Scientia Agropecuaria 11(2): 233 – 236 (2019)

SCIENTIA AGROPECUARIA a. Facultad de Ciencias Agropecuarias Scientia Agropecuaria Universidad Nacional de Website: http://revistas.unitru.edu.pe/index.php/scientiaagrop Trujillo

SHORT COMMUNICATION

Influence of dietary condition on the ratio of the compounds emitted by larvae valdiviana (: )

1,* 1 2 Luis J. Reyes-García ; María José Muñoz ; Pamela Cuevas

1 Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Chile. 2 Escuela de Tecnología Médica, Universidad Santo Tomás, Limonares 190, Viña del Mar, Chile.

Received February 8, 2020. Accepted May 22, 2020.

Abstract (Lepidoptera, Cossidae), locally known as "Gusano del Tebo", is a polyphagous pest that, in its larval stage, feeds on the wood of the host species. C. valdiviana is distributed in the southern region of Chile and Argentina and its larvae mainly attack and fruit trees. Previous research has reported the identification of the volatile compounds produced by this species in its larval stage. In this work, the effects of two dietary conditions on these volatile compounds were described: groups of individuals fed with wood vs. others without food. The results obtained provide empirical evidence that C. valdiviana modulates the emission of the compounds according to the effect of stimulus.

Keywords: volatile emission; Tebo worm; Chilecomadia valdiviana; dietary condition.

acetate, and (Z)-5-Tetradecenyl acetate, 1. Introduction with relative abundances of 44%, 37%, and Chilecomadia valdivian (Philippi) (Lepidop- 14%, respectively (Bergmann et al., 2007). tera, Cossidae) is a polyphagous There is no consensus about the biological native to Chile that is associated with activity of these compounds. However, , antarctica, empirical evidence suggests that the ace- Nothofagus dombey, as well as other fruit tate compound of (Z)-5,13-tetradecadienyl species with economic importance for Chile, could act as an aggregation pheromone such as avocados, apple trees, olives, and (Reyes-García et al., 2011). This work aimed (Herrera et al., 2016). The larva forms to study the effects of two dietary numerous galleries in the host species, with conditions: groups of individuals fed with diameters of between 10 and 12 mm, wood vs. others without food. Based on the producing a large amount of sawdust and results of the feeding performance assay, debris. These consequences, the action of we further hypothesized that the nutritional woodpeckers and the entrance of orga- status of the larva (starved vs. nonstarved nisms such as fungi, ultimately cause rotting larvae) affects the ratio of the volatile of the wood (Ramos-González, 2017). There compounds emitted by the insect. No is little clarity about the life cycle of this previous reports are describing this species, but this has been estimated at behavior in larvae. between 1 and 3 years (Urra, 2016). This insect produces a series of volatile 2. Materials and methods compounds (short-chain acetates, 2.1 . Larvae of C. valdiviana were saturated and unsaturated) that, in previous purchased in fishing equipment stores in studies, were identified in larval hexane Quilpué and were identified according to the extracts. The major compounds found were morphological characteristics described by (Z)-5,13-tetradecadienyl acetate, dodecyl Olivares and Angulo (1992).

Cite this article: Reyes-García, L.J; Muñoz, M.J.; Cuevas, P. 2020. Influence of dietary condition on the ratio of the compounds emitted by larvae Chilecomadia valdiviana (Lepidoptera: Cossidae). Scientia Agropecuaria 11(2): 233 – 236.

------* Corresponding author © 2020 All rights reserved E-mail: [email protected] (L. Reyes-García). DOI: 10.17268/sci.agropecu.2020.02.10

-233- L.J. Reyes-García et al. / Scientia Agropecuaria 11(2): 233 – 236 (2020)

