Showing 4 results for Aphids
Fatemeh Momeni Shahraki, Kambiz Minaei, Shalva Barjadze,
Volume 5, Issue 4 (12-2019)
Abstract
The paper presents a comprehensive compilation of 543 species and 24 subspecies of aphids, within 144 genera, belonging to 15 subfamilies, 3 families and three superfamilies of Aphidomorpha recorded to date from Iran. Among them, 35 species of aphids are endemic to Iran.
Samir Ali-Arous, Malika Meziane, Khaled Djelouah,
Volume 9, Issue 1 (3-2023)
Abstract
The survey was carried out in some citrus orchards in the area of Bernalda, in the region of Basilicata, south Italy. Aphids and their natural enemies were monthly sampled from citrus tree canopies and spontaneous plants in four citrus orchards differently managed (organic and conventional with and without herb layer). Four weed species (Rumex crispus, Sonchus oleraceus, Euphorbia peplus and Vicia sp.) were reported as hosts of four non-pest aphids of citrus, which were Myzus persciae, Acyrthosiphon pisum, Hyperomyzus lactucae and Aphis rumicis, serving as preys for natural enemies including coccinellids (Coleoptera, Coccinellidae), lacewings (Neuroptera, Chrysopidae), hoverflies (Diptera, Syrphidae) and various parasitoid species (Hymenoptera, Braconidae) that were recorded on citrus canopies. Statistical analysis of collected data showed a positive correlation between weed management systems and wild plants hosting aphidophagous communities. Furthermore, organic weeding approaches had a positive effect on aphidophagous richness and abundance, whereas the conventional weeding method could cause scarcity of aphid natural enemies, but interactions among strata (entomofaunal diversity on citrus tree canopies & wild plant cover) are still unclear. Overall, this work is a further step towards the investigation of the interaction between plants, crops and arthropods in citrus orchards in the Mediterranean basin to make weed management strategy a key for aphid management in crops.
Volume 11, Issue 5 (11-2009)
Abstract
Population dynamics of three main alfalfa aphids, namely: pea aphid, Acyrthosiphon pisum (Harris), spotted alfalfa aphid, Therioaphis trifolii forma maculata (Buckton), black alfalfa aphid, Aphis craccivora Koch, and their most abundant predators and parasitoids in three sites and in two subsequent years in Isfahan, Iran, were investigated. The results revealed that frequency and temporal occurrence of alfalfa aphids and their natural enemies in different regions were varied, but aphid natural enemy populations were more or less coincident with aphid populations. Populations of aphids were mainly affected by alfalfa harvesting, ambient temperature, and coccinellid predators. Hemipterous predators in contrast with coccinellids, had little effect on aphid populations. Parasitoids seem to be effective on low populations of alfalfa aphids. Air humidity and rainfall had no effect on populations of alfalfa aphids.
Volume 27, Issue 3 (11-2024)
Abstract
Environmental stressors such as heat, cold, or natural enemies may alter insect genetics, behavior, morphology, or physiology, increasing their offspring's survival. Special traits and variations in population characteristics of insects enhance their resistant genotypes and can lead to adaptation to stressors under local conditions. Insects' reactions to stressors, such as toxins, plant defense toxicants, or insecticides, trigger internal hormonal secretions. Changes in host plants or feeding on blood produce metabolic stress and neural signal responses in insects. Mild stress is often tolerated by insect pests. Continued stress may activate the neuroendocrine system and produce hormones that defend against stress, increasing the pest's tolerance. Mimesis and camouflage in insects are evolutionary responses to escape the stresses of natural enemies. Fluctuating asymmetry and morphological changes in pest populations are also caused by stress. The reaction of cells to stress involves cytogenetic changes and the formation of various proteins through genetic signals that affect cell energy acquisition. In this article, we discuss the effects of stress on a few species of medically important insects and how pests cope with stress factors that affect their biology.
