Weiquan Qin

Effect of temperature on the population growth of Rhynchophorus ferrugineus (Coleoptera: Curculionidae) on sugarcane.

ABSTRACT The effect of temperature on the developmental time, survival, and reproduction of Rhynchophorus ferrugineus (Olivier) reared on sugarcane was studied at seven constant temperatures (16, 20, 24, 28, 32, 36, and 40°C). The developmental threshold temperatures and effective accumulated temperatures for the whole generation were 17.41°C and 1,590.72 DD, respectively. One generation had the highest survival rate (26.67%) at 28°C. The egg failed to survive at 16 and 40°C. The population trend index (I = 38.22) and net reproductive rate (Ro = 38.3) were highest at 28°C. The net reproductive rate (Ro = 3.36), intrinsic rate of increase (rm = 0.0028), and finite capacity of increase (&lgr; = 1.0028) were lowest at 20°C. The mean generation time (To = 85.82) was shortest at 36°C. The population double time (PDT = 27.08) was shortest at 32°C. Based on these studies, we concluded that the temperatures from 28 to 32°C were the most suitable temperatures for the development of R. ferrugineus.

Identification and tissue expression profiling of odorant binding protein genes in the red palm weevil, Rhynchophorus ferrugineus

BackgroundThe red palm weevil, Rhynchophorus ferrugineus, is a lethal pest of the palms. The identification of odorant binding protein (OBP) genes will be helpful for clarifing the mechanism of odorant detection of this pest. By sequencing the full length cDNA library of its antenne, 11 OBP genes (RferOBP1-11) were identified.FindingsThe result showed RferOBP1-7 and RferOBP8-11 belonged to the minus-C and classic family, respectively qPCR revealed that RferOBP1-10 highly transcribed in the antennae, of which RferOBP1, RferOBP4, RferOBP8 and RferOBP10 were obviously male-biased expression. RferOBP7 and RferOBP11 exhibited highly expression in female head and male thorax. RferOBP2, RferOBP5 and RferOBP6 were highly expressed in the female thorax, leg and abdomen respectively.ConclusionsThe results paved the way towards a future understanding of the olfaction in this species.

Development and characterization of microsatellite markers for the fruit fly, Bactrocera tau (Diptera: Tephritidae)

The fruit fly, Bactrocera tau (Walker), is one of the most important invasive worldwide pests on fruits and vegetables. In order to facilitate species identification and population genetic analysis, we isolated 22 microsatellite loci through an enriched genomic library protocol. Polymorphisms were evaluated in 30 individuals. The number of alleles per locus ranged from 2 to 9, and the observed and expected heterozygosities ranged from 0.048 to 0.862 and 0.136 to 0.852, respectively. The polymorphic information content values were from 0.124 to 0.818. Eight loci had significant deviations from the Hardy–Weinberg equilibrium. These SSR markers can be used to understand the population genetics and evolutionary patterns of the B. tau complex.

Effectiveness of the Botanical Insecticide Azadirachtin Against Tirathaba rufivena (Lepidoptera: Pyralidae)

Abstract Tirathaba rufivena Walker (Lepidoptera: Pyralidae) is an important pest of areca palm, Areca catechu L. (Arecaceae), in China. The effects of azadirachtin on the development and mortality of T. rufivena were determined. All larval instars were susceptible to azadirachtin, but the stomach and contact toxicities diminished as the larvae matured. The LC25 and LC50 dosages had no effect on larval hatch when applied directly to the eggs on different days after deposition, but the LC90 treatment retarded hatch from eggs treated 1 to 3 d after deposition. The tested concentrations significantly affected the survival of neonate larvae from treated eggs, especially larvae that emerged from eggs treated 3 d after deposition. Azadirachtin also prolonged larval development and duration of the pupal stage. The percentage of adult emergence decreased, and longevity of the emerged adults was shortened, following treatment. Also, egg production and viability from females treated as larvae with azadirachtin were significantly affected.

Effect of temperature on the population growth of Tirathaba rufivena (Lepidoptera: Pyralidae) on Areca catechu (Arecaceae)

Abstract Tirathaba rufivena Walker (Lepidoptera: Pyralidae) is a major insect pest of Arecaceae such as Areca catechu L. (areca), Cocos nucifera L. (coconut), and Elaeis guineensis Jacq. (African oil palm). The larvae feed mainly on the palm flowers, fruits, and leaves, leading to the dropping of flowers and fruits, and they have caused economic damage and crop losses. In order to provide a foundation for the forecasting and scientific management of this pest, the effect of temperature on the development time, survival, and reproduction of T. rufivena reared on A. catechu was studied at 7 constant temperatures (16, 20, 24, 28, 32, 36, and 40 °C). The lower development threshold temperature and the effective accumulated temperature for the completion of the life cycle were 13.4 °C and 1,428.6 degree-days, respectively. The highest survival rate (30.0%) occurred at 28 °C. Eggs failed to survive at 16 and 40 °C. The population trend index (I = 19.04) and net reproductive rate (R0 = 10.40) were highest at 28 °C. The net reproductive rate (R0 = 4.13), intrinsic rate of increase (rm = 0.0334), and finite capacity of increase (λ = 1.0340) were lowest at 20 °C. The mean generation time (T0 = 18.70) was shortest at 36 °C. The population doubling time (PDT = 7.77) was shortest at 28 °C. Based on these results, we concluded that temperatures from 28 to 32 °C were most suitable for the development of T. rufivena reared on A. catechu.