Susceptibility of the adult eye gnat Liohippelates collusor (Diptera: Chloropidae) to neonicotinoids and spinosad insecticides.

Imidacloprid, thiamethoxam (first and second generation neonicotinoid insecticides), and spinosad (a naturally derived biorational insecticide) were evaluated in the laboratory against adult eye gnats, Liohippelates collusor (Townsend), using two modes of exposure. Ingestion experiments revealed that toxicity was the highest for thiamethoxam (Platinum soluble concentrate) followed by technical thiamethoxam, imidacloprid (Admire 2 flowable concentrate), and spinosad (Success* soluble concentrate). When incorporated into 5% sucrose solutions, eye gnat mortality was significantly increased compared to the same concentrations of aqueous insecticide solutions. Contact toxicity experiments revealed that thiamethoxam formulation (Platinum) was the most toxic, followed by technical thiamethoxam, imidacloprid, and spinosad. Increasing the duration of exposure time from 15 min to 30 min significantly increased adult eye gnat mortality, but no further mortality occurred by extending exposure from 30 min to 60 min. Our results suggest that Platinum has good ingestion and contact activity against adult eye gnats. Admire and Success have appreciable ingestion toxicity but low contact activity against adult eye gnats.     

Grass Flies (Diptera,Chloropidae) of Crimean Peninsula

The fauna of grass flies (Diptera: Chloropidae) of the Crimean Peninsula is reviewed for the first time. The study is based on examination of the collection of the Zoological Institute, Russian Academy of Sciences (St. Petersburg), which includes the material collected in Crimea by the authors, the collections of the Zoological Museum of the M. V. Lomonosov Moscow State University and V. I. Vernadsky Crimean Federal University (Simferopol). The annotated list includes 92 species in 34 genera and three subfamilies. Most of the species (61) are recorded from Crimea for the first time. Six species, Chlorops horridus Becker, Ch. puncticornis Loew, Dicraeus (Oedesiella) beschovskii Nartshuk, Lasiosina chandleri Ismay, Meromyza meigeni Nartshuk and Oscinimorpha longirostris (Loew) are recorded for the first time from Russia and Eastern Europe. The characters for distinguishing Oscinimorpha arcuata Duda from O. longirostris (Loew), i.e., the structure of head and the male genitalia, are provided. The boreo-montane species Oscinella vastator (Curtis) and Meromyza curvinervis (Zetterstedt) are found on the Chatyrdag Mountain and Yaila (mostly forestless plateau in the Crimean Mountains). Species with southern European, Mediterranean and Macaronesian-Mediterranean ranges were recorded mostly on the South Coast of Crimea. The Crimean fauna of Chloropidae is compared with the faunas of Sardinia and Turkey.     

Host plan preferences of Oscinella spp. (Diptera: Chloropidae) in the laboratory

The oviposition preferences of Oscinella frit, O. vastator, O. nitidissima, O. albiseta andO. nigerrima for differenct Gramineae were investigated in the laboratory. O. frit, laid most eggs on oats, Lolium multiflorum and Festuca rubra, relatively few eggs were laid on barley and virtually none on Dactylis glomerata None of the other Osinella species oviposted on cereals. Of the other species, O. vastator appeared to be the most polyphagous and the preferred hosts were L. multiflorum, Lolium perenne and Festuca pratensis; few eggs were laid on either F. rubra, Agrostis tenuis or Poa pratensis. The host ranges of the remaining species were much more limited. Although a few eggs were laid by O. nitidissima on Lolium, the preferred host was A. tenuis. Oscinella albiseta oviposited only on D. glomerata whilst nearly all the eggs laid by O. nigerrima were deposited on shoots of Arrhenatherum elatius. The distribution of eggs by O. frit on L. multiflorum and A. tenuis was different from that on oats; on grasses most eggs were laid inside withered leaf sheaths whereas on oats most were deposited inside the coleoptile. The oviposition sites of O. nitidissima, O. nigerrima and O. albiseta on their respective host grasses were similar to those of O. frit on grasses. O. frit laid most eggs on grasses which were at the five-leaf stage and tailoring.     

Grass-fly larvae (Diptera,Chloropidae): Diversity,habitats, and feeding specializations

The fly family Chloropidae belongs to the higher Diptera series Acalyptratae. It is distributed worldwide and globally comprises 200 genera and about 3000 species in 4 subfamilies: Oscinellinae, Siphonellopsinae, Rhodesiellinae, and Chloropinae. In the fossil record, Chloropidae are known since the Oligocene, with 2 genera found in Baltic amber: one extinct, the other recent. The family includes several important agricultural pests (frit flies, gout flies, Meromyza, seed pests) which injure corn. The feeding preferences of chloropid larvae vary strongly: there are saprophages in the broad sense, true phytophages using both woody and grassy plants (mainly monocots), predators on egg masses of insects and spiders, as well as on scale insects and aphids, and ectoparasites of frogs. Among the 100 families of monocots (Liliopsida), only 11 include species serving as food plants for chloropid larvae. The greatest diversity of habitats and feeding types is observed in the subfamily Oscinellinae. The most advanced subfamily Chloropinae includes mostly phytophagous larvae. A possible scenario of ecological evolution within the family is briefly discussed.     

