The Metathoracic Scent Gland of the Leaf-Footed Bug,Leptoglossus zonatus

Abstract

The metathoracic scent gland of 25-day-old adults of both sexes of the leaf-footed bug, Leptoglossus zonatus (Dallas) (Heteroptera: Coreidae), are described based on optical microscopy analysis. No sexual dimorphism was observed in the glandular composition of this species. The gland is located in the anteroventral corner of the metathoracic pleura between the middle and posterior coxal pits. The opening to the outside of the gland is very wide and permanently open as it lacks a protective membrane. In the internal part, there is a pair of metathoracic glands that consist of piles of intertwined and occasionally bifurcated cellular tubes or columns. These glands discharge their pheromonal contents into the reservoir through a narrow cuticular tube. The reservoir connects with the vestibule via two opposite and assembled cuticular folds that can separate muscularly in order to allow the flow of liquid away from the insect. The external part consists of an ostiole from which the pheromone is emitted. The ostiole is surrounded by a peritreme, a structure that aids optimum pheromone dispersion. The described gland is of the omphalien type.

Benzoquinones in the defensive secretion of a bug (Pamillia behrensii): a common chemical trait retrieved in the Heteroptera

“…As is typical for chemical release from the metathoracic scent gland of other bugs, we found that the yellow, quinone secretion is also expelled from this gland complex as small droplets ( Fig 2C ). The MTG was located between thorax segment II and III ( supplement Fig S1A ) and generally showed an outer morphology comparable to other Heteropteran glands (Aldrich 1988; Gonzaga-Segura et al 2013; Hepburn and Yonke 1971): two adjacent cuticular folds form flaps/lips on the anterior and posterior edges of the gland opening ( Fig 2C ). The edges of the cuticular folds constitute the ostiolar peritreme, which likely aids in carrying the glandular secretions away from the opening and fosters increased compound dispersion ( Fig 2C ).…”

Behavioral Response of Leptoglossus zonatus (Heteroptera: Coreidae) to Stimuli Based on Colors and its Aggregation Pheromone

“…Our results indicate that males and females of L. zonatus release an aggregation pheromone. This possibility had been suggested previously as [ 29 ] reported the presence of metathoracic scent glands in both sexes but no biological evidence was available at that time. In many Heteropteran species, one or both sexes release sex or aggregation pheromones [ 47 , 48 ].…”

“…This idea is supported by the fact that Leal et al [ 30 ] reported aggregations of this insect and unsuccessfully tried to identify the aggregation pheromone but instead reported an alarm pheromone. Leptoglossus zonatus males and females have metathoracic scent glands [ 29 ] and may release a different concentration of the pheromone depending on the situation. The identification of the aggregation pheromone is mandatory to validate this idea.…”

“…The adults and nymphs feed on many important crops, like maize, sorghum [ 22 ], pomegranate [ 24 ], citrus [ 25 , 26 ], and Jatropha curcas L. (Malpighiales: Euphorbiaceae), an important source of biodiesel [ 27 , 28 ]. In 2003, the metathoracic scent gland of males and females of this insect was described [ 29 ]. Despite its importance as a vector and crop pest, many aspects of its biology remain unknown.…”