2.2 Extracts. The crude extract of larvae was mode with an injector temperature of 250 °C. prepared by maceration according to Teh et Helium was used as a carrier gas. al., (2017). For the analyzes of the studied The GC-MS analysis was performed with a treatments, larvae were taken at 24, 48, and Shimadzu team (Shimadzu, GCMS-QP2010 72 h. Ultra, Kyoto, Japan), using an RTX-5 column, and was programmed in a similar 2.3 Collection of volatiles. Larvae in their way to that described in the previous para- last stage were kept under controlled graph. The mass spectrum was acquired at conditions (25 ± 2°C, 40% relative humidity, 70 eV, and Helium was used as the carrier photoperiod L16: D8); ten individuals were gas. placed in each of two 2.5-L glass bottles conditioned as aeration chambers (Vera et 2.5 Statistic analysis. The relative per- al., 2016). Teflon tubes were used. centage of each compound was determined Eucalyptus wood was used to feed the in triplicate and analyzed by analysis of larvae. Air purified by activated charcoal variance (ANOVA), followed by the Tukey (50–200 mesh, Fisher Scientific Company, test (p ≤ 0.05), using the XLSTAT program Pittsburgh, PA) was passed through the (2009). chamber at a flow of approximately 2.5 L min-1. Volatiles were adsorbed on 200 mg of 3. Results and discussion activated charcoal (50–200 mesh, Fisher In the treatment of wood-fed larvae, a Scientific Company, Pittsburgh, PA), which gradual decrease (every 24 h) in the was placed in a glass tube (4 mm in diameter emission of compounds generated by the and 5 cm long). Glass wool was used to fix larva was detect, including (Z)-5-dodecenyl the charcoal in the tube. Samples were acetate (Z5-12:OAc), 7-dodecenyl acetate taken after 24, 48, and 72 h from the (7-12:OAc), 11-tetradecenyl acetate (11- beginning of the experiment. The adsorbed 12:OAc), and dodecyl acetate (12:OAc). volatiles was eluted with 1.5 mL of hexane About the compounds of (Z)-5,13- (Suprasolv, Merck). The samples were tetradecadienyl acetate (Z5,13-14:OAc) and concentrated using a gentle flow of (Z)-5-tetradecenyl acetate (Z5,14:OAc), an nitrogen. Samples were stored in screw cap increasing trend in the emission was vials at -20 °C until further analysis. detected (Fig. 1A). These compounds were detected in a greater proportion. In this ex- 2.4 Chemical analysis. The analysis by gas periment, the compounds 13-tetradecenyl chromatography was carried out using a acetate (13,14:OAc) and tetradecyl acetate Shimadzu equipment (Shimadzu, GC-2010 (14:OAc) were not detected. The ratio of Plus, Kyoto, Japan), which was equipped compounds present in the larva was with a flame ionization detector (FID), and a determined by the realization of hexane fused silica RTX-Wax capillary column RTX extracts, as described by Bergmann et al. was used (30 m × 0.25 mm RTX®-5 film, (2007), a study that described only the Restek, Bellefonte, PA, USA). This was percentage of compounds in the hexane programmed as follows: from 60 °C for 5 min extract, and in which variation in the up to 220 °C at 10 °C min-1. The gas emission of volatiles, overtime was not chromatograph was operated in splitless described.

Figure 1. The relative percentage of volatiles emitted by larvae of C. Valdiviana; A: feeding with wood and B: no feed. Statistical analysis was performed-by-compound. The values followed by different letters are statistically different (p < 0.05 according to ANOVA followed by the Tukey-Kramer test).

