Native Isolates And The Effect Of Aviary Litter On The Pathogenicity And Virulence Of Entomopathogenic Nematodes For The Control Of The Lesser Mealworm, Alphitobius Diaperinus (Panzer) (Coleoptera: Tenebrionidae)

Lesser mealworms cause great damage to poultry. Its control is difficult because of the insect's habit of living in the middle of the aviary bed. However, entomopathogenic nematodes (NEPs) can be an effective control of these insects, as they are indicated against pests that live or pass a phase in the soil. The objective of this study was to select native isolates of entomopathogenic nematodes and to evaluate the effect of poultry litter on its pathogenicity and virulence, with the aim of using these to control the lesser mealworm in poultry. Fourteen native isolates and two non-native isolates were used in the selection test, and the three most virulent isolates were used in the concentration test (10, 20, 40, and 50 infective juveniles (Jls) per cm(2)). Both experiments were performed in a completely randomized design, with the data from the selection test being submitted to the Scott-Knott mean test (P <= 0.05) and the concentration test to regression analysis. The effect of poultry litter (new and old) was evaluated on Steinernema feltiae (IBCB-n 47), S. carpocapsae (All), and Heterorhabditis amazonensis (UEL 08), and the test was conducted in 2 x 3 factorial (two types of litter and three isolates) design, and the data were subjected to Tukey's mean test (P 0.05). In the selection test with adult hosts, the three most virulent isolates were H. amazonensis (UEL 07), H. amazonensis (RSC 05), and S. carpocapsae (all) with 76.5%, 73.5%, and 70% mortality, respectively. For larvae, the isolates Heterorhabditis sp. (NEPET 11), S. feltiae (IBCB-n 47), H. amazonensis (UEL 07), Heterorhabditis sp. (IBCB-n40), and H. amazonensis (UEL 08) were the most virulent and differed statistically from the control. In the concentration test, the highest mortality in adults (98%) and larvae (98%) was observed with S. feltiae at concentrations of 30 Jls/cm(2) and 50 Jls/cm(2), respectively, and the native isolate evaluated (UEL 07) presented the worst performance. Regarding the effect of litter, it was observed that S. feltiae (IBCB-n 47) and S. carpocapsae (All) caused the highest mortalities, both in new litter (60.7% and 58.7%, respectively) and in old litter (80.0% and 74.7%, respectively), which were higher than that observed for the native isolate (UEL 08).