Biology of Lasioerythraeus Johnstoni (Acari: Erythraeidae)

Biology of Lasioerythraeus johnstoni (Acari: Erythraeidae), Ectoparasitic and Predaceous on the Tarnished Plant Bug, Lygus lineolaris (Hemiptera: Miridae), and Other Arthropods

O. P. YOUNG1 AND W. C. WELBOURN2

Ann. Entomol. Soc. Am. 80: 243-250 (1987) ABSTRACT One hundred fifty-one host records obtained in 1984-85 from Washington County, Miss., are reported for Lasioerythraeus johnstoni Welbourn & Young. Thirteen insect species from three orders are recorded as hosts of the larval stage, with nymphs of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), representing 52% of all records. Attached larval mites were obtained from undisturbed old-field habitats during the period of 20 March-13 September, with most of the records obtained in July. Parasitization levels for some host species were as high as 46%. Of the attached larval mites, >90% occurred on the dorsal head and thorax, usually at a molt suture. In the laboratory, field-collected attached larval mites killed their hosts and detached within 2 d, passed through several nymphal stages, and became adults in ca. 21 d. Both the active deutonymph and adult forms were predaceous on tarnished plant bug nymphs. L. johnstoni appears to have considerable natural control potential for the tarnished plant bug.

KEY WORDS ectoparasite, predator, Lasioerythraeus johnstoni, Lygus lineolaris

ERYTHRAEIDAE (Acari: Parasitengona) is a large Materials and Methods and cosmopolitan family of mites with predatory Field Sampling Program. From 17 April to 30 postlarval instars preying on ground and aerial ar- September 1984, 28 sites in the Mississippi Delta thropods in many habitats (Krantz 1978). Larvae (Washington County), Miss., were sampled weekly in most erythraeid genera are ectoparasitic on in- by suction (D-Vac). From 20 February to 20 Sep- sects and arachnids. Species in the genera Balaus- tember 1985, 78 sites were sampled intermittently tium, Erythraeus, and Callidosoma are predators by sweep net or suction. The sites all contained or parasites on such economically important pests substantial populations of Erigeron spp. (Compos- as the European red mite, Panonychus ulmi itae), a genus of fleabane asters known to include (Koch); San Jose scale, Quadraspidiotus pernicio- important host plants of the TPB (Young 1986). sus (Comstock); California red scale, Aonidiella Samples were brought into the laboratory and all aurantii (Maskell); apple aphid, Aphis pomi TPB as well as all insect hosts with attached mites DeGeer; and various noctuid and geometrid Lep- were counted and retained alive for further study. idoptera (Ebeling 1934, Whitcomb & Bell 1964, Laboratory Rearing. The life cycle of the Er- Putman 1970, Sharma et al. 1983). ythraeidae (and other Parasitengona) consists of Given the potential importance of this family egg, prelarva, parasitic hexapod larva, calyptostat- of mites, it is unfortunate that little is known about ic protonymph, active predaceous deutonymph, the biology, ecology, and behavior of its members. calyptostatic tritonymph, and active predaceous This is particularly true for the larval and nymph- adult (Grandjean 1938, Johnston & Wacker 1967). al forms because most species are described based Fourteen TPB and three cicadellid early instars on the adult stage and the larval instars and nymphs obtained from site 2 in 1984, each with a single are unknown. The purpose of this report is to pres- attached mite, were confined separately with a slice ent laboratory and field observations on the biol- of snapbean, Phaseolus vulgaris L., in a glass jar ogy and ecology of a newly described mite, La- (60 ml) covered with a fine-mesh organdy cloth. sioerythraeus johnstoni, and to place this Jars were then maintained in an environmental information in the context of the known biology chamber at 26°C, 80% RH, and 14:10 (L:D) pho- of the family Erythraeidae (Welbourn & Young toperiod. Each engorged larval mite was placed 1986). The potential of L. johnstoni as a natural separately in a glass jar (16 ml) with a snap cap control agent for the tarnished plant bug (TPB), following detachment from its host. Each contain- Lygus lineolaris (Palisot de Beauvois), will be dis- er was previously half-filled with a hardened 9:1 cussed. mixture of plaster of paris and activated charcoal, which was slightly moistened (Wharton 1946). Jars were examined twice daily at 0730 and 1600 hours. 