Outbreak of Trichophyton verrucosum in China Transmitted from Cows to Humans

Twenty percent of 1000 dairy cows were infected with Trichophyton verrucosum in a newly established dairy farm in western China. The disease was transmitted to 30 of 100 animal workers. The source of the outbreak is unknown but it is suspected that naïve cattle which were transported from Holland to China became infected after they arrived in Xinjiang province (West China) where the fungus is endemic in nature, prepuberty school children and various livestock.     

Unique haplotypes in ant‐attended aphids and widespread haplotypes in non‐attended aphids

Aphid species within the genus Tuberculatus Mordvilko (Hemiptera: Aphididae) exhibit a variety of interactions with ants, ranging from close associations to non‐attendance. A previous study indicated that despite wing possession, ant‐attended Tuberculatus species exhibited low dispersal rates compared with non‐attended species. This study examined if presence or absence of mutualistic interactions and habitat continuity of host plants affected intraspecific genetic diversity and genetic differentiation in mitochondrial DNA cytochrome oxidase I (COI) sequences. Sympatric ant‐attended Tuberculatus quercicola (Matsumura) (Hemiptera: Aphididae) and non‐attended Tuberculatus paiki Hille Ris Lambers (Hemiptera: Aphididae) were collected from the daimyo oak Quercus dentata Thunberg (Fagales: Fagaceae) in Japan and examined for haplotype variability. Seventeen haplotypes were identified in 568 T. quercicola individuals representing 23 populations and seven haplotypes in 425 T. paiki representing 19 populations. Haplotype diversity, which indicates the mean number of differences between all pairs of haplotypes in the sample, and nucleotide diversity were higher in T. quercicola than T. paiki. Analysis of molecular variance (AMOVA) showed higher genetic differentiation among populations within groups of T. quercicola (39.8%) than T. paiki (22.6%). The effects of attendant ant species on genetic differentiation in T. quercicola were not distinguishable from geographic factors. Despite low dispersal rates, host plant habitat continuity might facilitate widespread dispersal of a T. quercicola haplotype in Hokkaido. These results suggested that following T. quercicola colonization, gene flow among populations was limited, resulting in genetic drift within populations. However, frequent T. paiki dispersal is clearly evident by low genetic differentiation among populations within groups, resulting in lower haplotype diversity.     

Development and use of molecular diagnostic tools to determine trophic links and interspecific interactions in aphid-parasitoid communities in Hawaii

There has been much debate regarding the impact of parasitoid competition and hyperparasitism on the successful biological control of aphid pests. Difficulty in the evaluation of interspecific interactions and trophic links using conventional rearing and dissection methods has prevented a deeper understanding of such relationships. The analysis of trophic links in the parasitoid community associated with the melon aphid (Aphis gossypii) in Hawaii provides a unique opportunity to assess complex interactions that occur in a system where all of the aphids and parasitoids have been introduced. Here, we developed and applied multiplex PCR assays to investigate the occurrence of in-host competition between parasitoids and/or hyperparasitoids on melon aphids collected from fields of Colocasia esculenta. To fully document the parasitoid-hyperparasitoid community within A. gossypii, both live and mummified aphids were examined. A total of 818 live and 245 mummified aphids were analyzed using the multiplex assays, with congruent rearing of over 600 mummified aphids serving as a basis for qualitative comparisons in terms of species composition and trophic linkages. The rearing and the DNA methods showed similar trends, with sharp declines in one parasitoid species followed by sharp increases in another during the course of the season. Molecular analyses revealed that hyperparasitism and multiparasitism of live aphids is remarkably low, whereas hyperparasitism of mummified aphids was extraordinarily high in both rearing and molecular analyses. In comparison to reared samples, molecular analysis of the parasitoid community was more complete and permitted the identification of previously unknown or unconfirmed trophic linkages. The potential of this approach in future studies on the biological control of aphids in Hawaii, particularly in light of new parasitoid introductions, is discussed.     

