Sexual communication in day-flying Lepidoptera with special reference to castniids or 'butterfly-moths'.

Butterflies and moths are subject to different evolutionary pressures that affect several aspects of their behaviour and physiology, particularly sexual communication. Butterflies are day-flying insects (excluding hedylids) whose partner-finding strategy is mainly based on visual cues and female butterflies having apparently lost the typical sex pheromone glands. Moths, in contrast, are mostly night-flyers and use female-released long-range pheromones for partner-finding. However, some moth families are exclusively day-flyers, and therefore subject to evolutionary pressures similar to those endured by butterflies. Among them, the Castniidae, also called 'butterfly-moths' or 'sun-moths', behave like butterflies and, thus, castniid females appear to have also lost their pheromone glands, an unparallel attribute in the world of moths. In this paper, we review the sexual communication strategy in day-flying Lepidoptera, mainly butterflies (superfamily Papilionoidea), Zygaenidae and Castniidae moths, and compare their mating behaviour with that of moth families of nocturnal habits, paying particular attention to the recently discovered butterfly-like partner-finding strategy of castniids and the fascinating facts and debates that led to its discovery.

Variations in the mitochondrial cytochrome c oxidase subunit I gene indicate northward expanding populations of Culicoides imicola in Spain.

Culicoides imicola is the main vector for bluetongue (BT) and African horse sickness (AHS) viruses in the Mediterranean basin and in southern Europe. In this study, we analysed partial mitochondrial cytochrome c oxidase subunit I (COI) gene to characterize and confirm population expansion of Culicoides imicola across Spain. The data were analysed at two hierarchical levels to test the relationship between C. imicola haplotypes in Spain (n = 215 from 58 different locations) and worldwide (n = 277). We found nineteen different haplotypes within the Spanish population, including 11 new haplotypes. No matrilineal subdivision was found within the Spanish population, while western and eastern Mediterranean C. imicola populations were very structured. These findings were further supported by median networks and mismatch haplotype distributions. Median networks demonstrated that the haplotypes we observed in the western Mediterranean region were closely related with one another, creating a clear star-like phylogeny separated only by a single mutation from eastern haplotypes. The two, genetically distinct, sources of C. imicola in the Mediterranean basin, thus, were confirmed. This type of star-like population structure centred around the most frequent haplotype is best explained by rapid expansion. Furthermore, the proposed northern expansion was also supported by the statistically negative Tajima's D and Fu's Fs values, as well as predicted mismatch distributions of sudden and spatially expanding populations. Our results thus indicated that C. imicola population expansion was a rapid and recent phenomenon.

Factors affecting Culicoides species composition and abundance in avian nests.

Mechanisms affecting patterns of vector distribution among host individuals may influence the population and evolutionary dynamics of vectors, hosts and the parasites transmitted. We studied the role of different factors affecting the species composition and abundance of Culicoides found in nests of the blue tit (Cyanistes caeruleus). We identified 1531 females and 2 males of 7 different Culicoides species in nests, with C. simulator being the most abundant species, followed by C. kibunensis, C. festivipennis, C. segnis, C. truncorum, C. pictipennis and C. circumscriptus. We conducted a medicationxfumigation experiment randomly assigning bird's nests to different treatments, thereby generating groups of medicated and control pairs breeding in fumigated and control nests. Medicated pairs were injected with the anti-malarial drug Primaquine diluted in saline solution while control pairs were injected with saline solution. The fumigation treatment was carried out using insecticide solution or water for fumigated and control nests respectively. Brood size was the main factor associated with the abundance of biting midges probably because more nestlings may produce higher quantities of vector attractants. In addition, birds medicated against haemoparasites breeding in non-fumigated nests supported a higher abundance of C. festivipennis than the rest of the groups. Also, we found that the fumigation treatment reduced the abundance of engorged Culicoides in both medicated and control nests, thus indicating a reduction of feeding success produced by the insecticide. These results represent the first evidence for the role of different factors in affecting the Culicoides infracommunity in wild avian nests.

Biting rates of Culicoides midges (Diptera: Ceratopogonidae) on sheep in northeastern Spain in relation to midge capture using UV light and carbon dioxide-baited traps.

Biting midges in the genus Culicoides (Diptera: Ceratopogonidae) were collected near sunset by direct aspiration from sheep in northeastern Spain to determine species-specific biting rates and crepuscular activity. Midges were also collected by UV-baited light traps and CO2-baited traps over the same period to compare species diversity and abundance using these common surveillance methods to actual sheep attack rates. Culicoides aspirated from sheep included C. obsoletus, C. parroti, C. scoticus, C. punctatus, and C. imicola. Peak host-seeking activity during the time period examined for the two most commonly collected species (C. obsoletus and C. parroti) occurred just before sunset and activity ceased within 1 h after sunset. Host attack rates near sunset averaged 0.9 midges/min for both species with maximum attack rates of 3/min for C. obsoletus and 4/min for C. parroti. For both species, approximately 35% of midges collected from the sheep were engorged, giving a maximum biting rate of 1.1/min for C. obsoletus and 1.5/min for C. parroti. Traps baited with CO2 collected fewer midges of each species relative to other collection methods. Traps baited with UV light provided a good indication of species richness but significantly underestimated the host attack rate of C. obsoletus and C. parroti while overestimating the host attack rate of C. imicola. Animal-baited collecting is critical to interpret the epidemiological significance of light trap collections used for surveillance of the midge vectors of bluetongue virus and African horse sickness virus.

