeks afterthe eggs have been deposited, and metamorphosis is completedafter about one additional week. Oxynoe azuropunctata n.sp.feeds on Caulerpa paspaloides, C. cupressoides and C. sertularioides.Details of the feeding process in Oxynoe are described for thefirst time. The junction of the oral tube and the pharynx isequipped with a complex muscular buccal apparatus, part of whichis everted during feeding. The protrusible parts of the buccalapparatus completely surround part of an algal filament, whichis then slit with the radula, and the cell sap is sucked out.The protrusible parts are retracted after the filament has beenreleased. ^*Present address: Ellebjergvej 22, 1 t.h., DK-2450 CopenhagenSV, Denmark (Received 13 November 1979;     

Fine Structure of Human Malaria In Vitro*†

SYNOPSIS. The erythrocytic cycle of the human malaria parasite, Plasmodium falciparum, was examined by electron microscopy. Three strains of parasites maintained in continuous culture in human erythrocytes were compared with in vivo infections in Aotus monkeys. The ultrastructure of P. falciparum is not altered by continuous cultivation in vitro. mitochondria contain DNA-like filaments and some cristae at all stages of the erythrocytic life cycle. The Golgi apparatus is prominent at the schizont stage and may be involved in the formation of rhoptries. In culture, knob-like protrusions first appear on the surface of trophozoite-infected erythrocytes. The time of appearance of knobs on cells in vitro correlates with the life cycle stage of parasites which are sequestered from the peripheral circulation in vivo. Knob material of older parasites coalesces and forms extensions from the erythrocyte surface. Some of this material is sloughed from the host cell surface. The parasitophorous vacuole membrane breaks down in erythrocytes containing mature merozoites both in vitro and in vivo. Merozoite structure is similar to that of P. knowlesi. The immature gametocytes in culture have no knobs.     

Revision of Microlaimidae, Erection of Molgolaimidae fam.n., and Remarks on the Systematic Position of Paramicrolaimus (Nematoda, Desmodorida)

The family Microlaimidae contains Bolbolaiminae subfam.n. (Bolbolaimus syn. Pseudomicro-laimus) and Microlaiminae ( Calomicrolaimus, Ixonema and Microlaimus ). The new family Molgolaimidae contains Aponematinae subfam.n. ( Aponema gen.n.) and Molgolaiminae subfam.n. ( Molgolaimus and Prodesmodora ). The main differentiating characters applied are: structures of the head region, shape of the oesophagus, position of the excretory pore, shape of the tail, structure of the gonads and ornamentation of the cuticle. The significance of porids and preanal supplements as distinguishing characters is, discussed. Microlaimidae are closely related to Desmodoridae; Molgolaimidae related to Spiriniidae. Paramicrolaimus is transferred from Microlaimidae to Spiriniidae.–Six species from the Øresund, Denmark, are redescribed: Microlaimus punctulatus Gerlach, 1950 and M. acinaces Warwick & Piatt, 1973; Aponema torosus (Lorenzen, 1973) gen.n., comb.n. (syn. Microlaimus torosus Loren-zen, 1973); Molgolaimus allgeni (Gerlach, 1950) comb.n. (syn. Microlaimus allgeni Gerlach, 1950) and M. turgofrons (Lorenzen, 1972) comb.n. (syn. Microlaimus turgofrons Lorenzen, 1972); Paramicrolaimus spirulifer Wieser, 1959.     

Associative learning of host presence in non‐host environments influences parasitoid foraging

1. Parasitoids are known to utilise learning of herbivore‐induced plant volatiles (HIPVs) when foraging for their herbivorous host. In natural situations these hosts share food plants with other, non‐suitable herbivores (non‐hosts). Simultaneous infestation of plants by hosts and non‐hosts has been found to result in induction of HIPVs that differ from host‐infested plants. Each non‐host herbivore may have different effects on HIPVs when sharing the food plant with hosts, and thus parasitoids may learn that plants with a specific non‐host herbivore also contain the host. 2. This study investigated the adaptive nature of learning by a foraging parasitoid that had acquired oviposition experience on a plant infested with both hosts and different non‐hosts in the laboratory and in semi‐field experiments. 3. In two‐choice preference tests, the parasitoid Cotesia glomerata shifted its preference towards HIPVs of a plant–host–non‐host complex previously associated with an oviposition experience. It could, indeed, learn that the presence of its host is associated with HIPVs induced by simultaneous feeding of its host Pieris brassicae and either the non‐host caterpillar Mamestra brassicae or the non‐host aphid Myzus persicae. However, the learned preference found in the laboratory did not translate into parasitisation preferences for hosts accompanying non‐host caterpillars or aphids in a semi‐field situation. 4. This paper discusses the importance of learning in parasitoid foraging, and debates why observed learned preferences for HIPVs in the laboratory may cancel out under some field experimental conditions.     

Interactive effects of herbivory and sand burial on growth of a tropical dune plant, Ipomoea pes-caprae

1. This study examined the effects of insect herbivory, sand burial, and the interactive effects of these factors, on the growth of beach morning glory, Ipomoea pes-caprae, a common tropical dune plant. Levels of herbivory and sand burial were manipulated on individual shoots, and effects on stem growth, leaf production, and production of adventitious roots and axillary branches by nodes were examined.
2. Sand burial had a significant positive effect on the production of roots, but did not affect growth in stem length or leaf production.
3. Effects of herbivory were consistently negative, and persisted for 6 weeks after the herbivore damage was incurred. Stem growth rates and leaf production decreased and the production of bare nodes (with no roots or branches) and mortality of apical meristems increased.
4. Interactive effects of herbivory and sand burial influenced both leaf production and root production. In the case of root production, the effects of herbivory in decreasing the proportion of nodes that produced roots occurred only in the presence of burial. In contrast, burial masked the negative effects of herbivory on leaf production.