Colonisation of sub-Antarctic Marion Island by a non-indigenous aphid parasitoid <Emphasis Type="Italic">Aphidius matricariae</Emphasis> (Hymenoptera,Braconidae)

Over the past two decades seven non-indigenous vascular plant or arthropod species have established reproducing populations at sub-Antarctic Marion Island (46°54′S, 37°55′E). Here we record the eighth establishment, a braconid wasp Aphidius matricariae Haliday, which uses the aphid Rhopalosiphum padi (Linnaeus) as its only host on the island. Molecular markers (18S rDNA and mtCOI) support the conventional taxonomic identification and indicate that all individuals are characterized by a single haplotype. Surveys around the island show that adult abundance and the frequency of aphid parasitism are highest at Macaroni Bay on the east coast, and decline away from this region to low or zero values elsewhere on the coast. The South African research and supply vessel, the SA Agulhas, regularly anchors at Macaroni Bay, and Aphidius sp. have been collected from its galley hold. Current abundance structure, low haplotype diversity, and the operating procedures of the SA Agulhas all suggest that the parasitoid was introduced to the island by humans. Regular surveys indicate that this introduction took place between April 2001 and April 2003, the latter being the first month when this species was detected. The wasp’s establishment has significantly added to trophic complexity on the island. Low haplotype diversity suggests that propagule pressure is of little consequence for insect introductions. Rather, single or just a few individuals are probably sufficient for successful establishment.     

Age-Specific Functional Response of <Emphasis Type="Italic">Aphidius matricariae</Emphasis> and <Emphasis Type="Italic">Praon volucre</Emphasis> (Hymenoptera: Braconidae) on <Emphasis Type="Italic">Myzus persicae</Emphasis> (Hemiptera: Aphididae)

The green peach aphid, Myzus persicae (Sulzer), is one of the most important aphid pests on pepper. Aphidius matricariae Haliday and Praon volucre (Haliday) are known as biological control agents for aphids in vegetable crops. In this research, age-specific functional responses of these two parasitoids were evaluated on different densities of 2, 4, 8, 16, 32, and 64 green peach aphids. Type of functional response varied from type II to type III for different ages of A. matricariae, but type of functional response was not affected by female age for P. volucre. The functional response of P. volucre was determined as type II in the whole parasitoid lifetime. The searching efficiency (a), b, and handling time (T _h ) were estimated using the Rogers equations. The highest searching efficiency (a) and lowest handling time were observed during the first half of lifetime of A. matricariae and P. volucre. Aphidius matricariae and P. volucre caused reasonable mortality of the green peach aphid by parasitism of 52.17 and 47.05 host aphids, respectively, in 24 h. Therefore, they are suggested as suitable candidates for control of M. persicae in pepper greenhouses.     

Parasitism of <Emphasis Type="Italic">Spodoptera litura</Emphasis> (Lepidoptera: Noctuidae) by <Emphasis Type="Italic">Microplitis prodeniae</Emphasis> (Hymenoptera: Braconidae)

Spodoptera litura Fabricius is a major vegetable pest that is widely distributed throughout tropical, subtropical and temperate regions. Microplitis prodeniae Rao and Chandry is a solitary endoparasitoid of S. litura. To assess the potential use of this parasitoid as a biological control agent, the reproductive schedule, fecundity and functional response of M. prodeniae were investigated under conditions of 28 ± 1°C and 70 ± 10% relative humidity with a 14:10-h L:D photoperiod. The parasitoid’s average lifetime fecundity was 171.0 ± 10.4 eggs, of which approximately 50% were laid within the first 3 days. Additionally, M. prodeniae exhibited a Holling type II functional response, and the estimated maximum numbers of the 1st, 2nd and 3rd instar larvae that were parasitized by a single M. prodeniae female were 71.6, 78.4 and 41.5 larvae over a 24-h period, respectively. The results of this study suggest that M. prodeniae has great potential as a candidate for controlling S. litura and can guide efforts in its mass production.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

