The echolocation of flying insects by bats

It is well known that the American dog tick, Dermacentor variabilis Say, can be reared through its entire life cycle on guinea pigs. In the course of permitting successive batches of larvae of this tick to engorge on the same guinea pig, it was repeatedly observed that, while the first batch always gave a large number of engorged larvae, the following batches gave few or none. This suggested that guinea pigs, after one infestation with larvae of D. variabilis, acquire an effective immunity against these ectoparasites. The experiments reported in this paper show that such an immunity is indeed developed, and that it may be solid enough to prevent larvae from engorging and to reduce the amount of blood taken by nymphs and adults.

Acquired Immunity to Ticks.

The role of aquatic biology in the water
pollution control program of the U. S.
Environmental Protection Agency includes field
and laboratory studies carried out to establish
water quality criteria for the recognized
beneficial uses of water resources and to
monitor water quality.
Field studies are employed to: measure the
toxicity of specific pollutants or effluents to
individual species or communities of aquatic
organisms under natural conditions; detect
violations of water quality standards ; evaluate
the trophic status of waters ; and determine
long-term trends in water quality.
Laboratory studies are employed to : measure
the effects of known or potentially deleterious
substances on aquatic organisms to estimate
“safe” concentrations ; and determine environmental
requirements (such as temperature, pH,
dissolved oxygen, etc.) of the more important
and sensitive species of aquatic organisms. Field
surveys and water quality monitoring are
conducted principally by the regional
surveillance and analysis and national enforcement
programs. Laboratory studies of water
quality requirements, toxicity testing, and
methods development are conducted principally
by the national research programs.

Biological Field And Laboratory Methods For Measuring The Quality Of Surface Waters And Effluents

The fIrst draft version of this book, written in systematics of Neoptera) had two different editions English and named "Draft revision of supraspecies in Russian - in 1999 and in 2000 (Kluge 2000). taxa of Ephemeroptera (without Atalophlebiinae)", English version of this fIrst volume is also prepared, was prepared as an Internet publication in 1998; but not published yet. thanks to Dr. Michael Hubbard (Florida A & M Uni- versity), it has been available from the web site "Ephemeroptera Galactica" since 1998. The second NEW TERMS, TAXA NAMES AND version, written in Russian and named "Revision of SYNONYMS supra-species taxa of Ephemeroptera (except for Atalophlebialfgl)", was prepared as an Internet publication in 2000; from 2001 till now it has been New terms: plesiomorphon (instead of wrongly available from the web site of Biological Faculty of used "plesion", p. 16); basitornal margin, tornoapical S-Petersburg University, http://www. bio. pu. ruJwinl margin, amphitornal margin of wing or wing bud entomollKLUGEIEPHEMER -"content_. htm. Both (p. 31); tergalius (instead of formerly used "tergalia" versions contain the systematics of all mayflies or "tergalium", p. 35); caudalius, tricaudale, basitri- except for Atalophlebialfgl. The present Volume 1 caudale, cercotractor (p. 38). does not contain the systematics of Turbanoculata For some morphological terms type taxa are (i. e. Baetidae auct. ) nor of all Leptophlebialfg1 (i. e. designated. Till now this was not practised, but in Leptophlebiidae auct.

The Phylogenetic System of Ephemeroptera

Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever, was lethal for the majority of experimentally and transovarially infected Rocky Mountain wood ticks (Dermacentor andersoni). Overall, 94.1% of nymphs infected as larvae by feeding on rickettsemic guinea pigs died during the molt into adults and 88.3% of adult female ticks infected as nymphs died prior to feeding. In contrast, only 2.8% of uninfected larvae failed to develop into adults over two generations. Infected female ticks incubated at 4°C had a lower mortality (80.9%) than did those held at 21°C (96.8%). Rickettsiae were vertically transmitted to 39.0% of offspring, and significantly fewer larvae developed from infected ticks. The lethal effect of R. rickettsii may explain the low prevalence of infected ticks in nature and affect its enzootic maintenance.

James G. Needham

Papers

A guide to the study of fresh-water biology : with special reference to aquatic insects and other invertebrate animals

A guide to the study of fresh-water biology

Culture Methods for Invertebrate Animals

Guía para el estudio de los seres vivos de las aguas dulces

Aquatic insects in the Adirondacks