1 Southern Field Crop Insect Manage. Lab., ARS-USDA, P.O. After emergence from the inactive protonymph Box 346, Stoneville, MS 38776. stage, each active deutonymph was placed in a - Acarology Lab., Dep. of Entomology, The Ohio State Univ., Columbus, OH 43210. glass jar (60 ml) containing 10 first-instar TPB as

243 244 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 80, no. 2

Table 1. Host records of L. johnstoni

Site Collection date No. records Taxon Host stage (1984-85) Hemiptera Miridae L. lineolaris Nymph 1 14 May 2 Nymph 3 16 May 1 Nymph 1 20 May 1 Nymph 1 27 May 3 Nymph 1 24 June 1 Nymph 4 25 June 3 Nymph 1 25 June 1 Nymph 1 3 July 1 Nymph 5 5 July 1 Nymph 2 11 July 11 Nymph 2 12 July 12 Nymph 2 13 July 36 Nymph 2 9 Aug. 1 Nymph 3 9 Aug. 1 Nymph 3 23 Aug. 1 Nymph 1 30 Aug. 2 Nymph 1 13 Sept. 1 Polymerus basalis (Reuter) Nymph 5 5 July 3 Nymph 7 11 July 1 Taylorilygus pallidulus Blan. Nymph 1 5 July 1 Nymph 1 15 July 1 Pseudatomoscelis seriatus (Reuter) Nymph 1 16 May 1 Nymph 1 27 May 1 Anthocoridae Onus insidiosus (Say) Nymph 12 July Lygaeidae Undetermined species Nymph 24 June Pentatomidae Holcostethus sp. Nymph 1 2 Aug. 1 Nymph 1 30 Aug. 1 Podisus maculiventris (Say) Nymph 5 5 July 1 Nymph 5 15 July 1 Rhopalidae Undetermined species Nymph 8 12 July 2 Nymph 2 13 July 1 Nymph 1 15 July 1 Homoptera Aleyrodidae Undetermined species Adult 5 5 July 1 Adult 1 9 Aug. 1 Cicadellidae Undetermined species Nymph 1 20 Mar. 1 Nymph 1 4 Apr. 2 Nymph 6 6 May 1 Nymph 3 24 June 1 Adult 5 5 July 1 Nymph 5 5 July 3 Nymph 2 13 July 3 Nymph 3 15 July 3 Nymph 5 15 July 1 Nymph 2 24 July 3 Nymph 2 9 Aug. 11 Nymph 2 24 Aug. 6 Nymph 2 30 Aug. 10 Undetermined family Nymph 3 27 May 1 Nymph 3 15 July 1 Diptera Undetermined muscoid species Adult 5 July Acari Erythraeidae L. johnstoni Larva 5 July Araneae Micryphantidae Undetermined species Immature 5 July 1 Total 151 March 1987 YOUNG & WELBOURN: BIOLOGY OF L. johnstoni 245 a food source. The jar was again covered with a Table 2. Relative parasitization of tarnished plant bug fine-mesh organdy cloth, placed back in the en- first and second instar nymphs and early instar cicadellid vironmental chamber, and examined twice daily. nymphs by L. johnstoni larvae at site 2 in 1984 When each deutonymph became quiescent upon No. entering the calyptostatic tritonymph stage, it was No. hosts Date Host sampled para- para- placed in one of the same 16-ml glass jars used for sitized sitized the protonymph stage and maintained as before. 11 July TPB 134 11 8.2 After adult emergence, each mite was either pre- Cicadellid 200+ 0 0.0 served in alcohol or offered TPB nymphs for 24 h 12 July TPB 37 12 32.4 and placed in alcohol. Four selected specimens in Cicadellid 300+ 0 0.0 13 July TPB 117 36 30.8 each stage of development were preserved in al- Cicadellid 200+ 3 <1.0 cohol for subsequent identification and descrip- 14 July0 tion. 16 July TPB 10 0 0.0 Cicadellid 100+ 0 0.0 Attachment Sites on Hosts. Thirty-eight TPB 19 July TPB 15 0 0.0 and 40 cicadellid early-instar parasitized nymphs Cicadellid 87 0 0.0 were preserved in alcohol, subsequently examined 21 July" under magnification, and the site of mite attach- 24 July TPB 17 0 0.0 Cicadellid 101 3 3.0 ment recorded. 