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To better understand the semiochemical detection and reception mechanisms that involved in intra- and interspecific communication, host selection and mating behavior of Echinothrips americanus (Thysanoptera: Thripidae), scanning electron microscopy was used to examine the external morphology, distribution and ultrastructure of the sensilla on antennae and mouthparts. According to serial SEM images, seven types of antennal sensilla in total were observed in both sexes. Sensilla on mouthparts were observed concentrating on the maxillary palps, labial palps, and paraglossa, which is consistent with the previous conclusions. Possible function of the external sensilla is also discussed.

Glutathione S-transferases (GSTs) in insects are widely known for their role in the detoxification of both endogenous and xenobiotic compounds. Grape phylloxera, Daktulosphaira vitifoliae (Fitch) (Hemiptera: Phylloxeridae) is a serious grape pest, which causes great economic damage in vineyards, and has currently spread throughout the world. In this study, eight putative GST genes were identified by analyzing the transcriptomes of grape phylloxera. Phylogenetic analyses showed that there are seven cytosolic DviGSTs and one microsomal DviGST. These cytosolic DviGSTs are clustered into four different classes including two delta genes, one omega gene, one theta gene, and three sigma genes. Among candidate cytosolic DviGSTs, a conserved N-terminal domain and a less conserved C-terminal domain were identified. For the candidate microsomal DviGST, three transmembrane regions were predicted. Multiple sequence alignment analysis of the candidate microsomal DviGST was conducted with other insect microsomal GSTs and the result showed that there is a conserved sequence pattern. Semiquantitative polymerase chain reaction was used to examine the tissue expression of these transcripts, and the results revealed that DviGSTs were ubiquitously expressed in the head and the body, but DviGSTd1, DviGSTd2, DviGSTs2, and DviGSTs3 were abundantly expressed in the head and body. This is the first study of the molecular characteristics of GST genes in grape phylloxera. Our results will provide a molecular basis for future studies of the detoxification mechanisms in grape phylloxera.

Numerous studies have reported that larval experience can affect subsequent host plants selection and future oviposition decisions of many different species, but the investigation of pre-imaginal experiences on host preference of adults has rarely been tested for soil-dwelling insects. In this study, we present evidence that larval feeding experience can affect adult host preference in the onion maggot, Delia antiqua. By rearing D. antiqua on different host plants, we were able to examine the role of the natal host of different generations and the effect of larval density on host-choice behaviour. We also performed bioassays by means of switched host treatment to evaluate the host-selection principle. Choice bioassays among the three host species demonstrated that D. antiqua females preferred to oviposit on their natal host in each generation and host-switching treatments. Additionally, increasing larval density could intensify this ovipositional preference on the natal host. The overall results showed that host preference of female D. antiqua is determined by larval experience and density. These findings also add support for the controversial Hopkins’ host-selection principle.

Stenchaetothrips gaomiaoensis sp. nov. is described from bamboo in southwestern China. Stenchaetothrips bambusicola Mound 2011, collected from Poaceae grasses, is newly recorded from China. An identification key to the twenty-one species of Stenchaetothrips from China is also provided.

Anaphothrips obscurus is a cosmopolitan pest feeding on cereals and other grasses. The effects of constant temperatures on the biology of A. obscurus are not well known. Laboratory studies were conducted to assess the effects of temperature on the development, survival, longevity, fecundity and population parameter of A. obscurus at six constant temperatures (15, 20, 25, 30, 32, 35 °C). The hatchability was the lowest at 15 °C, the highest at 25 °C and no eggs hatched at 35 °C. Developmental rates increased linearly as the temperature increased. The lower developmental threshold temperature was 10.6 °C and 200 degree-days were required to complete development from egg to adult. Adult longevity decreased with increasing temperature, and ranged from 68.87 d at 15 °C to 16.41 d at 32 °C. The highest total fecundity occurred at 20 °C with 162 eggs per female. The temperature-dependent total fecundity, age-specific oviposition rate, and age-specific survival rate models were described. The intrinsic rate of increase (rm) was significantly higher at 30 and 32 °C (0.239 and 0.250) than at other temperatures. This study suggests that optimal developmental and reproductive temperatures for A. obscurus ranges between 25 and 30 °C and this may help this species adapt to warmer areas and widen its distribution and potential for damage in response to global warming. These findings will also be useful in developing monitoring programs, population dynamic models, and timing of control measures for A. obscurus.

