Search Results (3)

Marchalina hellenica Gennadius (Hemiptera: Marchalinidae) is a scale insect native to Greece and Turkey and presently invasive in Australia, where it damages pine plantations. The silver fly, Neoleucopis kartliana Tanasijtshuk (Diptera: Chamaemyiidae), is the most abundant predator of M. hellenica in Greece and is presently being investigated as a potential biological control agent following the scale’s introduction in Australia. This study, conducted in Northern Greece, revealed the presence of a second lineage, closely related to N. kartliana, referred to as Neoleucopis n. sp. B. Field surveys and laboratory experiments were conducted on M. hellenica and a taxonomically related scale insect, Icerya purchasi Maskell (Hemiptera: Monophlebidae), to test the larval growth and survival of the flies on the two prey species and assess their specificity for M. hellenica. The results suggest that both Neoleucopis spp. exhibit a high preference for M. hellenica when compared to I. purchasi. Larval growth was higher on M. hellenica than on I. purchasi but the difference was significant for N. kartliana only. Survival was significantly higher for both predators when provided M. hellenica compared to I. purchasi. Field surveys showed that both predators are abundant on M. hellenica colonies, whereas none of the two Neoleucopis lineages was found to have preyed on I. purchasi. Full article

Climate change creates favourable conditions for the growth of insect populations. Today, the world is seeing an increase in the number of insect pest infestations associated with a long-term increase in the average temperature of climatic systems. For example, local invasions of Icerya purchasi Maskell, a citrus pest recognized worldwide, have increased in size and number in recent years. Controlling this pest is complicated because not all chemical insecticides are effective, and their use is undesirable since citrus fruit is used for food and chemical agents cumulatively harm human health. In this article, we demonstrated for the first time the successful use of a short single-stranded fragment of the 28S ribosomal RNA gene called “oligoICER-11” to control cottony cushion scale, and we propose the use of green oligonucleotide insecticides with a low carbon footprint for large-scale implementation in agriculture and forestry. Using the contact oligonucleotide insecticide oligoICER-11 at a concentration of 100 ng/μL on I. purchasi larvae resulted in a mortality of 70.55 ± 0.77% within 10 days. Thus, climate change is driving the need in both agriculture and forestry for oligonucleotide insecticides (DNA insecticides, olinscides): safe, effective, affordable insecticides with a low carbon footprint and long operational life. Full article

Climate change is predicted to alter the geographic distribution of a wide variety of taxa, including insects. Icerya aegyptiaca (Douglas) and I. purchasi Maskell are two polyphagous and invasive pests in the genus Icerya Signoret (Hemiptera: Monophlebidae) and cause serious damage to many landscape and economic trees. However, the global habitats suitable for these two Icerya species are unclear. The purpose of this study is to determine the potentially suitable habitats of these two species, then to provide scientific management strategies. Using MaxEnt software, the potential risk maps of I. aegyptiaca and I. purchasi were created based on their occurrence data under different climatic conditions and topology factors. The results suggested that under current climate conditions, the potentially habitable area of I. aegyptiaca would be much larger than the current distribution and there would be small changes for I. purchasi. In the future climate change scenarios, the suitable habitats of these two insect species will display an increasing trend. Africa, South America and Asia would be more suitable for I. aegyptiaca. South America, Asia and Europe would be more suitable for I. purchasi. Moreover, most of the highly habitat suitability areas of I. aegyptiaca will become concentrated in Southern Asia. The results also suggested that “min temperature of coldest month” was the most important environmental factor affecting the prediction models of these two insects. This research provides a theoretical reference framework for developing policies to manage and control these two invasive pests of the genus Icerya. Full article