scholarly journals Population Dynamics and Yield Loss Assessment for Pea Aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on Lentil in Morocco

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1080
Author(s):  
Karim El Fakhouri ◽  
Abdelhadi Sabraoui ◽  
Zakaria Kehel ◽  
Mustapha El Bouhssini

Pea aphid (Acyrthosiphon pisum Harris) is the major insect pest of lentil in Morocco. We investigated pea aphid mean numbers and yield losses on three lentil varieties at one location during three successive cropping seasons during 2015–2018. The effects of several weather factors on pea aphid population dynamics were investigated. Population density increased in early spring followed by several peaks during March–April and then steeply declined during the late spring. Aphid populations peaked at different times during the three years of the study. In 2016, higher populations occurred during the second and third weeks of April for Abda and Zaria varieties with averages of 27 and 28 aphids/20 twigs, respectively. In 2017, higher populations occurred on the 12th and 13th standard meteorological weeks (SMWs) for Zaria with averages of 24.7 and 27.03 aphids/20 twigs, respectively. In 2018, the population peaked for all varieties at three different times, 11th, 13th, and 17th SMW, with the highest for Zaria being 26.00, 47.41, and 32.33 aphids/20 twigs. Pea aphid population dynamics changed with weather conditions. The number of aphids significantly and positively correlated with maximum temperature, but significantly negatively correlated with relative humidity and wind speed. The minimum temperature and rainfall had non-significant correlations. Pea aphid infestation resulted in losses of total seed weight for all lentil varieties, with the highest avoidable losses for Bakria being 12.51% followed by Zaria with 7.72% and Abda with 4.56%. These losses may justify the development of integrated management options for control of this pest.

2005 ◽  
Vol 79 (3) ◽  
pp. 139-148 ◽  
Author(s):  
C. Girousse ◽  
R. Bournoville ◽  
I. Badenhausser

This study proposes a guide for the design of experiments to test alfalfa (Medicago sativa) for resistance to pea aphid infestation (Acyrthosiphon pisum). This test was conducted in controlled conditions on alfalfa seedlings. For the infestation, aphid population maintained on alfalfa was found to be more efficient than an aphid population reared on broad bean. When comparing alfalfa cultivars, a non-choice test gave the same results as a choice test, that was more difficult to perform. When infesting a unit of 54 seedlings at the cotyledon stage on the 1st and 5th day of the experiment, 360 mg compared with 180 mg and 540 mg aphids, led to the best compromise between levels of infestation and aphid stock culture availability. Infestation was stopped when more than 60% of susceptible cultivar seedlings were wilted or dead. Under these conditions, we calculated the number of replicates necessary to obtain a fixed level of difference. Six units per cultivar would distinguish between cultivars differing from 20% in their seedling mortality.


1990 ◽  
Vol 122 (3) ◽  
pp. 503-513 ◽  
Author(s):  
J.J. Soroka ◽  
P.A. Mackay

AbstractPopulations of pea aphid, Acyrthosiphon pisum (Harris), were sampled through the summer of 1984 on five cultivars and in 1985 and 1986 on six cultivars of field peas, Pisum sativum L., grown in field plots in southern Manitoba. Patterns of pea aphid population growth were generally similar among cultivars in any one year. Aphid populations on all cultivars in all years remained relatively low until mid-July, then increased rapidly, peaked at about the beginning of August, and declined sharply to low levels in late August. At the time of peak aphid numbers, significant differences in aphid population densities were found among cultivars in 2 years; the lowest densities were found on the cultivars Century and Tipu, and the highest densities on Triumph or Trapper. Pea aphid feeding was not detrimental to any yield parameters except 1000 seed weight. In 1984 Triumph and Tara, and in 1985 Triumph had significantly decreased 1000 seed weights in plots in which aphid densities were not controlled. Differences in the abundance of the aphid among cultivars were not reflected in their yield responses. Over 3 years the regression line of aphid densities upon Century seed weight was significantly steeper than those of Trapper, Lenca, or Tara. Trapper was least affected by aphid feeding. Results indicated that the economic threshold of pea aphids on peas other than Century needs to be re-evaluated.


2020 ◽  
pp. 120-125
Author(s):  
K. Elango ◽  
S. Jeyarajan Nelson

The rugose spiralling whitefly, Aleurodicus rugioperculatus Martin is a new exotic pest occurring in several crops including coconut since 2016 in India. Due to variation in the agro-climatic conditions of different regions, arthropods show varying trends in their incidence also in nature and extent of damage to the crop. Besides, abiotic factors also play a key role in determining the incidence and dominance of a particular pest and their natural enemies in a crop ecosystem. The population dynamics of new exotic whitefly species, A. rugioperculatus and their associated natural enemies was assessed on five-year-old Chowghat Orange Dwarf coconut trees at Coconut Farm of Tamil Nadu Agricultural University. The study indicated that RSW was found throughout the year on coconut and the observation recorded on weekly interval basis shows that A. rugioperculatus population escalated from the first week of July 2018 (130.8 nymphs/leaf/frond) reaching the maximum during the first week of October (161.0 nymphs/leaf/frond) which subsequently dwindled to a minimum during April. The parasitisation by E. guadeloupae on RSW ranged from 31.60 percent in Aug. 2018 to 57.60 percent in December 2018. The association of biotic and abiotic factors with A. rugioperculatus population showed a negative correlation with E. guadeloupae and C. montrouzieri. There was a significant positive correlation between maximum temperature and minimum temperature as well as relative humidity. However, rainfall showed a negative correlation with A. rugioperculatus population.


