Biological traits and life table of the exotic Harmonia axyridis compared with Hippodamia variegata, and Adalia bipunctata (Col., Coccinellidae)

Abstract

As part of an environmental risk assessment study of exotic natural enemies used in inundative biological control, life-history characteristics of Harmonia axyridis (Pallas), Hippodamia variegata (Goeze) and Adalia bipunctata (L.) (Col., Coccinellidae) were quantified under laboratory conditions at 25°C on Myzus persicae (Sulzer) as prey. Comparative studies showed significant differences among pre-adult development times: H. axyridis developed slower ( X ¼ 19.8 days) than H. variegata ( X ¼ 18.1 days) and A. bipunctata ( X ¼ 18.4 days). Differences were also evident in the duration of egg, larval and pupal stages. No measurable differences among the three species were found for fecundity, oviposition rate and adult longevity. Harmonia axyridis exhibited the longest pre-oviposition ( X ¼ 7.4 days) and interoviposition ( X ¼ 3.6 days) periods and the shortest oviposition period ( X ¼ 13.7 days). The Bieri model was used to describe age-specific fecundity for the three species of coccinellids. The intrinsic rate of increase (r m ), net reproductive rate (R 0 ) and mean generation time (T) were higher for H. variegata (r m ¼ 0.114, R 0 ¼ 52.75, T ¼ 41.88 days) than for H. axyridis (r m ¼ 0.089, R 0 ¼ 26.27, T ¼ 38.81 days) or A. bipunctata (r m ¼ 0.081, R 0 ¼ 18.49, T ¼ 40.06 days). Our findings show that the biological traits of H. axyridis do not seem to be factors that may contribute to the invasiveness of this coccinellid.

Larval Life History Responses to Food Deprivation in Three Species of Predatory Lady Beetles (Coleoptera: Coccinellidae)

“…Reduced consumption of some aphids has been ascribed to certain alkaloids and other allelochemicals not suitable for the constitution and metabolism of the ladybeetles (Okamoto 1966 (ElHag and Zaitoon 1996), and 9.4 days for H. variegata reared on Myzus persicae (Lanzoni et al 2004). Variation in the presented findings may be ascribed to factors such as prey species, host plant of prey, rearing conditions, etc., that are reported to affect various biological parameters (Lanzoni et al 2004). Besides, geographical variations in the predator-prey system may also be important (Dobzhansky 1933).…”

“…The 4 th instar larvae suffered more as the prey abundance decreased, as the higher metabolic needs could not be catered to (Cividanes et al 2010). Larval survival in the range of 50-75% has been reported for H. variegata by different studies (ElHag and Zaitoon 1996; Lanzoni et al 2004;Wu et al 2010). Wu et al (2010) reported the adult emergence of H. variegata fed A. gossypii, reared on five host plants, varied from 87.23 to 100%.…”

“…Overall, pre-adult survival was found to vary from 44.06 to 58.97% depending on the host plant of the prey. Lanzoni et al (2004) reported the immature survival of H. variegata reared on M. persicae as 49.1%, while ElHag and Zaitoon (1996) reported 61.8% immature survival of H. variegata reared on B. brassicae.…”

“…Higher palatability of B. brassicae for A. tetraspilota and H. variegata larvae may be attributed to their nutrient contents, which probably ease digestion (Pervez and Omkar 2004). Reduced consumption of some aphids has been ascribed to certain alkaloids and other allelochemicals not suitable for the constitution and metabolism of the ladybeetles (Okamoto 1966 (ElHag and Zaitoon 1996), and 9.4 days for H. variegata reared on Myzus persicae (Lanzoni et al 2004). Variation in the presented findings may be ascribed to factors such as prey species, host plant of prey, rearing conditions, etc., that are reported to affect various biological parameters (Lanzoni et al 2004).…”

“…The predator species feed either on aphids or coccids, with a few feeding on both types of prey (Weber and Lundgren 2009). Owing to their seasonal synchrony with specific preys, high foraging performance, and high reproductive efficiency, the coccinellids have the potential to be effectively employed in integrated pest management programmes (Lanzoni et al 2004). In addition to many attempts to use them in classical biological control, some being highly successful, ladybeetles are also being translocated or mass produced and released for the control of various pests (Pu 1976;Singh 2004).…”