Martin H. Muma

Some Generic Descriptions and Name Changes in the Family Phytoseiidae (Acarina: Mesostigmata)

Five newly delineated genera, Proprioseiulus, Noeledius, Chelaseius, Athiasia, and Orientiseius are described. Four genera are synonymized: Amblyseiulus with Proprioseiopsis, Paradromus with Kampimodromus, Cydnodromus with Neoseiulus, and Clavodromina with Paraseiulella. Ricoseius is elevated to generic status. Systematic problems in Phytoseius are discussed and clarified. Type synonymy in Clavidromus is indicated.

Food Habits of Phytoseiidae (Acarina: Mesostigmata) Including Common Species on Florida Citrus

Food habits of 11 species of phytoseiids found on or associated with Florida citrus trees were investigated with the following results. Data on Amblyseiella setosa Muma were inconclusive; Amblyseius aerialis (Muma) proved to be a general predator of tetranychids, tenuipalpids, and probably other families of mites; Amblyseius deleoni Muma and Denmark fed adequately and optimally on acarids, eriophyids and tetranychids, and predictably on other families; Euseius hibisci (Chant) fed adequately on coccid eggs and crawlers, aleurodid eggs and nymphs, and tetranychids; Galendromus (Galendromus) floridanus (Muma) proved to be an obligate predator of tetranychids; Iphiseiodes quadripilis (Banks) proved to be a general facultative predator capable of surviving on non-living organic materials; Phytoscutus sexpilis Muma fed optimally only on acarids but possibly survives on other hosts; data on Proprioseiopsis dorsatus (Muma) were inconclusive; Typhlodromalus peregrinus (Muma) proved to be a general facultative predator capable of surviving on fungi and nonliving organic materials; data on Typhlodromina subtropica Muma and Denmark were inconclusive; Typhlodromips simplicissimus (DeLeon) fed optimally on tetranychids but other phytophagus and non-phytophagus mites are probably adequate as food. Collation and correlation of the above findings with previously published work has indicated generic food habits for several genera of phytoseiids. Amblydromella spp. are probably facultative eriophyid and tetranychid predatos. Amblyseius spp. are probably general predators. Anthoseius spp. seem to be pollenophagus. Euseius spp. are pollenophagus, facultative, general predators. Galendromus spp. of the typical subgenus seem to be obligate tetranychid-eriophyid predators; inadequate data are available on species of other subgenera. Iphiseiodes spp. are probably facultative general predators. Macroseius spp. are obligate nematodeanoetid predators. Mesoseiulus spp. seem to be obligate tetranychid predators. Orientiseius spp. are probably obligate predators of eriophyids and tetranychids. Paraseiulus spp. possibly are tydeid predators. Phytoscutus spp. are probably acarid predators. Phytoseiulus spp. are obligate predators of tetranychids that may survive on other mites and insects. Typhlodromalus spp. are facultative general predators. Typhlodromips spp. are facultative general predators. Typhlodromus spp. are probably facultative eriophyid or tetranychid predators. Data on 5 other cited genera are inconclusive.

Some Phytoseiid mites of Paraguay (Phytoseiidae: Acarina)

A summary of the phytoseiids of South America is presented and 5 species are reported for the first time from Paraguay. These include Proprioseiopsis citri (Muma), Euseius citrifolius n. sp., Euseius flechtmanni n. sp., Euseius paraguayensis n. sp., and Galendromus sp. A key is constructed for the 3 new species of Euseius.

New Phytoseiidae (Acarina: Mesostigmata) from Florida

Since the reorganization of the supraspecific classification of the Phytoseiidae (Muma, 1961) several new species and one new genus of the family have been collected in Florida. These new forms are described and illustrated below. The types are deposited in the United States National Museum in Washington, D. C., and paratypes are in the University of Florida Collections in Gainesville, Florida, and the authors collection.

Entomophthora Floridana N. Sp. (Phycomycetes: Entomophthoraceae), a Parasite of the Texas Citrus Mite, Eutetranychus Banksi

Recently, Selhime and Muma (1966) studied the biology of an entomophthoraceous fungus attacking the Texas citrus mite, Eutetranychus banksi (McGregor). This study and a series of earlier publications including Fisher (1954), Muma (1955 and 1958) and Muma et al. (1961) have indicated the unusual frequency of the fungus in the field and its potential importance in the biological control of the Texas Citrus mite. This fungus, described in the present paper, is not the only Entomophthora known to infect Acarina. Petch (1940) described Entomophthorct acaricida from Halotydems destructor Tucker and later, Petch (1944) described E. acaridis from other infected Acarina. Recently, Batko (1965) recorded Conidiobolus brefeldianus Couch from Tyrophagus perniciosus Zachvatkin and other tyroglyphid mites. METHODS

