Life table parameters of Aphis gossypii Glover (Homoptera: Aphididae) on Gossypium hirsutum L. were determined at six temperatures (10, 15, 20, 25, 30, and 35 ± 0.5 °C) in the laboratory. Relationships of life table parameters with temperature were described with mathematical equations. Development was fastest at 30 °C, with a pre‐larviposition period of 4.6 d. Survival to adult was greatest at 25 °C (81%). Fecundity was highest at 25 °C, with a total fecundity of 28.3 nymphs per female and a mean reproductive rate of 3.1 nymphs per female per day. Threshold temperatures for development in the first through fourth instar and the adult were 8.2, 8.0, 7.2, 6.2 and 7.9 °C, respectively. The durations of these stages, expressed as temperature sums above these thresholds, were 24.2, 23.7, 23.0, 25.5 and 168.8 degree‐days (D°), respectively. A. gossypii achieved its maximum net reproductive number (24.4 nymphs per female) and greatest intrinsic rate of increase (0.386 d−1) at 25 °C. The high relative rate of population increase at 25 °C results in a daily population increase of 47% and a doubling time of only 1.8 d, illustrating the tremendous growth capacity of A. gossypii populations under favourable conditions. Compared to literature sources, our source of A. gossypii, fed on cotton, showed a comparatively great heat tolerance.

Experiments and models are described that quantify the functional responses of the larval and adult stages of the sevenspot ladybeetle, Coccinella septempunctata L. toward mixed stage populations of the cotton aphid, Aphis gossypii Glover, in cotton. In the laboratory, functional responses were measured for Þve beetle stages and three size groups of prey at Þve temperatures (15 to 35ЊC). The 75 resulting functional responses were each characterized by a search rate (cm 2 / predator/d) and a handling rate (prey/predator/d). Both search and handling rates increased with predator stage. Search rates increased, while handling rates decreased, with prey size. Search rate increased linearly with temperature, while handling rate showed an optimum response to temperature. Field cage studies were conducted to verify whether the search rates determined in the laboratory were valid under Þeld conditions. Search rates of predators derived from observations in Þeld cages yielded parameter estimates that were similar to those found in the laboratory. A comprehensive model, allowing for effects of temperature, stage distribution of the aphid population, and plant leaf area on predation rate, was then constructed to calculate predation by larvae and adults of C. septempunctata on multi stage populations of prey. This model gave good correspondence to the cage observations if two-sided leaf area was input into the model as search substrate for the predator. The model appears suitable for calculating predation rates of C. septempunctata on A. gossypii under Þeld conditions. A sensitivity analysis of the functional response model shows the crucial effect of crop leaf area on predation.KEY WORDS Coccinella septempunctata L., Aphis gossypii Glover, functional response, simulation model, leaf area, temperature COTTON APHID, Aphis gossypii Glover (Homoptera: Aphididae), is a cosmopolitan pest species that is a major pest and virus vector in Þeld crops in the tropics and in glasshouse crops in temperate regions (Blackman and Eastop 1985). A. gossypii is the key pest of seedling cotton (Gossypium hirsutum L.) in the provinces Hebei, Shandong, and Henan of Northern China, with a total cotton growing area of Ϯ3 million ha (Fang et al. 1992). Infestations with cotton aphid occur generally during mid-May, when the crop is hardly beyond the cotyledon stage and very vulnerable to aphid injury. Incidence often approaches 100% (Fang et al. 1992). Biological control is of enormous importance, especially because of pesticide resistance in the aphid population (Xia 1993). The sevenspot ladybeetle, Coccinella septempunctata (Coleoptera: Coccinellidae) is

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Single-marker genome-wide association study (GWAS) is a convenient strategy of genetic analysis that has been successful in detecting the association of a number of single-nucleotide polymorphisms (SNPs) with quantitative traits. However, analysis of individual SNPs can only account for a small proportion of genetic variation and offers only limited knowledge of complex traits. This inadequacy may be overcome by employing a gene-based GWAS analytic approach, which can be considered complementary to the single-SNP association analysis. Here we performed an initial single-SNP GWAS for bone weight (BW) and meat pH value with a total of 770,000 SNPs in 1141 Simmental cattle. Additionally, 21836 cattle genes collected from the Ensembl Genes 83 database were analyzed to find supplementary evidence to support the importance of gene-based association study. Results of the single SNP-based association study showed that there were 11 SNPs significantly associated with bone weight (BW) and two SNPs associated with meat pH value. Interestingly, all of these SNPs were located in genes detected by the gene-based association study.

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