Sensory neuron membrane proteins (SNMPs) in insects are critical peripheral olfactory proteins and act as markers for pheromone detection. However, the SNMPs for onion maggot, Delia antiqua Meigen, a world-wide subterranean pest, have not been previously characterized. In this study, we first report the cloning and characterization of two novel SNMPs from D. antiqua, DantSNMP1 and DantSNMP2. Sequence alignment and phylogenetic analysis showed that DantSNMP1 and DantSNMP2 are very similar to the previously reported SNMP1 and SNMP2 isolated from other dipteran insects but they share low identity with each other. Further expression profile experiments showed that DantSNMP1 is antenna-specific, while DantSNMP2 is expressed both in antennae and nonantennal tissues. Immunocytochemical localization experiments showed that DantSNMP1 was expressed only in sensilla trichodae, which suggests that this protein is involved in pheromone reception in insect olfaction.

Lepidopteran larvae upon infection by baculovirus show positive photo-tactic movement during tree-top disease. In light of many insects exploiting specific spectral information for the different behavioral decision, each spectral wavelength of light is an individual parsimonious candidate for such behavior stimulation. Here, we investigated the responses of third instar Helicoverpa armigera larvae infected by Helicoverpa armigera nucleopolyhedrovirus (HearNPV) to white (broad-spectrum), blue (450&ndash, 490 nm), UVA (320&ndash, 400 nm), and UVB (290&ndash, 320 nm) lights for the tree-top disease. Our findings suggest that tree-top phenomenon is induced only when the light is applied from above. Blue, white and UVA lights from above induced tree-top disease, causing infected larvae to die in an elevated position compared to those larvae living in the complete dark. In contrast, UVB from above did not induce tree-top disease. Blue light exerted the maximum photo-tactic response, significantly (p &lt, 0.01) higher than white light. The magnitude of the response decreased with decreasing wavelength to UVA, and no response at UVB. Our results suggested that the spectral wavelength of the light has a significant effect on the induction of the tree-top disease in H. armigera third instar larvae infected with HearNPV.

The morphology and ultrastructure of the compound eye of the predatory bug, Montandoniola moraguesi (Puton, 1986) was investigated using scanning and transmission electron microscopy. Its compound eyes, which contain ∼195 ommatidia per eye, have the following characteristics: each ommatidium possesses a laminated corneal lens measuring ∼9 μm in diameter and ∼7 μm in thickness, a tetrapartite eucone crystalline cone, which is approximately 5.5 μm long, like a dumbbell with the distal end larger than the proximal end, eight clustered retinula cells ∼25.6 μm in length, two primary pigment cells and eight secondary primary pigment cells. The rhabdomeres of the eight retinula cells form a circular, tiered rhabdom of two elongated and six peripheral retinula cells. The rhabdomeres of cells R7 and R8 are distributed along the basolateral surface of the cone and form a centrally-fused rhabdom that spans nearly the full length of the ommatidium. The microvilli of the peripheral rhabdom (R1–R6) are radially arranged and form a bilobed, V-like shape in the central rhabdom. Based on the similarity of the compound eye of M. moraguesi to the eyes of other predatory insect species, the evolution and function of eyes in predators are briefly discussed.

Anaphothrips obscurus (Muller) is a cosmopolitan pest feeding on cereal crops and grasses. This species exhibits wing polyphenism. Differences in the life history traits of female macropterous and brachypterous A. obscurus were compared in the laboratory for this study. Experiments were performed in climate chambers set at 20 and 25 ± 1 °C, 60 ± 10% RH under a 16 L:8D photoperiod. The duration of total pre-adult stage, adult pre-oviposition period and total pre-oviposition period of macropterous morphs were significantly longer than in the brachypterous morphs both at 20 and 25 °C. No significant differences were found in adult longevity, survival rate or total fecundity between the two wing morphs, while early fecundity was significantly higher for brachypterous females compared with that for macropterous females at two temperatures.

Heat shock proteins (Hsps) are prominent proteins that greatly contribute to insect survival under stress conditions. In this study, we cloned two Hsp transcripts (Aohsp70 and Aohsp90) from the grass thrip, Anaphothrips obscurus (Müller) (Thysanoptera: Thripidae), which is a polymorphic winged pest of corn and wheat. The cDNA sequences of Aohsp70 and Aohsp90 are 2382 and 2504 bp long, and encode proteins with calculated molecular weights of 70.02 kDa and 83.40 kDa, respectively. Aohsp90 was highly expressed in adults of both brachypters and macropters. Aohsp70 had different expression patterns in brachypters and macropters and was also highly expressed in the pupae of macropters. After adults were exposed to an ascending series of heat shocks, the expression of both Aohsp70 and Aohsp90 were up-regulated. In macropters and brachypters, the maximum induced levels of Aohsp70 (approximately 90-fold and 280-fold, respectively) were higher than Aohsp90 (approximately 2.4-fold and 1.8-fold, respectively). In addition, the up-regulation of Aohsp70 was significantly higher in brachypters than in macropters. Brachypters had a significantly higher Ltem50 (43.2°C) than macropters (42.5°C), which implied that brachypters are more tolerant to thermal stress than macropters. This study has shown that the expression patterns of Aohsp70 and Aohsp90 are variable among different life stages and thermal stress induced different levels of expressions in macropterous and brachypterous adults.