Comparison of Ground Surface Spiders in Four Central Florida Ecosystems

Ground surface spider populations were studied using can traps for 3-1/2 years on sand-pine dunes, pine flat-woods, citrus groves, and residential areas in central Florida. Twenty-three prevalent (0.5 or more percent of total population) species involving, primarily, 6 prevalent (5.0 or more percent of total population) families occurred in distinctive, specifically different, ground surface spider populations in each ecosystem. The sand-pine dune population was 53% lycosid, 19% gnaphosid, and 18% salticid; the pine flat-woods, 64% lycosid, 21% salticid, and 5% linyphiid; the residential area, 54% lycosid, 23% theridiid, and 16% linyphiid; and the citrus grove, 38% clubionid, 19% theridiid, 18% lycosid, and 11% linyphiid. The population in the citrus grove was also only 1/3 as large as those of the other ecosystems. Most of the differences among the populations of the sand-pine dunes, pine flat-woods, and residential areas seemed to be the result of ecologically-equivalent species replacement, but the strikingly different citrus grove population could be the result of repeated soil surface disturbance during cover crop cultivation.

Biology of Entomophthora Floridana Attacking Eutetranychus Banksi

During experiments designed to evaluate the biological control of the Texas citrus mite, Eutetranychus banksi (McGregor), in citrus groves, it was found that counts of these mites and the known biological-control factors present did not adequately explain population increases and decreases. There are several species of predatory mites and a fungus, Entomophthora floridana Weiser and Muma, known to attack the Texas citrus mite. Need to increase count accuracy by refinement of counting technique was indicated. Since methods of counting predators in host mite samples had been verified it was suspected that the error involved estimates of diseased host mites. A laboratory investigation demonstrated that this was true. When Texas citrus mites were cleared in hot lactic acid, fungus tissues and mite structures were sharply differentiated. This led to a rapid, accurate determination of the number of fungus-infected and noninfected mites. At this point, it became obvious that a more complete knowledge of the life cycle and life stages of the fungus would be necessary to differentiate it from adventitious and saprophytic fungi also found on and in the mites. Review of pertinent literature revealed the following: Fisher (1954) first recorded an Entomophthora sp. from Texas citrus mites, noting that it appeared to be different from the unidentified species that she (Fisher 1951) had reported attacking citrus red mites, Panonychus citri. In her 1951 paper, Fisher discussed gross manifestations of diseased mites and presented a general discussion of the life cycle of Entomophthora taken from Steinhaus (1949), Bessey (1950), and Fitzpatrick (1930). Other publications on Entomophthora in citrus spider mites merely listed the association (Muma, Selhime, and Denmark, 1961), or discussed and evaluated fungus-caused epizootics in two species of spider mites (Muma 1955, 1958). The present study was initiated to determine the infective stage and life cycle of, and the epizootiology of the disease caused by E. floridana in Texas citrus mites. Susceptibility of the citrus red mites and six-spotted mites, Eotetranychus sexmaculatus, to the fungus was also investigated.

SPIDERS IN FLORIDA CITRUS GROVES

The author reports observations on spiders collected during 20 years of ecological investigations of citrus pests. Primitive, haplogyne spiders were represented by 5 species. Cribellate spiders were among the most abundant in the citrus grove; 12 species were taken on the trees. They fed mostly on midges, mosquitoes, and vinegar gnats. Five species of Gnaphosidae are known from citrus litter; those of the genus Drassylus were the most common. Vagrant spiders of the closely related families of Anyphaenidae and Clubionidae were at times quite common. The comb-footed spiders, family Theridiidae, are well represented in Florida citrus groves; altogether, 19 species were recorded. The sheet-web weavers and dwarf spiders were poorly represented; of the 18 orb weavers of the family Argiopidae now known to occur in citrus, only 5 are common to abundant. Although wolf spiders occur in commercial citrus groves, only 4 species have been taken in sufficient number to be considered relatively common. Thomisidae, Heteropodidae, Ctenidae, and Oxyopidae are poorly represented. Salticids are not particularly common; 9 species have been recorded.

Populations of Common Mites in Florida Citrus Groves

Emphasis in entomological research on citrus in Florida has recently been shifted to the control of mites. Since effective control of injurious nites is predicated on an understanding of the bionomics of the several associated species, the population study reported here was initiated as a preliminary effort to obtain such an understanding. This paper is concerned only with those species or species complexes that in some stratum, season, or area averaged one or more individuals per sample. These arbitrarily chosen, common or abundant forms are referred to here as prevalents. In the discussions that follow, prevalents in more than one strata, season, or area are referred to as common prevalents; prevalents represented by 20 or more specimens in two or more strata, seasons, or areas are referred to as abundant prevalents. For the purposes of this paper, populations and infestations are considered synonymous and include all of the individuals in a citrus grove as an ecological association.

Natural Control Potential of Galendromus Floridanus (Acarina: Phytoseiidae) on Tetranychidae on Florida Citrus Trees

The identity, life cycle, food habits, and host-predator relationships of the predatory mite, Galendromus floridanus (Muma), are reviewed and new substantiating data are presented. It is concluded that the predator is capable of reducing six-spotted mite infestations but is probably ineffective in the natural control of the Texas citrus mite or citrus red mite.