Predation of the apefly,Spalgis epius(Lepidoptera: Lycaenidae) on citrus mealybug,Planococcus citri(Hemiptera: Pseudococcidae)

Abstract

The citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is a serious pest of economically important crops worldwide. The apefly, Spalgis epius (Westwood) (Lepidoptera: Lycaenidae) is a potential predator of various species of mealybugs. Earlier investigation on its daily preying capacity and preference for prey stages on P. citri is incomplete. Hence, a study was conducted to find out the daily prey consumption ability and preference for prey stages by different larval instars of S. epius reared on P. citri in the laboratory. Through the 8-day developmental period with four larval instars, the daily prey consumption of S. epius increased from the first to the seventh day and decreased on the eighth day prior to the prepupal stage. Generally, there was a significant difference in the prey consumption on different days. When the prey stages were offered separately, the first to fourth instar larva of S. epius consumed, respectively, a mean of 199.6, 722.6, 1908.8, and 4625.6 eggs or 21.5, 77.0, 168.5, and 670.5 nymphs or 3.2, 7.2, 16.0, and 35.1 adults of P. citri. When an S. epius larva was fed on P. citri eggs, nymphs and adults separately, it consumed a mean of 7456.7 eggs, 937.6 nymphs, or 62.3 adults during its entire development. When the prey stages were offered all together, a single S. epius larva consumed 2618.4 eggs, 170.4 nymphs, and 39.7 adults of P. citri throughout its entire development. The study revealed that S. epius is a voracious predator of P. citri and thus could be utilized as a major biological control agent.

Inter- and intraspecific interactions in two mealybug predators Spalgis epius and Cryptolaemus montrouzieri in the presence and absence of prey

“…Several species of mealybugs (Hemiptera: Pseudococcidae) are serious pests on various crops e.g., coffee, citrus, cocoa, guava, grapes, papaya, cotton, mango, mulberry, vegetable crops, ornamental plants, etc. worldwide (Browning, 1992; Franco et al , 2001; Dinesh & Venkatesha, 2011 a , b ). Mealybugs possess a protective wax body coating and have the ability of being protected inside bark crevices and other inaccessible parts of plants; hence satisfactory control measures have not been achieved with insecticides (Joyce et al , 2001).…”

Mass rearing ofSpalgis epius(Lepidoptera: Lycaenidae), a potential predator of mealybugs (Hemiptera: Pseudococcidae)

“…To rear S. epius in the laboratory, P. citri was cultured on pumpkins (Cucurbita maxima Duchesne) following standard methods for production of natural enemies (Dinesh and Venkatesha 2011a). The mealybug-infested pumpkins were maintained individually in nylon rearing cages (30 )30 )30 cm) similar to rearing of the mealybug predator, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) (Chacko et al 1978).…”

“…(Hemiptera: Dactylopiidae) and Chloropulvinaria polygonata (Ckll.) (Hemiptera: Coccidae) (see Dinesh and Venkatesha 2011a). Moreover, S. epius has been reported as a potential predator of P. citri, P. lilacinus, and M. hirsutus in the field (Chacko, Bhat, and Ramanarayan 1977;Mani 1995;Gowda, Manjunath, Datta, and Kumar 1996;Rahiman and Vijayalakshmi 1998).…”

“…Spalgis epius occurs in India, Burma, Sri Lanka, Philippines, Java, Bangladesh, Thailand, and Krakatau Island (Indonesia) (see Dinesh and Venkatesha 2011a). Adults of S. epius are found in agricultural and wooded areas and are inconspicuous in the field because of their small size and drab colour (Venkatesha, Shashikumar, and Gayathri Devi 2004).…”

“…Venkatesha et al (2004), Venkatesha (2005), and Vinod Kumar, Vasudev, Seetharama, Irulandi, and Sreedharan (2008a) reported the interactions between S. epius and ants in the field. The predatory activity and feeding potential of S. epius on different species of mealybugs has been studied both in the field and laboratory (Pushpaveni, Rao, and Rao1973;Mani andKrishnamoorthy 1996, Rahiman andVijayalakshmi 1998;Vinod kumar, Vasudev, Seetharama, Irulandi, and Sreedharan 2008b;Venkatesha 2011a, Dinesh andVenkatesha 2011b). Furthermore, S. epius has been reported as an effective predator of mealybugs in the field (Mani 1995;Mani and Krishnamoorthy 1996;Rahiman and Vijayalakshmi 1998;Thangamalar, Subramaian, and Mahalingam 2010;Mahalingam et al 2010).…”