1987 . The Journal of Arachnology 15 :132 females produced egg sacs a few days after they had captured a large prey . The interval between egg sacs and the number of eggs per sac seemed to be influence d by the nutritional condition of the female. The number of total eggs produced pe r female varied from 242 to 1866 (mean = 881 .7). In the laboratory, each of 15 females produced 9 .7 egg sacs containing a total of 1812 .7 eggs at intervals of 8.1 days in average (Miyashita, K . 1987. J. Arachnol . 15 :51-58). Valerio (1976. Bull. British Arachnol. Soc., 3 :194-198) examined egg sac production in tropical Costa Rica and reported that, although one femal e produced 20 sacs, the mean number of sacs per female was 14 .1, and that the mean number of eggs per female was 3211 .9. Valerio's search of the literature showed that the number of egg sacs produced per female in the temperate region s ranged from 4 to 7 except for one record of 17 reported by Bonnet (1935. Bull. Soc. Hist. Nat. Toulouse, 68 :335-386). As shown in Table 1, the "egg period", which means the number of days fro m egg sac production to the spiderlings ' emergence, became shorter later in th e season. This may be influenced by rising temperatures at that time. In the laboratory at 25° C, the mean egg period was 11 .0 days.

Kazuyoshi Miyashita, Department of Biology, Faculty of Science, Toky o Metropolitan University, Setagaya-ku, Fuakazawa 2-1-1, Tokyo 158, Japan .

Manuscript received December 1985, revised April /986.

PREDATION BY (ARANEAE, CLUBIONIDAE) ON LARVAL PHYLL ONOR YCTER BLANCARDELLA (, GRACILLARIIDAE) IN A GREENHOUSE

The spotted tentiform leafminer, Phyllonorycter blancardella (F.) (Lepidoptera , Gracillariidae), has become an important pest in commercial apple orchards i n eastern North America since its introduction from Europe (Pottinger and LeRoux 1971). The larvae form tentiform mines in leaf tissues of apple (Malus pumila Mill.) and other closely related plants (Pottinger and LeRoux 1971) . Although many parasitoids of this insect have been recorded (Laing 1984, Ridgewa y and Mahr 1985), little attention has been directed towards predators of larval P . blancardella. Cheiracanthium mildei L. Koch, a native of Europe, is a clubionid spider commonly found in synanthropic habitats in eastern North America (Dondale and Redner 1982) . In Israel, this species was found to be very common i n unsprayed apple orchards where it is important for control of various insect pests , especially the larvae of littoralis (Boisd.) (Lepidoptera, ) (Mansour et al . 1980a,b) . Mansour et al . (1980a) indicated that C. mildei preys on larvae and adults of P. blancardella under laboratory conditions. 1987. The Journal of Arachnology 15 :133

This note reports our observations of specialized predation by C. mildei on the larvae of P. blancardella in a greenhouse . In the winter of 1985, as part of an ongoing parasitization study, larval P. blancardella were reared on young apple trees in the greenhouse of the Biologica l Control Laboratory, University of Guelph, Ontario . The trees were put in sleeve cages and adult P. blancardella were released into the cages for oviposition on apple leaves. A high level of predation on the larval leafminers was found i n some cages, although the rate was not quantified. Predation was indicated by single triangular rents (1-2 X 2-3 mm) in the undersurfaces of mines and th e absence of larvae. Larval losses in the greenhouse sleeve cages were severe an d hampered the rearing program for the spotted tentiform leafminer . Various unidentified species of Salticidae, Araneidae, Linyphiidae, Philodromi- dae, and Theridiidae were also present in the greenhouse, but only C. mildei was found regularly on leaves in the vicinity of attacked mines . Individuals of these clubionid spiders spun (and were found within) silken retreats on the lowe r surface of mined apple leaves . Many clubionids construct and inhabit similar retreats (Dondale and Redner 1982). We suspected that C. mildei actively sought out trees infested with leafminers . C. mildei was rarely found on uninfested trees in the greenhouse. Although other species of spiders (unidentified salticids especially) were found in some sleeve cages, predation on larval leafminers was observed only in cages containing C . mildei. Two or three individuals of each of the various hunting spiders found in th e greenhouse were isolated in covered plastic petri plates with freshly picked appl e leaves that contained mines formed by the tissue-feeding instars . Because of th e relatively sedentary habits and the nature of prey capture behavior generall y observed in web-building spiders, predation on leafminers by web-building specie s present in the greenhouse (such as araneids and linyphiids) was considered to b e unlikely. Spider attacks on larvae were not observed directly, but only leave s isolated with C. mildei received characteristic mine damage and predation on the leafminer larvae . Predation is typically difficult to quantify because predators often do not leav e evidence of their work (J . E. Laing pers. comm .). However, predation on leaf- mining larvae is detectable because the mines are damaged (Pottinger and LeRoux 1971) and the type of damage often is characteristic of the predator . For example, the larvae of chrysopids feed on P. blancardella through the top surfac e of the mine and do not remove their prey (J . M . Heraty pers. comm.) . Birds also attack the larvae through the top of the leaf leaving a large entrance hol e (Pottinger and LeRoux 1971) . On the other hand, C. mildei attacks throughthe bottom surface of the mine . Thus, it is possible to identify the predator in absentia by its mode of entry into the mine . Presently, predation by spiders ma y be incorrectly attributed to more obvious predators such as entomophagous birds . Although larval P. blancardella are infrequently attacked by invertebrat e predators because of the concealment afforded by their mines, C. mildei apparently is able to detect and attack the larvae through the leaf epidermis . This phenomenon of search and extraction of a cryptic food source has not been previously reported for C. mildei. Because of this specialized feeding behavior, we suspect that C. mildei may prove to be an important predator of P. blancardella and worth considering in integrated control programs for this insect . 1987 . The Journal of Arachnology 15 :134

