Scope of Pentatomidae as bio-control agents in India
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S Salini and KJ David
Pentatomidae, commonly known as stink bugs, are a diverse assemblage of insects, yet often under estimated for their economic importance either as pest or predators. There are four sub-families viz., Asopinae, Pentatominae, Podopinae and Phylloce-phalinae known from India (Salini and Viraktamath, 2015). Of these Asopinae are exclusively predators whereas more than 80% of species of Pentatomidae belongs to a single subfamily Penta-tominae. Pantatominae comprises pests of agricultural crops (Nezaraviridula, Bagradahilaris, Eurydema spp., Cappaeataprobanensis, Rhynchocorishumeralis, Dolyocoris indicus, Ago-noscelisnubilis, Udonga- montana, Menida versicolor etc.), ebible species (Udongamontana), invasive pests of quarantine importance (Halyomorphahalys), vectors of phytoplasma (Halyomorphahalys) and species causing public nuisance (Udongamontana, Catcanthus incarnatus, Agonoscelisnubilis). A major pest rice black bugs is a Pentatomid pest belonging to Podopinae, involves an array of species with diverse distribution. Phyllo-cephalinae are major grass root feeders, a very underexploited group.
Pentatomidae are known for their cyptic and warming colouration. Some are known to merge with their surroundings, especially those groups of genera, which are specialized to inhabit tee trunks. This can be considered as an evolutionary adaptation for these bugs to compartmentalize the resources as well as to re-route natural enemy. This is particularly evident in their ability to camouflage with the bark colouration. Majority of these genera were also found to be nocturnal and are confined to concealed habitat like trunk holes or any cracks or crevices of bark during day time.
ASOPINAE AS BIOCONTROL AGENTS
Asopinae, commonly known as predatory stinkbugs or soldier bugs possessing a predaceous feeding habit for both nymphs (with the exception of first instars) and adults. First instars of Asopinae are not predaceous and take up only water or plant juices (De Clercq, 2000). They are characterised by having a crassate rostrum. The first segment is markedly thickened and free, only the base being embedded between the bucculae. This enables a fully forward extension of the rostrum and thus facilitates feeding prey. The stylets are inserted at any soft area of the prey body and inject salivary toxin into the prey body by which they can quickly immobilize the prey. While feeding the prey, the only contact between predator and prey is by the labium and stylets (De Clercq, 2000). The feed on a variety of insects such as Coleoptera, Lepidoptera, Hymenoptera especially at larval stages, and other small and soft bodied arthropods (Lefroy and Howlett, 1909; Fletcher, 1914; Kalshoven, 1981). However, they also feed on other insect orders or developmental stages.
Members are often observed to feed on plants, that provides them with moisture and perhaps some supplemental nutrients at critical time, though the damage inflicted to plants by sucking o plant sap is negligible (De Clercq, 2000). Though they feed on plants at times, in contrast to other predatory heteropterans (e.g. Geocoris, Dicyphus, Marcolophus), plant feeding asopines have not been reported to injure crops.
Many Asopines are known for their brilliant and aposematic colouration like AmyoteaEllenreider, ZicronaAmyot& Servile etc. A few of them like CaziraAmyot&Serville, are well equipped with various armature and have a bizarre appearance. Approximately 303 species of Asopinae are known from worldwide (Rider et al., 2018), of which only 10% have been studied in more or less detail. Certain species however, received much attention across the world regarding their potential to manage the agricultural pests. There are about 30 species of Asopinae are known to occur in India but the knowledge of their prey or feeding potentials of majority of these Asopines remain poorly understood. Only a small proportion of the species belonging to this subfamily have been studied so far. Future studies on their biology of this group of bugs are essential for exploring them for their biocontrol potential.
Majority of Asopines are generalist predators attacking a wide range of prey in a diverse habitat whereas a few f them appears to be ore closely associated with a limited number of insect pest species occur in a few habitats (D Clercq, 2000). For example, the spined soldier bug, Podisusmaculiventris (Say), which is being commercialized in North America and Europe mainly for biological control of the Colorado potato beetle in potatoes and of noctuid caterpillars in vegetables, shows a particular preference for Lepidop- teran larva. P. maculiventris was found feeding on more than 90 insect species from eight orders, including Coleo-ptera, Diptera, Ephemeroptera, Hetroptera, Homoptera, Hymenoptera, Lepidoptera, and Orthoptera (De Clercq, 2000).
