Marava arachidis (Yersin, 1860) inimigo natural de dactylopius opuntiae (Cockerell, 1896)?

Abstract

The forage cactus (Opuntia ficus-indica (L.) Mill.) plays a significant socioeconomic role in Brazil's semiarid regions. However, the carmine scale insect, Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), is considered its main pest, capable of severely compromising plant development. Although the use of resistant varieties is currently the most widely used method for pest management, other strategies, such as biological control, show promising potential and require further investigation. Therefore, this study aimed to evaluate the effect of different population densities of D. opuntiae on M. arachidis. The experiment was conducted at the Invertebrate Laboratory (LABIN) of the Department of Biosciences, Center for Agricultural Sciences, Federal University of Paraíba, Areia, Paraíba. D. opuntiae nymphs were offered at five densities (5, 10, 15, 20, and 25) to first-, second-, third-, and fourth-instar individuals, as well as M. arachidis adults. Predation was monitored until the molt in the nymphal stages and, in the adults, until oviposition of pairs. The experimental design was completely randomized, with 25 treatments and 10 replicates. The means were compared using contrasts obtained through generalized linear models. The results indicated a significant increase in the predation rate with increasing prey density, with a density of 25 nymphs resulting in the highest consumption by both nymphs and adults of the predator. It is concluded that M. arachidis has high potential as a biological control agent for D. opuntiae, constituting a promising alternative for integrated pest management in forage cactus pear crops.