Mitsuaki Shimazu

Isolation and characterization of Entomophaga maimaiga sp. nov., a fungal pathogen of gypsy moth, Lymantria dispar, from Japan.

Abstract A Japanese zygomycete pathogen from the gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), is described as Entomophaga maimaiga sp. nov. (Entomophthorales: Entomophthoraceae). This fungus belongs to the Entomophaga aulicae species complex. Isolates from the E. aulicae species complex were tested for infectivity and pathogenicity toward larvae of the gypsy moth, and only those isolates from gypsy moths were pathogenic to gypsy moth larvae. Electrophoretic studies of isoenzymes indicated that the Japanese gypsy moth isolates differed from other Japanese and North American strains of the E. aulicae species complex. Among the isolates of E. maimaiga from Japan, ARSEF 1400 appeared most promising for biological control use; it caused 90–95% mortality in third instar larvae after an average of 5.2 days and can be cultured in both protoplast and mycelial vegetative stages. In host range trials, ARSEF 1400 infected only a few of the lepidopteran species tested. Among these alternate hosts, mortality was the greatest (92.5%) for the Douglas-fir tussock moth, Orgyia pseudotsugata, another economically important lymantriid.

Maturation Feeding and Transmission of Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) by Monochamus alternatus (Coleoptera: Cerambycidae) Inoculated with Beauveria bassiana (Deuteromycotina: Hyphomycetes)

Abstract We examined the amount of maturation feeding and transmission of pinewood nematodes, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle (Nematoda: Parasitaphelenchidae), to healthy pine (Pinus spp.) trees by pine sawyer Monochamus alternatus Hope (Coleoptera: Cerambycidae) adults infected with Beauveria bassiana (Balsamo) Vuill. (Deuteromycotina: Hyphomycetes). Inoculated beetles fed less than noninoculated beetles, probably because feeding by inoculated beetles began to decrease at about 4 d postinoculation and inoculated beetles ceased to feed for several days before their death. In inoculated beetles carrying >1,000 nematodes, some beetles died before nematode departure. The remaining heavily nematode-infested beetles lived until the beginning of nematode departure, but they had stopped feeding, preventing the nematodes from entering pine twigs. We suggest that microbial control of pine sawyer adults by B. bassiana may be effective in preventing transmission of pine wilt disease to healthy pine trees.

Characterization of Paecilomyces cinnamomeus from the camellia whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), infesting tea in Japan

The whitefly, Aleurocanthus camelliae Kanmiya and Kasai (Hemiptera: Aleyrodidae), is an invasive species in Japan that was first discovered in 2004 on tea in Kyoto. Soon after its arrival epizootics of an entomopathogenic fungus were observed in populations of the whitefly in many tea-growing regions. Here we identify this fungus as Paecilomyces cinnamomeus (Petch) Samson and W. Gams (Hypocreales: Clavicipitaceae) based on morphological characteristics and molecular analyses. This is the first record of P. cinnamomeus in Japan and also the first time it has been recorded from the genus Aleurocanthus. A isolate of P. cinnamomeus caused greater than 50% and 90% infection in whitefly nymphs at 1×10(6) and 1×10(7)conidia/ml respectively, while the commercial mycoinsecticides Preferd® (Isaria fumosorosea) and Mycotal® (Lecanicillium muscarium) caused <10% infection at their recommended field rates (5×10(6) and 9×10(6)conidia/ml, respectively), suggesting that P. cinnamomeus may be more useful as a control agent than the currently available mycoinsecticides. Optimum and upper limit temperatures for in vitro growth of P. cinnamomeus isolates were 22.5-25°C and 32.5°C, respectively. At field rates, the fungicide thiophanate-methyl caused some inhibition of in vitro growth of P. cinnamomeus isolates, and the bactericide copper oxychloride and the insecticides tolfenpyrad and methidathion were strongly inhibitory. The findings obtained in this study will be useful in the development of microbial control programs using P. cinnamomeus against A. camelliae.