Video-documentation of the effects of Bt corn and the progression of signs and symptoms of septicemia on neonate ostrinia furnacalis (Guenee)

Issue Date

10-2017

Abstract

Bt corn is effective against the Asian corn borer (ACB), Ostrinia furnacalis (Guenee), providing excellent protection against newly hatched (neonate) and second instar larvae. The initial feeding pattern of neonates was recorded on video, as well as the corresponding progression of signs and symptoms of septicemia, and the time spent before death. A neonate larva was carefully placed on the adaxial side of the expanded leaf of corn next to the whorl. A 30-day old Bt corn plant was used in the observation. Larval movement, infestation, crawling, ballooning, transferring from one part of the leaf to another, scraping and feeding, feeding time , and part of leaf fed upon, and the time until complete manifestation of septicaemia on the larva were recorded. Clearly, signs and symptoms of septicaemia gradually developed hours after feeding on the leaf. The symptoms include “vomiting-like” reaction and the slow darkening on the anal area. Also, the larval thoracic area that probably corresponds to the internal midgut portion – became narrow during “vomiting.” The abdomen then appeared to be bloated after the narrowing of the thorax. After this, the larva moved slowly until it was stationary, the whole body slowly turning black and eventually completely motionless, and died. The video-documentation will help explain the initial injury on Bt corn plants, but which do not progress further, and elucidate to farmers what is often seen as lack of knockdown effect among Bt transgenic plants.

Source or Periodical Title

The Philippine Entomologist

ISSN

0048-3753

Volume

31

Issue

2

Page

160-161

Document Type

Article

College

College of Agriculture and Food Science (CAFS)

Frequency

semi-annually

Language

English

En – AGROVOC descriptors

MAIZE; TRANSGENIC PLANTS; OSTRINIA FURNACALIS; SEPTICAEMIA; BACILLUS THURINGIENSIS; INSECTA; PESTS; PEST OF PLANTS; PEST INSECTS; TRANSGENICS; GENETICALLY MODIFIED ORGANISMS; BACTERIAL PESTICIDES; DOCUMENTATION

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