Factors influencing parasitism of adult Japanese beetles,Polillia japonica (Col.: Scarabaeidae) by entomopathogenic nematodes

Abstract

Several factors that influence the activity of steinernematid and heterorhabditid nematodes against adult Japanese beetles were examined in the laboratory. The effect of nematode concentration on mortality of adult beetles was evaluated using a Petri plate bioassay. The adults were exposed to 1,000 to 10,000 infective stage juveniles (J3) of Steinernema glaseri per 10 beetles with or without food for 24 hr after which they were held with food for an additional 6 days. The LC50s for males with and without food during exposure were 3,435 and 2,854 J3s/10 adults, respectively. The LC50s for mixtures of males and females with and without food were 5,228 and 1,762 J3s/10 adults respectively. Although mortality occurred during and shortly after exposure, significant additional mortality was observed 1-4 days following exposure. Exposure of males and females with food to 10,000 J3s/10 adults for 6, 12, 18, or 24 hr resulted in 47, 58, 72, and 77 % mortality, respectively. Comparative activity of S. glaseri, S. carpocapsae (All strain), S.feltiae (Biosys experimental cold adapted strain = bibionis), S.feltiae (Biosys experimental strain 27), Heterorhabditis bacteriophora, and Heterorhabditis sp. (Terceiran isolate) was evaluated against adult Japanese beetles using a 24 hr exposure to 8,000 J3s/10 adults. The most virulent species were S. glaseri, S.feltiae (= bibionis), the Terceiran isolate of Heterorhabditis and S. carpocapsae producing 55, 44, 36 and 34 % mortality respectively. Our results indicate that adult Japanese beetles infected with entomopathogenic nematodes could serve as a mechanism for nematode dispersal.

Comparative dispersal and larvicidal activity of exotic and Azorean isolates of entomopathogenic nematodes against Popillia japonica (Coleoptera: Scarabaeidae)

“…The methods of production of S. glaseri used in bioassays were published previously (Lacey et al, 1993). IJs were produced on a pork kidney medium as described by Bedding (1981).…”

An autodissemination station for the transfer of an insect growth regulator to mosquito oviposition sites

“…Autodissemination is particularly well suited to use with insect pathogens because of the small size and host replication ability that are characteristic of infectious microbes and, accordingly, insect pathologists have pioneered this area of investigation. Most studies have examined the dissemination of entomopathogenic fungi and baculoviruses (Soper, 1978; Yu & Brown, 1997; Klein & Lacey, 1999), but even nematode autodissemination has been considered (Lacey et al , 1993). These strategies tend to centre on the use of a pheromone lure to bring insects into a contamination station in which they are topically contaminated with a pathogen before they exit the station.…”

Nematode Pathogenesis of Insects and Other Pests

“…For example, infected mole crickets (Scapteriscus spp.) can serve as spreaders of the nematode S. scapterisci , which can serve as biocontrol for Popillia japonica Newman (Coleoptera: Scarabaeidae) (Lacey, Bettencourt, Garrett, Simões, & Gaugler, 1993). Also, the adult of the large pine weevils, Hylobius abietis L. (Coleoptera: Curculionidae) were described as potential phoretic host to EPN ), even if they can serve for infection .…”