Effect of green-belly stink bug, Dichelops furcatus (F.) on wheat yield and development

Abstract

The green belly stink bug, Dichelops furcatus (F.) (Hemiptera: Heteroptera: Pentatomidae) is a pest of corn and soybean in southern Brazil. It also occurs on wheat, but information on its damage to this crop is limited. To determine the need for sustainable IPM programs, the impact of this bug on wheat production should be determined. Studies were conducted in the screenhouse with 1, 2 and 4 bugs caged for 16 days on single plants, cv. 'BRS Parrudo'. During the vegetative period (plants ca. 25 cm tall), all infestation levels significantly reduced plant height and ear head length, but did not reduce grain yield. Feeding damage caused tissue necrosis on leaves. During the booting stage, grain yield was significantly reduced with 2 and 4 bugs per plant; ear heads were small, discolored and abnormally developed. In 2013 and 2014 field trials, plants were infested for 18 days with 2, 4 and 8 bugs per m 2 at vegetative, booting, and milky grain stage. At these infestation levels, there was no significant reduction in grain yield. There was a significant decrease in the number of normal seedlings resulting from seeds exposed to 8 bugs per m 2 at the milky grain stage. Results suggest that, in general, there is no need to control D. furcatus on wheat, unless numbers are !8 bugs per m 2 during reproductive period.

Prevalence, damage, management and insecticide resistance of stink bug populations (Hemiptera: Pentatomidae) in commodity crops

“…Panizzi et al . () noted that the low damage observed was a result of the cultivar tested (BRS Parrudo), apparently resistant to insect injury, as well as to the lower outdoor temperature, which may inactivate stink bug feeding.…”

“…in corn crops, sampling measures should be adopted before the sowing period. For this purpose, monitoring can be performed counting Dichelops individuals inside one square metre in equidistant points (Panizzi et al ., ) or using baits based on soybean seeds soaked in water plus sodium chloride (1 g of salt per 30 g of soybean seeds) and distributed in the field a few days before sowing corn. Seed treatment and/or insecticide application are recommended when three to five baits show the presence of stink bugs (Bianco, ).…”

Probing Behavior of Dichelops furcatus (F.) (Heteroptera: Pentatomidae) on Wheat Plants Characterized by Electropenetrography (EPG) and Histological Studies

“…Damage on this latter plant is similar to that of the congener Dichelops melacanthus (Dallas) ( Ávila and Panizzi 1995 , Chocorosqui and Panizzi 2004 ), which also feeds on the reproductive structures of host plants. On wheat plants, Triticum aestivum L., D. furcatus damages the crop in Southern Brazil causing seed yield reduction ( Chocorosqui and Panizzi 2004 , Panizzi et al 2016 ), where it has been observed to increase in abundance. Another pentatomid, Thyanta perditor (F.), has also been observed to cause damage on wheat plants cultivated in Brazil ( Ferreira and Silveira 1991 ).…”

Development of Dichelops furcatus (Hemiptera: Heteroptera: Pentatomidae) Reared on Spring Cereals Versus Soybean

“…In addition, D. furcatus colonizes other spring cereals in southern Brazil such as oat, Avena sativa L. (Poaceae), during the vegetative (early plant development) and the reproductive periods (booting and seed-filling stage of the plant heads) ( Pereira et al 2013 ). On soybean, the main damage occurs during the pod-filling stage ( Panizzi et al 1977 ); conversely, on wheat and maize, severe damage occurs primarily on seedlings ( Panizzi et al 2016 ). However, on wheat, green-belly stink bugs damage the booting and/or milk-grain stages resulting in discolored seed heads, and undeveloped and malformed grain ( Panizzi et al 2016 ); eventually, this damage may be of concern to wheat growers.…”

“…On soybean, the main damage occurs during the pod-filling stage ( Panizzi et al 1977 ); conversely, on wheat and maize, severe damage occurs primarily on seedlings ( Panizzi et al 2016 ). However, on wheat, green-belly stink bugs damage the booting and/or milk-grain stages resulting in discolored seed heads, and undeveloped and malformed grain ( Panizzi et al 2016 ); eventually, this damage may be of concern to wheat growers.…”