Essential Oil Trunk Injection Into Orchard Trees: Consequences on the Performance and Preference of Hemipteran Pests

Abstract

Apples and pears are among the most widely cultivated fruit species in the world. Pesticides are commonly applied using ground sprayers in conventional orchards; however, most of it will not reach the target plant, increasing the contamination of nontarget organisms such as natural predators, pollinators, and decomposers. Trunk injection is an alternative method of pesticide application that could reduce risks to beneficials and workers. Essential oils represent a ‘green’ alternative to pesticides due to their reported insecticidal, antimicrobial, antiviral, nematicidal, and antifungal properties. The aim of this study was, therefore, to evaluate the impact that the injection of a cinnamon essential oil solution into the trunk of apple and pear trees could have on their respective pests, Dysaphis plantaginea and Cacopsylla pyri, respectively. The feeding behavior (preference), the life history traits (performance), and the timing of this effect were measured. The injection of an essential oil emulsion in trees impacted hemipteran host-plant colonization, as for both species a modification of their preference and of their performance was observed. The feeding behavior of D. plantaginea was altered as a significantly lower proportion of aphids ingested phloem sap on injected trees, suggesting that the aphids starved to death. On the contrary, the feeding behavior of the psyllids was little changed compared to the control condition, implying that the observed mortality was due to intoxication. The results presented here could theoretically be used to control these two orchard hemipteran pests, although the effectiveness in real conditions still has to be demonstrated.

The Effect of Essential Oils from Asteraceae Plants on Behavior and Selected Physiological Parameters of the Bird Cherry-Oat Aphid

“…The longer latency time indicates that aphids were reluctant to probe. Such behavior is usually associated with negative factors located at the plant's surface [34,36], and in our bioassays, it could be explained by the repellent effect of the applied essential oils, which discouraged the aphids from initiating probing. These findings corroborate the relatively high anti-settling activity of yarrow and Santolina oils, which was observed in the choice tests.…”

“…Several authors suggest that lipophilic active compounds of essential oils can penetrate the plant surface, pass into deeper tissue layers, and consequently interfere with aphid-feeding behavior [30,34,37]. The disturbances in the feeding process result in a reduction in nutrient intake and lead to a limitation of aphid development [36,38]. The results of our previous study have shown that essential oils from S. chamaecyparissus and T. patula negatively affected the bionomic parameters of R. padi and M. persicae.…”

An Evaluation of Insecticidal Trunk Injections for the Control of the European Cherry Fruit Fly Rhagoletis cerasi L. (Diptera: Tephritidae)

“…Endotherapy treatment is often used in urban plant protection for deciduous trees. Several experiments have demonstrated the successful use of trunk injection against different pests [21][22][23][24][25]. Walnut trees have been effectively treated with abamectin against the walnut husk fly (Rhagoletis completa) [24].…”