Mermithids (Nematoda: Mermithidae) of biting midges (Diptera: Ceratopogonidae): Heleidomermis cataloniensis n. sp. from Culicoides circumscriptus Kieffer in Spain and a species of Cretacimermis Poinar, 2001 from a ceratopogonid in Burmese amber.

Heleidomermis cataloniensis n. sp. (Nematoda: Mermithidae) is described from Culicoides circumscriptus Kieffer (Diptera: Ceratopogonidae) in Spain. Diagnostic characters include prominant elevations with multiple genital papillae on either side of the cloacal opening, only one row of genital papillae on the lateral surface of the tail, the tapering tip of the spicule and a reduced vagina. A male intersex of C. circumscriptus parasitised by H. cataloniensis n. sp. has mouthparts resembling those of the female. Two 100 million year-old fossil specimens of an un-named species of Cretacimermis Poinar, 2001, from an Early Cretaceous Burmese amber biting midge of the genus Leptoconops Skuse, show the antiquity of ceratopogonid-mermithid associations.

Differentiation of Culicoides obsoletus and Culicoides scoticus (Diptera: Ceratopogonidae) based on mitochondrial cytochrome oxidase subunit I.

Culicoides obsoletus (Meigen) and Culicoides scoticus Downes & Kettle (Diptera: Ceratopogonidae) are sibling species of the Obsoletus group. This group comprises species of biting midges that are suspect vectors of bluetongue virus (family Reoviridae, genus Orbivirus, BTV) and African horse sickness virus (family Reoviridae, genus Orbivirus, AHSV). BTV and AHSV have been isolated several times from females of this group, although it has not been possible to determine the particular species harboring the virus, because of the inability to clearly identify the females of each species based on morphology. Both sexes of C. obsoletus and C. scoticus midges from Catalonia and the Balearics (Spain) were sequenced for the mitochondrial gene cytochrome oxidase subunit I (COI), and these sequences were analyzed to determine intra- and interspecific genetic variability. Species-specific primers for C. obsoletus and C. scoticus were designed and a polymerase chain reaction (PCR)-based diagnostic assay based on the COI gene and using a hemi-nested PCR technique was developed for reliably distinguishing the females of both species. The species-specific PCR diagnostic was compared with morphological discrimination of C. obsoletus and C. scoticus females. The morphologic characters were not fully reliable.

Results of current surveillance of likely bluetongue virus vectors of the genus Culicoides in Catalonia, Spain.

Following the outbreaks of bluetongue (BT) disease in sheep on the Balearic islands in 2000, a survey was conducted for Culicoides vectors along the eastern Catalonian cost of continental Spain where the presence of only C. obsoletus (Meigen) and C. pulicaris (Linnaeus) was known. Light-trap collections made at eight sites in 2002 yielded nine species of Culicoides, including C. imicola Kieffer (represented by a gravid female caught at Dosrius at a latitude of 41 degrees 35'N) and C. scoticus Downs and Kettle. The following season (2003), C. imicola was captured consistently at all sites and in greater numbers (maximum catch of 46) from August to November. The findings suggest that the distribution of C. imicola is extending northwards into Europe. The presence of four bluetongue vectors (C. imicola, C. obsoletus, C. pulicaris and C. scoticus) in Catalonia is of concern.

Culicoides midges in Catalonia (Spain), with special reference to likely bluetongue virus vectors.

Midges of the genus Culicoides (Diptera: Ceratopogonidae) were trapped weekly from May 2001 through December 2002 on two farms in the province of Barcelona (Spain). Dosrius farm was stocked with sheep and goats whereas Bellaterra farm had only sheep. This trapping programme was carried out within the framework of an investigation into the occurrence/absence of possible vectors of bluetongue virus (BTV) in mainland Spain. A total of 30,079 Culicoides specimens were collected from 165 light trap collections, comprising nine species: C. obsoletus (Meigen), C. pulicaris (Linnaeus), C. circumscriptus Kieffer, C. newsteadi Austen, C. imicola Kieffer, C. scoticus Downes & Kettle, C. punctatus (Meigen), C. pallidicornis Kieffer and C. flavipulicaris Dzhafarov. The last five are new to Catalonia, C. pallidicornis is also new to Spain and C. flavipulicaris is new to Iberia. The seasonal occurrence of these species is described here. Of those species, C. imicola is the main BTV and African horse sickness virus (AHSV) vector in Europe, whereas species belonging to the so-called Obsoletus group (C. obsoletus and C. scoticus in our study) are considered to be potential vectors for BTV.