In insects, odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) are primary peripheral olfactory proteins playing critical roles in odorant detection. In this study, we present the first identification of OBPs and CSPs from the transcriptome of grape phylloxera Daktulosphaira vitifoliae Fitch, an important pest that damages both roots and leaves of grapes. The OBPs contained six conserved cysteine residues and the CSPs contained four conserved cysteine residues in this insect. Phylogenetic analysis showed that most of the olfactory proteins were closely related to OBPs and CSPs from other aphids. However, DviOBP7 and DviCSP9 were different because they were classified into different independent branches, respectively. Real-time polymerase chain reaction (RT-PCR) was used to examine the tissue expression of these transcripts. DviOBP1, DviOBP6, and DviOBP7 were uniquely or primarily expressed in antennae and not in the body. DviOBP2 was more abundantly expressed in the body than in the antennae. The expression levels of OBPs and CSPs of phylloxera varied depending upon where they were expressed in different body tissues.

Three pheromone-binding proteins of Helicoverpa armigera were cloned and expressed in Escherichia coli. In order to characterize their physiological properties, ligand-binding experiments were performed using five biologically relevant substances including sex pheromones and interspecific signals. The results showed that one of the pheromone-binding proteins, HarmPBP1, binds strongly to each of the two principal pheromone components of H. armigera, (Z)-11-tetradecenal and (Z)-9-hexadecenal, but not to the interspecific signal (Z)-9-tetracecenal. The two remaining pheromone-binding proteins, HarmPBP2 and HarmPBP3, showed only weak affinities with the ligands tested. The 3-D structure of HarmPBP1 was predicted and the docking experiments indicate that the key binding site of (Z)-9-hexadecenal to HarmPBP1 includes Thr112, Lys111, and Phe119 whereas that of (Z)-11-tetradecenal includes Ser9, Trp37, Phe36, and Phe119.

This paper describes one new species P. cycasae sp. nov. of Pseudaonidia from China. A key to species of the genus Pseudaonidia from the Oriental Region is proposed and a checklist of Oriental Region species is provided.

The genus Chortinaspis Ferris from China is reviewed and a new species, Chortinaspis tianmuensis Wei & Feng, sp. nov., is described. Chortinaspis biloba Maskell is also redescribed from specimens collected in China. A key to the species of Chortinaspis and a checklist of all known species of the world is provided.

One new species of the Oriental planthopper genus Varma Distant (1906) (Hemiptera: Fulgoroidea: Tropiduchidae), V. serrata Men & Qin, sp. nov. (southern China: Yunnan) is described and illustrated. A checklist of known species of the genus Varma along with a key to known species are provided. The type specimens of the new species are deposited in the Entomological Museum, Northwest A & F University, Yangling, Shaanxi Province, China (NWAFU).

Onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), is an important pest on onion and cabbage. Two reproductive modes--arrhenotoky and thelytoky--are found in this species and co-occur in the field. We compared life table traits between arrhenotokous and thelytokous T. tabaci on cabbage and onion. Experiments were conducted in cages to determine which reproductive mode is more competitive. Additionally, host adaption of the arrhenotokous and thelytokous T. tabaci between onion and cabbage was investigated. On onion, arrhenotokous T. tabaci performed better than thelytokous T. tabaci, while on cabbage the opposite occurred. When comparing life table and demographic growth parameters (net reproductive rates R(o), mean generation time T, the intrinsic rate of natural increase r(m), finite rate of increase A, and population doubling time T(d)) on different host plants, we found that arrhenotokous T. tabaci performed better on onion than on cabbage, whereas thelytokous T. tabaci performed better on cabbage than on onion. Host-related performance differences in this species suggest that the divergence between two reproductive modes might be associated with host adaption. Pest management strategies for this global pest should recognize that the two reproductive modes can impact population dynamics on different crops.

Echinothrips americanus Morgan, an invasive pest on various ornamentals and greenhouse crops, was introduced into mainland China recently, posing a potential threat to ornamentals and greenhouse crops. It exhibits two different reproductive modes: arrhenotokous parthenogenesis and sexual reproduction. Laboratory studies were conducted to compare the developmental and reproductive biology of E. americanus in these two reproductive modes. Results showed that the oviposition period, and longevity of female adults using sexual reproduction were longer than those using parthenogenesis. Furthermore, sexual female adults had higher fecundity and survival rates. However, no significant differences were found among immature stages in the durations of first and second instars, prepupae, and pupae between the two reproductive modes, with the exception of the duration of the egg stadium. The survival rates for eggs and first and second instars were higher in sexual E. americanus whereas there were no survival differences for prepupae and pupae. These results provide valuable insights into the mechanisms of parthenogenesis and sex determination in Thysanoptera.