Life tables are indispensable in IPM, offering an analysis of insect population dynamics. These tables record survival rates, fecundity, and other parameters at various developmental stages, enabling the identification of key factors that affect population numbers and the prediction of growth trajectories. This review discusses the application of life tables in agricultural pest management, including the assessment of the pest control capacity of natural enemies, the evaluation of biological agents, and the screening of insect-resistant plant species. In vector insect control, life tables are used to evaluate the transmission risks, model the population dynamics, and interfere with the life cycles of vector insects. For invasive pests, life tables help us to monitor population dynamics and predict future population sizes. In chemical pest control, life tables assist in evaluating the fitness costs of pesticide resistance, guiding insecticide selection, and optimizing application timing. In the final section, we explore future research directions, emphasizing the potential of integrating new technologies such as genomics, ethology, and satellite remote sensing to enhance life table analysis and improve IPM strategies.
With the application and development of high-throughput sequencing technology, the structure and function of insect gut microbiota have been analysed, which lays a foundation for further exploring the intricate relationships between gut microbiota and host feeding behaviour. The microbial community in the insect gut, as an important ecological factor, affects the host’s food selection and nutritional metabolic processes through various mechanisms, which play a key role in population dynamics and ecosystems. The implications of these interactions are profound, affecting agricultural practices, biodiversity, and the broader environment, such as pollination and pest control. In-depth exploration of the molecular mechanism of the interaction between gut microbiota and hosts contributes to the grasp of insect biology and evolution and offers novel avenues for manipulating insect behaviour for practical applications in agriculture and environmental management. This paper focuses on the possible mechanisms of insect gut microbiota regulating host feeding behaviour. It inspires further research on the interaction between gut microbiota and insects affecting host behaviour.
Macrophages, as a critical component of innate immune cells, exhibit significant plasticity. When confronted with danger signals such as pathogens or microenvironmental alterations, macrophages can differentiate into various phenotypes and functions to safeguard the host. However, numerous pathogens manipulate macrophage metabolic pathways to modify their functional expression, facilitating immune evasion and ensuring long-term survival during chronic infections. Therefore, the role of macrophage metabolic reprogramming in chronic infections has received growing attention. This review elucidates the primary metabolic pathways of macrophages and their association with polarization. It examines how pathogens modulate macrophage functional expression through metabolic reprogramming to sustain chronic infection. Additionally, it delineates how macrophage metabolic reprogramming in chronic infections reconfigures the microenvironment through interaction with other immune cells and its contribution to trained immunity.
Macrophages are innate immune cells with essential roles in the immune response during helminth infection. Particularly, the direction of macrophage polarization could contribute to pathogen trapping and killing as well as tissue repair and the resolution of type 2 inflammation. This study establishes that the recombinant protein of Thelazia callipaeda macrophage migration inhibitory factor (T.cp-MIF) induces THP-1-derived macrophages to undergo M1 to M2 type dynamic polarization, using the methods of flow cytometry, real-time quantitative PCR, differential transcriptomic analysis and western blot. Interestingly, there was an increase in protein and mRNA expression of M1-type proteins and cytokines after the use of PI3K inhibitors, suggesting that the polarization state tends to favor the M1 type after M2 type inhibition. In conclusion, the dynamic polarization mechanism of T.cp-MIF-induced human THP-1-derived macrophages from M1 to M2 type is related to the binding of TLR4. It can first affect the M1 type polarization of macrophages by activating its downstream NF-κB pathway. Activation of the PI3K/Akt pathway and inhibition of NF-κB phosphorylation affects the M2 type polarization of macrophages.
Human thelaziasis caused by Thelazia callipaeda is being increasingly reported worldwide. Notably, an epidemic trend is observed in Southwest China. Whether Phortica okadai found in Southwest China can act as a vector of T. callipaeda and human-derived T. callipaeda animal infections has not been widely reported. Here, P. okadai was maintained in a laboratory and experimentally infected with first-stage larvae collected from adult T. callipaeda that were isolated from infected human subjects. Dead P. okadai were subjected to PCR assay and dissected every two days to detect T. callipaeda. Subsequently, live flies were used to infect a rabbit. The infection procedures were performed once a day (20 min) for two weeks. The results show that L1 collected from the adult T. callipaeda could successfully parasitize P. okadai captured in Zunyi, a city in Southwest China, and developed into L3, and a rabbit was successfully infected with T. callipaeda using P. okadai as the intermediate host. The present study demonstrates a human-derived T. callipaeda infection in rabbits, through P. okadai, under laboratory conditions for the first time. These results provide insights into the transmission cycle of T. callipaeda and constitute a foundation to develop an effective treatment protocol for T. callipaeda infection.
Phortica okadai, a polyphagous pest, serves as a vector for Thelazia callipaeda in China. Currently, there are no effective control strategies for this vector. Agricultural pest control may cause P. okadai to become a threat due to the development of pesticide resistance. Cytochrome P450s (CYP450) plays a significant role in detoxifying xenobiotics in insects. In this study, we performed RNA sequencing of P. okadai exposed to β-cypermethrin for 0 and 1 h and then gene cloning of the five up-regulated CYP450 genes. Three CYP450 genes were successfully cloned, and their expression patterns in different developmental stages and in different tissues were analyzed by RT-qPCR. Pocyp4d2 was observed to have the highest expression in the midgut (fold change 2.82 for Pocyp4d2, 2.62 for Pocyp49a1, and 1.77 for Pocyp28d2). Functional analysis was carried out according to overexpression in S2 cells from the pfastbac1 vector and RNAi with siRNA. The results of the CCK8 assay indicated that the overexpression of the recombinant protein PoCYP4D2 suppressed the decrease in S2 cell viability due to β-cypermethrin. The expression levels of PoCYP4D2 decreased significantly, and the mortality rates increased from 6.25% to 15.0% at 3 h and from 15.0% to 27.5% at 6 h after Pocyp4d2-siRNA injection. These results suggest that Pocyp4d2 may be an essential key gene in the metabolism of β-cypermethrin in P. okadai. This study constitutes a foundation to explore further the functions of P. okadai CYP450 genes in insecticide metabolism.