Vairimorpha invictae N. Sp. (Microspora: Microsporida), a Parasite of the Red Imported Fire Ant,Solenopsis invicta Buren (Hymenoptera: Formicidae)12

ABSTRACT. Vairimorpha invictae n. sp. infects the red imported fire ant, Solenopsis invicta Buren, in Brazil. The parasite is dimorphic, producing two morphologically distinct types of spores, which develop sequentially in the same fat cells or oenocytes in the fat body. The binucleate free spores develop from disporous sporonts; the uninucleate octospores develop from multinucleate sporonts within a sporophorous vesicle. Infected cells are transformed into large sacs which contain both types of spores in mature adult hosts. Mature free spores are often present by the time the larvae pupate, but mature octospores are found only in adult hosts. Masses of spores may be seen through the intact cuticle by low power phase-contrast microscopy; there are no other physical signs and no behavioral signs of infection. Attempts to transmit the infection in the laboratory failed.     

Cardiovascular Function in Turtles During Anoxia and Acidosis: In vivo and in vitro Studies

During prolonged experimental submergence, freshwater turtlesbecome anoxic and develop a combined respiratory and non-respiratoryacidosis. Anoxia and acidosis are known to depress cardiac functionin turtles and other vertebrate species. In vitro studies ofventricular and atrial tissue of turtles indicate that increasedextracellular Ca⁺⁺ concentration can reverse these depressantactions. Intact turtlesutilize this compensatory mechanism duringanoxia and other conditions leading to acidosis byincreasingplasma Ca⁺⁺ concentration. In addition, cardiac cells may releaseCa⁺⁺ from cell organelles to compensate for induced respiratoryacidosis. Both mechanisms presumably improve cardiac contractilityby elevating the level of sarcoplasmicCa⁺⁺.     

Influence of habitat and temperature on dispersal behaviour of two pteromalid parasitoids of houseflies during an inundative release at a dairy barn

1. About 11,000 each of Muscidifurax raptor Girault and Saunders and Urolepis rufipes (Ashmead) were released weekly for 7 weeks at a commercial dairy farm in central New York state, U.S.A. Dispersal behaviour was monitored by parasitism rates of house fly, Musca domestica L., pupae placed in sentinel bags. 2. M. raptor, which was released inside the barn, parasitized fly pupae both inside and outside, and it achieved highest rates of parasitism in indoor straw calf-bedding and in outdoor manure and silage. 3. U. rufipes, which was released outside the barn, did not attack pupae inside the barn, and its highest rates of parasitism occurred in outdoor manure and silage. 4. M. raptor appeared to be more effective than U. rufipes in parasitizing pupae located at sites where natural fly-breeding occurred. 5. Interspecific competition did not appear to explain these distribution patterns. 6. There was no significant trend in parasitism by M. raptor as a function of distance from the release station. Furthermore, high rates of parasitism near open doorways and at an outdoor site 30 m away suggests that M. raptor dispersed throughout the barn and its immediate surroundings. 7. Air temperature was positively correlated to flight activity, but not to parasitization activity in natural fly-breeding substrates.     

Two new genera and species of Braconinae (Insecta, Hymenoptera, Braconidae)from Brunei

Fuvihracon gen.n. (typc-species: Fuvibracon gauldi sp.n.) and Spurhulibrucon (type-species: Sparhulibracon dayi sp.n.), both lrom Brunei, are described and illustrated. The relationships of the two new genera and of the Carnpyloneurus Szépligeti and Chelonogaslra Ashmead generie groups are discussed.     

A yellow–green algal symbiont in the freshwater sponge, Corvomeyenia everetti: convergent evolution of symbiotic associations

1. A previously undescribed symbiotic relationship is reported between the freshwater sponge Corvomeyenia everetti , which occurs throughout eastern North America, and a yellow-green alga.
2. Ultrastructural and pigment analyses place the algal endosymbiont within the class Eustigmatophyceae in the division Heterokontophyta.
3. The relationship of the alga with C. everetti appears to be specific and it contributes significantly to the energy budget of the host.
4. Although the growth form of C. everetti is very similar to other freshwater sponges that usually have green-algal symbionts, its phylogeny has been proposed to be quite distinct, suggesting convergent evolution by both algae and sponges in the development of symbiotic associations in fresh water.     

Morphology of the antenna cleaner in the Hymenoptera with particular reference to non-aculeate families (Insecta)

An electron microscopic survey of antenna cleaner morphology, mainly in non-aculcate Hymenoptera, is presented. Modified, scale- or paddle-shaped setae on the fore basitarsus were found to be widely distributed throughout the order, but were particularly well developed in the Xyeloidea. Megalodontoidea, Blasticotomidae, Siricoidca, Orussoidea, Cephoidea and Chalcidoidea. as well as in the aculeate family Formicidae. A comb of fine setae on the fore basitarsus was present in all Apocrita, with the exception of the Trigonalyoidea, Evaniidae, and some families of Chalcidoidea, but among the symphytan families was present only in the Orussidae. Members of the symphytan family, Anaxyelidae have a distinct line of discrete setae in the same position as the fine comb of the Orussidae and apocritans which we term a protocomb; members of the Cephidae also show an indication of a protocomb, in the form of a line of more widely spaced, erect setae, that could form part of the same transition series. Members of the Trigonalyoidea and of the Evaniidae have no comb of fine setae but do possess one or more rows of highly modified, plate-like structures on the fore basitarsi.     

Testing for MacArthur-Wilson Equilibrium with the Arthropods of the Miniature Spartina Archipelago at Oyster Bay, Florida

SYNOPSIS. The unique features of the MacArthur-Wilson modelof equilibrium biogeography are the immigration and extinctioncurves. In the model, the immigration rate for each island isnegatively correlated with species number, and island extinctionrate is positively correlated with species number. Direct tests of the sign and statistical significance of immigrationand extinction curves were done, with data on arthropods oftiny Spartina alterniflora islets, in north Florida. Rey (1981)defaunated six islets in the spring, then censused the recolonizationweekly, for one year. Two control islets and a mainland plotwere also censused. Distinct tendencies in favor of MacArthur-Wilsoncorrelations were present for both immigration and extinction.But sufficient extraneous variation occurs in immigration andextinction rates to make correspondence to MacArthur-Wilsoncurves statistically non-significant, unless probabilities arecombined among islands. Thus, mathematical deductions from theMacArthur-Wilson model, which treat the curves as deterministiclines with no variance, are less appropriate than approachesthat incorporate stochastic variation. The study of community patterns, by models such as the MacArthur-Wilsonmodel, are not a substitute for careful autecological studies.Mechanisms of colonization and co-existence are only dimly hintedat by gross community patterns.