30 July TPB 185 0 0.0 Cicadellid 23 0 0.0 1 Aug." Results 2 Aug. TPB 11 0 0.0 Cicadellid 13 0 0.0 Field Sampling Program, 1984. Only four of 9 Aug TPB 1 1 100.0 the 28 sites sampled contained larval L. johnstoni Cicadellid 24 11 45.8 attached to TPB nymphs (Table 1). One site also 24 Aug. TPB 0 0 0.0 contained larvae attached to early-instar Cicadel- Cicadellid 13 6 46.2 lidae (Homoptera) nymphs. The 28 sites were of 30 Aug. TPB 0 0 0.0 Cicadellid 876 10 1.5 two major types, roadside margins (20) and old- field habitats (8). All attached mites were obtained " Insecticide application. from four old-field habitats, which are characterized here. Site 1 was a 2.5-ha fallow field 3 km south- the west by a 50-ha cotton field, and on the south southeast of Leland, Washington County, bor- by a deciduous-tree-lined creek bank. Approxi- dered on the east by a paved road and adjacent mately 20% of the site (the northernmost portion) 32-ha cotton field, on the north by residences, on was occupied by E. strigosus at a plant density of the west by a deciduous-tree-lined creek bank, and five per square meter. on the south by old-field habitat. Although mixed One hundred sixty-seven samples of insects col- grasses predominated, Erigeron strigosus was the lected from Erigeron spp. over 5 mo were exam- principal flowering plant and was scattered ined for attached mites, with 17 samples yielding throughout the field as well as in a nearly homo- positive results. Nine of the positive samples were geneous 0.4-ha section along the eastern edge. from one site (site 2), from 11 July to 30 August Site 2 was an 8.0-ha hayfield 8 km south-south- 1984, and contained 93 individual hosts with at east of Indianola, Sunflower County, Miss., bor- least one attached mite (Table 2). The largest dered on the east by a 100-ha fallow pasture, on number of parasitized TPB occurred on 13 July, the north by a 40-ha cotton field, on the west by when 36 of 117 individuals possessed attached mites a deciduous-tree-lined slough, and on the south by (31% parasitization). The largest number of para- a dry slough. Mixed grasses predominated, with E. sitized cicadellids occurred on 9 August, when 11 strigosus as the most abundant flowering plant, of 24 individuals possessed attached mites (46% distributed evenly over the entire field at a density parasitization). of 2.5 plants per m2. Field Sampling Program, 1985. Sampled were Site 3 was 0.5-ha abandoned home site 4 km 78 sites, but only 6 contained larval L. johnstoni south-southeast of Leland, bordered on the east attached to arthropod hosts (Table 1). The 78 sites by a mixed grass open field, on the north by a were classified as either roadside margin (62) or paved road and adjacent deciduous-tree lined creek old-field habitat (16). Attached mites were ob- bank, on the west by a 1-ha pecan grove, and on tained from one of the roadside margins, and from the south by a 100-ha cotton field. Mixed grasses five of the old-field habitats. Two of the old-field predominated, with E. strigosus the most abun- habitats produced larval mites in 1984 (sites 1 and dant flowering plant at a density of one plant per 3); the other four sites are characterized here. square meter. Site 5 was a 20-ha hay field 3 km southeast of Site 4 was 0.75-ha old-field habitat 5 km east of Leland, bordered on the east by a deciduous-tree- Leland, bordered on the east by a deciduous-tree- lined creek bank, on the north by old-field habitat, lined creek bank, on the north by a four-lane di- on the west by a sanitary land-fill, and on the south vided highway with broad and grassy margins, on by a 50-ha cotton field. Ninety percent of the 246 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 80, no. 2

Fig. 1. TPB nymph. (A) Exuvial separation lines. (B) Percentage of total attachments. ground cover was coastal Bermuda grass; the re- Two hundred forty-four samples of insects were maining cover consisted of clovers and Erigeron examined for attached mites, with 17 samples spp. It was mowed in early May, early June, and yielding positive results. Site 1 produced the most late July. parasitized TPB nymphs (7), but levels of parasit- Site 6 was a 6-m-wide roadside/field margin 1.5 ization were relatively low compared with 1984 km north of Leland, bordered on the east, west, (maximum of 7% on 24 June). and south by paved roads and on the north by a Laboratory Rearing. The mean duration, under 0.5-ha cotton field. Mixed grasses predominated, laboratory conditions, of the immature stages of with Oenothera sp. and Erigeron spp. the only L. johnstoni, from attached larva to adult, was plants in flower. 