Telenomus remus (Nixon) is a dominant egg parasitoid of the destructive agricultural pest Spodoptera frugiperda (J. E. Smith), and so is used in augmentative biocontrol programs in several countries. An optimized mass-rearing system is essential to produce biological control products in a timely and cost-effective manner. In this study, the photoperiod, host egg:parasitoid ratio, and exposure time were evaluated to identify the optimal rearing conditions for T. remus on the alternative host Spodoptera litura (Fabricius) eggs. Results showed that increasing photoperiod above 12L:12D remarkably improved parasitoid progeny yield and life table parameters. Overlong photoperiods shortened female longevity, but within acceptable limits. There was a significant negative correlation between parasitism rate and host egg:parasitoid ratio under exposure times of 12 and 36 h, but not 24 h. Percentage of female progeny increased significantly along with increasing the host egg:parasitoid ratio. A significant negative relationship between the number of emerged adults per egg and the host egg:parasitoid ratio was observed at an exposure time of 36 h. It was concluded that T. remus may be mass-reared most efficiently on S. litura eggs using a photoperiod of more than 12L:12D, a 14–20:1 host egg:parasitoid ratio, and an exposure time of 24 h. These findings can be used to produce T. remus more efficiently and at lower costs.

Accurate evaluation of morphological and physiological traits is critical for selection of wheat (Triticum aestivum L.) cultivars exhibiting high yield, which is stable over different growing conditions. In order to use selection index based on high yield, high grain quality and drought tolerance in wheat, a set of 145 CIMMYT Wheat Physiological Germplasm Screening Nursery lines and seven local spring wheat varieties were phenotyped and evaluated for physiological and yield traits under two irrigation regimes during the 2011 and 2012 growing seasons in Xinjiang, China. The results showed that drought-stress significantly increased canopy temperature but reduced grain yield, grain weight per spike, normalized difference vegetation index at the flowering and grain filling stages, chlorophyll content at the grain filling stage, grain plumpness, grain number per spike, thousand-grain weight, and plant height. Grain weight per spike, plant height and grain plumpness explained 61.8% of the total phenotypic variation in grain yield under no-stress conditions, where they were the three principal factors most closely related to grain yield. Under drought-stress conditions, canopy temperature at the grain filling stage, plant height and grain plumpness were the three principal factors affecting grain yield, and contributed 44.8% of the total phenotypic variation in grain yield. Finally, ten genotypes, including three local varieties, ‘Xinchun 11’, ‘Xinchun 23’ and ‘Xinchun 29’, with appropriate plant height and high and stable yield under both no-stress and drought-stress conditions over the two years of trials, were identified and can be recommended as core parents for spring wheat drought tolerance breeding in Xinjiang, China.

Understanding predator–prey interactions is essential for successful pest management by using predators, especially for the suppression of novel invasive pest. The green lacewingChrysopa formosais a promising polyphagous predator that is widely used in the biocontrol of various pests in China, but information on the control efficiency of this predator against the seriously invasive pestSpodoptera frugiperdaand nativeSpodoptera liturais limited. Here we evaluated the predation efficiency ofC.formosaadults on eggs and first- to third-instar larvae ofS.frugiperdaandS.liturathrough functional response experiments and determined the consumption capacity and prey preference of this chrysopid. Adults ofC.formosahad a high consumption of eggs and earlier instar larvae of both prey species, and displayed a type II functional response on all prey stages. Attack rates of the chrysopid on different prey stages were statistically similar, but the handling time increased notably as the prey developed. The highest predation efficiency and shortest-handling time were observed forC.formosafeeding onSpodopteraeggs, followed by the first-instar larvae.C.formosaexhibited a significant preference forS.lituraoverS.frugiperdain a two-prey system. In addition, we summarized the functional response and predation efficiency of several chrysopids against noctuid pests and made a comparison with the results obtained fromC.formosa. These results indicate thatC.formosahas potential as an agent for biological control of noctuid pests, particularly for the newly invasive pestS.frugiperdain China.

Dendroctonus rufipennis (Coleoptera: Curculionidae) is a major forest pest in North America, yet molecular studies on this species remain limited due to the lack of validated reference genes for quantitative gene expression analysis. This study systematically evaluated eight candidate reference genes (AK, EF1A, RPL32, RPS18, SDHA, TUBA, TUBB, and UBIQ) across diverse experimental conditions and developmental stages of the insect. The expression stability of these genes was assessed using four widely accepted algorithms: geNorm, NormFinder, BestKeeper, and ΔCt method. Our findings demonstrate that RPL32, RPS18, and SDHA exhibit the highest stability across developmental stages; TUBB and RPS18 are optimal for sex-specific and larval facultative diapause studies; RPL32 and RPS18 perform best for adult obligatory diapause termination and short-term cold exposure experiments. The relative expression levels of target gene kr-h1 significantly varied according to normalization with recommended combinations and the least suited reference genes. These findings provide a robust set of reference genes for normalizing gene expression in D. rufipennis, offering a valuable foundation for future molecular research on this ecologically significant pest.

Spodoptera exigua has emerged as a globally agricultural pest due to its strong adaptability to diverse nutritional conditions. In this study, we used artificial diets with a protein-to-carbohydrate (P:C) ratio of 1:1 as the control and examined the effects of extreme nutritional imbalances (P:C = 1:7 or 7:1) on survival and the activities of nine enzymes in third-stage larvae. The results showed that survival rates of larvae in both unbalanced diet groups were lower than those in the control group. High-carbohydrate-low-protein diets enhanced carboxylesterase, polyphenol oxidase, superoxide dismutase, peroxidase and three digestive enzymes (trypsin, amylase, lipase), cope with overeating and peroxide accumulation. The high-protein-low-carbohydrate diet exclusively increased lipase activity, confirming that larvae compensate for carbohydrate deficiency through lipid mobilization. These findings provide novel insights into polyphagy mechanisms in S. exigua, establishing a theoretical basis for predicting pest dispersal and developing control strategies.