Impact of the Temperature on the Phenology of Diaphorina citri (Hemiptera: Liviidae) and on the Establishment of Tamarixia radiata (Hymenoptera: Eulophidae) in Urban Areas in the Lower Colorado Desert in Arizona

2019 ◽  
Vol 48 (3) ◽  
pp. 514-523 ◽  
Author(s):  
Francesc Gomez-Marco ◽  
Marco Gebiola ◽  
Bobby G Baker ◽  
Richard Stouthamer ◽  
Gregory S Simmons
Plant Disease ◽  
2021 ◽  
Author(s):  
Xuejin Cui ◽  
Kehong Liu ◽  
Jie Huang ◽  
Shimin Fu ◽  
Qingdong Chen ◽  
...  

Citrus Huanglongbing (HLB) is present in 10 provinces in China and is associated with “Candidatus Liberibacter asiaticus” (CLas), which is transmitted by the Asian citrus psyllid (Diaphorina citri, ACP). To date, HLB and ACP have expanded to Yibin city of Sichuan Province, posing an imminent threat to the citrus belt of upper and middle reach of Yangtze River, an important late maturing citrus-producing area in China. To understand the epidemiological route of CLas and ACP in newly invaded regions of Sichuan and thereby better establish an HLB-interception zone ranging from Leibo to Yibin, we evaluated the molecular variability of 19 CLas draft genomes from citrus or dodder (Cuscuta campestris). They include three type-specific prophage loci, three variable numbers of tandem repeat (VNTR) loci, a miniature inverted-repeat transposable element (MITE) types, and population diversity of 44 ACP mitochondrial genomes. The results indicated that CLas isolates in the newly invaded area (Pingshan) were more diverse than those in the HLB endemic areas (Leibo and Ningnan). Phylogenetic analysis based on mitochondrial genomes demonstrated that ACPs in Leibo, Pingshan and Xuzhou (rural areas) represent a new group (MG4), distinguished by the three unique SNPs in cox1, nad4 and cytb. However, the ACPs sampled from the urban areas of Cuiping and Xuzhou belonged to the southeastern China group (MG2-1). Altogether, our study revealed multiple sources of ACP and CLas in the HLB-interception zone and proposed their transmission route. This study contributes to the formulation of precise HLB prevention and control strategies in the HLB-interception zone in Sichuan and could be useful for HLB management efforts in other regions.


2020 ◽  
Vol 168 (9) ◽  
pp. 695-702 ◽  
Author(s):  
Francisco F. Laranjeira ◽  
Tâmara A. Santos ◽  
Alécio S. Moreira ◽  
Ícaro B. Sanches ◽  
Antônio S. Nascimento ◽  
...  

2019 ◽  
Vol 112 (6) ◽  
pp. 2824-2832 ◽  
Author(s):  
Andrew Chow ◽  
Darek Czokajlo ◽  
Joseph M Patt ◽  
Mamoudou Sétamou

Abstract An ‘attract-and-kill’ (AK) device was evaluated for suppression of adult Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), on residential citrus. The AK device, made from weather-resistant plasticized PVC, lured D. citri adults by simulating the color of citrus flush and killed them with beta-cyfluthrin. This study evaluated: 1) lethality of AK devices weathered up to 8 wk on residential citrus; 2) survival of psyllids caged with potted plants and AK devices; 3) psyllid suppression achieved by AK devices on individual dooryard trees. AK devices weathered for up to 8 wk remained lethal to psyllids. Greenhouse trials evaluated survival of adult psyllids caged for 4 d with orange jasmine plants that were: 1) treated with an (beta-cyfluthrin-infused) AK device; 2) treated with a blank (no insecticide) AK device; or 3) ‘untreated’ with no AK device. After 4 d, psyllid survival was on average 95% lower among adults exposed to plants with AK devices than adults exposed to untreated plants or plants with blank AK devices. Less than half of the adults exposed to plants with AK devices were alive after 1 d and nearly all were dead after 4 d. Deployment of 20 AK devices per tree provided significant psyllid suppression on infested lemon trees from winter to summer and reduced mean reproduction (cumulative eggs) by 91% and mean attack intensity (cumulative psyllid-days) of adults by 59% and nymphs by 53%. AK devices could be an effective control option for D. citri in urban areas.


1996 ◽  
Vol 22 (3) ◽  
pp. 167-174
Author(s):  
J A Cantrill ◽  
B Johannesson ◽  
M Nicholson ◽  
P R Noyce

2001 ◽  
Vol 60 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Holger Schmid

Cannabis use does not show homogeneous patterns in a country. In particular, urbanization appears to influence prevalence rates, with higher rates in urban areas. A hierarchical linear model (HLM) was employed to analyze these structural influences on individuals in Switzerland. Data for this analysis were taken from the Switzerland survey of Health Behavior in School-Aged Children (HBSC) Study, the most recent survey to assess drug use in a nationally representative sample of 3473 15-year-olds. A total of 1487 male and 1620 female students indicated their cannabis use and their attributions of drug use to friends. As second level variables we included address density in the 26 Swiss Cantons as an indicator of urbanization and officially recorded offences of cannabis use in the Cantons as an indicator of repressive policy. Attribution of drug use to friends is highly correlated with cannabis use. The correlation is even more pronounced in urban Cantons. However, no association between recorded offences and cannabis use was found. The results suggest that structural variables influence individuals. Living in an urban area effects the attribution of drug use to friends. On the other hand repressive policy does not affect individual use.


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