Potential of Hymenopteran larval and egg parasitoids to control stored-product beetle and moth infestation in jute bags

Abstract

The control of stored-product moths in bagged commodities is difficult because the developmental stages of the moths are protected by the bagging material from control measures such as the application of contact insecticides. Studies were carried out to assess the ability of Hymenopteran parasitoids to locate their hosts inside jute bags in the laboratory. The ability of different parasitoids to penetrate jute bags containing rice was investigated in a controlled climate chamber. Few Habrobracon hebetor (Say) (Hymenoptera: Braconidae) passed through the jute material while a high percentage of Lariophagus distinguendus (Förster), Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), Theocolax elegans (Westwood) (Hymenoptera: Pteromalidae) and Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) were able to enter the Petri-dishes. Significantly more L. distinguendus and T. elegans entered compared to H. hebetor. There was significant difference in the mean percentage parasitoids invading depending on species. Head capsules and/or thorax widths were measured in order to determine whether the opening in the jute material would be large enough for entry of the parasitoids. These morphometric data differed depending on parasitoid species and sex. The parasitoid Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae) did not enter the bags, but located host larvae inside the jute bags and parasitized rice moths Corcyra cephalonica larvae by stinging through the jute material. Venturia canescens significantly reduced the number of C. cephalonica adults emerging from the bagged rice; therefore, it could be released in storage rooms containing bagged rice for biological control of C. cephalonica. The use of parasitoids to suppress stored-product insect pests in bagged commodities could become a valuable supplement to the use of synthetic pesticides.

Two new fossil genera and species of Cerocephalinae (Hymenoptera, Chalcidoidea, Pteromalidae), including the first record from the Eocene

“…Females visit trees for oviposition and have a much higher chance of being trapped in resin than males. Members of the family Ptinidae, a common host group of Cerocephalinae (Adarkwah et al 2014), are closely associated with resin-producing trees and rank among the four most abundant beetle families in Baltic amber (Bukejs and Alekseev 2015). Other known hosts for Cerocephalinae are ambrosia beetles (Curculionidae: Platypodinae), which are diverse and common inclusions in Dominican amber (Peris et al 2015) and were found as syninclusions of Dominocephala vibrissae (Krogmann 2013).…”

“…All species are assumed to be parasitoids of small endophytic beetles (Bouček 1988), which makes them potentially potent biological control agents. Members of the genera Cerocephala and Theocolax have hereby proven to be effective against pests like Stegobium paniceum Linnaeus, 1758, Rhyzopertha dominica Fabricius, 1792 and other crop-feeding beetles (Flinn and Hagstrum 2002, Adarkwah et al 2014). …”

Lariophagus distinguendus (Hymenoptera: Pteromalidae) (Förster)—Past, Present, and Future: The History of a Biological Control Method Using L. distinguendus against Different Storage Pests

“…Results indicate that host location outside the commodity is strongly influenced by factors such as light and that the number of wasps released should be higher than the number recommended for use inside the commodity. Additional research on dispersal and host finding was conducted by Adarkwah et al who looked at the ability of L. distinguendus to reach hosts inside jute bags and bulk maize [68,69]. They showed that the wasps, depending on mesh size, are able to penetrate the bags and reduce pest infestations by 81%, while reduction was about 37% one meter inside the maize bulk.…”

Predator‐parasitoid‐host interaction: biological control of Rhyzopertha dominica and Sitophilus oryzae by a combination of Xylocoris flavipes and Theocolax elegans in stored cereals

“…Biological control may provide an affordable and sustainable option for reducing losses to pests in stored food products (Bellows, ; Shin et al., ; Adarkwah et al., ). The use of natural enemies to control insect pests in storage situations is not a new concept, but it has only recently received serious attention – pathogens, parasitoids, and predators have been investigated in the context of stored product protection (Schöller & Flinn, ; Adarkwah et al., , , , , ; Adarkwah & Schöller, ; Flinn & Schöller, ). Currently, modern protection of stored products is seeking to apply biocontrol strategies such as the combination of predators and parasitoids, which would eventually become an integral part of the integrated pest management (IPM) approach, especially in Africa where stored‐product insect pests concurrently infest stored grains.…”