Body position of the stink bug Dichelops melacanthus (Dallas) during feeding from stems of maize seedlings

Abstract

The Neotropical green-belly stink bug, Dichelops melacanthus (Dallas) is a major pest of maize, Zea mays L. in the main production areas of Brazil. It usually feeds on the stems of young plants (seedlings) causing heavy damage by affecting the plant growth and mitigating seed yield. Laboratory studies were conducted to determine body position (upward or downward) of the bug on plant (seedling) stem during feeding and not feeding activities. Ten visual records were taken per day, each spaced one hour during 30 days of 10 adult bugs of similar age exposed to maize seedlings inside cages (plastic tubes). At each observation, it was recorded if the bug was feeding on the stem (i.e., stylets inserted into the plant tissue) or not, and its body position. During feeding, waveforms were recorded using the EPG (electropenetrography) technique, which were correlated with histological studies to reveal the feeding sites. Results indicated that when they were feeding, the majority of the bugs were in the downward position. In contrast, when the bugs were on the plants, and not feeding, they were mostly in the upward position. Waveforms generated using the EPG coupled with histological studies demonstrated that during ingestion bugs fed from the xylem vessels and from the parenchyma tissue using cell rupture strategy in the latter. No clear explanation was found to explain the preferred downward body position during ingestion, but some hypothesis are speculated.

Unveiling the Feeding Behavior of Tibraca limbativentris (Hemiptera: Pentatomidae) on Rice Using an Electropenetrography Waveform Library

“…Tibraca limbativentris faced downward while feeding on the vertical rice stalk. The same behavior was observed in D. melacanthus while feeding on the stems of maize seedlings ( Panizzi and Lucini 2019 ). Both insects share the same feeding strategies (cell rupture and salivary sheath), which, according to the authors, may be more effective when facing downward and against the flow of xylem sap, which travels up from the roots to the leaves.…”

Life history of Dactylopius opuntiae (Hemiptera: Dactylopiidae) on Moroccan resistant cactus germplasm

“…To avoid this misconception, new tools have been developed. For stink bugs, for example, electrical penetration graph (EPG) techniques have recently begun to be used to characterize feeding behavior [50,51] and may be used in the future to characterize plant resistance categories. Second instar weights were significantly higher on the Belara genotype (5.5 mg) and no differences were observed among the other genotypes.…”

Circadian feeding rhythm of green-belly stink bug in corn cultivation

“…One day before starting the evaluations (to allow of acclimation of insects in the field), each cage was infested with 5 pairs of insects (10 individuals), obtained from a laboratory colony that was maintained using the procedure described by Ribeiro et al (2018). On each assessment day (V3 and V5 stages, in both first and second growing seasons), the infested plants were checked every 3 hours (at 6:00, 9:00, 12:00, 15:00, 18:00, 21:00 and 0:00 h), in order to visually verify the number of stink bugs feeding on the plant stems, following the feeding behavior described by Panizzi & Lucini (2019). For the nocturnal evaluations, a red LED flashlight (Limatec, Cruz das Almas, BA, Brazil) was used to visualize the insects on plants without interference.…”

“…For this, knowing the habits of this insect in corn cultivations is essential. Several studies on the bioecology of D. melacanthus have been carried out (Chocorosqui & Panizzi, 2008;Bortolotto et al, 2016;Oliveira et al, 2019), and some aspects of D. melacanthus feeding on corn stems -such as body position, ingestion site, frequency, duration, and ingestion and excretion rates -were elucidated in laboratorial studies, by using the electropenetrography (EPG) technique (Lucini & Panizzi 2017a, 2017bPanizzi & Lucini, 2019). In Brazil there is a prevailing "belief" that the greenbelly stink bug is more active and feeds in the early morning hours, while taking shelter under the straw layer in the warmest hours of the day; however, this "belief" cannot be entirely sustained, since there is a lack of scientific information on the circadian feeding rhythm of this species in corn fields.…”