Zoology

An aphid and virus survey was conducted from 1993 and 1999 on the eastern lowlands in Hungary. Aphid flight was monitored with two yellow pan traps placed on the edge and in the middle of seed potato fields. From 1993 and 1997, aphid flight was monitored with a Rothamsted type suction trap. The aphid and virus survey was continued in four different regions of Hungary in 2000. Aphid flight activity recorded by the suction trap and the yellow pan traps was different. Cumulative vector intensity based on yellow pan trap catches revealed a greater variation between years than among the different locations. In 4 years out of 8, aphid flight was less intensive and quality seed potato was harvested regardless of the production site. Cumulative vector intensity is a good means to forecast the time of haulm destruction in seed potatoes.

BACKGROUND: Aphids cause both quantitative and qualitative yield losses in cereals. Aphid feeding resulted in a significant decrease in gliadin/glutenin ratio in soft-kernel wheat. Effect of aphid feeding on hard-kernel wheat was examined.RESULTS: Plants of two different hard-wheat cultivars were artificially infected by two aphid species: Sitobion avenae and Diuraphis noxia. Three different levels of caging regulated aphid density. Aphid density was highest in the cages, followed by open cages and lowest under no-cage conditions. Numbers of D. noxia were generally higher compared to those of S. avenae. There was no significant difference in head length, mean kernel number/head, mean kernel mass/head or mean individual kernel mass between the two cultivars. Glutenin, gliadin and total protein content was analysed using size-exclusion HPLC. Quality parameters of wheat flour were significantly different between the two cultivars. Gliadin content, total protein content and gliadin/glutenin ratio were significantly higher in Mv Magdaléna compared to Mv Magvas regardless of the level of caging and infestation, while glutenin content of uninfected Mv Magvas was significantly higher than that of Mv Magdaléna in the open cages. Aphid feeding did not induce any significant reduction in the gliadin, total protein content and gliadin/glutenin ratio of the examined hard wheat cultivars.CONCLUSION: Individual kernel mass reduction is the major factor in yield loss caused by aphids. Aphid feeding did not change the protein structure of hard-kernel wheat. Copyright © 2007 Society of Chemical Industry

The Carpathian Basin has been classified as one of the model areas of Russian wheat aphid (= RWA), Diuraphis noxia (Kurdj.), expansion from the southeast to Central Europe. Explorations in 2002 as well as the summarized information published earlier centered the evidence for RWA in the northern and northeastern parts of the area and its occurrence was detected and verified in the area up to the submountains of the Carpathian Mountain Range. The history and distribution peculiarities of RWA in the Carpathian Basin and area are reviewed and discussed.

Flight patterns of migrant alate Russian wheat aphids (=RWA),Diuraphis noxia (Kurdj.) during its expansion from the south-east to Central Europe were determined. Samples were taken by Rothamsted-type suction air traps in Hungary (one location, 1990–1997) and in the Czech Republic (5 locations, 1994–1998). The results document a progressive expansion of RWA, and population variation in the individual years and periods of the season. A comparison of the evidence on RWA in the individual years since its detection in Hungary and in the Czech Republic supports the presumption on the occurrence of an expansion route from the south-east (Turkey) to Central Europe. This expansion is classified as an adventive route of the over-all expansion that has covered the whole West-Mediterranean (South Europe, North Africa).