Intraguild predation on the aphid parasitoid <Emphasis Type="Italic">Aphelinus asychis</Emphasis> by the ladybird <Emphasis Type="Italic">Harmonia axyridis</Emphasis>

We investigated intraguild predation (IGP) on an aphid parasitoid, Aphelinus asychis Walker (Hymenoptera: Aphelinidae), by the multicolored Asian ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), and used the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) as the prey/host in the laboratory. The ladybirds reared on artificial diet and on aphids consumed more aphids than mummies, while those reared on parasitized aphids consumed similar numbers of aphids and mummies. The ladybirds chose more mummies in treatments when mummies were more abundant, and more aphids when numbers of aphids and mummies were equal, or when aphids were more abundant. However, at all density treatments, rejection rates of mummies (36%) were much greater than of aphids (2%). H. axyridis prey on more aphids than A. asychis mummies, which enhances biological control by the two species. However, prior feeding experience affected subsequent choice, increasing the competition between natural enemies which would reduce their combined effectiveness for biological control.     

Dynamic host-feeding and oviposition behavior of an aphid parasitoid <Emphasis Type="Italic">Aphelinus asychis</Emphasis>

In order to maximize the lifetime reproductive success of parasitoids, they should be induced to dynamically accept individual hosts that have different suitability for oviposition. Parasitoids tend to exhibit higher host-selective behavior when their egg load is limited, and are less selective if they are facing time constraints. Here, we evaluated the effects of parasitoid age on egg load, fecundity and host instar preference of a honey-fed aphid parasitoid, Aphelinus asychis Walker (Hymenoptera: Aphelinidae). Host selective experiment was conducted to measure host-preference of honey-fed A. asychis females at different ages, using the second and fourth instars of the green peach aphid Myzus persicae as their hosts. The results showed that the choice of host-instar for oviposition was significantly influenced by the parasitoid age. Honey-fed parasitoids in the age groups of 1, 5, 10 and 20 days tended to parasitize predominantly second-instar aphids, whereas 15-days old parasitoids showed no significant preference of host instars. On the other hand, host-feeding preference was not affected by parasitoid age. Parasitoid females of all ages preferred younger aphids to older aphids. This result could help evaluate the effectiveness of A. asychis for biological control of M. persicae when they encountered mixed-instar aphids in the field. In addition, the results might be helpful in assessing the host killing effects of other host-feeding parasitoids.     

A review of the tribe Phanerotomini (Hymenoptera,Braconidae, Cheloninae) in Turkey,with a new host record for <Emphasis Type="Italic">Phanerotoma</Emphasis> (<Emphasis Type="Italic">Bracotritoma</Emphasis>) <Emphasis Type="Italic">permixtellae</Emphasis>

In this study, the Phanerotomini of Turkey collected between July 1959 and July 2004, are listed. A total of thirteen Phanerotomini species were determined, and six of these are reported for the first time from Turkey. Phanerotoma (Bracotritoma) permixtellae Fischer, 1968 was reared from a new natural host Recurvaria pistaciicola (Danilevskii, 1955) (Lepidoptera: Gelechiidae). With this present study an illustrated identification key for the Phanerotomini of Turkey is given. The distribution of the Phanerotomini species is discussed according to the phytogeographical provinces of Turkey.     

New combinations and typifications in <Emphasis Type="Italic">Bistorta</Emphasis>, <Emphasis Type="Italic">Persicaria</Emphasis>, <Emphasis Type="Italic">Polygonum,</Emphasis> and <Emphasis Type="Italic">Rumex</Emphasis> (Polygonaceae)

New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.     

Revision of the <Emphasis Type="Italic">Serrulati</Emphasis> species of <Emphasis Type="Italic">Penstemon</Emphasis> section <Emphasis Type="Italic">Saccanthera</Emphasis> subsection <Emphasis Type="Italic">Serrulati</Emphasis>

A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.