Searching Behavior of the Aphid Parasitoid Aphidius nigripes (Hymenoptera: Aphidiidae) Foraging on Potato Plants

1990 ◽  
Vol 19 (2) ◽  
pp. 222-228 ◽  
Author(s):  
Conrad Cloutier ◽  
France Bauduin
1984 ◽  
Vol 62 (8) ◽  
pp. 1513-1520 ◽  
Author(s):  
Yves Bouchard ◽  
Conrad Cloutier

The parasitoid Aphidius nigripes spent more time searching on potato plants previously infested with aphids than on fresh plants, suggesting the presence of searching stimulants on infested plants. Water extracts of aphid honeydew applied to the surface of foliage or to filter paper discs increased searching time and affected the locomotory behavior of parasitoids. When crossing a honeydew-treated area on filter paper, female parasitoids exhibited arrestment, antennal examination, abdominal protraction, reduced walking speed, and increased turning. Upon losing contact with honeydew-contaminated substrate, parasitoids often exhibited a klinotactic response which drove them back to the treated area. The time spent by individual parasitoids within a honeydew-treated area on filter paper decreased with successive visits, but the initial response level was restored when the insect was prevented from contacting honeydew for 1 h. The retention response exhibited by parasitoids contacting a honeydew-treated area increased with honeydew concentration, but levelled off at high concentrations. Naive parasitoids were more responsive to the retention effect of honeydew than experienced individuals.


2011 ◽  
Vol 57 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Salah-Eddin Araj ◽  
Steve Wratten ◽  
Alison Lister ◽  
Hannah Buckley ◽  
Ihab Ghabeish

1985 ◽  
Vol 117 (10) ◽  
pp. 1231-1237 ◽  
Author(s):  
John J. Obrycki ◽  
Maurice J. Tauber

AbstractDuring 2 field seasons, Coccinellidae (primarily Coccinella transversoguttata richardsoni, Coleomegilla maculata, Hippodamia convergens, H. tridecimpunctata, and H. glacialis) were the most abundant predators on potato hybrids (Solanum tuberosum × S. berthaultii, F3) with various densities of glandular pubescence. Highly pubescent clones had the highest percentage of predator eggs, while clones with the lowest trichome densities had the highest percentages of immature and adult predators. By comparison, high numbers of aphid parasitoid mummies (primarily Aphidius and Praon spp.) occurred on clones with moderate to high densities of glandular pubescence. During both years, predators and parasitoids were most abundant in late July and August.


1984 ◽  
Vol 62 (7) ◽  
pp. 1367-1372 ◽  
Author(s):  
Conrad Cloutier ◽  
Lothar A. Dohse ◽  
France Bauduin

Females of the solitary aphid parasitoid Aphidius nigripes do not consistently avoid superparasitizing their hosts, the potato aphid Macrosiphum euphorbiae. Tests were conducted in which two attacks separated by a time interval ranging from 1 to 24 h were allowed per host. No evidence of host discrimination was found when the interval was <2 h. For longer intervals, host discrimination was an increasing function of the length of the interval up to 24 h after the initial attack. Various mathematical models, permitting time-related rejection of parasitized hosts, were used to simulate the parasitoids–host distributions following two attacks. The best fitting models also had to incorporate time-dependent discrimination against hosts that had been attacked but not successfully parasitized. The results are discussed with respect to possible mechanisms of host discrimination in A. nigripes and its significance in intraspecific competition.


2018 ◽  
Vol 17 (6) ◽  
pp. 159-166
Author(s):  
Halina Kurzawińska ◽  
Stanisław Mazur ◽  
Małgorzata Nadziakiewicz ◽  
Jacek Nawrocki

The aim of this study was to determine whether the weeds accompanying potato crops can be a source of Alternaria spp. causing Alternaria leaf blight and to determine the genetic similarities of Alternaria alternata isolates infecting selected weeds: Chenopodium album, Cirsium arvense and tested potato cultivar. Three-year field experiment was conducted on the potato cultivar ‘Vineta N’. The isolates were classified into different species on the basis of macro- and microscopic features. In each year of the study, A. alternata dominated among the isolated fungi colonizing the leaves of potato plants and the selected weeds. The genetic similarities of A. alternata isolates was determined by the RAPD-PCR method. Tested genetic forms of A. alternata were closely related; only small differences in the pattern of the separated amplification products was evidenced. The dominance of A. alternata on the weeds accompanying potato crops suggests that if weed infestation is extensive, the pathogen is very likely to spread and its population to increase.


