Leaf consumption and duration of instars of the cassava defoliator Erinnyis ello (L., 1758) (Lepidoptera, Sphingidae)

Abstract

ABSTRACT. The objectives of this research were to evaluate leaf consumption and the developmental time of the larvae of Erynnyis ello (L., 1758) (Lepidoptera, Sphingidae) reared on cassava, in order to obtain information for the integrated management of this pest. The larvae were reared on excised cassava leaves in Petri dishes and later in gerbox, and kept in chambers at 24 ± 2 ºC and 75 ± 10% RH. The total leaf area consumed by the larva to complete its development was 589.67 cm 2 ; each of the five instars consumed, respectively: 1.89 cm 2 ; 5.74 cm 2 ; 17.48 cm 2 ; 76.66 cm 2 ; and 487.90 cm 2 . The consumption by the first three instars was insignificant, and did not reach 5% altogether; the 4 th represented 13%; the 5 th presented a consumption significantly higher, about 82.7%. The total time for the larval development was 22.61 days, and the duration for each of the five larval instar was, respectively: 4.35; 3.19; 3.32; 4.52; and 4.94 days. The pre-pupal period lasted 2.29 days. Since the highest consumption is by the 5 th instar larva, the control should be applied before this age to avoid heavier damages to the cassava crop.

Effect of Nitrogen Source on Pac Choi (Brassica rapa L.) Chemistry and Interactions with the Diamondback Moth (Plutella xylostella L.)

“…Feeding equivalents were obtained by multiplying the number of each larval instar counted on plants by the estimated relative proportion of leaf tissue required for each larval instar to complete development. Because the relative instar consumption values are unknown for DBM, we estimated consumption from those reported by Pratissoli et al (2002) for Erinnyis ello (Lepidoptera: Sphingidae). Both species are defoliating caterpillars that increase their amount of consumption incrementally from the first to fourth instar (Bellotti et al, 1992;Talekar and Lin, 1998).…”

Selectivity of Insecticides Against Adult Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) on Cassava

“…An estimated 21 million tons of cassava roots have been planted, corresponding to more than 1.4 million hectares of cultivated land (IBGE, 2017). Unfortunately, crop productivity can be reduced by the action of pest insects, such as the moth Erinnyis ello, which is a major pest that can cause defoliation of cassava plants (Pratissoli, Zanuncio, Barros, & Oliveira, 2002). In general, attempts to control pests generally make use of chemical or biological insecticides.…”