Population size and spatial distribution pattern of Schizaphis graminum (Hemiptera: Aphididae) on some wheat cultivars and lines

Abstract

Field experiments were conducted at wheat program of El-Mattana Agricultural Research Station, Luxor Governorate, Egypt during two successive growing seasons (2017/2018 and 2018/2019) to study the performance of some wheat cultivars and lines to infestation by Schizaphis graminum (Rondani) (Hemiptera: Aphididae) and their spatial distribution pattern. Results indicated that the total population density of S. graminum during the first growing season (2017/2018) was higher than second growing season (2018/2019). Also, the total mean of S. graminum population through the whole season was 20.83 ± 0.54 and 13.57 ± 0.34 individuals per 10 tillers over the first and second growing seasons, respectively. The obtained results indicated that Giza 171 and Giza 12 cultivars and lines of wheat (6, 11 and 13) were the highly susceptible varieties (HS) during the two seasons. On the other hand, Shandwel 1 and Sides 14 cultivars and lines 4 and 12 were rated as resistance to infestation (R) during the two seasons, these cultivars and lines of wheat plants should be promoted in the areas of high aphid infestation. It was also, noticed that the mean maximum population density of S. graminum was observed on Giza 171 cultivar, while, the minimum individuals of population were recorded on line 4 of wheat plants through the two growing seasons. Data were analysed using 21 distribution indices. All distribution indices indicated a significant aggregation behaviour during each growing season in all the tested wheat cultivars and lines. These pieces of information can be useful for planning an IPM program of aphid on wheat plants.

Spatial distribution pattern of male adults of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in lemon orchards in Northern Portugal

“…According to Green's model, it is recommended to place 2-3 delta traps with pheromone per hectare during periods of high population density and increasing the number of traps during periods when the population is typically low. The estimation of optimum sample size is fundamental for reducing the time required for monitoring pests (Bakry & Shakal, 2020;Ward et al, 1985).…”

“…According to Green's model, it is recommended to place 2–3 delta traps with pheromone per hectare during periods of high population density and increasing the number of traps during periods when the population is typically low. The estimation of optimum sample size is fundamental for reducing the time required for monitoring pests (Bakry & Shakal, 2020; Ward et al., 1985). Typically, the monitoring of P. citrella population involves the observation of larvae on young branches (Jahnke et al., 2008; Jesus & Redaelli, 2008; Liu et al., 2008; Tsagkarakis et al., 2011).…”

The Striped Mealybug Ferrisia virgata (Hemiptera: Pseudococcidae)Monitoring and Population Dispersion on Acalypha Shrubs and its Control in Luxor Region, Egypt

“…Many researchers have concluded that hemipteran pests have a high aggregated distribution behavior. Example: Chauliops fallax (Hemiptera: Malcidae) on soybean (Bala and Kumar, 2018), Waxiella mimosae on sunt trees (Bakry, 2018), Parlatoria oleae on mango trees (Bakry, 2020), Aulacaspis tubercularis (Hemiptera: Diaspididae) on mango trees (Bakry and Abdel-Baky, 2020), Icerya seychellarum on guava trees (Bakry and Arbab, 2020), Schizaphis graminum (Hemiptera: Aphididae) (Bakry and Shakal, 2020), and Phenacoccus solenopsis on okra plants . The data presented in Table (4) and Figure (5) showed the toxicity activity of some insecticides against F. virgate after 72 hrs of treatment.…”

“…These models can be converted from probability distributions to frequency distributions by multiplying each probability by the size of the mealybugs sample. This provides several advantages, such as expressing the spatial dispersion of the mealybug population in mathematical terms, evaluating errors in population parameters, comparing spatial and temporal shifts in mealybugs population density, and estimating the impact of ecological factors (Bakry, 2020;Bakry & Abdel-Baky, 2020;Bakry & Shakal, 2020;.…”

Responses of Local Wheat Varieties to Greenbug Schizaphus graminum and Bird-Cherry Oat Aphid Rhopalosiphum padi Infestation

“…Zeb et al (2011) tested the resistance of different varieties (Pirsabak-2004, pirsabak-2005, pirsabak-2008, KT2004, Khyber-81, PR1, R2, NRL0320, and Saleem-2000,they found that the susceptible variety PR1 recorded the highest average density for aphids, including S. graminum, with an average of 42.20 aphids.plant -1 , compared to the sensitive variety Pirsabak-2004, which recorded the lowest population density of aphids. Also, Bakry & Shakal (2020) stated that Giza-171 (susceptible variety) had the highest density of Greenbug, compared to variety Line 4 had the lowest density.…”