20.8 d. No data on the interval between egg de- Site 7 was a 100-ha pecan grove 8 km south of position and larval attachment were obtained. The Leland, bordered on the east by a paved road, on only mite mortality was that associated with the the north by a 250-ha soybean field, on the west preserving in alcohol of specimens from each de- by a dirt road and canal, and on the south by velopmental stage. All hosts died within 1-2 d of deciduous woods. Ground cover was predomi- capture, usually coincident with mite detachment. nantly unmowed grasses, with patches of Erigeron The larva remained attached to the host for an spp. in the unshaded portions. average of 1.5 d after capture (n = 17). The en- Site 8 was a 0.5-ha abandoned home site 2 km gorged larva became inactive soon after detach- north of Leland, bordered on the east by a paved ment and entered the calyptostatic protonymphal road, and on the north, west, and south by resi- stage, which lasted an average of 4.5 d (n = 13). dential sites. Ground cover was predominantly un- The protonymph developed entirely within the mowed grasses, with Erigeron sp. and Coreopsis larval exuvium. The octopod deutonymph was ca- sp. scattered throughout. pable of quite rapid movement and readily cap- March 1987 YOUNG & WELBOURN: BIOLOGY OF L. johnstoni 247

Fig. 2. Cicadellidae nymph. (A) Exuvial separation lines. (B) Percentage of total attachments. tured and fed upon first-instar TPB, which were Forty parasitized cicadellid early-instar nymphs approximately the same size as the deutonymphs. were examined, and 98% of the attached mites The average consumption was 1.5 nymphs per 24 were located on exuvial separation lines. Only 10% h over a 72-h period. The deutonymphs remained were not attached along the dorsal midline suture active for an average of 8.6 d (n = 9) before be- (Fig. 2). coming quiescent and entering the inactive trito- One L. johnstoni was observed attached to a nymphal stage. This stage lasted an average of 6.2 cicadellid nymph, while the host underwent ec- d (n = 5) and like the protonymph remained in dysis. The mite was attached at the dorsal midline the exuvium of the previous active stage. The adult of the head, and remained attached there for the forms were about the same size as TPB of the late duration of ecdysis. The exuvium had split at the third or early fourth instars, and very easily cap- point of attachment and apparently did not dis- tured and fed upon these and earlier-stage TPB turb the mite. Because all parasitized hosts died nymphs. 24-48 h after mite attachment, molting during Larval Attachment Sites on Hosts. Of the 38 this period was probably a rare event. parasitized TPB nymphs preserved for further ex- Although most hosts (>95%) had only one larval amination, 63% (24) had larval L. johnstoni at- mite attached, multiple attachments did occur. tached along the lines of exuvial separation (molt TPB nymphs were obtained with two and three sutures). Thirty-four percent were attached on the mites attached and cicadellid nymphs were ob- head, 58% on the thorax, and the remaining 8% tained with two mites attached. were attached on the abdomen (where exuvial sep- Other Attached Mites. Collections in Washing- aration lines are not apparent). Of all mites, 47% ton County, Miss., in 1985 revealed another ery- were attached on the dorsal midline molting su- thraeid mite parasitic on the TPB. On 20 May ture, with another 15% concentrated on a molting sweep-netting of Erigeron sp. in an old-field hab- suture between the base of the right antenna and itat obtained five first-instar TPB nymphs, each the anterior edge of the right compound eye (Fig. with a single attached deutonymph of Balaustium 1). sp. Comparison of these specimens with type ma- 248 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 80, no. 2

