Aphids and their parasitoids persist using temporal pairing and synchrony

The study analyzed the population dynamics of aphids and their parasitoids in winter cereals in southern Brazil, using wavelet transform (WT) to detect patterns of periodicity and synchronization over a decade (2011 to 2020). The wavelet analysis revealed different patterns of population peaks between aphid species and their parasitoids. Aphids, such as Rhopalosiphum padi L., Sitobion avenae (Fabricius), Schizaphis graminum (Rondani), and Metopolophium dirhodum (Walker), showed varied peak frequencies, with M. dirhodum consistently exhibiting a shortening interval between outbreaks. In contrast, parasitoids maintained more-constant patterns, with peak frequencies predominantly around 12 mo. Cluster analysis identified 4 highly synchronized aphid-parasitoid pairs: S. graminum-Diaeretiella rapae (MacIntosh), R. padi-Aphidius platensis Brèthes, S. avenae-Aphidius uzbekistanicus Luzhetzki, and M. dirhodum-Aphidius rhopalosiphi De Stefani-Perez. The wavelet coherence (WC) showed significant correlations between the time series of these pairs, ranging from in-phase to anti-phase relationships over time. The results indicate that wavelet analysis is a viable tool for characterizing non-stationary time series, such as aphid and parasitoid populations. Understanding these dynamics and synchronization patterns can support integrated pest-management strategies, enabling more effective and sustainable agricultural interventions.