8 colonies of caterpillars (5 colonies Imbrasia epimethea, 2 Bunaea alcinoe and 1 Imbrasia obscura) were purchased and transferred to trees at Songa Nzila IFD ...
CATERPILLAR PROJECT SUMMARY OF RESULTS JANUARY TO OCTOBER 2016
Augustin (centre) with villagers collecting leaves for feeding caterpillars
1. Study and rearing of caterpillars Cirina forda (Ngala) 43 clusters of eggs of Cirina forda, which had been deposited on Erythrophloeum africanum (see magnified photo right), were collected and transferred from Tsakala mbewa village in Bandundu province to Kilueka village in central Kongo and transferred to Crossopteryx febrifuga and 20 other local plants. On hatching, the larvae population of a cluster of eggs of Cirina forda ranges between 100 and 150. Of 21 plants tested, only 2 plants (Burkea africana and Bridelia ferruginea) were accepted as food by the young larvae hatching from these eggs. Unfortunately Crossopteryx febrifuga, the traditional food plant in central Kongo, was rejected by the caterpillars.
The larval cycle of the colonies of Cirina forda that survived on Burkea africana (left) revealed five growth stages each lasting 2 to 3 days. After each moult, the larvae move to the foliage of a new branch. Larvae of first and second stages are similar. The larvae change after the third, fourth and fifth moult to a new phenotype as seen below. The larval cycle from hatching to pupation in the ground took 75 days.
The colony of Cirina forda larvae reared on Burkea africana at Kilueka is currently in the pupal stage (below) and we expect the emergence of the moths in the coming days. When mating takes place we hope that spawning will produce a new generation of the caterpillar originally from Bandundu.
In addition 4 lots of the last stage of Cirina forda caterpillar from Bandundu, were purchased in the markets of Kinshasa, and are presently in the chrysalis stage at Kilueka.
Imbrasia epimethea (Mvinsu) and Bunaea alcinoe (Makedi kedi) A cluster of young larvae of Bunaea alcinoe collected on June 25, 2016 on Vitex doniana were successfully transferred to Acacia mangium and were studied to the last larval stage. These were transferred to cages covered with mosquito netting and began pupation on 6 July 2016. The emergence of 3 moths (2 males and 1 female) took place on the night of 8 to 9 September and mating took place on September 9 between 6 am and 7 am. The first female laid eggs on 11 September (32 eggs) and the second clutch were laid on 12 September with over 100 eggs! However the eggs did not hatch, for some reason! 8 colonies of caterpillars (5 colonies Imbrasia epimethea, 2 Bunaea alcinoe and 1 Imbrasia obscura) were purchased and transferred to trees at Songa Nzila IFD Kilueka and were tracked in the concession. They are currently in the pupation stage. The colony of Imbrasia obscura came from Piptadeniastrum
africanum and was transferred successfully Bridela ripicola (Kimuindu ki masa). We hope in the coming days to see a new generation on the same or neighbouring trees.
Male Bunaea alcinoe moth in breeding cage at Kilueka
2. Study of the propagation and multiplication of the caterpillar food plants. 2.1 Erythrophleum africanum A method of pre-germination seeds of E. africanum was tried out by soaking in hot water at about 80 to 85 ° C. for 10 minutes and after cooling, scarifying them. Scarified seeds were placed on a bed of paper towels then placed on a plastic tray and covered with a second layer of towels. The two layers of towels were regularly moistened with water. The culture tray was kept in a transparent polyethylene bag in shade. Germination started from the fourth day, instead of approximately 30 days in ordinary conditions.
By this method, with 3 lots of seeds received from Bandundu, we achieved a 65% germination rate from the second and third day. However many of the young seedlings (below) died after transplanting into polythene tubes. Germination experiments with 4 other caterpillar food plant seeds collected locally (Crossopteryx febrifuga, Bridelia ferruginea, Funtumia africana and Holarrhena floribunda) were carried out using the same method but without soaking in hot water. This time there was no losses, which made us suspect that the seeds of E. africanum we received from Bandundu were diseased. E. africanum seeds were also planted in partially sterilized soil (from underneath a site where charcoal had been made, mixed with plant ash) but a number of these plants were also affected by disease. An effective answer to the high mortality of seedlings of E. africanum in the nursery was found by applying a solution of Ivory 80 (Maconzèbe) spray to the germinating seedlings once a week. In addition a number of the young trees which had been planted out in the field have been destroyed by crickets (Brachytrupes membranaceus = Nzenze (Kongo)).
2.2. Propagation of plants Caterpillar food plants in the nursery at 30 October 2016 N°
Names of the plants
Number of seedlings
1
ERYTHROPHLOEUM AFRICANUM
1268
2
HOLARRHENA FLORIBUNDA
588
3
FUNTUMIA AFRICANA
189
4
ACACIA MANGIUM and A. AURICULIFORMIS
191
5
BRIDELIA FERRUGINEA
149
6
SYZYGIUM MALACCENSE
55
7
PENTACLETHRA MACROPHYLLA
50
8
RICINODENDRON HEUDELOTII
63
9
CROSSOPTERYX FEBRIFUGA
30
TOTAL
2583
Caterpillar plants planted out in the field N° 1 2 3 4 5 6 7 8
Names of the trees ERYTHROPHLOEUM AFRICANUM BRIDELIA FERRUGINEA RICINODENDRON HEUDLOTII ACACIA MANGIUM FUNTUMIA AFRICANA HOLARRHENA FLORIBUNDA PENTACLETHRA MACROPHYLLA SYZYGIUM MALACCENSE
