The infectivity, incubation time, and reproduction of three heterorhabditid nematodes, Heterorhabditis sp. Bacardis and FL2122 strains and H. bacteriophora Poinar HP88 strain were studied in two insect hosts, an apionid weevil, Cylas formicarius (F.), and a pyralid moth, Galleria mellonella (L.). Two of the nematodes, Heterorhabditis sp. Bacardis and FL2122 strains, were of tropical or subtropi...

Nuclear receptors (NRs) are a diverse class of transcription factors, which are involved in regulating a large number of physiological events in metazoans. However, the function of NRs is poorly understood in plant-parasitic nematodes. Here, members of the NR1J+K group of NRs in nematodes, including the free-living and plant parasites, were examined and phylogenetically analyzed. We found that ...

Nematodes are the most diverse animals and the most numerous multi-cellular organisms on earth. They exist in almost every ecological niche and vary in size from microscopic round worms to large classes such as Cestoda, which can grow to over 30 meters. Not only are nematodes greatly abundant, but they have significant impacts on human life. Nearly two billion people worldwide are infected by a...

Infective juveniles (J3) of the entomogenous nematodes Steinernema feltiae DD-136 (ca. 10,000 J3/100 ml) and S. glaseri (ca. 2,500 J3/100 ml) were incubated in steam-sterilized and nonsterilized sandy soil and bark compost for 8 weeks at 25 C. The nematodes were recovered by a two-step extraction procedure at 1-week intervals, and their infectivity to lepidopterous larvae (Spodoptera litura and...

Nematodes and bacteria are major components of the soil ecosystem. Many nematodes use bacteria for food, whereas others evolved specialized bacterial interactions ranging from mutualism to parasitism. Little is known about the biological mechanisms by which nematode-bacterial interactions are achieved, largely because in the laboratory nematodes are often cultured under artificial conditions. W...

Since 1903, when Metcalf (5) described a method for obtaining and rearing bacteriafree Rhabditis brevispina (Claus) Biitschli, many procedures have been published. Glaser and Stoll (6) used sodium hypochlorite for surface-sterilization of nematodes. Dougherty and Calhoun (2, 3) eliminated the microflora of R. pellio (Schneider) Btitschli with antibiotics and then substituted Escherichia coli. T...

Entomopathogenic nematodes (EPN) (Steinernematidae and Heterorhabditidae) have a mutualistic partnership with Gram-negative Gamma-Proteobacteria in the family Enterobacteriaceae. Xenorhabdus bacteria are associated with steinernematids nematodes while Photorhabdus are symbionts of heterorhabditids. Together nematodes and bacteria form a potent insecticidal complex that kills a wide range of ins...

We tested the hypotheses that management of the soil food web in the fall would enhance grazing on bacteria and fungi by microbivorous nematodes in the spring, consequently increasing N availability in cover-crop driven organic and low-input farming systems. The food web was manipulated by irrigating the dry soil of late summer and/or providing carbon sources. By creating conditions conducive f...

With the understanding of nematode-plant interactions at the molecular level, new avenues for engineering resistance have opened up, with RNA interference being one of them. Induction of RNAi by delivering double-stranded RNA (dsRNA) has been very successful in the model non-parasitic nematode, Caenorhabditis elegans, while in plant nematodes, dsRNA delivery has been accomplished by soaking nem...

Nematodes represent an especially abundant and species-rich phylum, with many free-living and parasitic species. Among the diversity of parasitic species is a guild of specialists known as entomopathogenic nematodes due to their unusual ability to quickly kill their hosts with the aid of pathogenic bacteria. Herein I discuss in detail the hallmarks of entomopathogenic nematodes and how they are...