Grassflies (Diptera, Chloropidae) in the middle Lena valley (Central Yakutia)

Sixty-one species of grassflies (Diptera, Chloropidae) have been found in the meadows in the middle Lena valley, Central Yakutia. Differences between the grassfly taxocenoses of different parts of the valley depend on specific features of a particular plant community. The dominant and subdominant chloropid species are distinguished. The differences of the riparian fauna from the complexes inhabiting the alases in Yakutia are shown. Six species of grassflies are recorded for Yakutia for the first time, all of them belonging to the subfamily Oscinellinae: Polyodaspis ruficornis Macquart, Tricimba cincta Meigen, Aphanotrigonum trilineatum Meigen, Trachysiphonella scutellata v. Roser, Rhopalopterum anthracinum Meigen, and Rh. fasciolum Meigen     

Twisted rhabdomeres in the compound eye of a tipulid fly (Diptera)

Summary The individual rhabdomeres of the outer retinular cells (R1–6) in the tipulid fly, Ptilogyna, twist about their long axes. Proximally, the rhabdoms become partitioned off by processes from the retinular cells, so that the basal region of each rhabdomere is enclosed in a pocket formed by its own cell (Fig. 2). This organisation of the rhabdom enables each rhabdomere to twist while supported within its own retinular cell, and while the cell itself maintains its orientation with respect to the entire ommatidium. Theory predicts that the rhabdomeral twisting should significantly reduce the polarisation sensitivity of R1–6, but have little effect on the efficiency with which unpolarised light is absorbed.     

Acoustic properties and geographic variation in the vibratory courtship signals of the european chloropid fly,Lipara lucens meigen (Diptera,Chloropidae)

Geographic variation in courtship vibratory signals inLipara lucens from 7 disjunctive European populations were examined. Simple female responding signals showed significant interlocal difference in the pulse-group intervals only in the English population. More differentiated male courtship signals were separated into anterior “preliminary vibration” and posterior “main vibration”. The latter, composed of a train of bursts, showed significant differences among populations in the number of pulses in a burst, burst duration (BD), burst interval (BI) and burst period (BP). Latvian, Hungarian and Bulgarian populations had more pulses in a burst than those of E. Germany, Belgium, Czechoslovakia and England. Latvian and Bulgarian populations showed significantly larger values of BD, whereas that of Belgium showed a significantly smaller value. BI in the English population had the smallest value, and those in the Latvian and Bulgarian populations had the longest values. No significant differences were observed in BD and BI between E. Germany, Czechoslovakia and Hungary. Multivariate statistic analyses on the time-amplitude variables of the male signals showed uniqueness in the Belgian, English, Latvian and Bulgarian populations. Genetic background of the geographic variations in the vibratory signals are discussed in this context.     

Two new species of Pselaphia (Diptera, Chloropidae) from Zambia

Pselaphia haladai sp. n. and Pselaphia zambiensis sp. n. are described from Zambia. All African Pselaphia species are keyed and main differential characters are illustrated.     

Mating behavior and thermoregulation of the reindeer warble fly,Hypoderma tarandi L. (Diptera: Oestridae)

Hypoderma (=Oedemagena) tarandi L. (Diptera: Oestridae) is characterized by a mating strategy in which both sexes meet and mate at two types of distinct topographical landmarks. In the expansive, treeless vidda (= tundra-like) biome, mating places are unique, rocky areas located along rivers and streams or in rocky areas of drying river and stream beds. In wooded valleys below the vidda, flies mated at certain topographical areas along dirt road tracks/paths. Thermoregulatory activities of males occupying perches at mating places included selection of substratum at perch site, orientation of body to sun's rays, crouching, stilting, and flights into upper cooler air. On warm sunny days males perched for just 1–2 min before flying up into cooler air to promote cooling. Laboratory and field studies revealed that flies could not metabolically cool down when held at 25–38°C. Time spent at mating places depended on temperature, duration of sunshine, and wind velocity. Males were very aggressive in pursuing allHypoderma-sized objects that passed by them or that landed near them, but they did not defend specific perch sites. Males either pursued and caught females in flight, or they hopped onto females that landed near them. During 5 years, 74 males and 14 females were seen at mating places. Dissection of six females caught at mating places revealed them to be recently eclosed flies full of fat body and with all eggs intact; two not paired with males were non-inseminated. Three experimentally paired females remainedin copulo for 10, 13, and 19.5 min.     

