Resposta funcional e aspectos biológicos de Ceraeochrysa everes (Banks) (Neuroptera: Chrysopidae) à Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae)

Abstract

Maconellicoccus hirsutus, is an introduced pest that threatens the production of fruits, vegetables and ornamental plants in Brazil. Among the natural enemies, the predatory insects of the Chrysopidae family have stood out in Integrated Pest Management Programs (MIP), due to their potential as predators of phytophagous arthropod populations. One of the native chrysopids associated with M. hirsutus is Ceraeochrysa everes, which usually occurs in abundance in several crops where M. hirsutus is present in Maranhão. Thus, the objective was to evaluate the predation potential of C. everes (3rd larval instar) at different stages of development of M. hirsutus through the performance of functional response bioassays and to study some biological aspects of this predator. Ten repetitions were made for each M. hirsutus density offered to the predator, and the type of the functional response curve was determined, through logistic regression, of the proportion of prey consumed as a function of the offered prey density. The logistic regression analysis revealed a type II functional response when feeding on eggs and nymphs (1st and 2nd instars) of M. hirsutus. Some biological parameters of C. everes life history were evaluated comparatively under the influence of two different diets (nymphs of the 2nd instar of M. hirsutus and eggs of Anagasta kuehniella). First, second and third instar larvae of C. everes were confined with nymphs of second instar of M. hirsutus to evaluate the time of development of immature stages, sex ratio, pre-oviposition period, oviposition, postoviposition, incidence of oviposition, egg viability, fertility (total and daily), fertility and longevity of adult predators. An additional treatment consisting of A. kuehniella eggs was offered to the larval instars of C. everes as a control. The duration of the larval phases of C. everes was longer when the predator was fed nymphs of the 2nd instar of M. hirsutus compared to the control treatment. Despite the differentiated effects of treatments on the biology of immature C. everes, a survival rate of 82.5 and 100% was observed when nymphs of the 2nd instar of M. hirsutus and eggs of A. kuehniella were offered, respectively. It is concluded that C. everes has a great potential to reduce populations of M. hirsutus, and C. everes is able to prey, develop and reproduce having nymphs of second instar of M. hirsutus as a food resource, therefore, this predator can be considered a good biological control agent for populations of this exotic mealybug.