Document Type : Research Paper
Authors
1
Corresponding author, Senior Research Expert, Research Division of Conservation and Protection, Research Institute of Forests and Rangelands, Agriculture Research, Education and Extension Organization (AREEO), Tehran, Iran, Email: babmorad@gmail.com
2
Assistant Prof., Research Division of Conservation and Protection, Research Institute of Forests and Rangelands, Agriculture Research, Education and Extension Organization (AREEO), Tehran, Iran
3
Research Expert, Research Division of Conservation and Protection, Research Institute of Forests and Rangelands, Agriculture Research, Education and Extension Organization (AREEO), Tehran, Iran
10.22092/ijfrpr.2024.365928.1625
Abstract
Background and objectives: Euphrates poplar (Populus euphratica) is a fast-growing species in the family Salicaceae, naturally occurring in many regions of Iran and valued for wood production. Egeirotrioza ceardi (Hemiptera: Triozidae) is a major pest of P. euphratica in both natural and cultivated habitats, including Tehran province. This pest induces dense gall formations on leaves, disrupting photosynthesis, causing yellowing, and leading to premature leaf drop. This study investigated the biology and natural control factors of E. ceardi on Euphrates poplar trees in the National Botanical Garden of Iran during 2018 and 2019, with the aim of understanding its life cycle and evaluating the role of effective factors in controlling the pest population.
Methodology: Field and laboratory investigations were conducted to monitor pest population dynamics, nymphal damage, and natural enemies on 10–12 trees at intervals of 7–15 days.
Adult sampling involved shaking 20 branches (50 cm in length) from four cardinal directions of each tree into Schneider traps, along with the random collection of 20 additional branches (30 cm in length). In the laboratory, 80 leaves and 20 twig tips per tree were randomly selected and examined under a binocular microscope to record eggs, nymphs, galls, and parasitized nymphs. Specimens were either reared or preserved in 75%–80% ethanol. Additionally, to study the pest’s developmental stages under controlled conditions, 100 pairs of adults were released onto enclosed seedling twigs in the field.
Results: In the National Botanical Garden of Iran, E. ceardi adults appeared on P. euphratica trees from early March to late April, with slight variations between years due to weather conditions. Adults began feeding on newly emerged leaf buds from mid or late March, and females laid eggs on twigs, lateral buds, and both sides of young leaves. The average number o eggs per female was 75.03 ± 13.47 in 2018 and 63.71 ± 12.04 in 2019, with oviposition periods of 10.30 ± 1.98 days and 7.24 ± 1.58 days, respectively. Eggs hatched from late March or early April, with incubation periods of 10.38 ± 3.42 days in 2018 and 13.87 ± 4.23 days in 2019. The insect undergoes five nymphal instars. Nymphs, which feed on leaf sap, develop within galls on both leaf surfaces from late March or early April to mid November. Egeirotrioza ceardi overwinters as fifth-instar nymphs inside galls on dried leaves and completes one generation per year. The sex
ratio (male: female) was 1:1.44 in 2018 and 1:1.92 in 2019. More than ten predatory arthropod species were observed feeding on various life stages of E. ceardi. Additionally, birds andIranian Journal of Forest and Range Protection Research Vol. 22 No. (2), 2025 334 parasitoid wasps, particularly Psyllophagus spp. (Encyrtidae), were identified as natural enemies of the nymphs.
Conclusion: While climatic factors, particularly cold temperatures and heavy rainfall from late February to mid-April, played a major role in regulating E. ceardi populations, natural enemies had a limited impact on its control. In Tehran province, chemical control targeting adults, eggs, and first-instar nymphs before gall formation (mid March to late April) is recommended. Mechanical control, involving the collection and destruction of dried leaves from late autumn to late February, is also suggested as an effective management strategy.
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