Host plant choice and effect of temperature on feeding behaviour of Perzelia arda (Lepidoptera: Depressariidae), a leaf‐tying larva, on Nothofagaceae from the Andean Patagonian forest

Abstract

Environmental temperature may cause changes in the physiology and feeding behaviour of herbivorous insects and, consequently, in the damage they can cause. In the Andean Patagonian forest, an eco-region dominated by trees of the Nothofagaceae family, it is common to find the leaf-tying larvae Perzelia arda consuming seeds and leaves of several species of Nothofagus genus. The pattern of damage caused by P. arda in these forests varies from year to year and even within seasons. We hypothesise that this phenomenon may be related to an increase in the ambient temperature of this region. The purpose of this work was to determine the host plant preferences of P. arda among four species of Nothofagus genus and to evaluate whether temperature influences the feeding behaviour of the larvae. We first evaluated the food preferences of P. arda by means of twochoice tests, using leaves of N. alpina, N. obliqua, N. antarctica and N. pumilio as stimuli. Secondly, we evaluated the effect of three levels of temperature on herbivory. Our results demonstrated that P. arda feed on and equally choose the four species of host plants studied. Temperature influenced the feeding behaviour of the larvae; high levels of consumption of N. obliqua occurred at 6°C and differed for the other host plant suggesting that consumption also depends on the type of food resource. In conclusion, the feeding behaviour of P. arda depends on a complex interaction between host plant and abiotic conditions. Further studies are required for a better understanding about the use of resources by this native insect, as well as the ecological consequences.

Host genetics determines food preferences of the moth Perzelia arda (Lepidoptera: Depressariidae)

“…These results agree with a previous study (Pietrantuono et al, 2017), which evaluated the preferences in P. arda between the leaves of several individuals of the closely related hosts N. obliqua and N. alpina, and showed that individual characteristics of each host plant (such as cellulose content) rather than taxonomic classification may determine herbivores choices. A preference gradient composed of individuals of both tree species was observed; that is, there is not one species more preferred than another but rather individual genotypes (see also Capobianco et al, 2021).…”

“…The data were analysed following the same methodology of Pietrantuono et al (2017) and Capobianco et al (2021). We evaluated the decisions made by the insects and established a scale of preferences based on the food choice of the larvae for each experiment.…”

“…According to previous works, the provenance Boquete is of great interest because it has a high genetic diversity and inhabits in a region that might keep suitability for the species under future climatic conditions (Marchelli et al, 2017). It is predicted that eastern locations might become climatically milder, and warmer conditions would increase the intensity of damage caused by P. arda (Capobianco et al, 2021). At the moment, this population has low densities of these species (pers.…”

“…The selected larvae were kept in transparent perspex containers (18 cm high × 13 cm wide × 26.5 cm long) with a lid with small perforations that allowed gas exchange but prevented their escape and were fed exclusively with N. obliqua leaves (inserted on a sponge with water to avoid dehydration) for 72 h, fed daily. Prior to the start of the experiment, all larvae were starved for 24 h (only a wick of cotton soaked in water was offered) to avoid the possible effect of their previous feeding on the choice (Capobianco et al, 2021; Pietrantuono et al, 2017). Those individuals that were not yet in this stage of development were maintained with the same feeding conditions until they reached the fifth stage and could be used for the experiment.…”

“…During the larval stage, P. arda feeds on seeds and leaves of N. alpina , Nothofagus antarctica , Nothofagus pumilio and Nothofagus obliqua (Baldini & Alvarado, 2008; Bauerle et al, 1997; Cerda et al, 1982; Grandon, 1996; Pietrantuono, 2020; Pietrantuono et al, 2017). Previous research has evaluated larvae decisions and herbivory among these four host plant species and determined the role of nutritional properties (i.e., lignin, hemi‐cellulose, cellulose, crude protein, dry matter, organic matter, non‐structural carbohydrates and apparent digestibility; Pietrantuono et al, 2017; Capobianco et al, 2021). These works demonstrated that for P. arda , certain sympatric host plant individuals are more attractive than others, regardless of the species to which they belong to and that the preference scale is strongly determined by a particular characteristic such as cellulose content.…”