Trichomes on Cotton Leaf Surface Affect the Feeding Behaviors of Cotton Aphids

Abstract

Aphis gossypii Glover is one of the most important pests in cotton seedling. The specialized mouthpart and short generation time allow them seriously restricted the quality and yield of cotton. With the electrical penetration graph (EPG), optical microscope, and scanning electron microscope, the physical characteristics of trichomes on the cotton leaf surface and their effects on the feeding behaviors of cotton aphids were investigated in this study. Two types of leaf trichomes, glandular trichomes, and asteroid non-glandular trichomes were observed on the surface of cotton leaves under optical and scanning electron microscopes. As a whole, EPG results mainly showed differences in a non-probe waveform which meant searching on the leaf surface, and a potential drop waveform which meant intracellular penetration. Whereas pathway waveform, xylem waveform, and phloem waveform showed inconspicuous differences. Detailed indicators were slightly different at different periods. Our results confirmed that the structure of trichomes may directly affect the searching behaviors of herbivorous insect pests and hence regulate the plant-environment interactions.

Predation and Biocontrol Potential of Eupeodes corollae Fabricius (Diptera: Syrphidae) on Wheat Aphids

“…DNA molecular detection was performed with reference to the multiplex polymerase chain reaction (PCR) system (10 µL total) described by Yang [21]. The reaction mixture contained ddH 2 O (2.0 µL, Tiangen Biochemical Technology Co., Ltd., Beijing, China), 2× Multiplex PCR Master Mix (5.0 µL, QIAGEN, Dusseldorf, Germany), Primer Mix (1.0 µL, Sangon Biotech Co., Ltd., Shanghai, China, Table 1), BSA (0.5 µL (10 µg/µL), Amresco, Solon, OH, USA), and DNA template (1.5 µL).…”

“…If a target band was present (R. padi 395 bp, S. graminum 296 bp, S. miscanthi 156 bp), it was concluded that the sample contained the corresponding species. The sensitivity of this multiplex PCR system has been described previously [21]. In addition to the 20 insect species described by Yang (2018), the specificity of this multiplex PCR system was tested using the main insects that occur in the same habitat as the three species of wheat aphids (Table S1) and M. persicae (prey used for the indoor rearing of E. corollae) as templates.…”