Insects

The cottony cushion scale Icerya jacobsoni is a serious pest of agriculture and forestry, and the ladybird Novius penicillioides is an important predator of this pest. Temperature strongly affects insect development and reproduction, but the thermal biology of N. penicillioides remains unknown. Here, N. penicillioides was reared at six constant temperatures (17–32 °C) for immature development and survival, and at five temperatures (17–29 °C) for adult reproduction and life table analysis. Developmental duration decreased with rising temperature, whereas survival and fecundity were highest at 20–26 °C. Egg hatch rate fell to 0.25 at 32 °C, and fecundity at 29 °C was 84.3% lower than at 20 °C. The intrinsic rate of increase and finite rate of increase peaked at 26 °C (0.091 and 1.095), identifying this as the optimal temperature for population growth. The lower developmental threshold for the egg-to-adult period was 3.76 °C, with a degree-day requirement of 476.19 degree-days. At 32 °C, only 18% of immatures reached adulthood and the few surviving females failed to reproduce, indicating that the upper thermal limit for population growth lies between 29 and 32 °C. Given that natural enemies often have lower optimal temperatures than their prey, a thermal asymmetry may exist between N. penicillioides and I. jacobsoni, and continued warming could reduce its summer control efficacy. These findings provide key thermal parameters for optimizing mass rearing and field release strategies of this predator.

Habitat management using flowering plants on rice bunds and field ridges surrounding rice paddies can enhance conservation biological control by supporting beneficial predatory insects. However, multi-year field evidence for sesame (Sesamum indicum) when deployed as these bund-side flowering strips, and there is no molecular gut-content confirmation that the key predatory mirid bug Cyrtorhinus lividipennis preys upon rice planthoppers pests under field conditions. Over a two-year field experiment, we compared rice paddies with sesame-planted bunds against control paddies without bunds. We surveyed major piercing-sucking pests (brown planthoppers Nilaparvata lugens, white-backed planthoppers Sogatella furcifera, leafhoppers, and thrips) and their primary predator C. lividipennis throughout different rice phenological growth stages. PCR-based laboratory digestion assays were used to quantify the detectability of N. lugens DNA in the gut of laboratory-reared and field-collected C. lividipennis. Sesame-planted bunds significantly increased natural-enemy abundance (C. lividipennis) and reduced planthoppers, leafhopper, and thrips densities. Treatment effects varied by rice stage, with suppression mainly occurring from booting/heading to grain filling and no significant differences at tillering, and effects at maturity were weak. In the laboratory, N. lugens DNA detection declined from 68.75% at 0 h to 0% at 16 h after feeding. In the field, 37.5% of C. lividipennis from sesame-bund paddies tested positive for N. lugens DNA. These findings provide field and molecular evidence that sesame-planted bunds conserve C. lividipennis and contribute to suppression of piercing-sucking rice pests, supporting their use as an auxiliary habitat-management tactic in rice integrated pest management.

Royal jelly (RJ), the glandular secretion that determines honeybee caste, is also a high-value apicultural product. China supplies about 90% of the world production volume, almost entirely through high RJ-producing bees (RJBs) selected from Apis mellifera ligustica over four decades, or Chinese-selected a. m. ligustica population; these yield up to ten times more RJ per colony than ITBs. Here, we review and assemble the morphological, proteomic, genomic and behavioural evidence for that unusual selection response at four levels. RJ production may be dominated by a heritable polygenic trait whose acceptance and secretion components carry significant genotypic variance, and the selected candidate genomic architecture combines a large inversion with the tandem mrjp cluster. RJB nurses could detect larval volatiles more sensitively, and cross-fostering suggests that larval acceptance depends on the genotype of the nurse bees, not that of the larvae. RJB hypopharyngeal glands develop larger acini, delayed regression and reinforced protein synthesis, whereas mandibular glands up-regulate the fatty-acid pathway that may yield 10-HDA. An expanded nurse-stage neuropeptidome and a remodelled brain membrane proteome may tune larval recognition, water homeostasis and pollen collection. The proposed three coupled feedback loops and outline the experiments needed to test the model.