PRODUCTION IN VIVO OF ENTOMOPATHOGENIC NEMATODES IN DIFFERENT HOST INSECTS

ABSTRACT

Entomopathogenic nematodes (EPNs) can be an effective tool in Integrated Pest Management programs (IPM). However, in vivo production for laboratory bioassays is still difficult, requiring tests with new host insects and different infection techniques aiming to improve the production. Thus, this work was aimed at evaluating the in vivo multiplication of 3 EPN species: Steinernema carpocapsae, Steinernema glaseri, and Steinernema arenarium, in last instar larvae of Galleria mellonella, Tenebrio molitor, Spodoptera frugiperda and Bombyx mori with three infection systems (injection, topic simple and topic complex). A 3x4 factored (3 infection systems and 4 hosts) randomized experimental design was used. Each treatment had 6 replicates (larvae). The largest productions took place in the first 3 days of IJ emergence. The treatments S. carpocapsae and S. arenarium with simple topic method in G. mellonella yielded the largest productions of IJs/larva, with 302,124 and 149,213 IJs/larva, respectively. S. arenarium was the only species to multiply by injection in G. mellonella, although with low production (1,076 IJs/larva), being a rather inefficient system for production of these species. An alternative host for in vivo production is T. molitor, since the treatment S. arenarium by topic complex yielded high production (103,059 IJs/larva). S. glaseri did not multiply by any infection system in T. molitor and B. mori. The multiplication of this species with the simple topic system in G. mellonella achieved a total production of 132,065 IJs/larva. The simple topic and complex systems presented the largest productions per larva. T. molitor for the species S. arenarium and B. mori for S. carpocapsae presented great possibilities as alternative hosts for in vivo production.

KEY WORDS:
Microbial control; multiplication; entomonematodes; insect pest.