Showing papers on "Uroleucon published in 2008"

Hieracium -associated aphid parasitoid guilds (Hymenoptera: Braconidae: Aphidiinae) in Europe

Abstract: Eleven aphidiine braconid species are associated with 10 aphid species to form over 50 tritrophic associations in Europe. The host aphids belong to five genera, Aphis L., Brachycaudus Van der Goot, Hyperomyzus Borner, Nasonovia Mordvilko, and Uroleucon Mordvilko, and feed on 11 Hieracium species. Five new host plant records are reported. The associated aphidiine guilds are linked with the taxonomic position of the host aphids. Host aphids such as Brachycaudus helichrysi (Kaltenbach) and Uroleucon spp. are broadly oligophagous, but Nasonovia spp., Aphis hieracii Schrank, and Hyperomyzus hieracii (Borner) are specific mainly to Hieracium and related plants. A key for the identification of aphidiine species associated with aphids on Hieracium plants in Europe is provided.

Integrated Pest Management Strategies against safflower aphid, Uroleucon compositae (Theobald).

Abstract: In the last 25 years, there has been a significant reduction in safflower area in India and else where. The growth rate is negative in India. In Karnataka state, the second largest producer of safflower, the area under safflower has reduced drastically from 2.5 lakh ha. in 1980’s to 1.5 lakh ha in 2006. Among the different factors responsible for reduction in area of safflower, safflower pests are one among them. Safflower is vulnerable to biotic and abiotic stresses. The biotic stresses involve insectpest and diseases. Out of a dozen insect-pests, the safflower aphid, Uroleucon compositae (Theobald) is a major pest which causes 30 to 80 per cent yield loss based upon the weather conditions. Therefore, integrated pest management approaches are very much essential for sustainable and profitable safflower production. The use of resistant varieties (A-1, Phule Kusume, NARI-H-15 and Bhima) is one of the important components in IPM in safflower. The other components include agronomic practices (summer ploughing, time of sowing, application of balanced fertilizer, intercultural operations, inter cropping, mixed cropping and clean cultivation), application of bioagents, bio-pesticides and chemical insecticides which have been discussed in detail in this paper.

Addition to the aphid fauna of Byelorussia (Homoptera: Aphidoidea) with detailed description of sexuales of Semiaphis anthrisci (Kaltenbach, 1843)

Abstract: For the fi rst time, Therioaphis luteola (Borner, 1949), Aphis chloris Koch, 1854, Aphis craccae Linnaeus, 1758, Aphis galiiscabri Schrank, 1801, Aphis newtoni Theobald, 1927, Aphis thalictri Koch, 1854, Aphis (Bursaphis) epilobiaria Theobald, 1927, Brachycaudus (Appelia) tragopoginis (Kaltenbach, 1843), Brachycaudus (Brachycaudina) aconiti (Mordvilko, 1928), Dysaphis hirsutissima (Borner, 1940), Acaudinum centaureae (Koch, 1854), Hydaphias molluginis Borner, 1939, Semiaphis anthrisci (Kaltenbach, 1843), Uroleucon (Lambersius) erigeronense (Thomas, 1878) and Uroleucon (Uromelan) campanulae (Kaltenbach, 1843) are recorded from Byelorussia. The detailed description of oviparous female and male of S. anthrisci are given.

A New Species of Uroleucon (Hemiptera: Aphididae) Living on Adesmia (Fabaceae)

Abstract: We describe the apterous and alate viviparous females of a new species of the subgenus Lambersius of the genus Uroleucon (Hemiptera Aphididae) from Argentina living on Adesmia (Fabaceae). Uroleucon adesmiae sp. n. is the first South American species of this genus exclusively living on a species of Fabaceae. A previous key for the apterous viviparous females of the Uroleucon species recorded in South America is modified to include the new species.

