Insects, being among the most diverse and abundant organisms in terrestrial ecosystems, are inevitably exposed to ubiquitous micro- and nanoplastic contaminants. Although studies on the impact of these contaminants on terrestrial insects are gradually emerging, they remain limited in scope. In this study, we investigated the biological traits (including foraging behavior, food assumption, digging ability, body weight and survival) of the Japanese carpenter ant, Camponotus japonicus, in response to exposure to polystyrene micro- and nanoplastic (PS-M/NP) solutions containing three particle sizes (0.05, 1 and 50 μm) and four concentrations (0.1, 1, 10 and 50 mg/mL). The results showed that worker ants exhibited significant foraging preference and food consumption for non-contaminated solutions in multiple-choice experiments, indicating that worker ants C. japonicus can differentiate and avoid feeding on PS-M/NP-contaminated solutions. Meanwhile, PS-M/NPs significantly reduced the foraging ability of worker ants in multiple-choice and no-choice experiments, with the smallest particle size (0.05 μm) and highest concentration (50 mg/mL) of PS-M/NPs resulting in the longest pre-foraging period, the lowest percentage of licking and the amount of food consumption. In addition, the weight of sand removed by worker ants, the body weight and survival of worker ants showed a dramatic decline with a decrease in particle size, increase in concentration and prolonged in exposure time of PS-M/NP-contaminated solutions. The results of this study confirm that PS-M/NPs have an adverse effect on these worker ants in a particle size, concentration and exposure time-dependent manner, with small particle size, high concentration and longer exposure time being the key factors in decreasing the foraging behavior and biological traits of this insect.

The camphor sawfly, Mesoneura rufonota Rohwer, is an economically important leaf-chewing pest of the genus Cinnamomum Trew. However, little is known about the range of species that it can infest within this genus or whether larvae show preferences for particular species. We conducted preference and performance experiments under laboratory conditions to assess larval host preference and suitability as a host plant of five congeneric trees species: C. camphora (Linn) Presl, C. bodinieri Levl., C. burmanni (Nees et T. Nees) Blume, C. pauciflorum Nees, and C. micranthum (Hay.) Hay. In no-choice, two-choice and multiple-choice feeding trials, significantly higher feeding rates were found on C. camphora, followed by C. bodinieri, compared to those on the other three tree species. In two-choice behavior trials, larvae moved to occupy leaves of C. camphora faster and more frequently, followed by C. bodinieri, than when offered the other three tree species. In no-choice fitness trials, the survival of larval and pupal stage was the highest, the developmental duration of larval and pupal stage was the shortest, the pupal body weight was the heaviest and adults lived the longest on C. camphora followed by C. bodinieri, while M. rufonota did not complete development on C. burmanni, C. pauciflorum or C. micranthum. Our results demonstrate that larvae consistently prefer and perform better on C. camphora leaves, that they can utilize C. bodinieri, but it is less preferred, and that C. burmanni, C. pauciflorum, and C. micranthum appear to be unsuitable as a host for M. rufonota.

The mealybug genus Saccharicoccus Ferris includes three species: S. isfarensis (Borchsenius, 1949), S. sacchari (Cockerell, 1895) and a new species, S. chinensis Zhang, Wu & Wu sp. n. The new species, collected on Miscanthus sp. (Poaceae) and other poaceous weeds in China, is described and illustrated, and molecular analyses based on the mitochondrial gene cytochrome c oxidase subunit I (COI) are provided. Additional data on the distribution and host-plants of each species are given, and a key to the adult females of Saccharicoccus species is provided.

A study of the mealybug genus Planococcus Ferris, 1950 (Hemiptera, Coccomorpha, Pseudococcidae) known from China is presented and 12 species are recognised. Of these, Planococcus camelliae Zhang, sp. nov. is described as new to science based on the morphology of the adult female, and P. bambusifolii (Takahashi, 1951) is recorded from China for the first time. Molecular analyses based on the mitochondrial gene cyto chrome c oxidase subunit I (COI) of the new species and a key to species of the genus Planococcus in China are also given.

The Cosmococcus species (Hemiptera: Coccomorpha: Lecanodiaspididae) found in China are reviewed. Based on morphological and molecular data, C. albizziae Borchsenius, 1960 syn. nov. and C. euphorbiae Borchsenius, 1959 syn. nov. are placed as junior synonyms of C. erythrinae Borchsenius, 1959. The wax tests of both sexes and the slide-mounted adult female of C. erythrinae Borchsenius are redescribed.

A new species of false pit scale (Hemiptera, Coccoidea, Lecanodiaspididae), Lecanodiaspis jiangxiensis Zhang & Wang, sp. nov., collected on Castanea mollissima Blume (Fagaceae) in Jiangxi, south China, is described and illustrated based on the morphology of the adult female. A taxonomic key and an updated checklist of false pit scales known from China are provided.