2020 ◽  
Vol 287 (1934) ◽  
pp. 20201493
Author(s):  
Gaurav Pandharikar ◽  
Jean-Luc Gatti ◽  
Jean-Christophe Simon ◽  
Pierre Frendo ◽  
Marylène Poirié

Legumes can meet their nitrogen requirements through root nodule symbiosis, which could also trigger plant systemic resistance against pests. The pea aphid Acyrthosiphon pisum , a legume pest, can harbour different facultative symbionts (FS) influencing various traits of their hosts. It is therefore worth determining if and how the symbionts of the plant and the aphid modulate their interaction. We used different pea aphid lines without FS or with a single one ( Hamiltonella defensa , Regiella insecticola, Serratia symbiotica ) to infest Medicago truncatula plants inoculated with Sinorhizobium meliloti (symbiotic nitrogen fixation, SNF) or supplemented with nitrate (non-inoculated, NI). The growth of SNF and NI plants was reduced by aphid infestation, while aphid weight (but not survival) was lowered on SNF compared to NI plants. Aphids strongly affected the plant nitrogen fixation depending on their symbiotic status, suggesting indirect relationships between aphid- and plant-associated microbes. Finally, all aphid lines triggered expression of Pathogenesis-Related Protein 1 ( PR1 ) and Proteinase Inhibitor (PI) , respective markers for salicylic and jasmonic pathways, in SNF plants, compared to only PR1 in NI plants. We demonstrate that the plant symbiotic status influences plant–aphid interactions while that of the aphid can modulate the amplitude of the plant's defence response.


1984 ◽  
Vol 116 (7) ◽  
pp. 950-963 ◽  
Author(s):  
A. P. Gutierrez ◽  
J. U. Baumgaertner ◽  
C. G. Summers

AbstractThe field population dynamics of pea aphid (Acyrthosiphon pisum) and blue alfalfa aphid (A. kondoi) in alfalfa (Medicago sativa), as influenced by weather, competitors (Egyptian alfalfa weevil = EAW, Hypera brunneipennis), predation from coccinellids (Hippodamia convergens) and harvesting practices, are examined with a stochastic multitrophic level simulation model. The model incorporates a demand-driven functional-response model to estimate prey consumption, and a metabolic pool model to determine the rates and priorities of food allocation to respiration, growth, reproduction, and egestion.The model results compare favorably with field data, and are used to examine the effects of removal of each of the above factors on the dynamics of the aphids. The model shows that the observed density of EAW did not affect the aphid dynamics, but did reduce the standing crop of alfalfa. The predator H. convergens had a significant effect on the population dynamics of the aphids and the plant. Harvesting greatly affected the aphid population dynamics, as well as the dynamics of plant growth and reserve accumulation. However, high temperatures mediated through species-specific respiration costs and possibly a fungal pathogen were responsible for the observed dominance of blue aphid populations in the cool parts of the year and pea aphid populations during warmer parts of the year.


Author(s):  
Joni Kumar ◽  
Bishwajeet Paul

Present studies deal with continuous observation of aphid population on different brassica species at every fourteen days interval. Five plants were selected randomly from each plot. The top 10cm terminal portion was used for counting of aphid population. The first appearance of aphid population was found at end of December in Brassica rapa var toria, B. rapa var yellow sarson and Brassica juncea. The correlation coefficients between aphid population and abiotic factors revealed contradictory results. Except for a few instances the abiotic parameters show a low order of association with aphid population. A significant negative correlation of aphid population was found with maximum temperature in B. rapa var toria (r= -0.963**), B. rapa var yellow sarson (r= -0.877*) and B. juncea (r= -0.913*). The population dynamics study of coccinellid beetles revealed that its population increased gradually with the increase of aphid population and vice-versa. In our experiment none of the weather parameters alone was responsible for the multiplication and growth of the aphid but it is assumed that during major part of rabi season, the meteorological parameters remained conducive for the rapid multiplication of aphid.


1970 ◽  
Vol 4 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Md. Altaf Hossain ◽  
Jannatul Ferdous ◽  
MMR Salim

Relative abundance of lentil aphid, Aphis craccivora Koch were investigated and yield loss assessment at different sowing dates during rabi season of 1999-2000 and 2000-2001 at Ishurdi Bangladesh. Lentil aphid appeared in field in the first week of January. The maximum aphid population (15.82/twig) was recorded in the first week of February 2000-2001, but the population reached to the peak was in the last week of January in 1999-2000, subsequently rainfall caused a sudden reduction of aphid population in latter dates. Aphid population and infestation increased with the delayed dates of sowing. The crop sown in November received less aphid infestation and consequently produced higher yield than the crop sown in December. During 1999-2000, the avoidable yield loss due to aphid infestation was recorded 0.90 to 6.78% and in 2000-2001 it was 2.65 to 9.00% depending on the different dates of sowing. Avoidable yield loss was less in November sowing crop than the crop sown in December. On the other hand, yield increased by 0.91 to 7.27% and 2.72 to 9.89% in 1999-2000 and 2000-2001 respectively, due to protection measures taken against aphids and this was also depend on different dates of sowing. Key words: Lentil aphid, delayed sowing, infestation, yield.