A PCR-based tool for the cultivation-independent monitoring of Pandora neoaphidis

Pandora neoaphidis is one of the most important fungal pathogens of aphids and has a great potential for use in biocontrol. Little is known on how this fungus persists in an area and in particular on its overwintering strategies. It is hypothesized that natural areas play an important role for survival and that soil may serve as a source of inoculum for new aphid populations in spring. To test these hypotheses, a cultivation-independent PCR-based diagnostic tool was developed, that allows the detection of P. neoaphidis in the environment. Two P. neoaphidis specific PCR primer pairs were designed, targeting sequences in the ribosomal RNA gene cluster. Specificity of both primer pairs was demonstrated with P. neoaphidis and non-target close entomophthoralean relatives. Moreover, single amplicons of expected sizes were obtained with both primer pairs from various environmental sample types, including aphid cadavers, plant material, and soil. The PCR-based diagnostic tool was applied to investigate the persistence of P. neoaphidis in soil samples obtained in 2004/2005 from a nettle field harboring infected aphids in fall 2004. P. neoaphidis was detected in every sample collected in November 2004 and March 2005, suggesting an overwintering stage of P. neoaphidis in top soil layers. The developed cultivation-independent PCR-based tool will be valuable for further investigation of the ecology of P. neoaphidis and for the development and future implementation of management strategies against aphids involving conservation biocontrol.     

Parasitoids associated with the common pistachio psylla, Agonoscena pistaciae, in Iran

The parasitoids associated with the common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer, were investigated at three pistachio plantations in Rafsanjan, Iran. Of the 6504 wasps emerging from mummified psyllids, 46% were the primary parasitoid Psyllaephagus pistaciae Ferrière, and the remaining 54% represented six species of hymenopterous hyperparasitoids, including Chartocerus kurdjumovi (Nikol’skaja), Marietta picta (André), Pachyneuron aphidis (Bouché), Pachyneuron muscarum (Linnaeus), Psyllaphycus diaphorinae (Hayat), and Syrphophagus aphidivorus (Mayr). Lysiphlebus fabarum Marshall, the parasitoid of Aphis gossypii Glover and Aphis craccivora Koch present on weeds, was found to be an alternative host for three major hyperparasitoids of A. pistaciae. The most abundant hyperparasitoid was S. aphidivorus, appearing during the growing season in all trial locations on psyllids and aphids in pistachio orchards. The weed-infesting aphids, along with their primary parasitoid, can act as a reservoir of A. pistaciae secondary parasitoids. Therefore, parasitized aphids allow populations of secondary parasitoids to increase and consequently to apply higher pressure on P. pistaciae. We detected that two primary parasitoid species, including P. pistaciae and L. fabarum, attacking different species of hosts interact indirectly through shared secondary parasitism. It is suggested that the community structure of A. pistaciae may be influenced by apparent competition, although more work is needed to provide firm evidence.     

苦豆碱及顺式氯氰菊酯对莱田蚜虫群落的毒力研究

研究了植物源杀虫剂苦豆碱及顺式氯氰菊酯对菜田蚜虫群落结构的影响 ,并测定了其对第一优势种菜缢管蚜的杀伤毒力。苦豆碱在 1 %浓度下 ,以药膜法和喷雾法 ,测定其击倒作用 ,KT50 分别为2 9 74和 2 5 38min ;顺式氯氰菊酯在 0 1 %浓度下 ,KT50 分别为 1 73和 0 78min。以点滴法测定此两种杀虫剂对菜缢管蚜的触杀作用 ,LD50 分别为 7 7× 1 0 -4 及 9 2 0 1 μg 头 ,田间以 0 1 %喷雾 ,苦豆碱 1 0d校正防效均可达到 80 % ,而顺式氯氰菊酯仅能达到 30 %。结果显示 ,苦豆碱对菜缢管蚜有极强的毒杀作用 ,同时喷药前后菜田蚜虫群落结构也发生着明显的变化。     

Cornicle length in Macrosiphini aphids: a comparison of ecological traits

Abstract 1. Aphids often emit cornicle droplets when attacked by predators. While the function of cornicle droplets has long been debated (i.e. mechanical protection vs. chemical signalling), it is not understood why aphid species have cornicles of different lengths.
2. It was hypothesised that aphids living in more scattered colonies have longer cornicles to scent-mark predators with cornicle droplets containing alarm pheromone, so that clone-mates are provided with advanced warning of a threat, even if not at the predation site. To test this hypothesis, multiple regression analyses were used, due to a lack of phylogenetic information on these taxa, to address which ecological traits (amount of wax on an aphid, degree of colony aggregation, feeding shelter, ant attendance) are correlated with cornicle length.
3. Aphids living in dense colonies tended to have shorter cornicles than aphids living in more scattered colonies. Also, aphids with more protection (i.e. wax) on their bodies had shorter cornicles. Aphids also tended to have shorter cornicles when tended by ants. The presence of a feeding shelter was not a good predictor of cornicle length.
4. It is suggested that longer cornicles function to scent-mark predators with alarm pheromone to increase the inclusive fitness of a clone; however the negative correlation between the amount of individual protection, and also ant attendance, and cornicle length argues for a trade-off between different forms of defence.     

