Equine Culicoides hypersensitivity in Florida: biting midges aspirated from horses

Nine species of Culicoides were aspirated from horses in Florida during the second phase of a study of equine Culicoides hypersensitivity (CHS). Approximately 90% of the 2933 midges were Culicoides insignis Lutz, 4% were C.stellifer (Coquillett), 3% were C.niger Root and Hoffman, 2% were C.alachua Jamnback and Wirth and the remaining 1% included C.venustus Hoffman, C.scanloni Wirth and Hubert, C.lahillei Iches (= C.debilipalpis Lutz), C.pusillus Lutz, and C.edeni Wirth and Blanton. Culicoides were sampled on seven farms located throughout Florida. The location and seasonality of lesion development on horses with CHS correlated with the Culicoides spp. collected directly from the horses as to their sites of attack, their seasonality and geographical distribution.     

Light and suction trap catches of Culicoides midges in southern England

1. The seasonal flight periods are given for eleven species or species groups of Culicoides midges at Pirbright, Surrey, U.K., from 1979 to 1981 and in 1983. 2. Most species were relatively uniformly distributed both within the study site and between years; only C.clintoni Boorman was limited in its spatial distribution and only C.segnis Campbell and Pelham-Clinton varied greatly in numbers between years. 3. Species fall into one of three patterns of seasonal abundance: spring emergers, summer emergers, or spring to autumn emergers. 4. Only the C.obsoletus group showed a pattern of emergence that could correspond to distinct generations, of one or more species in the group. Three distinct emergences were observed, and possible explanations for these discussed. 5. For all species except C.impunctatus Goetghebuer the catches from suction/light and suction only traps are poorly correlated whereas for C.impunctatus they are highly correlated. This may suggest that this species is not greatly attracted to light.     

Light trapping of biting midges Culicoides spp. (Diptera: Ceratopogonidae) with green light-emitting diodes

Abstract  A study of responses by Culicoides spp. to light traps with light-emitting diodes (LEDs) confirmed that the livestock virus vector, Culicoides brevitarsis Kieffer, was preferentially attracted to green light. Four species shown previously to respond to blue light exhibited significantly higher responses to ultraviolet (UV) light. Field trials comparing green LEDs with incandescent lights in New South Wales, Northern Territory and East Timor confirmed the superiority of green LEDs for catching C. brevitarsis . The green LED traps also had a significant advantage over incandescent traps for a wide range of Culicoides species. These included: species whose ultimate preference was for UV, most species that are proven or potential vectors of viruses affecting Australian livestock and native animals and the main species affecting humans in northern Australia. Use of green LEDs has been adopted for trapping C. brevitarsis , especially in its marginal and low-density areas, and for detecting incursions of new Culicoides spp. into Australia. Use could be possible for species in other insect Orders.     

Mouthparts, antennae and genitalia of intersex Culicoides stellifer parasitized by mermithid nematodes

Abstract A 12-month study of Culicoides in Bulloch County, Georgia, U.S.A., revealed that twelve of 23 ,859 specimens (0.05%) of C.stellifer were intersexes as a result of being parasitized by mermithid nematodes. Of these, eleven had male genitalia and female type antennae and one had female genitalia with male type antennae.     

Feeding and survival of Culicoides sonorensis on cattle treated with permethrin or pirimiphos-methyl

The persistence of permethrin (5% a.i.) and pirimiphos-methyl (27% a.i.), applied to the dorsum of calves in the field against Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), was estimated using a hair-blood-feeding bioassay in the laboratory. Hair clippings were taken before treatment and 3, 7, 14, 21, 28, 42 and 56 days after treatment from the dorsum, side and belly of treated and control calves. Laboratory-reared insects were allowed to feed through thin hair layers and a parafilm membrane on sheep blood warmed using a water-jacketed feeder. Some intoxication after exposure to hair was noted up to 28 days after treatment with permethrin and up to 14 days after treatment with pirimiphos-methyl. Hair from the dorsum caused more intoxication for a longer period than hair from other body regions. Permethrin and pirimiphos-methyl applied to the back did not significantly reduce overall engorgement (body regions pooled) after treatment. Permethrin residues on hair remained far higher on the back than other body regions and were related to insect intoxication and reduction in engorgement in the laboratory. Residues on belly hair never exceeded 12p.p.m. and did not result in significantly reduced feeding at any time. Engorged insects that exhibited sublethal intoxication from feeding through permethrin-treated hair did recover and matured numbers of eggs comparable to controls. Field trials using treated and control calves and enclosure nets showed that dorsal applications of 5% permethrin were not effective in reducing engorgement, despite some intoxication. Vacuum samples from a calf showed that C. sonorensis fed primarily on the belly. A 0.2% permethrin application on the belly (250 ml) did result in > 80% reduction of C. sonorensis in the enclosure nets at 3 and 7 days after treatment, but activity had subsided by 10 days after treatment. The utility of insecticidal treatments for suppression of this vector is discussed.     

