650 Journal of Nematology, Volume 15, No 4, October 1983 Table 1. Effect of Pangola digitgrass on Meloidogyne arenaria, M. hapla, M. javanica, and M. incognita*

N umber Fresh weight (g) second-stage larvae Treatment Roots Tops TopsJ- In roots~.

M. arenaria Pangola 10.9 17.8 24 48 Tomato (control) 3.1 8.4 12,180 4.120 M. hapla Pangola 19.2 18.8 12 11 Tomato (control) 6.5 5.5 4,609 307 M. javanica Pangola 14.6 15.1 3 9 Tomato (control) 5.5 3.6 2,412 475 ,11. incognita Pangola 9.2 17.9 36 12 Tomato (control) 2.5 9.6 7,152 429

¢lnitial inoculum was 15 egg masses/pot of 1.200 cma soil. tPer pot, average of five replicates. ++Per root system.

LITERATURE CITED Soc. 74:201-204. 4. Taylor, A. L., and J. N. Sasser. 1978. Biology, 1. Haroon, S., and G. C Smart, Jr. 1983. Devel- identification, aml control of root-knot nematodes opment of Meloidogyne incognita inhibited by (Meloidogyne species). Raleigh: North Carolina Digitaria decumbens cv. Pangola. J. Nematol. 15: State University Graphics. 102-105. 5. Winchester, J. A., and N. C. Hayslip. 1960. 2. Jenkins, W. R. 1964. A rapid centrifugal flo- The effect of land management practices on the tation technique for separating nematodes from root-knot nematode Meloidogyne incognita acrita soil. Plant Dis. Rept. 48:692. in south Florida. Proc. Fla. State Hort. Soc. 73: 3. Overman, A. J. 1961. Nematodes associated 100-104. with Pangola grass pastures. Proc. Fla. State Hort.

Isolation of an Unusual Entaphelenchid (Tylenchidm Entaphelenchidae) from the Hemocoel of Platysoma punctigerum LeConte (Coleoptera: ) ~ ROBIN N|. GfBL1N and HARRY K. KAYA ~

species belonging to the Silphidae, Staptty- Key words: entomogenous nematode, morphol- linidae, and Curculionidae (2,3). Recently, ogy, biocontrol. an entaphelenchid was isolated from Platy- Nematodes in the family Entaphelenchi- soma punctigerum LeConte, a in dae are obligate parasites of coleopterous the family Histeridae. The addition of an- other coleopterous family containing a Received for publication 7 February 1983. parasitic entaphelenchid is not unexpected. XThls study was supported by U.S. Forest Service Co- operative Agreement 19-327. However, this nematode had some unusual -"Division of Nematology, University of California, Davis, characters which we describe herein for CA 95616. Present address of senior author: Departn'~ent of Nematology, University of California, Riverside, CA 92521. fttture reference. We thank Mr. Torn Powers, University of California, Riverside, for assistance with the scanning electron micro- P. punctigerum is a predator of eggs scope and Dr. Fred Andrews, California Dept. of Food and and adults of the western pine beetle, Agriculture, Sacramento, for identification of the histerid beetle. Dendroctonus brevicomis LeConte (Cole- Research Note: Giblin, Kaya 651

Fig. 1. Unusual spot (arrow) under the cuticle of a female entaphelenchid isolated from the hemocoel of a histerid beetle. A. Scanning electron microscope, B. Photomicrograph with Nomarski optics. optera: Scolytidae) (I). When P. puncti- = 58 /~m (53-63 /~m), E (length from the gerum, collected from logs from Pollock head to the base of the metacorpus) = 112 Pines, Placer County, California, was dis- /zm (110-113 /~m), stylet = 19 /zm (17-23 sected in invertebrate saline (0.6% Na C1), ~m), V = 71% (69-73%). The postvulval eight female entaphelenchid adults were sac was about 75 t~m long. found in the hemocoel of one specimen. There are presently four genera in the The nematodes were coiled in a helix while family Entaphelenchidae (2). The nema- alive and remained that way after being tode reported herein is similar to Entaphe- heat-killed and processed slowly into glyc- lenchus in size, stylet length and morphol- erol. The helical posture was flattened to ogy, presence of perivaginal glands, and a S-shape when the nematodes were per- postvulval sac length. It differs from the manently mounted. Adult males of another described genera of the Entaphelenchidae entaphelenchid in the genus Peraphelen- by the presence of two large and laterally thus also have this coiled (corkscrew) pos- positioned sac-like organs under the cuticle ture (4); however, the females do not coil. of the head and the coiled posture of the Besides this coiled posture, two unusual female adult. Males, infective females, and spots under the nematode's cuticle in the mature parasitic females must be examined anterior region were visible with a dissect- before a species or generic diagnosis is pro- ing microscope. Light and scanning elec- posed. Two permanent slides of this enta- tron microscopic observations of the nema- phelenchid nematode have been deposited todes confirmed the presence of two large, in the museum at the Division of Nema- laterally situated sac-like structures under tology, University of California, Davis. the cuticle of the head region (Fig. 1A, 1B). Females possessed four lips (Fig. 1A), LITERATURE CITED stylet without basal knobs, single anteriorly 1. Berryman, A. A. 1970. Evaluation of directed ovary, perivaginal glands, and post- predators of the western pine. beetle. Pp. I02-I12 in vulval sac filled with sperm. The anus was R. W. Stark and D. L. Dahlsten, eds. Studies on not visible. None of the females examined the population dynamics of the western pine beetle, were at the egg-laying stage. The presence Dendroctonus brevicomis LeConte (Coleoptera: Scolytidae). University of California, Berkeley. of sperm in the postvulval sac suggests that 2. Nickle, XV. R. 1970. A taxonomic review of fertilized females are the infective stage as the genera of the Aphelenchoidea (Fuchs, 1937) with Entaphelenchus oxyteli Wachek Thorne, 1949 (Nematoda: Tylenchida). J. Nematol. which parasitizes the staphylinid, Oxytelus 2:375-392. De Geer (4). The measurements for 3. Poinar, G. O., Jr. 1975. Entomogenous nema- piceus todes. E. J. Brill, Leiden, Netherlands. three of these females in glycerol were as 4. ~achek, F. 1955. Die entoparasitischen Ty- follows: I, = 1.86 mm (1.80-1.91), GBW lenchiden. Parasitol. Schriftenr. 3:1-119.