Pupation site choice of a North American lycaenid butterfly: the benefits of entering ant nests

Abstract.

• 1 Larvae of the North American lycaenid butterfly Hemiargus isola Reakirt tended by the ant Formica perpilosa Wheeler often enter nests of this ant species, and pupate in tunnels and chambers near the surface. Untended larvae and those tended by the ants Dorymyrmex Forel sp. (smithi complex), Forelius foetida (Buckley), and Myrmecocystus mimicus Wheeler pupate in crevices in the ground, under bark, and on leaves; but rarely inside ant nests.
• 2 The location and structure of F.perpilosa nests facilitates discovery by H.isola prepupae. At the southeast Arizona study site, F.perpilosa nests are located at the base of H.isola's host plant, whereas other species’nests are in open ground. Also, F.perpilosa nest openings are wide, whereas those of other species may be too narrow for prepupae to enter.
• 3 Prepupae associated with F.perpilosa spent 67% less time on the ground searching for pupation sites than prepupae associated with other ant species. Pupae in artificial chambers connected to F.perpilosa nests were 4–5 times less likely to disappear overnight, presumably due to predation, than those not connected to nests.
• 4 Formica perpilosa ants tend pupae inside nests. However, in the laboratory experiments tended pupae did not lose more weight prior to eclosion than untended ones, suggesting that chemicals or sounds produced by pupae as ant attractants are inexpensive, or are produced whether or not ants are present.
• 5 Newly-eclosed butterflies exited nests unmolested by ants in the field, but were attacked if confined with ants for several minutes after eclosion in the laboratory.

     

The effect of water potential on soil-borne diseases of wheat seedlings

Under glasshouse conditions, Fusarium culmorum caused more injury to wheat seedlings in soil at 33% saturation (approximately – 1 bar) than at 66% (–0·1 bar). The same effect occurred with inoculated seeds raised on soil moisture tension tables at –0·1 and –0·5 bar, at 20° and at 15°C. In controls, spontaneous infection by soil-borne F. culmorum was unaffected by soil water potential. Inoculated F. nivale, at 127deg; and at 15°C, showed a similar, but smaller, effect to that with inoculated F. culmorum. Water potential in this range did not affect disease incidence with inoculated Gaeumannomyces graminis, but disease was more severe in the drier soil. On tension tables, seedlings did not consistently develop faster under wetter conditions, and factors other than host growth rate probably played a part in limiting fungal attack.     

New Specificity of Australia Antigen

THE immunodiffusion laboratory at the Institute for Cancer Research frequently acts as a reference laboratory to test anti-Australia antigen sera for our colleagues in many parts of the world. Because Australia antigen is known to possess different antigenic specificities^1–4, a panel was established which consisted of Australia antigen specimens selected from hepatitis and Down's syndrome patients and from clinically normal residents of the Lau area in Malaita, British Solomon Islands. Sera from normal blood donors without Australia antigen were included as negative controls. All antisera received after August 1971 were tested against this panel to detect heterogeneity among both the antibodies tested and the antigens included in the panel. Immunodiffusion was performed in a seven-hole Ouchterlony pattern with the antiserum in the centre well and a positive Australia antigen control serum from a Pennsylvania Down's syndrome patient in the top and bottom wells. The patterns were cut in a layer of 1.1% agarose in veronal buffer, pH 8.2, on glass lantern slides^6,7.     

Relationship between Position on the Parent Plant and Dormancy Characteristics of Seeds of Three Cultivars of Celery (Apium graveolens)

Germination and seedling emergence studies were made on seeds harvested from four different umbel positions of three cultivars of celery (Apium graveolens L.). Although heavier seeds were produced from primary umbels than from other umbels, these were less viable as measured by the germination percentage at I8°C in the light. However, germination of viable seeds from quaternary umbels was lower than that of seeds from primary umbels at 18°C in the dark when incubated with GA₄, (2 × 10 ^?4M) and seed from secondary and tertiary umbels tended to be intermediate in response. All viable seeds germinated when N⁶-benzyladenine (10^?2M) was used in combination with GA₄. Seeds from quaternary umbels of two of the cultivars had a lower high-temperature limit for germination in the dark than did seeds from other umbels. In glasshouse experiments the emergence of viable ‘quaternary’ seeds of these cultivars was higher than that of ‘primary’ seeds. Under these conditions the time to 50% of the final emergence as determined after 42 days was similar for seeds from all umbel positions within each cultivar. In two varieties seedling weights were greater from seeds of primary as compared to quaternary umbels, and in general, the largest seedlings arose from the heaviest seeds and the smallest from the lightest seeds in all three cultivars.     