Safflower fly (acanthiophilus helianthi), aphid (uroleucon carthami) and leafhopper empoasca decipiens

Abstract: I& F 9 9 780 JA! ? K = L ! 0 K (0& F M F! N ? =C > + 9 J 20 @ :O; @O 6 < P 780 9 ) Acanthiophilus helianthi ( D+ @ 0! + 1 2 3 4 Q FG @ 0" + N 4 > > F! P F . O 0 S @ 3 O4 0O5 1 2 6 0 > < =2 * 780 9 < P D+ @ P 780 9 :; + 0! + 4 T # @ * Q P $ O! UV ? /V ? WV ? ,,V ,-V 0A X 4 0 > 4 X 4 YZ[ 0 A + \4 $ [ B ]0 ^ 014 @ G 4 "8 @ [ 8 @ 780 9 F! . P 3 4 _` 0 a\8 ? + 3[ 0 C <0[ ^ #0 [ 0 + >S K Y b H E < c @ * ! d 09 O+ O O4 F ! d >N C e F 8 + 09 @= . 6 @Ab > F 8 @A! Uroleucon carthami B0"8 ? Empoasca decipiens 8 780 9 :; < =2 Fc * K F8 780 9 :; Q 4 780 9 9 0 09 + F . 8 A + @[ 8 T 0! + ! d Q F O8 0f[ FC * 6 > 780 9 :; ) -. / H 4 0 :; ( @A! ) U/ / ,gU @4 @A! ( 0! + 1 2 3 4 Q F! + F ) ,-V O 0OA X 4 4 0 > X 4 0 ( 6 . 780 9 @8 0I 3 I 2 3 4 8 * >! 0 @ . 0O @O F+FO! I 2 3 4 0O! + Q ! d F 8 * h6 + 6 3 > < P 780 9 :; i \X 780 9 3 H/ -V Fc 0I 09 P + F . 3 4 C J+ I 2 jF8 /V 0A X 4 X 4 > 4 0 0 0 Z @ J+ 0 @ < 0 C > 6 =8 3 >! @ 0c * 8 (P k0\ ? + 6 F! . J & J+ 0 6 >G4 B0"8 > 0 5l4 1 2 3 4 > + 3 . Fc 0S8 780 9 :; < =2 $m FC 9 NP 0! K + ! d F Q ) .g / ,U Fc ( 0! 01 0f[ FC + ! d Q F! ) U / ,g./ [ OA1 09 O ( 8 O * P /V 0A X 4 0 > 4 X 4 F! $c C 0 .

Screening of safflower germplasm accessions for resistance against safflower aphid (Uroleucon compositae Theobald).

