Functional Response of Harmonia axyridis to the Larvae of Spodoptera litura: The Combined Effect of Temperatures and Prey Instars

Abstract

Functional responses are central to predator–prey dynamics and describe how predation varies with prey abundance. Functional responses often are measured without regard to prey size (i.e., body mass) or the temperature dependence of feeding rates. However, variation in prey size within populations is ubiquitous, and predation rates are often both size and temperature-dependent. Here, we assessed functional responses of larvae and adult Harmonia axyridis on the 1st, 2nd, and 3rd instars of the prey Spodoptera litura across a range of temperatures (i.e., 15, 20, 25, 30, and 35°C). The type and parameters of the functional responses were determined using logistic regression and fitted to the Roger's random predator equation. The magnitude of predation varied with the predator and prey stage, but prey predation increased with warming and predator age. Predation by the female and 4th instar of H. axyridis on the 1st instar of prey was greater, followed by the 2nd and 3rd instar of prey S. litura. No predation occurred on the larger prey for the 1st, 2nd, and 3rd instars of H. axyridis. The larvae and adult H. axyridis produced a type II (hyperbolic) functional response curve across all temperatures and the three prey types they consumed. Space clearance rates, handling time, and maximum predation rates of H. axyridis changed with temperature and prey size, increasing with temperature and decreasing with prey size, suggesting more predation will occur on younger prey. This study indicates an interactive role of temperature and prey/predator size in shaping functional responses, which might complicate the planning of effective biocontrol strategies against this serious pest.

Functional response of larval and adult Coccinella septempunctata to eggs and larvae of Plutella xylostella on canola

“…Temperature also affected the predation rate by adult N. kingbergii on P. xylostella but did not alter the functional response type (Ma et al, 2005). Low attack rates or handling times at low temperatures, as observed in our study, can be attributed to reduced effort invested in foraging for prey or longer resting times by the predators (Brown et al, 2004;Pruitt et al, 2011;Nunes et al, 2020;Islam et al, 2022;Lin et al, 2022). As temperatures increase, predator mobility increases, which allows for higher attack and consumption rates (Lang et al, 2012;Nunes et al, 2020;Gvoždík & Boukal, 2021;DeLong & Uiterwaal, 2022).…”

“…Among others, abiotic factors can influence predator–prey interactions and the functional response of predators to variation in prey density. Temperature variations can significantly change the nature of the functional response of insect predators, and their overall predatory behaviour, as insects are poikilothermic (Sentis et al., 2012; Chen et al., 2019; Islam et al., 2022). Such changes can be attributed to temperature‐driven variations in biochemical and physiological response rates in predators (Laws, 2017; Boukal et al., 2019; Gvoždík & Boukal, 2021) and can change trophic level interactions and energy transfer (Gillooly et al., 2001).…”

“…Linkage between temperature and functional responses of predators may thus help to predict the effectiveness of biological control programs, given that temperature is a key driving factor underlying invertebrate predator–prey interactions (Nunes et al., 2020; Lin et al., 2022). This is particularly relevant as climate change effects on agroecosystems have become a key concern because predator–prey interactions can be directly impacted by changes in temperatures (Garcia et al., 2018; Islam et al., 2022). Knowledge of predator–prey interactions is thus critical for the development of effective integrated pest management (IPM) tactics, particularly with reference to temperature effects on biological control with predators.…”

Effect of temperature on the life cycle of Harmonia axyridis (Pallas), and its predation rate on the Spodoptera litura (Fabricius) eggs

“…The population parameters and feeding rate of this predator have been shown to depend on the temperature and resource 30 . Using laboratory experiments, we showed that foraging by H. axyridis on the eggs and larvae of S. litura (eggs and larvae) is temperature-derived 23 , 35 . Predator (larvae and adults) increases its foraging with warmer temperatures and decreases with colder temperatures.…”

“…The family Coccinellidae includes a globally widespread group of predatory beetles that are polyphagous 16 and indicate preference for resource including transitions across kingdoms (Animalia, Fungi, and Plantae) and trophic levels (carnivorous and herbivorous) 17 . Many coccinellids are important predators of hemipterans, including aphids 10,18 , whitefly 19 , mealybugs 20 , scale insects 21 and immature lepidopterans 22,23 . Resource quality, thermal surroundings, mobility 24 , nutritional status 25 , as well as density and size of the prey 26 are critical determinants of predator development, biology 16 and predation parameters 12,[27][28][29] .…”