An Experimental Study of Competition Between Seed-eating Desert Rodents and Ants

Reciprocal increases in rodent and ant densities on 0.1 ha plotsfrom which the other taxon had been excluded demonstrate thatthese distantly related desert granivores compete for seeds.Relative to unmanipulated control plots, numbers of ant coloniesincreased 71% on plots where rodents were excluded; rodentsincreased 20% in numbers of individuals and 29% in biomass inthe absence of ants. Comparisons of seed levels in the soiland of annual plant densities on experimental and control plotsprovide evidence that the rodent and ant populations are limitedby and compete for food. Greater numbers of seeds and annualsoccurred on plots where rodents and ants had been excluded thanon plots where both taxa were present. Particular species ofannuals were reduced in density by foraging of rodents. Antsincreased species diversity by differentially harvesting seedsof the most common species. Results of these and other recentstudies suggest that competition among distantly related organismsplays a major role in the organization of ecological communities.     

Flagellar Membrane and Paraxial Rod Proteins of Leishmania: Characterization Employing Monoclonal Antibodies

Flagella-specific proteins of Leishmania have been identified employing the monoclonal antibody technique. Six monoclonal antibodies recognized 3 different proteins. A doublet of protein of Mr 69,000 and 74,000 Da identified by monoclonal antibodies F-3, F-4 and F-6 is continuously distributed along the flagellum by immunofluorescence. Immunocytochemical electron microscopic studies localize these molecules to the paraxial rod of the flagellum. A single protein of Mr 13,200 Da is recognized by monoclonal antibodies F-1, F-2 and F-5. The distribution of the Mr 13,200 protein appears irregular, occurring in localized patches along the length of the flagellum, especially at the flagellar tip. Immunocytochemical electron microscopic experiments show that the Mr 13,200 molecule is associated with the membrane of the flagellum. Indirect immunofluorescence experiments demonstrated these monoclonal antibodies cross-reacted with members of the Kinetoplastida family ( Endotrypanum, Trypanosoma, Leishmania ) suggesting that these molecules may be evolutionarily conserved.     

Timing of sperm transfer in Diacamma pallidum

Abstract.  Diacamma species (Hymenoptera, Formicidae) differ from other ants by the extremely long duration of copulation. By using histological sections through mating pairs of Diacamma pallidum (F. Smith), it is demonstrated that the transfer of sperm to the female genital tract only takes 2 min and is completed quickly after the onset of copulation, although the male and female will remain connected for many hours. Next to the two traditional hypotheses of mate guarding and mate manipulation commonly invoked to explain prolonged copulations, a new hypothesis is proposed linked to the interference of the nestmate workers with the mating pair, and suggestions for further research are given.     

Systematics of Vitaceae from the viewpoint of plastid rbcL DNA sequence data

A phylogenetic analysis of plastid rbcL DNA sequences for 20 species of Vitaceae s.l. (including Leeaceae) and eight outgroups from Dilleniaceae and Santalales is presented. Patterns of floral and vegetative morphology and ontogeny within the family are compared to the phylogenetic trees produced. Despite the limited sampling of large and variable genera, there is a good correspondence with hypothesized floral and vegetative ontogenetic trends, with Leea and Ampelopsis ancestral, Cissus and Ampelocissus intermediate and Vitis most derived. A clade containing Parthenocissus , Tetrastigma , Cyphostemma and Vitis is found in all shortest trees. Cyphostemma and Parthenocissus are shown to be closely related to Vitis , to which clade Tetrastigma and Cayratia comprise the sister clade. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 421–432.