Seasonal abundance of Heterotrioza chenopodii (Reuter, 1876) and distribution of the known psylloid species (Hemiptera: Psylloidea) in Egypt

Psylloids cause severe damages to their host plants and transmit serious plant diseases for several crops in different parts of the world. The species composition and geographical distribution of psylloids in Egypt were assessed. The abundance of Heterotrioza chenopodii (Reuter, 1876) on various host plants in different ecological zones and their monthly abundance in Wadi El-Natroun were monitored throughout three successive seasons. We used a sweep net and a mechanical aspirator to survey populations of Psylloidea species from 2014 to 2017. Twenty-six psylloid species belong to four families were recorded from six geographical zones. H. chenopodii was the most widely distributed psylloid species in Egypt. The total number of species collected per zone ranged from a minimum of two at Fayoum Basin (FB) to a maximum of 15 at Lower Nile Valley and Delta (LNVD). The highest number of psylloid species were sampled from the host plant Tamarix sp. (6 species) followed by Zygophyllum sp. (5 species). The negative binomial regression analysis showed that the abundance of H. chenopodii is more dependent on host plants (chi(2)= 61.5, P<0.001) than ecological zones (chi(2) = 11.9, P = 0.018). Density of H. chenopodii inWadi El-Natroun showed a bimodal seasonal pattern with two peaks of adult abundance: spring (April) and late autumn (December). Moreover, we recorded a drop in the psylloid densities during hot (summer) and cold (winter) seasons. Additional ecological and taxonomic studies on Psylloidea are needed to conduct integrated pest management against species with economic and pharmaceutical interests.