-234-

L. Reyes-García et al. / Scientia Agropecuaria 11(2): 233 – 236 (2020)

About the experiment where the larva was different phenotype from the ancestor kept without food, an increase in the (Henneken et al., 2017; Baker, 2002). For emissions of compounds Z5-12:OAc, 7- example, in the case of the species 12:OAc, 11-12:OAc, and 12:OAc was Trichoplusia ni (Lepidóptera, Noctuidae), increase; this effect is opposite to that the female can change the ratio of detected in the species fed. On the other compounds emitted due to a mutation of the hand, the compounds Z5,13-14:OAc and gene responsible for the production of Z5,14:OAc showed a decreasing emission pheromones, a change that is permanent (Fig. 1B), which is opposite to the results of and represents a reproductive disadvan- the first experiment (Fig. 1A). In this tage since this new mixture of compounds is experiment, the compounds 9-tetradecenyl not recognized by the males of this species acetate (9,14:OAc) and tetradecatrienyl (Allison, 2016). In other cases, diet- acetate (1,3,5-12:OAc) were not detected. mediated variation in the signal may provide Thus, the emission of these volatile indirect information about the signaller’s compounds differs according to the genotype, such as the genes responsible for stimulus over the insect is subjected, while an individual’s foraging ability (Henneken et the percentage of compounds found in al., 2017). extracts made by maceration of the larva In the case of the specific object of this was similar under the two tested conditions. study, the change in the ratio of compounds The compounds produced by the larva of the emitted is not permanent and can be C. Valdiviana species have been found in associated with epigenetic factors. In this other adult specimens of species belonging sense, the fact that the production of Z5,13- to the lepidopteran order and have various 14:OAc increases and the emission of reported biological activities. Thus, Z5- 12:OAc decreases (in the situation where 12:OAc, 7-12:OAc, and 11-12:OAc act the larvae are maintained with food), would mainly as pheromones of sexual attraction in indicate an alert to other individuals of their adult specimens (Zhang et al., 2016; species about the availability of food and Chynoweth et al., 2018; Williams et al., 2019; absence of threats, which would be a Fu-cun et al., 2017). On the other hand, condition of the oviposition site of adult 12:OAc has been reported in larvae of the females. Moreover, diet-related variation in species C. morei, cossus, and chemical cues emanating from predators Zeuzera pyrina. 12:OAc is also present in can be used by prey as cues revealing the species of the order Hymenoptera, in which presence of predators (Sharp et al., 2015). this compound has been reported as an In this way, the tendency of this species to alarm pheromone (De Bruijin et al., 2016; re-infest the trees already attacked in the Von Zuben et al., 2016). In the case of the previous season could be explained, as well insect Frankliniella occidentalis, 12:OAc as the presence of many larvae in the same works as a defense against several host. On the other hand, when the larva predators and is produced quickly after an remains without food, the fact that the attack. Thus, it is assumed that this behavior production of Z5,13-14:OAc decreases and facilitates its survival. On the other hand, the the emission of 12:OAc gradually increases compound Z5,13-14:OAc has been would alert individuals about the absence of identified in other larvae of the Cossus food, discouraging infestation of this sector. cossus family (Capizzi et al., 1983) although The results of this study could be explained the function of this compound is unknown, it through epigenetic mechanisms, which are was reported that, for the species C. conditioned by the environment in which the valdiviana, Z5,13-14:OAc acts as an species is found. Epigenetic modifications aggregation pheromone (Reyes-García et can change the expression of genes al., 2011). associated with the biosynthesis of these Several studies demonstrate the role of diet compounds (Antony et al., 2016; Benayoung quality for mate assessment pheromones et al., 2015), thus representing the complex across a wide range of taxa, including chemical communication system dependent insects (Baruffaldi and Andrade, 2015). on environmental variations. There are two mechanisms in which the relationship of mixtures of pheromonal 4. Conclusions components can vary, the first mechanism According to the results obtained, it can be involves small gradual changes of the concluded that larvae under different components, where the species stops dietary conditions (fed with wood and emitting a compound or changes the without food), showed specific differences relationship, while the second method in the volatiles emitted. Over the study’s involves a "saltational" change in which the period, there was a gradual change in the changes generate a large or completely ratio of the fatty acid derivatives emitted by

-235-

L. Reyes-García et al. / Scientia Agropecuaria 11(2): 233 – 236 (2020) the C. Valdiviana larva. This study is the first De Bruijn, P.; Egas, M.; Sabelis, W.; et al. 2016. Context- report describing the behavior of these dependent alarm signalling in an insect. Journal of Evolutionary Biology 29(3): 665-671. larvae about feeding. The evidence that Fu-cun, S.; Xiang-bo, K.; Su-fang, Z.; et al. 2017. dietary conditions can influence the Geographic Variation of Sex Pheromones in Three volatiles emitted by larvae suggests that this Populations of Dendrolimus kikuchii (Lepidoptera: Lasiocampidae). Forest Research 30(6): 993-998. information should be considered in the Henneken, J.; Goodger, J.; Jones, T.; et al. 2017. Diet- designing of experiments in similar studies. Mediated Pheromones and Signature Mixtures Can Enforce Signal Reliability. Frontiers in Ecology and Acknowledgments Evolution 4: 145. The authors acknowledge the financial support of Herrera, H.; Barros-Parada, W.; Flores, M.; et al. 2016. the Vice-Rectorate of Research and Postgraduate Identification of a Novel Moth Sex Pheromone Component from Chilecomadia valdiviana. Journal of of the University Santo Tomas (project code TAS Chemical Ecology 42: 908-918. o000022497). Olivares, T. and Angulo, A. 1992. Chilecomadia valdivia- na (Philippi): descripción de larva y pupa. (Lepi- ORCID doptera: Cossidae). Gayana Zoología 56: 181-184. L. Reyes-García https://orcid.org/0000-0002-7224-3226 Ramos-González, M. 2017. Las mariposas (Insecta:

