Infectivity of Entomopathogenic Nematode, Steinernema carpocapsae, on the Mango Shoot Borer, Rhytidodera simulans
Nematological Research (Japanese Journal of Nematology)
マンゴーを加害するカミキリムシRhytidodera simulansに対するSteinernema carpocapsaeの感染性
Infectivity of Steinernema carpocapsae strain All on larvae of the mango shoot borer Rhytidodera simulans, a serious pest of mango trees in Malaysia, was investigated under laboratory conditions. When the insect larvae were placed individually in a 6-cm-d petri dish containing 5g of moistened mango sawdust with 0, 10, 100, 1,000 or 10,000 infective juveniles (J3), the nematode caused insect death 2 days or later after inoculation at the inoculum levels higher than 1,000 J3 and then grew and
... d then grew and reproduced in the insect cadavers. Most of the insects which escaped nematode infection or those died later made gallery-like tunnel along the petri dish wall. About 1/2 to 1/6 individuals of insects introduced in the galleries artificially made in mango cut-branches were infected when the branches were either injected through small side holes reaching the galleries or sprayed over the holes with 1 m/ of nematode suspension containing 10,000 or 100,000 J3. The nematode infection on R. simulans larvae in galleries was found to be greatly affected by the insect feeding behavior. Jpn. J. Nematol. 23(1): 28-36. Mango is a very important tropical fruit and, in Malaysia, is attacked by various species of insects; colleopterans (Rhytidodera simulans, Deporaus marginatus, Hypomeces squamosus, Sternochetus frigidus, S. mangiferae, Anomala cupripes), dipteran (Dacus dorsalis), hemipteran (Mictis longicornis), homopteran (Lepidosaphes euryae), and lepidopterans (Parasa lepida, Setora nitens, Chlumetia transversa, Penicillaria jocosatrix)(8). Of these pests, the most serious one is the mango shoot borer, R. simulans which distributes wherever mango is planted. Rhytidodera simulans larva bores into the shoot and continues to tunnel into the branch (20). Therefore the branch attacked by the insect will die and often break off in storms. So far the most practical control method of the insect is to prune the branches at an initial stage of infestation. Chemical control of the insect pests is generally not so effective due to a cryptic habitat of the insect. The present preliminary studies on the infectivity of entomopathogenic nematode Steinernema carpocapsae were conducted under laboratory conditions to provide a basis for the insect biocontrol by nematodes.