Biology of Agathis unicolor (Schrottky) and Agathis gibbosa (Say) (Hymenoptera: Braconidae), primary parasites of the potato tuberworm
AuthorsJ. A. ?d?biyi
E. R. Oatman
Authors AffiliationsJ. A. ?d?biyi was Assistant Professor of Entomology, Department of Agricultural Biology, University of Ibadan, Nigeria, formerly graduate student, Department of Entomology, University of California, Davis; Earl R. Oatman was Professor and Entomologist, Division of Biological Control, University of California, Riverside.
Hilgardia 45(5):123-151. DOI:10.3733/hilg.v45n05p123. August 1977.
Studies were conducted on the biology, and on temperature and humidity responses, of Agathis unicolor (Schrottky), and exotic species. Results were compared with similar studies on the native species, A. glbbosa (Say), and their common host, the potato tuberworm, Phthorimaea operculella (Zeller). The two species of parasites were reared at several constant temperatures and humidities, and life-table data were obtained in each test environment. These data were used to calculate the intrinsic rate of natural increase, which was used as a bioclimatic index for each of the two species. The influence of several different constant temperatures and humidities on the parasites, and on host-parasite relationships, was evaluated on the basis of relative changes in the intrinsic rate of increase, developmental time, and the mean generation time.
The egg of A. unicolor is deposited in a ganglion of the ventral nerve cord of the host larva. Parasite larvae develop within the host body cavity and, after emergence, spin their silky-white cocoons inside the host cocoons. There are three larval ins tars, the first being both caudate and mandibulate, and the other two, hymenopteriform. The mean minimum developmental time from egg to adult emergence was 18 days at 26.7 C 50 ± 2 percent relative humidity (RH). Measurements and morphological descriptions of the immature stages are presented, and mating and ovipositional behavior of the adults are described. The optimum host density for maximum parasite progeny was 85 larvae per tuber. The biology of A. unicolor is similar to that of A. gibbosa.
Temperature and rate of development of both parasites were linearly related. However, at 35.0 C, A. unicolor could not develop beyond the prepupal stage. Longevity and reproductive periods were inversely related to temperature, and survivorship curves of both parasites conformed to the curves of physiological longevity.
On the basis of the intrinsic rate of natural increase, A. unicolor survived and reproduced from 21.1 to 32.2 C. Agathis gibbosa survived and reproduced from 21.1 to 35.5 C. Both parasites developed best at 50 percent relative humidity. Comparisons of the intrinsic rate of natural increase, developmental time, and mean generation time indicated that A. gibbosa would be better able to suppress populations of the host than A. unicolor.
Andrewartha H. G., Birch L. C. The distribution and abundance of animals. 1954. Chicago: Univ. Chicago Press. 782p.
Barlow C. A. The influence of temperature on the growth of experimental populations of Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas). Can. J. Zool. 1962. 40:145-56. DOI: 10.1139/z62-019 [CrossRef]
Birch L. C. The intrinsic rate of natural increase of an insect population. J. Anim. Ecol. 1948. 17:15-26. DOI: 10.2307/1605 [CrossRef]
Bodenheimer F. S. Animal ecology today. 1958. The Hague: Monogr. Biolog. VI. W. Junk. 276p.
Burnett T. Effects of initial densities and periods of infestation on the growth-forms of a host and parasite population. Can. J. Zool. 1960. 38:1063-77. DOI: 10.1139/z60-112 [CrossRef]
Bursell E., Rockstein M. Environmental aspects: Temperature. The Physiology of Insecta. 1964. 1:Academic Press. p. 283-321.
Cardona C. Biology and physical ecology of Apanteles subandinus (Blanchard) (Hymenoptera: Braconidae), with notes on temperature responses of Apanteles scutellaris (Muesebeck) and its host, the potato tuberworm. Hilgardia. 1971. 43:1-51. DOI: 10.3733/hilg.v43n02p053 [CrossRef]
Cardona C., Debach P. Biological control of insect pests and weeds. 1964. London: Chapman and Hall. 844p.
Dondale C. D. Biology of Agathis laticinctus (Cress) (Hymenoptera: Braconidae), a parasite of the eye-spotted bud moth, in Nova Scotia. Can. Ent. 1954. 86:40-47. DOI: 10.4039/Ent8640-1 [CrossRef]
Force D. C., Messenger P. S. Fecundity, reproductive rates, and innate capacity for increase of three parasites of Therioaphis maculata (Buckton). Ecology. 1964. 45:706-15. DOI: 10.2307/1934918 [CrossRef]
Force D. C., Messenger P. S. The use of laboratory studies of three hymenopterous parasites to evaluate their field potential. Jour. Econ. Ent. 1968. 61:1374-78.
Lamb K. P. Some effects of fluctuating temperature on metabolism, development, and rate of population growth in the cabbage aphid, sBrevicoryne brassicae. Ecology. 1961. 42:740-45. DOI: 10.2307/1933502 [CrossRef]
Leong J. K. L., Oatman E. R. The biology of Campoplex haywardi (Hymenoptera: Ichneumonidae), a primary parasite of the potato tuberworm. Ann. Ent. Soc. Am. 1968. 61:26-36.
Messenger P. S. Use of life tables in a bioclimatic study of an experimental aphid-braconid wasp host-parasite system. Ecology. 1964. 45:119-31. DOI: 10.2307/1937113 [CrossRef]
Muesebeck C. F. W. Braconid parasites of the pink bollworm, Pectinophora gossypiella (Saunders). Boll. Lab. Zool. e Agr., Portici. 1956. 33:55-68.
Oatman E. R., Platner G. R. Parasitization of the potato tuberworm in southern California. Environ. Entomol. 1974. 3:262-64.
Odebiyi J. A., Oatman E. R. Biology of Agathis gibbosa (Hymenoptera: Braconidae), a primary parasite of the potato tuberworm. Ann. Ent. Soc. Amer. 1972. 65:1104-14.
Platner G. R., Oatman E. R. An improved technique for producing potato tuberworm eggs for mass production of natural enemies. Jour. Econ. Ent. 1968. 61:1054-57.
Platner G. R., Greany P. D., Oatman E. R. Heat extraction technique for recovery of potato tuberworm larvae from potato tubers. Jour. Econ. Ent. 1969. 62:271-72.
Platner G. R., Scriven G. T., Braniger C. E. Modification of a compact refrigerator for bio-ecological studies under controlled physical parameters. Environ. Entomol. 1973. 2:1118-20.
Rockstein M., Miguel J., Rockstein M. Aging in insects. The Physiology of Insecta. 1973. 1:Academic Press. p. 371-478. DOI: 10.1016/B978-0-12-591601-1.50013-2 [CrossRef]
Schrottky C. Neue argentinische Hymenopteren. An. Mus. Nat. Buenos Aires. 1902. 7:91-117.
Sokal R. R., Rohlf F. J. Biometry: the principles and practice of statistics in biological research. 1969. San Francisco: W. H. Freeman and Company. 776p.
Watson T. F. Influence of host plant condition on population increase of Tetranychus telarius (Linnaeus) (Acarina: Tetranychidae). Hilgardia. 1964. 35:273-322. DOI: 10.3733/hilg.v35n11p273 [CrossRef]
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