M.J. Muñoz https://orcid.org/0000-0003-2318-0684 Lepidoptera) depositadas en el Museo de Historia

P. Cuevas https://orcid.org/0000-0002-5611-1688 Natural de Concepción, Chile. Colecciones Digitales, Subdirección de Investigación DIBAM. 1-27. Reyes-García, L.; Flores, M.; Vera, W.; et al. 2011. References Biological activity of the larval secretion of

Allison, J. 2016. Pheromone Communication in : Chilecomadia valdiviana. Journal of Chemical Evolution, Behavior, and Application. Editorial Ecology 37: 1137-1142. University California Press. Oakland, California, Sharp, J.; Garnick, S.; Elgar, M.; et al. 2015. Parasite and USA. predator risk assessment: nuanced use of olfactory Antony, B.; Ding, B.; Moto, K.; et al. 2016. Two fatty acyl cues. Proceedings of the Royal Society B: Biological reductases involved in moth pheromone biosynthe- Sciences 282: 1-5. sis. Scientific Reports 6: 29927. Teh, C.; Nazni, W.; Nurulhusna, A.; et al. 2017. Baker, T.C. 2002. Mechanism for saltational shifts in Determination of antibacterial activity and minimum pheromone communication systems. Proceedings of inhibitory concentration of larval extract of fly via the National Academy of Sciences 99: 13368-13370 resazurin-based turbidometric assay. BMC Baruffaldi, L.; Andrade, M. 2015. Contact pheromones Microbiology 17: 1-8. mediate male preference in black widow spiders: Urra, F. 2016. El gusano del tebo, la ansiada carnada. avoidance of hungry sexual cannibals? Available at: https://www.mnhn.gob.cl/613/w3- Behavior 102: 25-32. article-73189.html?_noredirect=1 Benayoun, B.; Pollina, E.; Brunet, A. 2015. Epigenetic Vera, W.; Parra, L.; Quiroz, A.; et al. 2016. Attraction to regulation of ageing: linking environmental inputs to host plant volatiles and feeding performance genomic stability. Nature Reviews Molecular Cell of Naupactus Xanthographus (Coleoptera: Curculio- Biology 16: 593-610. nidae) is affected by starvation. Journal of Insect Bergmann, J.; Lopez, K.; Buono-Core, G. 2007. Behavior 29(1): 48-56. Identification and synthesis of some fatty acid Von Zuben, L.; Schorkopf, D.; Elias, L.; et al. 2016. Interspecific chemical communication in raids of the derivatives from larvae of Chilecomadia valdiviana (Lepidoptera: Cossidae). Natural Product Research robber bee Lestrimelitta limao. Insectes Sociaux 21: 473-480. 63(2): 339-347. Capizzi, A.; Tonini, E.; Arsura, G.; et al. 1983. Sex Williams, L.; Serrano, J.; Johnson, P.; et al. 2019. 13- pheromone components of the European goat moth, Tetradecenyl acetate, a female-produced sex phe- . Journal of Chemical Ecology 9(2): romone component of the economically important 191-200. click beetle Melanotus communis (Gyllenhal) Chynoweth, R.; Rolston, P.; McNeill, M.; et al. 2018. Red (Coleoptera: Elateridae) Scientific Reports 9: 16197. clover casebearer moth ( deauratella) is Zhang, S.; Kong, X.; Ze, S.; et al. 2016. Discrimination of widespread throughout New Zealand. New Zealand cis-trans sex pheromone components in two Plant Protection 71: 232-239. sympatric Lepidopteran species. Insect Bioche- mistry and Molecular Biology 73: 47-54.

-236-