Abstract
A new species ofTrichogrammatoidea which is being described byH. Nagaraja asT. armigera, has been reared from eggs ofHeliothis armigera onPolianthes tuberosa and from those of an unidentified Lepidopteron onCajanus cajan. In the laboratory the parasite was successfully bred onCorcyra cephalonica, Achaea janata, Gnorimoschema operculella andPlutella xylostella; it did not show any perceptible preference for any of these hosts. It also parasitised eggs ofSpodoptera litura, but although development proceeded to the adult stage, adults failed to emerge, suggesting unsuitability of this host.
The males ofT. armigera are found to exhibit dimorphism — one form being alate and the other typically apterous. The apterous males were almost exclusively produced only by fertilised females and in the progeny of virgin females these forms were extremely rare (1 apterous male: 1,500 winged males). Among the progeny of a single mated female, an apterous male developed invariably in association with a female, but this rule did not apply when a singleCorcyra egg was parasitised by more than one parental female. However, in no case did an apterous male alone emerge from a single host egg.
The biology ofT. armigera has been studied at 25°C±1°C. and R.H. 75%, usingC. cephalonica eggs. The parasite completed its life-cycle in 7–9 days — the egg, larval and pupal periods occupying, 1, 2–3 and 4–5 days, respectively. When fed honey, the average longevity of females was 7 (max. 11) days, of alate males 6 (max. 10) days and of apterous males 1 (max. 2) day. The maximum fecundity was 118 while the average was about 63. From 2–26 (average 9) eggs were parasitised per day. The sex-ratio was 62% females: 38% males (35% alate and 3% apterous). An alate male during its lifetime inseminated upto 10 (Av. 9) females while an apterous one inseminated up to 4 (Av. 3) females.
Résumé
Une nouvelle espèce deTrichogrammatoidea décrite parH. Nagaraja sous le nom deT. armigera a été obtenue d’œufs deHeliothis armigera surPolianthes tuberosa ainsi que d’œufs d’un Lépidoptère non identifié surCajanus cajan. Au laboratoire, le parasite a été élevé surCorcyra cephalonica, Achaea janata, Gnorimoschema operculella etPlutella xylostella; il n’a manifesté aucune préférence pour aucun de ces hôtes. Il a parasité également les œufs deSpodoptera litura, mais les adultes n’ont pas réussi à sortir; ce qui fait penser que cet hôte ne convient pas.
Les mâles deT. armigera présentent un dimorphisme: une forme est ailée et l’autre aptère. Cette dernière est presqu’exclusivement issue des femelles fécondées. Dans la descendance d’une femelle accouplée, un mâle aptère se développe invariablement en association avec une femelle, mais cette règle ne s’observe pas lorsqu’un œuf deCorcyra est parasité par plus d’une femelle. Cependant, en aucun cas, un mâle aptère ne sort d’un seul œuf parasité.
La biologie deT. armigera a été étudiée à 25°±1°C et 75% H.R. en utilisant des œufs deC. cephalonica. Le cycle du parasite s’effectue en 7 à 9 jours, les stades: œufs, larve, nymphe, durant respectivement 1, 2 à 3 et 4 à 5 jours. Alimentés sur miel la longévité moyenne des femelles est de 7 jours (max. 11), des mâles ailés de 6 jours (max. 10) et celle des mâles aptères de 1, jour (max. 2). La fécondité moyenne est de 63 avec un maximum de 118 œufs. De 2 à 26 œufs de l’hôte (en moyenne 9) sont parasités par jour. Le rapport des sexes est de 62% de femelles et 38% de mâles (35% d’ailés et 3% d’aptères). Un mâle ailé insémine en moyenne 9 femelles, tandis qu’un mâle aptère en insémine 3.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Beeson, C. F. C. &Chatterjee, S.N. — 1939. Further notes on the biology of parasites of teak defoliators in India. —Indian Forest Rec. N.S. (Ent.) 5, 355–379.
Manjunath, T. M., Phalak, V. R. &Subramanian, S. — 1970. First records of egg-parasites ofheliothis armigera (Hübn.) [Lep.: Noctuidae] in India. —Tech. Bull. Commonw. Inst. biol. Control,13, 111–115.
Salt, G. — 1937. The egg-parasite ofSialis lutaria: a study of the influence of the host upon a dimorphic parasite. —Parasitology,29, 539–553.
Schmieder, R. G. — 1933. The polymorphic forms ofMelittobia chalybii Ashmead and the determining factors involved in their production, [Hymenoptera: Chalcidoidea, Eulophidae]. —Biol. Bull. 65, 338–354.
Author information
Authors and Affiliations
Additional information
Manuscript species being described by Mr.H. Nagaraja C.I.B.C. Indian Station, Bangalore.
This resaerch has been financed in part by a grant made by the United States Department of Agriculture under PL-480.
Rights and permissions
About this article
Cite this article
Manjunath, T.M. Biological studies onTrichogrammatoidea armigera Nagaraja a new dimorphic egg parasite ofHeliothis armigera (Hübner) in India. Entomophaga 17, 131–147 (1972). https://doi.org/10.1007/BF02371125
Issue Date:
DOI: https://doi.org/10.1007/BF02371125