Lynch Arribalzaga Research Articles

Mosquito Flight Paths in Relation to the Environment. 1. Illumination Levels, Orientation, and Resting Areas

Suction traps were operated within and adjacent to a wooded swamp and in a field with various patterns of potted shrubs. Vehicle aspirator collections were made of mosquitoes in the daytime resting habitats. Aedes mitchellae (Dyar), A. sollicitans (Walker), Psorophora ciliata (F.), and P. confinnis (Lynch Arribalzaga) were field species, i.e., greatest numbers were taken, both day and night, in open grassy areas, and avoided woodland and the vicinity of shrubs. Many species preferred woodland for daytime resting but moved out nightly to forage in the field. At night this behavior resulted in a buildup of mosquitoes along the outside margin of the swamp or in a trap placed in a gap in a hedge row. The largest numbers of Culiseta melanura (Coquillett) and Culex nigripalpus Theobald remained in woodland throughout the diel. When these species were taken out in the field, the greatest numbers were found in the vicinity of shrubs. It is concluded that in the absence of other attractants or adverse meteorological conditions, physical objects guide mosquito flight paths in 3 ways: (1) by reducing the level of illumination, as beneath a forest canopy or adjacent to a forest edge; (2) by forming a visual image, to which each species responds according to its inherent behavior pattern; and (3) by serving as a physical barrier.

A LIST OF AUSTRALIAN SPECIES OFURANOTAENIALYNCH ARRIBÁLZAGA (DIPTERA: CULICIDAE)

Thirteen described species of Uranotaenia Lynch Arribalzaga are listed, including six new records for Australia; three undescribed species are recognised. Copyright

The ecology of Psorophora confinnis (Diptera: Culicidae) in Southern California. II. Temperature and development.

The developmental times, eclosion to emergence, of 18 broods of Psorophora confinnis Lynch Arribálzaga, observed in irrigated date groves in the Coachella Valley, Calif., ranged from 78 to 126 hours with a mean of 97 hours at average water temperatures of 77–88°F. In 38% of the broods, all pupae were stranded on mud by the disappearance of open water, but 50%–95% of these metamorphosed successfully although stranded for as much as 15 hours. Thus, at summer temperatures, irrigation water needs to persist only 3–3.5 days to permit emergence. At constant water temperatures of 65°–95°F, developmental time varied inversely with temperature, but the effect of a 5° increase was progressively less as temperature increased. Total development was fastest (86–89 hours) at 90°–95°F. Survival, from second-instar larva to adult, was maximum at 75°–85°F. For each immature stage there is agreement between the constant temperatures which allowed good survival in the laboratory and the range of water temperatures encountered in nature. The first- and second-instar larvae were most susceptible to temperature extremes; later stages were progressively more resistant. Pupae appeared normal at 115°F and metamorphosed after such exposure. The rapid development from eclosion to emergence and the high tolerance of the pupae, together with their ability to metamorphose on mud, are significant adaptations of the Coachella Valley populations of P. confinnis.

Pupae of the Genus Culiseta Felt. I. The Homology of Larval and Pupal Setae (Diptera: Culicidae)

Nerves connecting larval and pupal setae of prepupal mosquitoes were used to establish the homologies of the abdominal setae. Both larval and pupal setal patterns were then utilized to deduce serial (segment to segment) homologies. The chaetotactic system proposed is based on previous ones but contains several modifications suggested by the present work. The studies described were clone with prepupae of Culiseta inornata (Williston), Culex pipiens quinquefasciatus Say and Psorophora confinnis (Lynch Arribalzaga).

Studies on the Chromosomes of Mosquitoes1

The prophase and anaphase chromosomes of Aedes canadensis Theobald are illustrated, as are the metaphase chromosome complements of 16 other species, as follows: Culex quinquefasciatus Say, C. salinarius Coquillett, C. tarsalis Coquillett, C. territans Walker, Aedes atropalpus Coquillett, A. hendersoni Cockerell, A. triseriatus (Say), A. vexans (Meigen), A. zoosophus Dyar and Knab, Orthopodomyia alba Baker, O. signifera (Coquillett), Haemagogus equinus Theobald, Anopheles pseudopunctipennis Theobald, Culiseta inornata (Williston), Psoropliora longipalpus complex, and Toxorhynchites rutilans septentrionalis (Dyar and Knab). Additional species examined but not illustrated include Culex restitans Theobald. C. erraticus Dyar and Knab, C. coronator Dyar and Knab, Aedes sollicitans (Walker), Uranotaenia syntheta Dyar and Shannon. Psorophora confinnis (Lynch Arribalzaga), and P. discolor (Coquillett). The chromosomes of 16 of these species had not previously been examined. The number 2n = 6 was found in all species studied. Distinctive chromosome complements were found at prophase in O. alba, O. signifera , and T. r. septentrionalis , and at metaphase for Anopheles pseudopunctipeiinis . Except for this last, the chromosome complements of the species examined at metaphase are quite similar. Mitosis in Culex salinarius is illustrated and briefly compared with that previously reported for C. pipiens . These studies were made on brain tissue of prepupae, using the squash technique with aceto-orcein as the stain, and these techniques are discussed. Future work suggested includes studies of salivary gland chromosomes and of meiosis. continued search for unique karyotypes, the use of different tissues and techniques, and studies of mitotic stages other than metaphase.

Natural hosts of some species of Taeniorhynchus lynch Arribalzaga (Diptera, Culicidae) collected in Uganda, as determined by the precipitin test.

Natural hosts of some species of Taeniorhynchus lynch Arribalzaga (Diptera, Culicidae) collected in Uganda, as determined by the precipitin test.

The Genus Uranotaenia Lynch Arribalzaga in Puerto Rico

The discovery of Uranotaenia cooki Root in Puerto Rico has made it desirable to restudy all stages of the three local species of Uranotaenia . Uranotaenia Lynch Arribalzaga (1891) is such a well-defined genus that a number of authorities such as Dyar (2) and Neveu-Lemaire (8) have felt justified in making it the type genus of a distinct tribe Uranotaeniini in the subfamily Culicinae.