Genetic variation in populations of Culicoides variipennis complex in the six New England states, U.S.A.

Abstract. We investigated the identity and distribution of members of the Culicoides variipennis complex in the six New England states of the U.S.A., a region where bluetongue transmission has not been detected. Analyses of seven polymorphic isozyme-encoding loci showed that only C.v.variipennis , not considered to be a vector of the bluetongue viruses, was present. The populations of C.v.variipennis were significantly more hetero-zygous than C.v.sonorensis and Cv.occidentalis populations from similar studies in the state of California. Estimates of genetic diversity among populations of C.v.variipennis in New England were similar to C.v.sonorensis in the state of Colorado, but were significantly more genetically divergent than California populations of Cv.occidentalis. The impact of these findings on the status of New England as a possible bluetongue-free region for the purpose of international trade in ruminant livestock and their germplasm is discussed.     

Factors affecting numbers of Culicoides in truck traps in coastal Queensland

Abstract .Truck trap collections of Ceratopogonidae were made over a period of 27 months (November 1973–February 1976) at Tingalpa Creek, in southeast Queensland, Australia. Six collections were made on each of 95 days, giving 570 observations and a total of 29 378 Culicoides . Two collections were made before, one at, and three after sunset. Separate analyses were made of the catches of thirteen entities: male and female C. austropalpalis , C. brevitarsis , C. marksi , C. marmoratus and C. victoriae , female C. henryi and C. longior , and total C. bundyensis .
Catches were dominated by C. brevitarsis (35.2%) and C. marmoratus (32.3%) and, with C. victoriae , were taken on almost every collecting day over all seasons. Sex ratios (M:F) varied from 0:100 for C. longior to 130:100 for C. marksi . Collections of all entities, except female C. henryi , were greatest (50–70% of the daily catch) at sunset. In winter there was substantial activity in the hour before sunset. Time of day was the most important variable, accounting for 15–45% of the observed variation. Between-day differences were significant for all except C. austropalpalis, C. victoriae and male C. marksi . Culicoides brevitarsis, C. bundyensis and C. longior had highly significant annual cycles, C. victoriae and female C. austropalpalis had significant lunar cycles, and C. longior had a significant tidal cycle. Logarithms of catches of female C. austropalpalis, C. brevitarsis, C. henryi, C. marmoratus, and female and male C. victoriae were inversely related to linear wind speed. Log catches of female C. austropalpalis, C. brevitarsis, C. marmoratus and C. victoriae , and male C. marksi and C. victoriae were positively related to temperature (quadratic).     

A new type of collapsible insect-surveillance light trap for sampling Diptera

The newly designed Army Collapsible Insect Surveillance trap for nocturnal collection of flying Diptera that are attracted by light is described. A polyvinyl chloride construction increases durability, while the capability to collapse from a height of 92.1 cm to 24.1 cm facilitates transportation and storage.     

Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea in 2003

Surveillance of adult mosquitoes was conducted at 29 US military installations and training sites in six provinces in the Republic of Korea during 2003. Adult mosquitoes were collected in New Jersey light traps and dry ice‐baited New Jersey light traps from 1 May to 15 October. Mosquito surveillance was conducted to determine threshold levels to initiate pesticide applications and identify malaria infection rates at selected army installations and training sites. A total of 42 024 adult mosquitoes (32 594 females [77.6%] and 9430 males [22. 4%]) comprising 14 species and Anopheles sinensis s.l. (a complex of five species), representing seven genera, were collected. The most common species were members of the Anopheles sinensis Wiedemann complex (54.9%), followed by Aedes vexans nipponii (Theobald) (19.0%), Culex pipiens Coquillett (14.3%) and Culex tritaeniorhynchus Giles (10.6%). Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban communities.     

