Topic: Identification of the Greater Grain Borer (GGB)
Duration: 1 hour
Objectives:
At the end of this session, the participants should be able to:
(i) Name the phenotypic features of the GGB;
(ii) Differentiate the GGB from other similar storage insect pests.
Target Group:
- Subject Matter Specialists (SMS's)
- Technical Assistants (TA's)
- Farmers
- Customs officers, regular and administrative policemen
- Local leaders
- Traders and personnel of trading organizations (NCPB, Cotton Board)
Training Materials:
(i) Blackboard (BB) or flip chart (FC) stand
(ii) Chalk sticks or felt pens and flip chart paper
(iii) Preserved specimens (samples) of insect pests (at least five) including the GGB.
(iv) Magnifying glasses (lenses)
(v) Wall pictures showing the GGB and other grain storage pests.* Where possible, slides and slide projectors may be used.
Process:
10 to 15 minutes
Brainstorming:
a) The trainer should ask the participants to name any storage insect pests that they know of. Each pest named should be written on the black board or flip chart. The names should be written in two columns whereby the first column should be in English and the second column in the local language. This exercise will only succeed if, and only if, the trainer has earlier on made sufficient enquiries about the local names of the storage insect pests. If a participant is given the name of an insect pest in English, the trainer should write it in column 1 and then ask for the local name. If none of the participants knows the local name, the trainer should give it and then write it down in the second column. If a participant gives a local name, the trainer should write it in column 2 and then give the English name, which should then be written in column 1.At the end of this session, the BB or FC should have at least the following names:
- Greater or Larger Grain Borer (Prostephanus truncatus)
- Lesser Grain Borer (Rhizopertha dominica)
- Rust Red Flour Beetle (Tribolium castaneum)
- Grain Weevil (Sitophilus zeamays)
- Cowpea Weevil (Callosobruchus chinensis)
- Angoumois Grain Moth (Sitotroga Cerealella)10-15 minutes
General Exhibition and Identification of Insect Pests
b) The trainer should then hand out to each participant a small blank paper, plastic or glass packet/container. After that, the trainer should tell the participants that he/she is going to give out samples of insect pests which each participant is expected to identify and name. If the participants are literate, they should be encouraged to write down the names; otherwise, they should be asked to keep quiet until asked to give the name by the trainer.c) The trainer should briefly demonstrate how to use a magnifying lens by looking at a sample of an insect pest. Movement up and down in order to reach the best image should be emphasized and demonstrated to all participants who should gather around the trainer's desk for the purpose.
d) On return to their seats, the trainer should hand out the lenses (magnifying glasses) and immediately thereafter, the first sample of an insect pest. All samples/specimens should have been well preserved with no missing parts. They should preferably be pinned and labeled. The specimens should be handed out in such a way that the GREATER GRAIN BORER is received last of all. The participants should be asked to name the pest after a minute or so of observation. Participants should be asked to keep the specimens in the container provided.
e) It is important that, during the identification, differences of opinion with respect to the name of the specimen in question be ironed out thoroughly by the trainer. Re-examination should be required whenever there seems to be doubt among the participants. In all cases, the local names should be preferred. However, in the case of the specimen, the local name, GGB, dumuzi, etc. should be given.
5 minutes
The Features of the GGB
f) The trainer should ask participants to examine the GGB very carefully and to name its features. The following features should be identified:(i) colour: adult beetle is dark brown;(ii) body shape: cylindrical;
(iii) size: 3 to 4 mm. long;
(iv) posterior end: slopes towards back with two pronounced lateral ridges. Each end appears as if it has been cut straight;
(v) posterior of head (cannot be seen from above);
(vi) antennae: segmented with distinct clubs.
5 minutes
Comparing the GGB to the Lesser Grain Borer
g) The trainer should ask the participants to re-examine the Lesser Grain Borer, this time alongside the GGB. The distinguishing features should be brought to light, especially the following:- posterior end of elythra
Lesser Grain Borer
GGB
5 minutes
Comparing the GGB to the Granary Weevil
h) The trainer should ask the participants to look at the GGB alongside the maize weevil. Once again, the distinguishing features should be singled out, especially the following:- differences in the head
- body shape
- posterior end of abdomen
Maize weevil
GGB
5 minutes
Identification of Insect Pests in Pictures
i) The trainer should hand out a poster containing the pictures of the insect pests already discussed. The participants should then be asked to point out certain pests. The trainer should go round the class to ensure that the participants are pointing to the right pest. Emphasis should be on:* the GGB
* the Maize Weevil and
* the Lesser Grain Borerj) The trainer should allow time for participants to ask questions. At the end of their questions, the trainer may ask questions to ensure that the subject matter has been learnt, especially the physical features of the GGB and all the names by which it is commonly known.
k) The trainer should sum up the lesson by:
i) Going through the list of names of the crop storage insect pests, highlighting the local names.ii) Emphasizing the name GGB, which will thereafter be the subject of the course.
iii) Naming the physical features of the GGB.
iv) Giving each participant Hand-Out 1.
v) Collecting the samples, magnifying glasses, etc. which the participants had been using.