Egg cannibalism by Coleomegilla maculata lengi neonates: preference even in the presence of essential prey

Abstract 1. Egg cannibalism among coccinellids has been reported widely, however reasons why this type of behaviour is observed so frequently have been neglected. This experiment was undertaken to clarify whether cannibalistic behaviour is advantageous to Coleomegilla maculata lengi Thimberlake neonates and to understand the reasons for high levels of egg cannibalism.
2. Benefits gained by neonate cannibals were ascertained by comparing survival, developmental time, and second-instar weight of C. maculata larvae that were allowed to cannibalise conspecific eggs or not. Preference and behaviour tests were also conducted to assess the reasons for high levels of egg cannibalism.
3. Cannibal neonates grew faster and were heavier than non-cannibals. The developmental time of neonates was influenced more by prey vulnerability than by prey quality.
4. In choice tests, where three different proportions of conspecific eggs and aphids were offered (33–67, 50–50, and 67–33%), C. maculata neonates always consumed significantly more eggs. Manly's preference indexes indicated that neonates showed a consistent preference for conspecific eggs.
5. Seventy-five per cent of neonates observed went directly towards eggs and 90% of the first prey consumed by neonates were an egg. When aphids were painted with extract of crushed eggs and eggs with crushed aphids to determine whether neonates found eggs by chemical cues, neonates preferred aphids painted with egg extract to eggs painted with aphid extract.
6. It was concluded that C. maculata neonates benefited from cannibalistic behaviour. Moreover, egg cannibalism is not related only to frequency of encounter; chemical cues are also involved in egg searching.     

Jasmonate-mediated induced plant resistance affects a community of herbivores

1. The negative effect of induced plant resistance on the preference and performance of herbivores is a well‐documented ecological phenomenon that is thought to be important for both plants and herbivores. This study links the well‐developed mechanistic understanding of the biochemistry of induced plant resistance in the tomato system with an examination of how these mechanisms affect the community of herbivores in the field. 2. Several proteins that are induced in tomato foliage following herbivore damage have been linked causally to reductions in herbivore performance under laboratory conditions. Application of jasmonic acid, a natural elicitor of these defensive proteins, to tomato foliage stimulates induced responses to herbivory. 3. Jasmonic acid was sprayed on plants in three doses to generate plants with varying levels of induced responses, which were measured as increases in the activities of proteinase inhibitors and polyphenol oxidase. 4. Field experiments conducted over 3 years indicated that induction of these defensive proteins is associated with decreases in the abundance of all four naturally abundant herbivores, including insects in three feeding guilds, caterpillars, flea beetles, aphids, and thrips. Induced resistance killed early instars of noctuid caterpillars. Adult flea beetles strongly preferred control plants over induced plants, and this effect on host plant preference probably contributed to differences in the natural abundance of flea beetles. 5. The general nature of the effects observed in this study suggests that induced resistance will suppress many members of the herbivore community. By linking plant biochemistry, insect preference, performance, and abundance, tools can be developed to manipulate plant resistance sensibly and to predict its outcome under field conditions.     

Host-selection behaviour by genetically identical aphids with different plant preferences

The behaviour of summer and autumn winged forms of the black bean aphid, Aphis fabae Scopoli (Homoptera: Aphididae), was compared on two plants utilized at different stages of the insect’s life cycle. Adult autumn migrants (gynoparae) are monophagous, colonizing spindle (Euonymus europaeus), whereas polyphagous summer winged aphids (alate virginoparae) are associated with a variety of herbaceous plants, including broad bean (Vicia faba). When aphids from a single clone were given access to a spindle leaf and a bean seedling in choice tests, many virginoparae settled and larviposited on both plant species over 24 h. By contrast, gynoparae showed a clear preference for spindle, with 93.5% of settled adults and 98.3% of larvae on this plant species. Close‐up video monitoring showed that gynoparae discriminated beans from spindle within a 5‐min period, whereas virginoparae behaved similarly on both plant species. For gynoparae, the major behavioural difference on the two plants appeared after a brief (epidermal) stylet penetration, with many insects taking flight within a few seconds of stylet withdrawal from bean. Factors detected during stylet insertion by gynoparae must therefore inhibit take‐off on spindle. Electrical recording experiments showed that aphids often punctured a cell membrane during brief probes on both plant species, and intracellular stylet activities always included a waveform associated with ingestion. When gynoparae puncture spindle cells their behaviour is probably modified by intracellular metabolites detected via gustation of ingested epidermal cell sap. These cues may inhibit the take‐off reflex which otherwise follows probing.