Plasmodium hermani: Experimental transmission by Culex salinarius and comparison with other susceptible Florida mosquitoes

Culex salinarius is susceptible to Plasmodium hermani, a malarial parasite of wild turkeys in Florida. The sporogonous cycle was completed and mosquitoes with infected salivary glands transmitted the parasite by bites. Transmission was also achieved by intraperitoneal and intravenous injections of whole body slurry. This is the third species found to be susceptible to turkey malaria in Florida. A comparison of C. salinarius with two other susceptible Florida mosquitoes, Culex nigripalpus and Wyeomyia vanduzeei, revealed that C. salinarius was more susceptible to P. hermani based on oocyst counts. C. nigripalpus has previously been demonstrated as an experimental and a natural vector of P. hermani, whereas W. vanduzeei has been designated as an experimental host only. In W. vanduzeei at least 30% of the oocysts were melanized (“black bodies”) and this mosquito did not transmit the parasite via bites. Additional detailed comparisons of comparative susceptibility and transmission potentials of these three species to turkey malaria, P. hermani, have been made.     

Seasonal prevalence of mosquitoes collected from light traps in the Republic of Korea, 2005

Adult mosquito surveillance was conducted during 2005 at 22 US military installations and two training sites located in six provinces in the Republic of Korea. Adult mosquitoes were collected in New Jersey light traps from 1 May to 15 October to determine threshold levels to initiate pesticide applications based on trap indices. A total of 27 363 adult mosquitoes (22 368 [81.7%] females and 4995 [18.3%] males) comprising 15 species (including five members of the Anopheles sinensis group) belonging to seven genera were collected. The most common species collected were members of the Anopheles sinensis Wiedemann group (50.2%), followed by Culex tritaeniorhynchus Giles (30.6%), Aedes vexans nipponii (Theobald) (11.8%), and Culex pipiens Coquillett (6.3%) females. Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban or rural communities.     

Emergence of Chironomidae from Findley Lake and two ponds in the Cascade Mountains,U.S.A.

From Findley Lake and two ponds in the Cascade Mountains (U.S.A.) Chironomidae started to emerge as soon as the ice thawed in 1972 and 1973. The 1051 Chironomidae that emerged per m² from Findley Lake included 307 individuals ofTanytarsus and 358 ofProcladius. Tanytarsus outnumberedChironomus at all depths from 0 to 19.3 m. The 1506 Chironomidae that emerged per m² from the 4.5 m deep pond included 997 individuals ofTanytarsus. The 1490 Chironomidae that emerged per m² from the 2 m deep pond included 1363 Tanytarsus. The emerging biomass was 216 and 186 mg dry weight per m² in Findley Lake and the 4.5 m deep pond, respectively, and only 78 mg in the 2 m deep pond. Most species had their maximum emergence where there was organic detritus from the surrounding forest.Orthocladius emerged from sand bottom at 2.7 to 5.2 m depth.Stictochironomus emerged from mud and sand at 8.4 m depth.Chironomus emerged from soft mud at 15 to 27.5 m depth.     

Seasonal prevalence of mosquitoes collected from light traps with notes on malaria in the Republic of Korea, 2004

Adult mosquito surveillance was conducted during 2004 at 29 US military installations and training sites located in six provinces in the Republic of Korea. Adult mosquitoes were collected in New Jersey light traps and Magnet traps from 1 May through 15 October to determine threshold levels to initiate pesticide applications and to identify malaria infection rates at selected army installations and training sites. A total of 89 206 adults (78 454 [87.9%] females and 10 752 [12.1%] males) comprising 20 species (including five members of the Anopheles Hyrcanus Group) and belonging to seven genera were collected. The most common species collected were members of Culex tritaeniorhynchus Giles (49.4%) and Anopheles sinensis Wiedemann complex (39.1%), followed by Culex pipiens Coquillett (6.1%) and Aedes vexans nipponii (Theobald) (4.2%). Trap indices varied widely for species over their range, due in part to geographical distribution and degree of association with urban communities.     