1981 ◽  
Vol 21 (112) ◽  
pp. 506 ◽  
Author(s):  
PM Ridland ◽  
GN Berg

Twenty-two lines of lucerne, six of annual Medicago spp., seven of Trifolium subterraneum, six of T. repens and six of several other Trifolium spp. were tested for seedling resistance to pea aphid, Acyrthosiphon pisum (Harris), in glasshouse tests at Burnley, Victoria. In general, lucerne cultivars selected for resistance to North American biotypes of the aphid were resistant to the Victorian aphid population. However, in our tests, two cultivars (Matador and Pioneer Brand 545) that were classed as susceptible to pea aphid in the USA. were as resistant as WL 31 8, a cultivar selected in the U.SA. for resistance to pea aphid. Medicago truncatula cvv. Borung and Cyprus were highly susceptible to pea aphid. They were more severely damaged than M. sativa cv. Hunter River, which was the most susceptible of the lucerne cultivars tested. M. rugosa cv. Paragosa had a high level of resistance while M. truncatula cvv. Hannaford and Jemalong, and M. littoralis cv. Harbinger were stunted but had only a low level of seedling mortality. Of the seven cultivars of T. subterraneum tested, only cv. Clare had a high level of aphid resistance, and all lines of T. repens were susceptible. The lines of T. fragiferum, T. incarnatum and T. pratense were more resistant than the susceptible check, T. subterraneum cv. Daliak, and should at least be tolerant in the field.


2020 ◽  
Vol 17 (2) ◽  
pp. 155-164
Author(s):  
S Neupane ◽  
S Subedi

Population dynamics of lentil aphid Aphis craccivora (Hemiptera: Aphididae) was assessed in relation with climatic parameters at the research field of National Maize Research Program (NMRP), Rampur, Chitwan during winter season of two consecutive years 2016 to 2018. The experiment was organized in randomized complete block design consisting 20 lentil varieties with three replications. The crop was sown during last week of November in both the years. The daily meteorological parameters like maximum temperature (Tmax), minimum temperature (Tmin), relative humidity (RH) and rainfall (Rf) were recorded at the meteorological station located in NMRP, Rampur, Chitwan and then converted into weekly basis as the standard meteorological week (SMW) with correspondence to weekly population of aphid. The incidence of aphid was started from 2nd SMW of January (2 aphid/plant/10 cm apical twigs) during both experimentation years. Initially the population was low and gradually increased and reached to its peak (49 aphid/plant/10cm apical twigs) on 9th SMW i.e. first week of March with correspondence to weather parameters viz. maximum and minimum temperature (°C), relative humidity (%) and rainfall (mm) were 30.80, 15.34, 67.72 and 0, respectively over the years. The aphid population had significant positive correlation with Tmax (r= 0.94) while the Tmin showed highly significant correlation (r=0.99). The relative humidity (RH) had non significant negative correlation (r= -0.90) and rainfall (Rf) showed non significant negative impact (r= - 0.15) with aphid population. The regression model developed could explain 99% variation in aphid population in different cultivars of lentil. SAARC J. Agri., 17(2): 155-164 (2019)


Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 878
Author(s):  
Mohannad Ismail ◽  
Penelope Zanolli ◽  
Frédéric Muratori ◽  
Thierry Hance

Herbivore-induced plant volatiles constitute the first indicators of insect host presence, and these can affect the foraging behavior of their natural enemies. The density of insect hosts may affect the nature and concentration of these plant-induced volatiles. We tested the impact of infestation density (low, intermediate, and high) of the pea aphid, Acyrthosiphon pisum (Homoptera: Aphididae), feeding on the broad bean Vicia faba, on the attractiveness of the parasitoid Aphidius ervi (Hymenoptera: Braconidae), using a Y-tube olfactometer (infested vs. non-infested plants). The emitted volatile compounds from both infested and non-infested plants were collected and identified. In addition, two series of experiments were carried out to test the impact of the presence of a conspecific female parasitoid within the aphid/plant complex on the attractiveness to other females. Parasitoids were significantly more attracted to the plants with low and intermediate aphid infestation levels. The volatile blend composition of the infested plants changed in relation to aphid density and may explain the low attraction of parasitoids toward high aphid density. The presence of conspecific females on the aphid patch had no apparent impact on the behavioral choices of other parasitoid females. Our study adds a new aspect to understanding plant–aphid–parasitoid interactions, including the possibility that aphids may manipulate chemical cues of host plants affecting the orientation of parasitoids.


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