Seasonal trends, sampling plans and parasitoid complex of the Chinese wax scale, Ceroplastes sinensis Del Guercio (Hemiptera: Coccidae), in Mediterranean citrus groves

Abstract

Seasonal trends and the parasitoid complex of Chinese wax scale (Ceroplastes sinensis) was studied from July 2010 to February 2013. Six commercial citrus groves located in northeastern Spain were sampled fortnightly. Chinese wax scale completed a single annual generation. Egg oviposition started in May and continued until mid-July. Egg hatching began in mid-June, and in the first quarter of August, the maximum percentage of hatched eggs was reached. In the same groves, the parasitoid species of C. sinensis were determined together with their seasonal trends, relative abundance and occurrence on C. sinensis. Four hymenoptera were found parasitizing C. sinensis, mainly on third instars and females: Coccophagus ceroplastae (Aphelinidae), Metaphycus helvolus (Encyrtidae), Scutellista caerulea (Pteromalidae) and Aprostocetus ceroplastae (Eulophidae). The most abundant species was A. ceroplastae, corresponding to 54% of the parasitoids emerged. Coccophagus ceroplastae and M. helvolus represented 19%, whereas S. caerulea comprised 8% of the total. This study is the first published record of C. ceroplastae in Spain and the first record of M. helvolus on C. sinensis in Spain. Concerning the economical thresholds normally used, sampling plans developed for the management of C. sinensis in citrus groves should target population densities of around 12–20% of invaded twigs, equivalent to 0.2–0.5 females per twig. The sample size necessary to achieve the desired integrated pest management precision is 90–160 twigs per grove for the enumerative plan and about 160–245 twigs per grove for the binomial plan.

General Biology and Current Management Approaches of Soft Scale Pests (Hemiptera: Coccidae)

“… Coastal districts, Australia 1 ( Snowball 1970 ) Citrus spp. New Zealand 1 ( Cottier and Wellington 1939 ) Citrus reticulata Blanco, Citrus sinensis Osbeck Northern Spain 1 ( Martínez-Ferrer et al. 2015 ) Cissococcinae Cissococcini Vinsonia N/A Coccinae Coccini Coccus hesperidum Citrus Eastern Sicily, Italy 1 ( Longo and Benfatto 1982 ) Citrus Southern France 1–3 ( Panis 1977a ) Citrus Western Sicily, Italy 2–3 ( Monastero 1962 ) Citrus spp.…”

“… ( Kosztarab 1996 ) Early-July Central Greece Citrus sinensis ( Stathas et al. 2003a ) Nov. New South Wales, Australia Citrus ( Snowball 1970 ) June-July Northern Spain Citrus reticulata, C. sinensis ( Martínez-Ferrer et al. 2015 ) Coccus hesperidum Dec. and Jan. Chile Various fruit trees ( Bayer CropSCience Chile 2014 ) Coccus pseudomagnoliarum April Davis, California, USA Chinese hackberry ( Celtis sincmis ) ( Dreidstadt 2004 ) June Greece Citrus ( Argyriou and Ioannides 1975 ) June Italy Citrus ( Barbagallo 1974 ) June Spain Citrus ( Tena and Garcia-Mari 2008 ) June California, USA Citrus ( Bernal et al.…”

Neonicotinoid contamination in wildflowers collected from citrus orchards in a northwestern Mediterranean Region (Spain) after tree foliar treatments

“…Therefore, conservation biological control is crucial. Hymenoptera, diptera, coleoptera, phytoseiid mites, coniopterigidae, or chrysopidae (Garcia-Marí 2012; Jacas and Urbaneja 2010; Martínez-Ferrer et al 2015) are important regulators of citrus pests and, in many cases, it is not necessary to perform chemical treatments respecting these important pest/ natural enemies' equilibria.…”