Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2015
Publication Date: 3/30/2015
Citation: Esquivel, J.F. 2015. Stylet penetration estimates for a suite of phytophagous Hemipteran pests of row crops. Environmental Entomology. 44(3):619-626.
Interpretive Summary: Insects with piercing-sucking mouthparts (or stylets, enclosed within a beak) continue to plague cotton and other row crop producers throughout the Cotton Belt of the USA. Smaller-bodied insects such as the cotton fleahopper and tarnished plant bug and multiple larger-bodied stink bug species are problematic. These species have also been associated with transmission of pathogens causing diseases. Stylet penetration estimates were needed to determine whether these species could penetrate the walls of developing cotton fruit, and these estimates are provided here. Stylet penetration estimates for the smaller-bodied insects ranged from 212.79 (cotton fleahopper) – 912.19 (tarnished plant bug) micrometers (µm). For stink bugs, highest mean penetration was observed in brown stink bug (1,923 µm) followed by green stink bug (1,752 µm), yet green stink bugs possessed the longest beak. Similarly, rice stink bug possessed higher penetration estimates (1,221 µm) than red-banded stink bug (1,040 µm), yet red-banded stink bug possessed a longer beak. Thus, beak length should not be equated to penetration potential. Overall average penetration estimates for three other stink bug species ranged from were 1,527 to 1,642 µm. Cotton fleahopper and tarnished plant bug both infest early-season cotton and the ranges of observed penetration indicate these insects can penetrate the critical formative fruiting forms of cotton. Similarly, all stink bug species can penetrate the wall of 7-day-old bolls. The insects addressed here affect a multitude of crops worldwide and penetration estimates allow identification of growth stages susceptible to feeding and disease transmission. Also, understanding stylet penetration potential is a key factor in crop breeding to ensure toxins are expressed appropriately within cotton plant tissues for control of stink bugs and other insect pests that feed in the same manner.
Technical Abstract: Members of the Miridae (Lygus lineolaris Palisot de Beauvois and Pseudatomoscelis seriatus Reuter) and Pentatomidae (Acrosternum hilare Say, Euschistus servus (Say), E. tristigmus (Say), E. quadrator Rolston, Oebalus pugnax (Fabricius), Piezodorus guildinii (Westwood), and Thyanta custator accerra McAtee) comprise a piercing-sucking insect complex that continues to plague cotton production and damage other crops. These species have also been associated with pathogen transmission. Whether these insects could completely breach walls of developing fruit was unknown; thus, stylet penetration estimates were needed and are presented here. Stylet penetration estimates for the smaller-bodied Miridae ranged from 212.79 (P. seriatus) – 912.19 (L. lineolaris) µm. Among the Pentatomidae, highest mean penetration was observed in E. servus (1 923.44 µm) followed by A. hilare (1 752.10 µm), yet A. hilare possessed the longest rostrum. Similarly, O. pugnax possessed higher penetration estimates (1 221.08 µm) than P. guildinii (1 040.85 µm), yet P. guildinii possessed a longer rostrum. Thus, rostrum length should not be equated to penetration potential. Overall mean penetration estimates for E. tristigmus, E. obscurus, and T. c. accerra were 1 642.20, 1 631.92, and 1 527.16 µm, respectively. Pseudatomoscelis seriatus and L. lineolaris both infest early-season cotton and the ranges of observed penetration indicate these insects can breach the walls of critical pinhead squares and small bolls, respectively. Similarly, all pentatomid species can breach the wall of 7-d-old bolls. The insects addressed herein affect a myriad of crops globally and penetration estimates allow identification of growth stages susceptible to feeding and disease transmission. Also, understanding stylet penetration potential is a key factor in crop breeding to ensure toxins are expressed appropriately within plant tissues for control of stink bugs and other sucking-insect pests of cotton.