Combinations of entomopathogenic nematodes Steinernema longicaudum X-7 and Heterorhabditis bacteriophora H06 with chlorantraniliprole, diflubenzuron, and imidacloprid insecticides at different rates for the control of the white grub, Holotrichia oblita Faldermann (Coleoptera: Scarabaeidae), were evaluated both in the laboratory and in peanut fields. In the laboratory, the combinations had a synergistic or additive effect on the second-instar larvae of H. oblita and caused faster mortality than one nematode species or insecticide alone. Heterorhabditis bacteriophora–chlorantraniliprole and H. bacteriophora–imidacloprid showed synergistic effects on the larvae. When higher concentrations of the insecticides were combined with nematodes, the stronger synergistic effects were found. In peanut fields, S. longicaudum–imidacloprid, H. bacteriophora–imidacloprid, or H. bacteriophora–chlorantraniliprole also showed synergistic effects against the larvae. The three nematode–insecticide combinations produced similar percentage reductions of the grub larvae and less percentages of injured legumes, compared with the chlorpyrifos treatment. Cost–benefit analysis showed that H. bacteriophora 5.0 × 103 infective juveniles (IJs) per plant (equal to 7.5 × 108 IJ ha−1) combined with imidacloprid at the recommended concentration is a practical strategy for the practitioner to manage the white grubs in the peanut production.
This study explored the flower visiting behaviors and pollination abilities of mason bees (Osmia excavata Alfken (Hymenoptera: Megachilidae)), bumble bees (Bombus terrestris (Linnaeus, 1758) (Hymenoptera: Apidae)), and Italian honey bees (Apis mellifera ligustica Spinola (Hymenoptera: Apidae)) in apple orchards in early spring in Jinan (located in the central region of Shandong) and Yantai (located in the Peninsula of Shandong). We compared the pollen collection patterns, flower visiting behavior, flying speed, and effects on apple pollination of the 3 types of bees. The frequencies of flower visits were significantly higher for mason bees (12.89/min in Jinan and 10.63/min in Yantai) than bumble bees and Italian honey bees in the 2 regions. The single flower residence times were significantly higher for Italian honey bees (8.22 s in Jinan and 9.43 s in Yantai), but Italian honey bees were most affected by the climate. The 3 bees differed significantly in terms of the amount of apple pollen collected and their effects on the fruit setting rate in apples (mason bees > bumble bees > Italian honey bees). The results showed that the mason bee was the most suitable pollinating species for spring apple orchards; Bumble bees were more suitable as alternative pollinators during cloudy and low temperatures; Italian honey bees were able to take advantage of their large number of worker bees in sunny and warm weather. Compared to individual bee species, a combination of 2 or 3 species of bees might be more advantageous in dealing with complex and variable weather conditions.
‘Baiwei’ (swallowwort root, Cynanchum versicolor Bunge), is a perennial cranberry type of Chinese medicinal herb, and grows in mountains with wide distribution in many provinces including Shandong,...
Zeugodacus tau Walker (Diptera: Tephritidae) is a quarantine pest of cucurbit crops in China. In recent years, the damage it has caused to Trichosanthes kirilowii (Cucurbitales: Cucurbitaceae) has increased, but evidence for host adaptation and population growth on this plant remains limited. We investigated the suitability of T. kirilowii as a host plant for Z. tau, compared with the known suitable host Cucurbita moschata, by examining adult olfactory preference, oviposition choice, and demographic performance using an age–stage, two-sex life table. Females preferred T. kirilowii significantly more than C. moschata in cases of both peeled and unpeeled fruits, whereas males showed no significant difference. Oviposition was also higher on T. kirilowii and further increased on peeled fruit. Developmental duration, total longevity, ovipositing days, oviposition period, and hatching rate did not differ between the two host species. However, Z. tau reared on T. kirilowii exhibited significantly shorter APOP and TPOP, along with higher fecundity and increased pupal weight. Life table parameters indicated higher intrinsic (r = 0.1028 ± 0.0040 d−1) and finite rates of increase (λ = 1.1083 ± 0.0044 d−1) on T. kirilowii, whereas R0 was similar and mean generation time was shortened by 11.61 d. A 100-day projection predicted 11,980 adults from T. kirilowii compared to 1231 from C. moschata. Overall, T. kirilowii is a highly suitable host that supports the rapid population growth of Z. tau.
Agricultural intensification has weakened natural pest regulation by reducing habitat resources for natural enemies and limiting plant-mediated resistance. Here, we conducted field experiments during 2024–2025 to evaluate the combined effects of Cnidium monnieri field-margin planting and maize seeds coated with the endophytic fungal strains YC (Beauveria bassiana) and PL (Purpureocillium lilacinum) on predator conservation, pest suppression, and biological control in maize agroecosystems. Compared with natural grass margins, C. monnieri significantly increased predator abundance, species richness, and Shannon diversity, particularly of ladybirds, minute pirate bugs, and spiders (p < 0.05). Gut-content analysis detected C. monnieri DNA in ladybirds collected 10–40 m from field margins, confirming predator resource use and spillover into maize fields. Importantly, endophytic fungus-coated seeds did not reduce predator abundance or diversity. Moreover, combining C. monnieri with endophytic fungi enhanced pest suppression and achieved control efficacy comparable to imidacloprid (p > 0.05). These findings demonstrate that integrating functional plants with endophytic fungi simultaneously strengthens top-down biological control and endophyte-associated bottom-up pest suppression, providing an effective and environmentally sustainable strategy for pest management in maize.