The aphid transmissibility and within-plant movement of two PVY isolates belonging to PVYO and PVYN strains were studied. Potato plants were infected by Myzus persicae either 1 week after emergence or 30 or 45 days after emergence. Infected leaves, petioles of infected leaves, and different segments of the stems of plants infected 1 week after emergence were ELISA-tested 7, 11 and 14 days after infection. Segments of the plants infected 30 or 45 days after emergence were ELISA tested 30 days after infection. Normalised ELISA values were used for statistical analyses. Virus infection of progeny tubers was assessed by post-harvest inspection. The ability of 15 aphid species to transmit the virus isolates was also examined. There was no difference in the aphid transmissibility of the two isolates 7 or 11 days after exposure to M. persicae. However, normalised ELISA values were significantly affected by both isolate and sampling date 11 and 14 days after M. persicae transmission. The level of infection of different stem segments was significantly affected by both isolate and growth stage of the plant at infection. The proportions of infected leaves, stem segments and progeny tubers were all significantly higher for PVYN than for PVYO. PVYN was more effectively transmitted by a number of different aphid species than was PVYO. Newly described vectors of PVYN include Schizaphis graminum, Aphis fabae cirsiacanthoides, Aphis spiraecola, Myzus ligustri, Aphis fabae, Aphis spiraephaga, Myzus cerasi, Macrosiphum rosae, Diuraphis noxia, Aphis pomi and Rhopalosiphum padi, while those of PVYO include Aphis fabae cirsiacanthoides, Myzus cerasi and Myzus ligustri.

Abstract The common ragweed, Ambrosia artemisiifolia
is a widespread invasive weed species in Europe. In order
to estimate the deteriorative eVect of native arthropods on
the invasive ragweed the eVect of three indigenous aphid
species on plant development and pollen production was
studied. Common ragweed plants grown in a greenhouse
were artiWcially infested with Wve apterous individuals of
either Aphis fabae, Brachycaudus helichrysi or Myzus persicae
at the 4-leaf stage. Feeding by all three aphid species
over a 5-week period signiWcantly reduced plant height, the
number of male inXorescences, the length of racemes, pollen
emission and plant dry mass. Brachycaudus helichrysi
produced the largest colonies, followed by A. fabae and
M. persicae. In a host plant choice test, B. helichrysi showed
signiWcant preference for ragweed over sunXower, whereas
A. fabae preferred sunXower and M. persicae did not show
any preference. In a Weld experiment, the growth rate of
A. fabae on caged ragweed plants was similar to that in the
greenhouse, but the Wnal numbers of B. helichrysi and
M. persicae after 30 days was ten and seven times lower
than under greenhouse conditions, respectively. On exposed
Weld plants, B. helichrysi was more abundant than other
species. However, no aphid species aVected the height or

A survey of Pulsatilla grandis Wender revealed the presence of four aphid species colonizing Greater Pasque Flower in Hungary. Aphis pulsatillicola Holman, 1966 the monoecious Pulsatilla feeding aphid species is new record for the Hungarian fauna. The development of Cavariella theobaldi Gilette Bragg, 1918 on the isolated silky seed head proves that the host alternating aphid species (primary hosts are Salix species and summer hosts are Umbelliferae plants) was able to develop from nymph to alata on P. grandis. Winged forms develop in response to unsatisfactory quality of a host plant, while on suitable host apterae are produced. The polyphagous Aphis fabae Scopoli 1763 and Aphis gossypii Glover 1877 were able to overwinter and the progenies of fundatrices developed into wingless apterae on P. grandis.

Transparent mulches, blue mulches and black mulches were used between rows on
seed cucumber fields to repel aphids. The incidence of virus in leaf samples collected at
random every 2 weeks was determined by mechanically-inoculating herbaceous indicator
plants. The virus percentage was significantly reduced by 70 and 77% on plots mulched
with transparent and blue plastic foils respectively as compared with the untreated plots.
There was no decrease when black plastic mulch was used. Two aphid-borne viruses,
cucumber mosaic virus and watermelon mosaic virus, were isolated from virus-infected
cucumber samples, 77% and 23%, respectively.