areas of their insect hosts (Cross & Bohart 1969). Other mite species may attach anywhere on their hosts (Chmielewski & Lipa 1967). In the Ery- thraeidae, the parasitic larvae of the genus Leptus show no host-site preference (Baker 1982), and are able to attach almost anywhere on a wide variety of hosts (Welbourn 1983). Site preference on the host is unknown for most other erythraeids. To our knowledge there are no records of any species of parasitic mite attaching predominantly to molt sutures. It is not clear why L. johnstoni should do so. Comparison of the cheliceral length and distal width of 20 specimens of Leptus from spruce bud- worm moths from Maine with the 18 larval para- types of L. johnstoni was performed, with the chelicerae of L. johnstoni averaging 25% shorter and less than half the width of Leptus. This may limit the penetrating depth of Lasioerythraeus. During host ecdysis, some motile mites are known to migrate to the suture areas and move from the Fig. 3. Second-instar TPB with attached L. john- old to new cuticle (Behura 1956). Attachment at stoni larva. a molt suture for nonmotile forms may be a good strategy for surviving host ecdysis. Our observations, however, indicate that L. johnstoni kills its terial of the only two described Balaustium in host within 1-2 d and that the host usually does North America, B. dowelli Smiley and B. putmani not molt while the mite is attached. The only plau- Smiley, indicates that the Mississippi animal is sible explanation for the observed site preference probably an undescribed species. is the thinner or softer cuticle at the molt suture (Chapman 1982), facilitating penetration by the shorter and thinner chelicerae of the mite. Discussion This study has documented 151 host records of During a 2-yr period, >90 different sites were larval L. johnstoni during a 2-yr period (Table 1). sampled for the presence of L. johnstoni. Unfor- Ten of the 15 host species documented can be tunately, these sites do not represent the full range considered phytophagous and represent 95% of the of habitats in Washington County. At the present host records. Several of these 10 phytophages also time we can only characterize L. johnstoni as oc- can be considered economically important pests, curring in second-growth, old-field situations with particularly TPB, which represented 52% of the a dense forb layer and located within 200 m of host records. water. Attached larvae were collected from low A recent compilation of host records of larval ground-cover vegetation and from the forb layer Erythraeidae indicated that several species have a up to the canopy 1.5 m above ground. Unattached host range at least as broad as L. johnstoni (Wel- larvae were collected from the same range of strata. bourn 1983). One species, Leptus ignotus (Oude- The host species of L. johnstoni are typically ac- mans), has been recorded attached to hosts in two tive in the upper portion of the forb layer, and it orders of arachnids and five orders of insects. Most is likely that larval attachment occurs in that stra- larval erythraeids, however, are more restricted in tum. L. johnstoni attached larvae have yet to be their hosts, usually occurring only on species with- collected from cotton or soybeans in Washington in one taxonomic order or family. Host informa- County, though searches have been conducted on tion for the other two species of Lasioerythraeus many occasions. larvae is unknown. One species, L. whitcombi, is Little is known about habitat utilization by oth- known only from the postlarval instars, which were er members of the Erythraeidae. The most well- reported feeding on Heliothis zea (Boddie) eggs known species, B. putmani Smiley, is found in or- in an Arkansas cotton field by Whitcomb & Bell chards at all strata (Putman 1970). Adults of B. (1964). The other species, L. shirleyanneae, is dowelli Smiley and L. whitcombi (Smiley) have known only from a single unattached larva. been obtained from cotton plants in small fields The preponderance of L. johnstoni host records with weedy borders (Whitcomb & Bell 1964). The in the Hemiptera is of considerable interest. Al- only known L. shirleyanneae (McDaniel & Bolen) though there are approximately 23,500 species of larva was obtained from a tall-grass/forb habitat Hemiptera and 33,000 species of the closely