Author(s):  
M.S. Kolychikhina ◽  

In the small-plot experiment of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy against potato viruses in 2014-2019 were tested some kinds of preparations with antiviral activity: Pharmayod, GS (100 g/l of iodine); Immunocytophyte, TAB (20 g/kg arachidonic acid ethyl ester); Ecogel, WS (30 g/l of chitosan lactate); Amulet, TAB (composition of linear polyaminosaccharides (chitosan) in succinic acid solution); Zerox, WS (3000 mg /l colloidal silver); Viron, WS (biostimulant based on urea and citric acid with the addition of essential oils). According to the results of the studies, it was found that, in addition to the effect on the causative agents of viral diseases of potatoes, all tested preparations had a stable tendency to maintain or increase the yield of tubers of infected plants. The increase in the yield of tubers ranged from 0.5 to 1.3 kg/m2. In 2016 under the production conditions of Astrakhan region on the potato variety Impala infected with the PVM + PVS and PVM + PVS + PVY virus complexes a comparative assessment of the effect of Pharmayod and Immunocytophyte revealed a significant increase in the gross and marketable yield of potato plants in the areas with the use of these preparations compared to with control.


2019 ◽  
Vol 9 (2) ◽  
pp. 91
Author(s):  
Ghea Dotulong ◽  
Stella Umboh ◽  
Johanis Pelealu

Uji Toksisitas Beberapa Fungisida Nabati terhadap Penyakit Layu Fusarium (Fusarium oxysporum) pada Tanaman Kentang (Solanum tuberosum L.) secara In Vitro (Toxicity Test of several Biofungicides in controlling Fusarium wilt (Fusarium oxysporum) in Potato Plants (Solanum tuberosum L.) by In Vitro) Ghea Dotulong1*), Stella Umboh1), Johanis Pelealu1), 1) Program Studi Biologi, FMIPA Universitas Sam Ratulangi, Manado 95115*Email korespondensi: [email protected] Diterima 9 Juli 2019, diterima untuk dipublikasi 10 Agustus 2019 Abstrak Tanaman kentang (Solanum tuberosum L.) adalah salah satu tanaman hortikultura yang sering mengalami penurunan dari segi produksi dan produktivitasnya, akibat adanya serangan penyakit layu yang salah satunya disebabkan oleh Fusarium oxysporum. Tujuan penelitian ini adalah mengidentifikasi toksisitas beberapa fungisida nabati dalam mengendalikan penyakit Layu Fusarium (F. oxysporum) pada tanaman kentang (Solanum tuberosum L.) secara In Vitro. Metode Penelitian yang digunakan yaitu metode umpan beracun. Data dianalisis dengan Rancangan Acak Lengkap (RAL) dengan Analisis Varian (ANAVA) yang dilanjutkan dengan menggunakan metode BNT (Beda Nyata Terkecil). Hasil Penelitian, diperoleh nilai toksisitas fungisida nabati tertinggi yaitu pada ekstrak daun sirsak dengan nilai HR (69,44%), kategori berpengaruh, ditandai dengan diameter koloni 2,75 cm (100ppm) dan yang terendah toksisitasnya yaitu pada ekstrak daun jeruk purut dengan nilai HR (49,81%), kategori cukup berpengaruh ditandai dengan diameter koloni 3,75 cm (25ppm). Semakin tinggi konsentrasi yang diujikan maka semakin tinggi toksisitas dari fungisida nabati yang diberikan.Kata Kunci: fungisida nabati, Fusarium oxysporum, tanaman kentang, In Vitro Abstract Potato plants (Solanum tuberosum L.) is one of the horticulture plants which often decreases in terms of production and productivity, due to the attack of wilt, one of which is caused by Fusarium oxysporum. The purpose of this study was to determine the toxicity of several biofungicides in controlling Fusarium wilt (F. oxysporum) in potato plants (Solanum tuberosum L.) in Vitro. The research method used was the In Vitro method with the poison bait method. Data were analyzed by Completely Randomized Design with Variant Analysis (ANAVA), followed by the BNT method. The results showed that the highest biofungicide toxicity value was soursop leaf extract with HR values (69.44%), influential categories, characterized by colony diameter 2.75 cm (100ppm) and the lowest toxicity, namely in kaffir lime leaf extract with a value of HR (49.81%), quite influential category was characterized by colony diameter of 3.75 cm (25ppm). The higher the concentration tested, the higher the toxicity of the biofungicide given.Keywords: biofungicides, Fusarium oxysporum, Potato Plants, In Vitro.


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