Antioxidant Responses of Ragweed Leaf Beetle Ophraella communa (Coleoptera: Chrysomelidae) Exposed to Thermal Stress

Abstract

Ophraella communa LeSage is an effective biological control agent of common ragweed, Ambrosia artemisiifolia L., which competes with crops and causes allergic rhinitis and asthma. However, thermal stress negatively affects the developmental fitness and body size of this beetle. High temperatures cause a variety of physiological stress responses in insects, which can cause oxidative damage. We investigated the total protein content and activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidases (PODs) in O. communa adults when its different developmental stages were exposed to high temperatures (40, 42, and 44°C) for 3 h each day for 3, 5, 5, and 5 days, respectively (by stage), and a whole generation to high temperatures (40, 42, and 44°C) for 3 h each day. A control group was reared at 28 ± 2°C. Under short-term daily phasic high-temperature stress, total protein contents were close to the control as a whole; overall, SOD activities increased significantly, CAT activities were closer to or even higher than the control, POD activities increased at 40°C, decreased at 42 or 44°C; stage-specific response was also observed. Under long-term daily phasic high-temperature stress, total protein content increased significantly at 44°C, SOD activities increased at higher temperatures, decreased at 44°C; CAT activities of females increased at ≤42°C, and decreased at 44°C, CAT activities of males decreased significantly; POD activities of females increased at 40°C, decreased at ≥42°C, POD activities of males decreased at 44°C; and antioxidant enzymes activities in females were significantly higher than those in males. Antioxidative enzymes protect O. communa from oxidative damage caused by thermal stress.

Effect of short-term high-temperature exposure on the life history parameters of Ophraella communa

“…Ambrosia artemisiifolia seeds were collected from more than ten thousand plants in the town of Dajing (28°56′26″N, 113°14′38″E) in Miluo County, Yueyang City, Hunan Province, China, in late October 2010 74 . The seeds were then stored at 4 °C.…”

“…The seeds were then stored at 4 °C. Adequately stored seeds were germinated in a greenhouse in late March 2011, and when the seedlings reached a height of approximately 15 cm 74 , some of them were used in adult heat treatments and tests of longevity, fecundity, and F 1 egg hatching in O . communa .…”

Population Numbers and Physiological Response of an Invasive and Native Thrip Species Following Repeated Exposure to Imidacloprid

“…CarE, AchE, and MFO was determined spectrophotometrically at 600 nm, 412 nm, and 405 nm, respectively, by measuring the decrease of H 2 O 2 due to H 2 O 2 decomposition. One unit of CarE, AchE, and MFO activities were defined as the amount that decomposes 1 µmol of H 2 O 2 per second per mg protein (U mg −1 protein) (Jia et al, 2011;Chen et al, 2018).…”

“…POD activity was determined at 420 nm by catalyzing the oxidation of a substrate in the presence of H 2 O 2 . One unit of POD activity was defined as the amount that catalyzes 1 µg substrate per minute per mg protein (U mg −1 protein) (Jia et al, 2011;Chen et al, 2018).…”

The importance of timing of heat events for predicting the dynamics of aphid pest populations

“…The impacts of high temperature on insects are likely to be stage‐specific, because the behavior, thermal tolerance, physiological measures, developmental rates and metabolic rates following heat exposures vary ontogenetically in many taxa with complex life stages including Lepidoptera, Diptera, Coleoptera, Odonata and Blattaria . High temperature effects can also vary across stages in organisms with relatively simple life‐histories including Hemiptera and Homoptera .…”