ABSTRACT Several life history parameters (nymphal development time, prereproductive
period, reproductive period, postreproductive period, total life span, total fecundity, and agespecífic
natalíty) of Diuraphis noxia (Mordvilko) from South Afríca and Hungary were compared
on 2 South Afrícan wheat varieties ('Betta', which is D. noxia-susceptible, and 'SST 333',
which is D. noxia-resistant) and 1 Hungarian spring barley variety (Tsís', which is D. noxiasusceptíble).
Nymphal development time, reproductive period, and total life span were signíficantly
longer in Hungary than in South Africa. South Afrícan nymphs developed to adults
between 9.3 and 9.7 d, whereas those in Hungary took 10.7-11.1 d (the ranges indicate
variation in mean values among host plant species). The adult reproductive period lasted 22.9-
24.0 d in South Afríca and 35.2-37.1 d in Hungary. Total life span was 41.7-45.2 d in South
Afríca and 52.0-52.2 in Hungary. Total fecundity was significantIy higher in South Afríca (67.1-
75.1) than in Hungary (53.0-{)2.2) on Betta, SST 333, and Isis. Hungarian D. noxia not only
produced fewer nymphs but took much longer to do so; therefore, it is possible that the
Russian wheat aphíd in South Africa would reach economic thresholds in the field sooner than
in Hungary

... Növényvédelem 32 , 77–79. 22 Tóbiás, I., Maat, DZ, Huttinga, H., 1982: Two Hungarian isolates of cucumber mosaic virus from sweet pepper (Capsicum annum L.) and melon (Cucumis melo L.): identification and antiserum preparation. Neth. J. Plant Pathol. 88 , 171–183. ...

ABSTRACT Cereal aphid flight was monitored by 12.2 m suction traps at Szolnok in the middle of the Great Hungarian Plain and at Rothamsted, UK. Flight activities of Rhopalosiphum padi, Metopolophium dirbodum and Sitobion avenae were compared by the cross correlation function (CCF) between Hungary and UK. There was significant synchrony between flight a-tivity in Hungary and UK of R padi, M. dirbodum and S. avenae based on the eight years weekly sample data. The peak flight occurred 1, 3 and 2 weeks later at Rothamsted than at Szolnok for the three species (the CCF values were at – 1 week lag, r = 0.854, – 3 week lag r = 0.809, – 2 week lag r = 0.883, P < 0.05 respectively). When the flights in individual years were compared within species and between places the syn-chrony was lowest for R. padi: – in 4 years out of 8 and there was no synchrony, in the other years when synchrony occurred the time lag varied between – 1 week and – 4 weeks. For M. dirhodum the time lag varied between 1 and – 5 weeks, the synchrony was the best for S. avenae the week lag varied between 0 and – 3 weeks. Our results show that flight activity of cereal aphids at Szolnok occurs 1-3 weeks earlier than at Rothamsted. The crop season is earlier in Hungary than in England.

Russian wheat aphid, Diuraphis noxia (Kurdjumov) is a severe pest of cereals in South Africa and in the USA. In order to reduce D noxia damage, intensive resistance breeding programs have been undertaken, resulting in D noxia-resistant cultivars that are now widely used in South Africa and in the USA. However, there appear to be differences in the ability of different populations of D noxia to damage these resistant cereal cultivars. To determine whether different biotypes of D noxia are present, damage to eight wheat cultivars was compared when they were exposed to either Hungarian or South African aphid strains. It appeared that the Hungarian CVS MV Magdaléna, MV Magvas, and MV 17 were susceptible to D noxia from both Hungary and South Africa. The susceptible South African CV Betta was also severely damaged regardless of the country of origin of the aphids. None of the cultivars resistant in South Africa (Caledon, SST 333, SST 972 and Halt) were, however, resistant to Hungarian populations of D noxia. These cultivars, which carry resistance genes originating from the breeding lines PI 262660, PI 137739 and PI 372129, were severely damaged by the Hungarian D noxia. Apart from the highly resistant CV Halt, the resistant cultivars used in this study were developed in South Africa, with the biotype present there. Damage to all cultivars tested was significantly more severe in response to Hungarian than to South African D noxia, indicating that a more damaging aphid biotype occurs in Hungary. However, D noxia has not yet become a pest of wheat in Hungary, possibly due to a difference in cultural practices.