C‐type lectins (CTLs) are a superfamily of proteins found in almost all vertebrates and invertebrates. They play an important role in innate immune defences, development and epidermal structure. Here, a CTL with one carbohydrate‐recognition domain containing a highly conserved Gln‐Pro‐Asp (QPD) motif was identified in Tribolium castaneum and given the name TcCTL5. Spatiotemporal analyses showed that Tcctl5 was highly expressed in the late pupa stage and mainly existed in the central nervous system and haemolymph. The transcript level of Tcctl5 was prominently induced after bacterial infection. Recombinant TcCTL5 proteins (rTcCTL5) were found to bind to lipopolysaccharide, peptidoglycan and tested bacteria and induce microbial agglutination in the presence of Ca2+. Interestingly, when Tcctl5 was knocked down, the transcript level of antimicrobial peptides (AMPs) (attacin1, defensins3, coleoptericin1 and cecropins3) was prominently downregulated after induction with Gram‐negative Escherichia coli. More interestingly, Tcctl5 was knocked down, leading to increased mortality and loss of locomotor activity, which exhibited less travel distances among early adults. These results demonstrate that Tcctl5 plays an important role in the innate immune reaction and the movement of T. castaneum. Thus, it may represent an alternative molecular target for pest control and thus reduce the use of pesticides in agricultural production.

In this study, four land use type soils from Yingtan Jiangxi Province China, i.e., forest (F), bamboo (B), tea plantation (TP) and upland (U), were collected, and gene of ammonia-oxidizing archaea (AOA) and bacteria (AOB), nirS, nirK, and nosZ were determined, to identify the effects of land use on abundance of microorganism in red soil and their role to nitrification and denitrification. The result shows that AOA copy numbers ranged from 6.20 × 106 to 6.58 × 106 copies/g soil and AOB varied from 4.18 × 106 to 7.41 × 106 copies/g soil. The highest AOA and AOB were all measured in U soil that was the highest pH and the lowest C/N ratio. The Abundance of AOB is stimulated by enhancing soil pH due to lime application and more available NH4+ from N fertilization that could be responsible for the high net nitrification rate in U soil. Meanwhile, nirK copy numbers ranged from 6.46 × 106 to 7.05 × 106 copies/g soil, nirS from 5.50 × 106 to 5.85 × 106 copies/g soil, and nosZ from 6.57 × 106 to 7.35 × 106 copies/g soil. The nirS (p<0.05) and nirK (p<0.05) was positively correlated with soil potential denitrification rate.