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One of the major obstacles for studies of the biology, ecology, and behavior of Neotropical vectors of human Plasmodium has been the lack of reliable and efficient means of identifying many species. Although the subgenus Nyssorhynchus includes most species responsible for human transmission in South America, there are no polymerase chain reaction (PCR)-based techniques for identifying members of this taxon. We describe the first multiplex PCR for identifying four species in the subgenus Nyssorhynchus that are vectors of human Plasmodium spp. Four species specific primers, together with a universal primer that anneals to the 5.8S rDNA region, produce amplicons of the internal transcribed spacer two with base pair sizes of 131, 308, 371, and 441 for An. triannulatus, An. trinkae, An. strodei, and An. rangeli, respectively.

Changes in intraspecific social organization are of particular interest to sociobiologists, because an understanding of the genetic and ecological determinants of different social forms bears on the origins of sociality and mating isolation. The Southern Yellowjacket, Vespula squamosa (Drury), occurs as both polygyne and single queen nests. This study examined intra-caste size differences between both social forms of nests. Four polygyne and 13 single queen nests were collected from counties in Florida and Georgia. All single queen nests were one season old, whereas polygyne nests were at least 2 years old. The latter had significantly more workers per nest (p 0.72), whereas the lowest positive correlations were obtained between weight and all other measures of size (r < 0.64). Gynes of both social forms differed significantly in weight (p < 0.001) and thorax length (p < 0.04), whereas workers differed significantly for all six measures of size (p < 0.04 to p < 0.001).

One of the major obstacles for studies of the biology, ecology, and behavior of Neotropical vectors of human Plasmodium has been the lack of reliable and efficient means of identifying many species. Although the subgenus Nyssorhynchus includes most species responsible for human transmission in South America, there are no polymerase chain reaction (PCR)-based techniques for identifying members of this taxon. We describe the first multiplex PCR for identifying four species in the subgenus Nyssorhynchus that are vectors of human Plasmodium spp. Four species specific primers, together with a universal primer that anneals to the 5.8S rDNA region, produce amplicons of the internal transcribed spacer two with base pair sizes of 131,308,371, and 441 for An. triannulatus, An. trinkae, An. strodei, and An. rangeli, respectively.

Parity and survival rates of Anopheles punctipennis were studied at the site of a 1952 outbreak of malaria in the Sierra Nevada foothills of California with the purpose of estimating blood feeding frequency and survivorship of such populations. Anopheles punctipennis was the dominant species in landing collections conducted for 20 consecutive nights in August and September 1990. The mean parity rate of An. punctipennis was 0.82. The gonotrophic cycle was estimated to last three days based on time series analysis of the number of nulliparous and parous mosquitoes collected each day. Survivorship was estimated to be 0.79 per gonotrophic cycle and 0.92 per day. Ovarian dilatation data indicated that some females had completed eight gonotrophic cycles prior to being collected and 45% of the females completed two or more cycles. The high prevalence of multiparous individuals, high parity rate, long survivorship and a short three-day gonotrophic cycle estimate indicates that this population is long lived and has a capacity to be an efficient vector of malaria.

Sequence variation of the ribosomal DNA internal transcribed spacer 2 (ITS2) was examined for populations of the malaria vector Anopheles nuneztovari collected in Colombia, Venezuela, Bolivia, Suriname, and Brazil. Mosquitoes from Colombia and Venezuela had identical ITS2 sequences and were distinguished from sequences in other populations by three insertion/deletion events (indels) and by one transversion. The length of the ITS2 was 363-369 bp, and it had a G+C content of 55.3%-55.7%. Variation in the length of the ITS2 between and within populations was due to indels in simple repeats. ITS2 consensus sequences were similar or identical for samples from the following three groups: (1) Colombia, Bolivia, and Venezuela; (2) Suriname and northern Brazil; and (3) eastern and central Brazil. The presence of two different consensus sequences from a single location near Manaus, Brazil, suggests that populations from eastern Brazil and those from Suriname converge in this region of the Amazon Basin. These data show that putative cryptic species of An. nuneztovari are distinguished by very minor differences in DNA sequence of the ITS2 region.