relat- (McDaniel & Bolen 1981). ed Homoptera (Borror et al. 1976), a world-wide Mites, in general, are known to attach almost compilation of host records of the Erythraeidae anywhere on an insect (Krantz 1978), with some reveal 38 records in the Homoptera, but only three phoretic mites consistently attaching to specific known larval attachments to Hemiptera (Wei- March 1987 YOUNG & WELBOURN: BIOLOGY OF L. johnstoni 249 bourn 1983). The hemipteran records are: Bo- 1961), the only known exception being Balaus- chartia sp. on Psallus seriatus (Reut.) (Miridae) in tium putmani Smiley (Childers & Rock 1981). the United States, Leptus josifovi Beron on Phyl- Before L. johnstoni can be properly evaluated lomorpha laciniata (Coreidae) in Bulgaria, and as a biological control agent for hemipterans in Leptus sp. on Triatoma recurva Stol (Reduviidae) general and for TPB in particular, a number of in the United States (Welbourn 1983). The host parameters still need to be investigated (Schroder records presented thus constitute a major addition 1983). We have no knowledge of searching ability, to the world literature on hemipteran parasitiza- reproductive potential, prey consumption rates, and tion by mites. pesticide tolerance of L. johnstoni. Other param- Several authors have recently considered the bi- eters are only slightly better understood. There does ological control potential of erythraeid mites as- appear, however, to be enough known to warrant sociated with phytophagous insect pests (Eickwort further investigation. 1983, Schroder 1983, Welbourn 1983). Because so few mite parasites of Hemiptera were previously Acknowledgment known, these authors did not consider the control potential of mites on economically important We appreciate the technical assistance and artistry hemipterans. L. johnstoni has considerable poten- provided by T. C. Lockley, and the review of an earlier tial as a control agent for hemipteran pests for version of this manuscript by E. W. Baker, W. A. Bruce, several reasons. N. F. Johnson, and J. C. Moser. First, the host/parasite size ratio is close to un- ity. Most records of erythraeid larval mites attached to hosts involve relatively large insects such References Cited as grasshoppers or moths, where the relatively small Baker, G. T. 1982. Site attachment of a protelean mite has minimal adverse effects on the host parasite (Erythraeidae: Leptus). Experientia 38: 923. (Southcott 1966, Treat 1975). Hosts that are more Behura, B. K. 1956. The relationship of the tyro- similar in size to the mite, such as collembolans, glyphoid mite, Histiostoma polypori (Oud.), with the are often killed (Greenslade & Southcott 1980). earwig, Forficula auricularia L. J. N.Y. Entomol. Soc. Our data indicated that L. johnstoni will kill its 54: 85-94. host with a host/parasite size ratio of 4:1 involving Borror, D. J., D. M. Delong & C. A. Triplehorn. 1976. An introduction to the study of insects, 4th ed. Holt, second-instar TPB (Fig. 3). Most of TPB hosts re- Rinehart & Winston, New York. ported here are first instars, where the host/para- Chapman, R. F. 1982. The insects. Structure and site size ratio was closer to 2:1 and where the mite function, 3rd ed. Harvard Univ., Cambridge, Mass. always killed its host. Childers, C. C. & G. C. Rock. 1981. Observations on Second, infestation rates can be in the range of the occurrence and feeding habits of Balaustium 30-50% on several different insect host species putmani (Acari: Erythraeidae) in North Carolina ap- (Table 2). This is a significant level of parasitiza- ple orchards. Int. J. Acarol. 7: 63-68. tion, particularly for TPB, where hymenopteran Chmielewski, W. & J. J. Lipa. 1967. Biological and parasitization levels are no higher (Streams et al. ecological studies on Caloglyphus mite (Acarina: Acaridae) associated with Scarabaeidae. Ann. Par- 1968). Most reports of erythraeid infestation rates asitol. Pol. 14: 179-190. indicate levels of <5% (Southcott 1966). Crosby, C. R. & M. D. Leonard. 