The authors thank J . M. Heraty, D . T. Jennings, P. G. Kevan, J. E. Laing, and M. H. Greenstone for their reviews of the manuscript .

LITERATURE CITE D

Dondale, C . D. and J. H . Redner . 1982 . The and arachnids of Canada. Part IX . The sac sider s of Canada and Alaska (Araneae : Clubionidae). Agric . Canada, Publ. No . 1724 :1-194. Laing, J . E. 1984 . Phyllonorycter blancardella (F.), spotted tentiform leafminer (Lepidoptera , Gracillariidae) . Pp. 69-71 . In Biological Control Programmes Against Insects and Weeds in Canad a 1969-1980. (J . H . Kelleher and M . A . Hulme, eds .). Commonwealth Agricultural Bureaux . Mansour, F., D. Rosen, and A . Shulov . I980a . Biology of the spider Cheriracanthium mildei (Arachnida: Clubionidae). Entomophaga, 25(3) :237-248 . Mansour, F., D . Rosen, and A . Shulov . I980b . Functional response of the spider Cheriracanthiu m mildei (Arachnida: Clubionidae) to prey density . Entomophaga, 25(3) :313-316 . Pottinger, R . P. and E . J. LeRoux . 1971 . The biology and dynamics of Lithocolletis blancardella (Lepidoptera: Gracillariidae) on apple in Quebec . M . Entomol . Soc . Canada, 77 :1-437 . Ridgway, N . M . and D . L . Mahr . 1985 . Natural enemies of the spotted tentiform leafminer , Phyllonorycter blancardella (Lepidoptera, Gracillariidae), in sprayed and unsprayed apple orchard s in Wisconsin . Environ . Entomol ., 14 :459-463 .

James E. Corrigan, and Robert G . Bennett, Department of Environmenta l Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada .

Manuscript received February 1986, revised April 1986 .

ORTHOLASMA SETULIPES SHEAR AND GRUBER IS A SYNONYM OF ORTHOLASMA CORONADENSE COCKEREL L

In our recent revision of the opilionid subfamily Ortholasmatinae (1983 . Amer. Mus . Novitates no . 2757:1-65), we described Ortholasma setulipes as a new species from southern California (type specimens from Borrego Palm Canyon , San Diego County, deposited in AMNH) . We thought at that time that the nam e might fall as a synonym of O. coronadense Cockerell (Cockerell, T. 1916. Ent . News 27 :158), if the types of that species (from South Island, Coronados Group , Baja California, Mexico) ever were to turn up. Our requests to all major American museums failed to locate the specimens, and so, since Cockerell' s original description lacked the information needed to place the species, we liste d 0. coronadense with a few comments and described our southern Californi a material as new. We might have recognized the synonymy given here at that tim e but for the occurance in southern California (syntopically in two instances) o f two species (the other is O. levipes Shear and Gruber). Some time after our paper had appeared, our colleague James Cokendolpher made us aware that Ralph Crabill, curator of arachnids (since retired) at th e National Museum of Natural History, Smithsonian Institution, had written him that the holotype specimen was in the collection there, even providing a catalo g number. We borrowed the specimen courtesy of the present curator, Jonathan