We evaluated the direct effects of three different atmospheric CO₂ concentrations (380 ppm, 550 ppm and 750 ppm) on the population parameters of the cotton bollworm, Helicoverpa armigera fed an artificial diet. The life history and fitness of H. armigera were analyzed using an age-stage, two-sex life table. Our results showed significantly longer larval durations and lower female pupal weight under elevated CO₂ than under ambient CO₂. Additionally, the fecundity of H. armigera was lower under elevated CO₂ than under ambient CO₂. H. armigera reared under elevated CO₂ conditions showed lower intrinsic and finite rates of increase but higher net consumption and finite consumption rates than H. armigera reared under ambient CO₂ conditions. According to population projections, a much smaller total population size and reduced consumption capacities would be expected in an elevated CO₂ atmosphere due to higher mortality and lower growth rate compared with ambient CO₂ levels. These results indicate that the fitness of and potential damage caused by H. armigera would be affected by increased CO₂ relative to ambient CO₂ concentrations. Additional studies on the long-term direct and indirect effects of elevated CO₂ levels on H. armigera are still needed.

This study investigated the effects of diallyl trisulfide (DAT), an active substance from garlic essential oil, on the metabolism of the main energy substances of pre- and postmating males of Sitotroga cerealella. Males at 12 h postemergence were fumigated with DAT at a concentration (LC₁₀ = 0.010 µL/L) in a glass jar for 7 h. The main energy metabolites from pre- and postmating males were determined, including protein, triglyceride, glycogen, total soluble sugar, trehalose, and trehalase. The contents of total protein and total soluble sugar and the trehalase activity of premating males were significantly increased following DAT treatment, whereas the contents of protein from the accessory gland, triglyceride, glycogen, and trehalose were significantly decreased after treatment. Additionally, after mating, the total protein and soluble sugar contents were significantly increased and the glycogen content was significantly decreased in the treatment group relative to the levels in controls, but there was no significant difference observed in triglyceride, accessory gland proteins, trehalose content, or trehalase activity between the treatment and control groups. Furthermore, the changes in the main energy substances between pre- and postmating in males after the DAT treatment (∆DAT) were smaller than those in the control group (∆CK). This result indicated that DAT can accelerate the rate of metabolism in males at LC₁₀, leading to the accumulation of greater levels of total soluble sugar to support life activities and to the increased synthesis of proteins to resist an adverse environment.

The Angoumois grain moth, Sitotroga cerealella (Olivier, 1789) (Lepidoptera: Gelechiidae), is primarily a pest of stored products, that feeds inside the grain as larvae inducing significant economic loss in various stored commodities. Our previous studies proved that garlic essential oil and its active substances inhibit oviposition in moths. To further explore the effect on reproductive behavior and accurately interpret the results in terms of effective control of the moth population, moths were treated with diallyl trisulfide (DATS), an active substance of garlic essential oil, at a dose of 0.015 µL/L in air (LC₂₀, sub-lethal concentration). The results showed that fecundity and the proportion of viable eggs significantly decreased when the moths were treated with LC₂₀ DATS. Furthermore, female circadian mating rhythms and calling periodicity changed significantly after treatment. Compared with controls, the peak in mating occurred approximately 1 h earlier on the first day after DATS treatment, while it was significantly later on days 2 and 3. Moreover, mating frequency declined in presence of DATS compared with the controls. The percentage of females engaging in calling behavior decreased significantly with time, to less than 50%, 2 days after treatment, while a high calling percentage (>80%) was recorded for control moths on all 4 days. In addition, DATS had an inhibitory effect on the mating duration of S. cerealella. Moreover, a significant reduction was observed in the amount of sex pheromones extracted 8 h and 9 h after treatment. Our findings suggested that DATS has the potential to manipulate the moth population at LC₂₀ and would be an efficient alternative to synthetic insecticides for the control of pests having low toxicity to non-target organisms and ecosystems.

Osphya Illiger (Melandryidae: Osphyinae) as a species-poor insect group, exhibits a widespread distribution in the Northern Hemisphere, however, the research of the genus is poorly documented especially in East Asia. Herein, an interesting species is discovered in Shennongjia National Natural Reserve (Hubei, China). The examination of morphological characters and comparisons with others show it to be a new member of Osphya, which is described under the name of O. sinensis sp. n. The characteristic photos and a key to the species of Osphya from East Asia are provided. Meanwhile, the mitochondrial genome of O. sinensis sp. n. is sequenced and annotated. Based on this obtained mitogenome and the publicly available data, we reconstructed the phylogeny of Tenebrionoidea by different cladistics methods to investigate the relationships between the new species with others. The results consistently recover O. sinensis sp. n. sister to O. bipunctata (Fabricius) with high supporting values, which further confirm the placement of the new species in the genus Osphya. This is the first time reporting the genus Osphya, the only representative genus of melandryid Osphyinae from mainland China, which enriches the diversity of beetles from the Chinese fauna at both generic and subfamilial levels.