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The invasive mealybug Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) has become a key pest in Mediterranean citrus. This mealybug species excretes honeydew that can be consumed by ants, which may give rise to mutualistic relationships and increase the invasibility of this exotic pest. Here, we studied the interaction between D. aberiae and ants in 16 citrus orchards located in the main citrus-growing area of Spain (Valencia) during two consecutive years. Four native ant species were observed feeding on D. aberiae honeydew, and Lasius grandis Forel (Hymenoptera: Formicidae) represented more than 95% of these ants. Lasius grandis was observed attending D. aberiae throughout the year and in all the orchard sites where the mealybug was present. Mealybug colony size had a positive effect on both relative and absolute ant-attendance by L. grandis, but these interactions varied across seasons. Moreover, we found a positive correlation between L. grandis activity and D. aberiae density in all citrus orchards. Our results suggest that the native ant L. grandis and the invasive pest D. aberiae have established a mutualistic association that promotes the establishment and accelerate the invasion of D. aberiae in Spanish citrus orchards. Further research with the aim of evaluating whether the management of this ant species can improve the control of D. aberiae in citrus would be recommended. [ABSTRACT FROM AUTHOR]

The honeydew of Marchalina hellenica is collected by honeybees for pine honey production, which is of great economic importance in Turkey. During 2009-2011 we investigated the predators of M. hellenica, which is distributed mainly in the areas with a Mediterranean climate - in the Aegean, Marmara and Mediterranean regions of Turkey. The findings showed that M. hellenica has many predators in the studied areas and that these play an important role in the forest ecosystem. These predators are: Anystis baccarum (L.) (Acarina: Anystidae); Allothrombium triticium Zhang and Allothrombium pulvinum Ewing (Acarina: Trombidiidae); Neoleucopis kartliana (Tanasijtshuk) (Diptera: Chamaemyiidae); Myrrha octodecimguttata (L.), Rodolia cardinalis Mulstant, Scymnus subvillosus (Goeze) (Coleoptera: Coccinellidae), Dichochrysa genei (Rambur), Dichochrysa prasina (Burmeister) and Chrysoperla lucasina (Lacroix) (Neuroptera: Chrysopidae); Wesmaelius subnebulosus (Stephens) (Neuroptera: Hemerobiidae), Cardiastethus nazarenus Reuter and Elatophilus pachycnemis Horváth (Hemiptera: Anthocoridae). The most efficient and common predator was N. kartliana, here recorded for the first time from Turkey. [ABSTRACT FROM AUTHOR]

Recent research on invasive ants suggests that their success may be facilitated by increased resources at introduced locations stemming from the emergence of novel trophic interactions with abundant honeydew-producing Hemiptera. Moreover, those Hemiptera may themselves often be introduced or invasive. To test the importance of mutualisms for invasive species, we conducted a study in the southeastern United States of factors hypothesized to affect the abundance of an invasive ant native to South America, Solenopsis invicta. The study was conducted within grazing pastures, where S. invicta can be extremely abundant while also exhibiting substantial variability in abundance. A path analysis showed that the abundance of S. invicta was strongly and positively affected by the abundance of an invasive honeydew-producing mealybug native to Asia, Antonina graminis, and by the mealybugs' host grasses because of their strong positive effect on mealybug abundance. Abundance of the mealybug was primarily attributable to an invasive host grass native to Africa, Cynodon dactylon. The abundance of S. invicta was also positively affected by the abundance of other arthropods that they are likely to consume, and those arthropods were positively affected by the abundance of both the A. graminis host grasses and other plants. Thus the study shows that the distribution and abundance of different plant species could have important effects on the abundance of S. invicta through their effect on the ants' food resources. The results are also consistent with the hypothesis that the emergence of novel trophic interactions among invasive species can promote the abundance of invasive ants. [ABSTRACT FROM AUTHOR]