A supplement to the grassfly fauna of Japan (Diptera, Chloropidae)

Two new grassfly species, Gampsocera diversicolor closely related to G. tenuisinuosa Kanmiya, 1983 and Conioscinella subdivitis closely related to C. divitis Nartshuk, 1971, are described from Japan. Keys for the new species are given. Oscinisoma ussuriense Nartshuk, 1973, known in Primorskii Territory of Russia and Korea, was found in Japan (Honshu Island) for the first time. The genus Oscinisoma Lioy, 1864 was also first recorded in Japan.     

Abundance and host-seeking activity of the biting midge,Forcipomyia taiwana (Diptera: Ceratopogonidae)

The abundance and host-seeking activity of the biting midge, Forcipomyia taiwana (Shiraki), were measured in Central Taiwan at 418 locations with low, medium, and high densities using a human-bait method. Abundance estimates at 10 min after sampling commenced were comparable to longer sampling periods of 20 min, allowing a shorter 10 min sampling period to be used throughout. Host-seeking F. taiwana females were only active during daylight and biting activity did not occur after sunset. The diurnal activity of host-seeking females changed seasonally, beginning at around 07:00–08:00 during the spring equinox, summer solstice, and autumnal equinox, whereas activity began an hour later in winter. Most females were collected during 10:00–16:00, with a peak abundance during 13:00–15:00. Blood-sucking activity of female F. taiwana were positively correlated with ambient temperature with a minimum threshold of 18 °C. When different years, seasons, trapping times, environmental factors, and female adults trapped were analyzed using multiple regression model, the results showed that all these factors contributed to the regression model and the determination coefficient (R²) of this multiple regression model was 0.81.     

Genetic structure and demographic history of the melon fly Zeugodacus cucurbitae (Coquillet) (Diptera: Tephritidae) in Thailand

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Plant-feeding dipterans (Diptera,Chloropidae, Agromyzidae) from Wrangel Island (the Chukchi Sea)

Flies of the family Chloropidae were found in the arctic tundra for the first time. Oscinella frit L. was collected in several areas of the mountainous part of Wrangel Island, occurring mainly in the ground layer. Among three species of Agromyzidae, Napomyza mimula Spencer was the most numerous; it was found both in the mountains and on the coastal plain. Two other species, Phytomyza cineracea Hendel and Chromatomyia sp., were rare. The only biotope where all the four species were collected simultaneously was a zoogenic forb-grass meadow patch which developed around the arctic fox burrow.     

Host-seeking behavior in larvae of the robber fly Mallophora ruficauda (Diptera: Asilidae)

The robber fly Mallophora ruficauda is the most important pest of apiculture in the Pampas region of Argentina. Adults prey on honeybees and other insects, while larvae parasitize larvae of scarab beetles, which live underground. Females of M. ruficauda do not search for hosts but instead lay eggs in tall pastures. Once hatched, larvae drop to the ground and burrow underground to search for their hosts. We tested in the laboratory whether larvae of M. ruficauda actively search for their hosts using host and/or host-related chemical cues. We report that M. ruficauda detects its host using chemical cues that originate in the posterior half of the host's body, most likely from an abdominal exocrine structure. This particular host-searching strategy is described for the first time in Asilidae.     

Species of the genus Thressa Walker, 1860 from China (Diptera, Chloropidae)

A review of the species of the genus Thressa from China is provided. The following four species are described as new to science: Thressa bimaculatasp. n., Thressa daiyunshanasp. n., Thressa foliaceasp. n. and Thressa longimaculatasp. n. One species, Thressa flavior (Duda), is recorded from China for the first time. A key to the species of the Thressa from China is given.     

A new species of the grass fly (Diptera,Chloropidae), Incertella tschernovi sp. n., from the Kyzyl Kum Desert

A new grass fly species belonging to the subfamily Oscinellinae, Incertella tschernovi sp. n., is described from the Kyzyl Kum Desert, Uzbekistan. The new species is closely related to I. brevicosta Nartshuk, 1975, shares short costal vein of the wing and in the vein M sharply bent toward the anterior wing margin.     

橘小实蝇交配行为观察

在实验室内对橘小实蝇Bactrocera dorsalis（Hendel）的交配行为进行了观察。描述了橘小实蝇交配中雄虫的“求偶场”,雄雄相遇、雌雌相遇、雌雄相遇时的相互反应,雌雄虫的交配行为与交配后行为。