A polytene chromosome analysis was prepared from Anopheles freeborni collected from 25 locations in north and central California, and parts of Washington and Oregon. The X chromosome banding pattern, thought previously to be specific to An. hermsi, was common in mosquitoes collected from foothill regions in California, and in all samples from Washington and Oregon. At some of these locations, many mosquitoes had heterokaryotypes for the inversion that distinguishes the X chromosome of An. freeborni from that of An. hermsi. Use of rDNA restriction site analysis, and the results from crossing of different strains bearing either type of X chromosome, showed that An. hermsi does not have a unique or diagnostic X chromosome. Anopheles hermsi was collected in San Mateo County, CA, which is now the northernmost known limit of this species. Crossing studies, or the examination of rDNA restriction enzyme profiles, are presently the only means of identifying An. hermsi.

Data are presented on range, density, and distribution of Hemileuca oliviae Cockerell in Chihuahua, Mexico. Populations were found near Cuauhtemoc, Anahuac, and at various locations between Chihuahua City and El Sueco, but were absent from overgrazed and agricultural lands, and grasslands in the Chihuahua Desert. Egg clusters were distributed randomly at a height of 21.2 ± 9.5 cm from the base of grass stems, primarily Bouteloua gracilis (H.B.K.) Lag. Development of H. oliviae was asynchronous within and between sites. Sixth instars had a clumped distribution and a maximum recorded density of 24.44 per 100 m2

The inability to distinguishfemales ofPhlebotomuspapatasi (Scopoli) and P.bergeroti Parrot reliably is of considerable epidemiologi- cal significance since papatasi is well-known vector, and bergeroti is suspected vector, ofcutaneous leishmaniasis. Previous methods for distin- guishingthem eithervague (pharyngeal armature) unreliable (sper- mathecae). Detailed evaluation of the relative length of the ascoid the fourth antennal segment shows it to be unambiguous and reliable character for distinguishing both sympatric and allopatric populations. The biological differentiation of the two species is reviewed.

A search for parasitoids of Hemileuca oliviae Cockerell was initiated during summer 1983 in the state of Chihuahua, Mexico. Parasitoids that emerged from egg clusters collected near E1 Sueco were Anastatus semiflavidus Gahan, Microdontomerus sp., and Tetrastichus sp. Mean number of eggs per cluster ± SE was 126.12 ± 37.36, 83.33% of the clusters were parasitized, and 19.71% of all eggs were parasitized. Eggs of pentatomids and possibly mantids are alternate hosts for A. semiflavidus. Tachinid flies Leschenaultia sp. and Chetogena sp. parasitized 54 and 2%, respectively, of the late-instar caterpillars in one site, and the ichneumonid wasp, Enicospilus sp., parasitized 12% of these caterpillars. The chalcids, Brachymeria ovata (Say) and Spilochalcis mariae (Riley), parasitized 4.94 and 2.47% of the pupae, respectively, in one site, but were absent from three other sites. Six of the eight parasitoids (including two possible hyperparasites) found in H. oliviae are new records.

Techniques are described for mass rearing Anopheles freeborni. Eggs were incubated overnight at ca. 28 degrees C and then dried. Measured quantities of dried eggs were placed into styrofoam rings floating on the water surface of rearing trays. Water levels in larval rearing trays were kept shallow, and temperature was maintained with heat tapes at ca. 28 degrees C. Larvae were fed once a day on a slurry containing a 3:1:1:1 mixture of guinea pig chow, liver powder, yeast and hog chow. Pupation began on the 7th day after egg hatch, and pupae were harvested on the 8th, 9th and 10th days; ca. 1,700 pupae were harvested/tray. Adults emerged from 85% of the pupae, and about 40% were female. Individual males held in gallon-sized containers inseminated as many as 10 females. Although most sugar-fed males died within 2 weeks after emergence, over 35% of sugar-fed females survived for 3 weeks. Colonies were maintained on defibrinated bovine blood provided in natural membrane prophylactics. There were no significant differences in the number of blood-fed females or in the number of eggs they produced when mosquitoes were offered either guinea pigs or defibrinated bovine blood. Eggs were collected in plastic cups placed in cages. There was less than 6% mortality of eggs when these were dried and stored at 10 degrees C for 6 days.