Assessing stream dwelling caddisfly assemblages (Insecta: Trichoptera) collected by light traps in Hungary

In the present study the conservation status of light trap-collected stream dwelling caddisfly assemblages was evaluated on the basis of original data and also from the literature representing different regions in Hungary. Altogether the catches of eight complete seasons were compared. Species richness, diversity and endangerment indices as well as a newly introduced rarity index (RI) expressing the average rarity of the collected species in Hungary were calculated to evaluate the conservation status of the streams in the Bakony, Börzsöny and Bükk Mountains and in the Zala Hills. The results highlight the importance of streams in maintaining endangered species of caddisfly in Hungary and bring to attention the fact that species richness or diversity are not necessarily the best indicators of conservation status of caddisfly assemblages. Indicators, for instance RI, which take into consideration the general rarity of the species seem to reflect more sharply conservation status and thus are more appropriate for the assessment of caddisfly assemblages.     

Heider's "Anthropological Models of Incest Laws in the United States": A Comment

In his analysis of U.S. legal prohibitions of marriage with relatives, Heider rejects the Old Testament model as an explanation of the configuration of current state laws. Although Heider's statement is generally accurate, the statutes seem to express two basic models, an attenuated Biblical and a Western American pattern. These patterns are the inverse of each other with regard to prohibition of first-cousin marriage and marriage between affines. Historical review of statutes reveals a trend from Biblical to Western American patterns. The historical perspective suggests that confounding the two models may have weakened Heider's analysis.     

The surface waters component of the Environmental Monitoring and Assessment Program (EMAP): an overview

The U.S. EPA is developing a new monitoring program, the Environmental Monitoring and Assessment Program (EMAP), to monitor and assess the ecological health of major ecosystems, including surface waters, forests, near-coastal waters, wetlands, agricultural lands, arid lands, and the Great Lakes, in an integrated, systematic manner. The program is designed to operate at regional and national scales, for decades, and to evaluate the extent and condition of entire ecological resources. EMAP has a common sampling framework for all resource types. The frame consists of a systematic grid of about 12,500 points in the conterminous United States that can be subdivided into subgrids of varying densities. A subset of 3,200 40 km² hexagons will be selected for field sampling of surface water resources. A four-year resampling cycle will allow approximately 800 lakes and 800 stream sites to be evaluated annually. Ecological assessments for surface waters will address three environmental values of concern: biotic integrity, fishability, and trophic state. The focus will be on biological assemblages, including fish, zooplankton, macroinvertebrates, birds and diatoms, as response indicators of ecological condition.     

Culicoides responses to 1-octen-3-ol and carbon dioxide in salt marshes near Sea Island, Georgia, U.S.A.

Abstract. The semiochemicals carbon dioxide (CO₂) and l-octen-3-ol (octenol) were evaluated as attractants at several release rates, alone and in combination, for the major coastal species of biting midges in Georgia: Culicoides furens, C.hollensis and C.melleus (Diptera: Ceratopogonidae). The data show that CO₂ is an effective attractant for the females of all three species, but each has a different response pattern. In contrast, octenol was an effective attractant only for C.furens , either alone or in combination with CO₂; octenol had a repellent effect on the other two species. The combination of octenol and C0₂ had a synergistic effect on the collections of C.furens.     

A quantitative analysis of wing pattern in the Culicoides pulicaris species group (Diptera: Ceratopogonidae)

Wing pattern is very important in the taxonomy of the genus Culicoides. To date no quantitative method has been described permitting the inclusion of wing pattern characters with traditional morphometric characters in multivariate studies.
Two alternative methods for quantifying wing pattern are developed here. The first superimposes a grid onto a wing and the 420 'characters' generated are scanned for pigmentation. A second method recognizes 13 pattern elements from a sequentially arranged series of wings. The latter method was considered superior for several reasons: it uses logically acceptable characters, reduces character redundancy and allows easier and faster coding.
Empirical multivariate studies show the pattern element method to be of taxonomic value in the difficult C. pulicaris group, and to have considerable potential for use in this and other groups of Diptera with patterned wings.