Abstract: Safflower (Carthmus tinctorius L.) is one of the most important traditional rabi (post-rainy season) oilseed crops in India. Safflower aphid (Uroleucon compositae Theobald) is the key pest of the crop which causes yield losses to the extent of 20 to 60 % with an average of 37 % throughout India. Use of resistant varieties / genotypes is a way of lowering the cost of pest protection as part of Integrated Pest Management in safflower. Thus, the present studies were made to evaluate safflower germplasm accessions for resistance against safflower aphids. The experiment was conducted during 2006-2007 at ICRISAT-DOR Farm, Directorate of Oilseeds Research, Hyderabad by growing a total of 2000 safflower germplasm accessions on 24 November, 2006 in an augmented design. The plots were single rows 4 m long and spaced 45 cm apart with 20 cm between plants within rows. The cultivars CO-1 was included as a susceptible infester check and A-1 as a resistant check in rows after every 10 accessions. In addition, CO-1 as the infester was planted all around the experimental field under late sown conditions so as to get maximum build up of the aphid population. Observations were recorded during peak aphid incidence on number of aphids/5 cm on the central twig/plant and % foliage drying of whole plants due to aphid infestation from five randomly selected plants of each accessions along with checks. Grade and category were made on a scale of 1 to 5 based up on the % foliage drying by observing visual symptoms of the whole plants. It was found that out of 2000 safflower germplasm accessions, 18 accessions recorded foliage drying of 0-15 % with aphid population of 11-34 aphids/5 cm on the central twig/plant and graded as highly tolerant to aphids. Of the 18 most promising safflower germplasm accessions, GMU No. 4474, 2902, 4585, 2866 and 3854, recorded zero per cent foliage drying with minimum aphid population of 11-15 aphids/5 cm on the central twig/plant and maximum seed yield of 3-3.3 g/plant, however, GMU2866 was non-spiny type. Seven germplasm accessions, GMU No. 3714, 3725, 3764, 3936, 4176, 2609 and 2823, recorded 10 % foliage drying with 20-24 aphids/plant and seed yield of 2.8-3 g/plant and rest six germplasm accessions, GMU No. 2897, 2933, 3927, 3828, 3923 and 2596, recorded 15 % foliage drying with 29-34 aphids/plant and seed yield of 2.4-2.6 g/plant. Plant height, number of branches and capitulum had no correlation with susceptibility of aphids. In general, spiny genotypes with thin stems, pale green leaves were observed as tolerant / resistant to aphid infestation while non-spiny, late maturing and tall genotypes with succulent stems and green leathery leaves contributed for aphid susceptibility. Introduction Safflower (Carthmus tinctorius L.) is one of the most important traditional rabi (post-rainy season) oilseed crops in India especially grown in Maharashtra and Karnataka and to a limited extent in Andhra Pradesh, Gujarat, Orissa, Madhya Pradesh and Bihar which together occupies an area of 349.2 thousand ha with a production of 128.3 thousand tonnes and productivity of 367 kg/ha (2003-04). India is the highest safflower producer in the world. However, productivity per hectare of safflower is very low. One of the major reasons for the low productivity of safflower is infestation caused by insect pests. Out of over 80 species of insect, mite and nematode pests appearing throughout the world on safflower, as many as two dozen of them are of major economic importance in India and the safflower aphid (Uroleucon compositae Theobald) is the most destructive pest of safflower. Adults are black while nymphs are reddish dark brown in colour. Aphids are soft-bodied insects measuring 1.5 to 2 mm in length. Winged and wingless forms are abundantly seen from seedling stage till harvesting of the crop. The yield losses caused by aphids have been reported to the extent of 56 to 60 % in Kernataka (Basavanna et al., 1981), 20 to 55 % in Maharashtra (Naragalkar and Shivpuje, 1990; Ghorpade, 1995) and an average of 37 % throughout India (Singh and Prasad, 2005). A number of insecticides have been reported for the management of safflower aphids (Shetgar et at., 1993; Makar et al., 1994; Ghorpade et al., 1994). However, the pesticide usage can lead to health hazards and high cost inputs. The use of resistant varieties / genotypes is a way to lowering the cost of pest protection as part of Integrated Pest Management in safflower. Thus, the present studies were made to evaluate safflower germplasm accessions for resistance against safflower aphids. Materials and Methods The experiment was conducted during 2006-2007 at ICRISAT-DOR Farm, Directorate of Oilseeds Research, Hyderabad. A total of 2000 safflower germplasm accessions were collected from Safflower Germplasm Maintenance Unit (GMU), Directorate of Oilseeds Research, Hyderabad and planted under field conditions on 24 November, 2006 in an augmented design. The plots were single rows 4 m long and spaced 45 cm apart with 20 cm between plants within rows. The cultivars CO-1 was included as a susceptible infester check and A-1 as a resistant check in rows after every 10 accessions. In addition, CO-1 as the infester was planted all around the experimental field under late sown conditions so as to get maximum build up of the aphid population. Maintenance of experiment was routine as per the package of practices for safflower in this area except for elimination of plant protection measures. Since aphids breed profusely, it is very difficult to precisely count the population of aphids on the plants. Therefore, % foliage drying due to aphid infestation was graded on a scale from 1 to 5. When the crop was 60 days old from planting, during the first week of February, peak aphid incidence occurred. Observations were recorded on number of aphids/5 cm on the central twig/plant along with % foliage drying of whole plants from five randomly selected plants of each accession. These measurements were also made on A-1 and CO-1 as the resistant and susceptible checks. Grade and category were made on a scale of 1 to 5 based up on the % foliage drying by observing visual symptoms of whole plants (Table 1). Observations were also recorded on plant height (cm), softness/succulency, spiny or non-spiny, branches/plant, capitulum/plant and seed yield (g/plant). Table 1 Screening of safflower germplasm accessions against aphids based up on foliage drying Grade Category % foliage drying Visual symptoms --------------------------------------------------------------------------------------------------------------------1 Highly Tolerant (HT) 0 to 20 Healthy plant with normal seed yield 2 Tolerant (T) 21 to 40 Healthy plant but yellowing and drying of leaves on main stem, branches and normal capitula 3 Moderately Tolerant (MT) 41 to 60 Drying of 50 leaves on tender shoots of the plant, small to medium capitula with low seed setting 4 Susceptible (S) 61 to 80 Drying of leaves and tender shoots, withering of branches, stunted growth and less number of capitula with very poor seed setting 5 Highly Susceptible (HS) Above 80 Death of plant before maturity and no seed yield Results and Discussions This experiment was done under late sown crop conditions on 24 November so as to get maximum aphid infestation. Therefore, the load of aphid infestation initially on safflower in the field during the year was very heavy in general (>100 aphids/plant). It was found that none of the accessions of GMU was completely free from aphid infestation. Aphid infestation started from first week of January and reached its peak in the last weeks of January, continuing up to first week of March. In the prevailing heavy aphid infestation, it was indeed very interesting to note that out of 2000 safflower germplasm accessions screened, 18 accessions recorded foliage drying of 0-15 % with aphid population of 11-34 aphids/5 cm on the central twig/plant. These accessions were graded as highly tolerant genotypes to safflower aphids (Table 2). The national resistant check (A-1) recorded 15 % of foliage drying with aphid population of 30 aphids/5 cm on the central twig/plant and seed yield of 2.6 g/plant and susceptible check (CO-1) recorded 82 % of foliage drying, aphid population of 94 aphids/5 cm on the central twig/plant and zero seed yield. Table 2 Reaction of safflower germplasm accessions to aphids No. of accessions No. of aphids/pl % foliage drying Category Grade 18 11-34 0-15 Highly Tolerant (HT) 1 5 41-69 32-40 Tolerant (T) 2 197 70-80 46-58 Moderately Tolerant (MT) 3 620 81-89 60-80 Susceptible (S) 4 1158 90-158 81-100 Highly Susceptible (HS) 5 Of the 18 most promising safflower germplasm accessions, GMU accession No. 4474, 2902, 4585, 2866 and 3854 recorded zero per cent of foliage drying with minimum aphid population of 11 to 15 aphids/5 cm on the central twig/plant and maximum seed yield of 3 to 3.3 g/plant, however, GMU-2866 was a non-spiny type. Seven germplasm accessions, GMU No. 3714, 3725, 3764, 3936, 4176, 2609 and 2823, recorded 10 % of foliage drying with aphid population of 20 to 24 aphids/5 cm on the central twig/plant and seed yield of 2.8 to 3 g/plant and rest six germplasm accessions showed 15 % of foliage drying with aphid population of 29 to 34 aphids/5 cm on the central twig/plant and seed yield of 2.4 to 2.6 g/plant (Table 3). However, plant height, number of branches and capitulum had no correlation on susceptibility of aphids. Table 3 Reaction of most promising safflower germplasm accessions to aphid and their plant morphological characters Accession Aphids/ 5 cm Foliage drying Plant Plant Plant SP/ Branches Capitulum Seed No. central twig % Grade Cateheight softsuccuNSP (No./pl) (No./pl) yield / plant gory (cm) ness lency (g/pl) ------------------------------------------------------------------------------------------------------------------------------------------GMU-2596 34 15 1 HT 69 H NSU SP 16 23 2.5 GMU-2609 23 10 1