(To be contd)
Pentatomidae, commonly known as stink bugs, are a diverse assemblage of insects, yet often under estimated for their economic importance either as pest or predators. There are four sub-families viz., Asopinae, Pentatominae, Podopinae and Phylloce-phalinae known from India (Salini and Viraktamath, 2015). Of these Asopinae are exclusively predators whereas more than 80% of species of Pentatomidae belongs to a single subfamily Penta-tominae. Pantatominae comprises pests of agricultural crops (Nezaraviridula, Bagradahilaris, Eurydema spp., Cappaeataprobanensis, Rhynchocorishumeralis, Dolyocoris indicus, Ago-noscelisnubilis, Udonga- montana, Menida versicolor etc.), ebible species (Udongamontana), invasive pests of quarantine importance (Halyomorphahalys), vectors of phytoplasma (Halyomorphahalys) and species causing public nuisance (Udongamontana, Catcanthus incarnatus, Agonoscelisnubilis). A major pest rice black bugs is a Pentatomid pest belonging to Podopinae, involves an array of species with diverse distribution. Phyllo-cephalinae are major grass root feeders, a very underexploited group.
Pentatomidae are known for their cyptic and warming colouration. Some are known to merge with their surroundings, especially those groups of genera, which are specialized to inhabit tee trunks. This can be considered as an evolutionary adaptation for these bugs to compartmentalize the resources as well as to re-route natural enemy. This is particularly evident in their ability to camouflage with the bark colouration. Majority of these genera were also found to be nocturnal and are confined to concealed habitat like trunk holes or any cracks or crevices of bark during day time.
ASOPINAE AS BIOCONTROL AGENTS
Asopinae, commonly known as predatory stinkbugs or soldier bugs possessing a predaceous feeding habit for both nymphs (with the exception of first instars) and adults. First instars of Asopinae are not predaceous and take up only water or plant juices (De Clercq, 2000). They are characterised by having a crassate rostrum. The first segment is markedly thickened and free, only the base being embedded between the bucculae. This enables a fully forward extension of the rostrum and thus facilitates feeding prey. The stylets are inserted at any soft area of the prey body and inject salivary toxin into the prey body by which they can quickly immobilize the prey. While feeding the prey, the only contact between predator and prey is by the labium and stylets (De Clercq, 2000). The feed on a variety of insects such as Coleoptera, Lepidoptera, Hymenoptera especially at larval stages, and other small and soft bodied arthropods (Lefroy and Howlett, 1909; Fletcher, 1914; Kalshoven, 1981). However, they also feed on other insect orders or developmental stages.
Members are often observed to feed on plants, that provides them with moisture and perhaps some supplemental nutrients at critical time, though the damage inflicted to plants by sucking o plant sap is negligible (De Clercq, 2000). Though they feed on plants at times, in contrast to other predatory heteropterans (e.g. Geocoris, Dicyphus, Marcolophus), plant feeding asopines have not been reported to injure crops.
Many Asopines are known for their brilliant and aposematic colouration like AmyoteaEllenreider, ZicronaAmyot& Servile etc. A few of them like CaziraAmyot&Serville, are well equipped with various armature and have a bizarre appearance. Approximately 303 species of Asopinae are known from worldwide (Rider et al., 2018), of which only 10% have been studied in more or less detail. Certain species however, received much attention across the world regarding their potential to manage the agricultural pests. There are about 30 species of Asopinae are known to occur in India but the knowledge of their prey or feeding potentials of majority of these Asopines remain poorly understood. Only a small proportion of the species belonging to this subfamily have been studied so far. Future studies on their biology of this group of bugs are essential for exploring them for their biocontrol potential.
Majority of Asopines are generalist predators attacking a wide range of prey in a diverse habitat whereas a few f them appears to be ore closely associated with a limited number of insect pest species occur in a few habitats (D Clercq, 2000). For example, the spined soldier bug, Podisusmaculiventris (Say), which is being commercialized in North America and Europe mainly for biological control of the Colorado potato beetle in potatoes and of noctuid caterpillars in vegetables, shows a particular preference for Lepidop- teran larva. P. maculiventris was found feeding on more than 90 insect species from eight orders, including Coleo-ptera, Diptera, Ephemeroptera, Hetroptera, Homoptera, Hymenoptera, Lepidoptera, and Orthoptera (De Clercq, 2000).
(To be contd)