The lepidopteran pest, Spodoptera frugiperda (JE Smith), spread rapidly after its first detection in China and has caused significant yield loss to maize production in the southwestern part of the country. Although natural enemies of S. frugiperda are present in the field, biological control using naturally distributed predators is ineffective because their underlying populations are too low. To enhance our understanding of the potential role of natural enemies in regulating this invasive pest, functional response experiments were conducted to quantify the response of two predators, Orius sauteri (Poppius) (Hemiptera: Anthocoridae) and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in terms of consumption of S. frugiperda. Experimental results revealed that the predatory effects of nymphs of O. sauteri and H. axyridis on the eggs and larvae of S. frugiperda fitted Holling’s Type II functional response model. Importantly, the theoretical maximum number of prey consumed per day (N_a-max), the instantaneous attack rate (a′) and the handling time (Th) of O. sauteri nymphs on S. frugiperda eggs were 15.19, 0.7444 and 0.049 d, respectively; and the parameters on first instar larvae of S. frugiperda were 700.24, 0.5602 and 0.0008 d, respectively. These data contrast to those of H. axyridis, where the N_a-max, a′ and Th of adults on eggs of S. frugiperda were 130.73, 1.1112 and 0.085 d, respectively, and on the first instar larvae of S. frugiperda were 1401.1, 0.8407 and 0.0006 d, respectively. These results revealed that H. axyridis is a highly voracious predator of the eggs and young larvae of S. frugiperda and O. sauteri could also be used as biocontrol agent of this pest. Our work provides a theoretical framework for the application of natural enemies to control S. frugiperda in the field. Further research is required to strategize conservation biological control approaches in the field to increase populations of these predators and enhance the suppression of S. frugiperda.

Combining intercropping with the release of semiochemicals may strengthen biological control of aphids as a push-pull strategy that simultaneously repels aphids and attracts their natural enemies. This hypothesis was tested in the Henan Province of China in 2016 where aphids, their natural enemies and mummies were trapped and observed on crops in three treatments: wheat-pea strip intercropping solely (control), intercropping combined with the release of E-β-farnesene (EBF) and intercropping combined with the release of methyl salicylate (MeSA). Each treatment was repeated four times. The abundance of aphids throughout the growing season (9 weeks between March and May) was significantly decreased and the abundance of natural enemies and mummies were significantly increased in treatments with releases of semiochemicals compared to intercropping solely. The effect was stronger with MeSA than with EBF on the control of Rhopalosiphum padi and pea aphids as well as on the attraction of lacewings and hoverflies. Indeed, lacewings and hoverflies were on average twice more numerous in MeSA than in the other treatments. These results show that combining wheat-pea intercropping with the release of EBF or MeSA can significantly reduce aphid density and attract their natural enemies and that this effect is strengthen with MeSA when compared to EBF.

Ladybirds serve as crucial predators in agricultural ecosystems; however, their community dynamics in extremely arid regions are not well understood. We conducted a systematic survey of ladybirds across four habitat types—croplands, orchards, shelterbelts, and weedy margin—at 654 locations in the Taklamakan Desert–oasis ecotone in southern Xinjiang from May to September in 2018, 2019, and 2024. This was done using sweep-netting along with morphological and molecular identification methods. We collected a total of 5414 specimens, representing 23 different species. Hippodamia variegata and Stethorus punctillum were the most prevalent, making up 80.35% of the total individuals. The highest abundance and α-diversity were observed in June, which is significantly earlier than in temperate regions. Climatic factors alone accounted for the largest unique fraction of community variation (14.2%), followed by the shared habitat–month fraction (13.0%), with all predictor sets together explaining 32.5% of the variation. In this extremely arid region, climate accounted for the largest unique fraction among the measured predictor sets, while habitat and month jointly contributed, though 67.5% of community variation remained unexplained. Because climate was strongly confounded with month and geography, this fraction should not be interpreted as evidence of causal dominance. The assembly of ladybird communities was associated with the interaction of climate and habitat, but the relative importance of climate versus habitat requires further experimental validation. These results provide a correlational foundation for understanding ladybird community assembly in oasis agriculture, but further experimental work is needed before they can be translated into specific management actions.