1914. The tarnished Third, free-living deutonymph and adult forms plant bug, Lygus pratensis L. N.Y. (Cornell) Agric. are predaceous on the same species parasitized by Exp. Stn. Bull. 346: 463-525. the larval stage. Our laboratory rearing of L. john- Cross, E. A. & G. E. Bohart. 1969. Phoretic behavior stoni exclusively on TPB demonstrates this phe- of four species of alkali bee mites as influenced by nomenon for at least one host and prey species. season and host sex. J. Kans. Entomol. Soc. 42: 195- Such a situation would appear to be detrimental 219. to the local survival of the mite species, because Ebeling, W. 1934. A new predaceous mite from predation on older nymphs of TPB would decrease southern California (Acarina: Erythraeidae). Pan-Pac. Entomol. 10: 33-34. future population levels of the first instars neces- Eickwort, G. C. 1983. Potential use of mites as bio- sary for the larval mites. It is not known how fre- logical control agents of leaf-feeding insects. Univ. quently this phenomenon occurs in other ery- Calif. (Berkeley) Agric. Exp. Stn. Spec. Publ. 3304: thraeid species. 40-52. Finally, life-history parameters may be similar Grandjean, F. 1938. Sur l'ontogenie des Acariens. C. for the mite and its potential hosts and prey. In- R. Seances Acad. Sci. 206: 146-150. cidence of larval L. johnstoni in the field from Greenslade, P. J. M. & R. V. Southcott. 1980. Para- mid-March to mid-September (Table 1), com- sitic mites on sminthurid Collembola in Australia. bined with a larva-to-adult laboratory rearing pe- Entomol. Mon. Mag. 116: 85-87. Johnston, D. E. & R. R. Wacker. 1967. Observations riod of 21 d, suggest the existence of multivoltin- on postembryonic development in Eutrombicula ism. Potential hosts such as TPB have a generation splendens (Acari: Acariformes). J. Med. Entomol. 4: time of 20-30 d in warm weather and may pro- 306-310. duce six generations each year (Crosby & Leonard Krantz, G. W. 1978. A manual of acarology, 2nd ed. 1914). Most erythraeids are univoltine (Southcott Oregon State Univ., Corvallis. 250 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 80, no. 2

IYlcDaniel, B. & E. G. Bolen. 1981. A new species of Treat, A. E. 1975. Mites of moths and butterflies. Bochartia Oudemans from Texas. Proc. Entomol. Soc. Cornell Univ., Ithaca, N.Y. Wash. 83: 40-43. Welbourn, W. C. 1983. Potential use of trombidioid Putman, W. L. 1970. Life history and behavior of and erythraeoid mites as biological control agents of Balaustium putmani (Acarina: Erythraeidae). Ann. insect pests. Univ. Calif. (Berkeley) Agric. Exp. Stn. Entomol. Soc. Am. 63: 76-81. Spec. Publ. 3304: 103-140. Schroder, R. F. W. 1983. The potential use of mites Welbourn, W. C. & O. P. Young. 1987. A new genus in biological control of field crop pests. Univ. Calif. and species of Erythraeinae (Acari: Erythraeidae) (Berkeley) Agric. Exp. Stn. Spec. Publ. 3304: 36-40. from Mississippi with a key to the genera of North Sharma, G. D., A. T. Drooz & A. E. Treat. 1983. A American Erythraeidae. Ann. Entomol. Soc. Am. 80: new species of Callidosoma (Acari: Prostigma: Ery- 230-242. thraeidae) parasite on adults of Anacamptodes vel- Wharton, G. W. 1946. Observations on Ascoschon- livolata (Lepidoptera: Geometridae) as a larva, and gastia indica (Hirst 1915). Ecol. Monogr. 16: 151- predator of eggs of Lepidoptera as deutonymph and 184. adult. Ann. Entomol. Soc. Am. 76: 120-129. Whitcomb, W. H. & K. Bell. 1964. Predaceous in- Southcott, R. V. 1961. Notes on the genus Caeculi- sects, spiders, and mites of Arkansas cotton fields. soma (Acarina: Erythraeidae) with comments on the Univ. Arkansas Agric. Exp. Stn. Bull. 690: 1-84. biology of the Erythraeoidea. Trans. R. Soc. South Young, O. P. 1986. Host plants of the tarnished plant Aust. 84: 163-178. bug, Lygus lineolaris (Hemiptera: Miridae). Ann. 1966. Revision of the genus Charletonia Oudemans Entomol. Soc. Am. 79: 747-762. (Acarina: Erythraeidae). Aust. J. Zool. 14: 687-819. Streams, F. A., M. Shahjahan & H. G. LeMasurier. Received for publication 11 April 1986; accepted 7 1968. Influence of plants on the parasitization of November 1986. the tarnished plant bug by Leiophron pallipes. J. Econ. Entomol. 61: 996-999.