Influence of crop phenology on population dynamics of aphid, Uroleucon compositae Theobald and its predators.

Abstract: Field experiment was conducted during 2001-02 rabi to study the influence of crop phenology and meteorological factors on the incidence of aphid (Uroleucon compositae Theobald) on safflower (Carthamus tinctorius L). The aphid appeared in the safflower field in 51 standard week during 2007, i.e., December 3 week when the crop was seven weeks old. Later the population gradually increased up to 2 standard week of 2002 and reached the peak (118.4 aphids/ 5cm apical twig in 3 standard week. The mean maximum temperature of 28-30°C and minimum temperature of 13-16°C and relative humidity of 83.4% were found most conducive for aphid multiplication. The peak aphid population was observed at 83.4 per cent relative humidity. Lower relative humidity of 74.2 per cent and increase in temperature during first week of February set in a decline in aphid population. The predators C. septempunctata, M. sexmaculatus and C. carnea were found to appear one week after the appearance of U. compositae on safflower. The predators population peaked during third week of January when aphids were also maximum in number. Mean maximum temperature coupled with relative humidity had significant negative correlation (r=-0.63) on aphid population. But coccinellids and chrysopids had highly significant and positive correlation (r=0.97 and r = 0.96, respectively) with the aphids. The partial regression equations showed a highly significant negative impact of mean minimum temperature and positive relation of coccinellids and chrysopids with aphids.