Prey scarcity at the beginning of fifth instar: effect of Eucalyptus urophylla (Myrtaceae) plants on reproduction, longevity, and weight of the predator Brontocoris tabidus (Heteroptera: Pentatomidae: Asopinae)

Abstract

Intervals without prey during the fifth instar and nutrient quality may affect reproduction, longevity, and weight of the zoophytophagous predator Brontocoris tabidus (Heteroptera: Pentatomidae: Asopinae). This asopine was reared on Eucalyptus urophylla (Myrtaceae) trees under field conditions at 23 ± 6 o C, 76 ± 9 % RH and 13:11 (dark:light) h photoperiod. The experiment was developed with 60 B. tabidus nymphs individualized in organza bags (31 cm long × 21 cm diameter). One group of nymphs received only Tenebrio molitor (Coleoptera: Tenebrionidae) pupae and water without E. urophylla trees (T1). Other nymphs were reared on E. urophylla trees and fed with T. molitor pupae and water during the second, third, and fourth instars and twenty of them per group after zero, five, and 10 days from the beginning of the fifth instar making up the treatments T2, T3, and T4, respectively. The period without prey increased duration of the fifth instar for males in the T3 and T4 while female weight was lower in the T4. The oviposition period was shorter and the number of egg masses of B. tabidus was lower in the T1 than in the T2, T3, and T4. The highest egg numbers were found in the T2 and T3 with about 4 times more eggs than in the T1. The number of nymphs was low and the percentage of nymph hatching higher in the T1. The interval of five and 10 days without prey from the beginning of the fifth instar did not affect the duration and survival of this instar and supplementation with E. urophylla increased the reproductive capacity of the predator B. tabidus.

Keywords

• insect predator; plant feeding; starvation; supplementation; survival; zoophytophagy