Biology and temperature responses ofChelonus KellieaeandChelonus phthorimaeae(Hymenoptera: Braconidae) and their host, the potato tuberworm,Phthorimaea operculella(Lepidoptera: Gelechiidae)

Abstract

MATERIALS AND METHODS Environmental ConditionsStock cultures of the host and parasite were maintained in an insectary room at 26.7±1°C and 50% RH. Light was supplied by eight 40-watt, cool, fluorescent tubes, and was reg ulated by an automatic time switch set for alternating periods of 12 hours of light and 12 hours of darkness. A fan circulated air in the room to prevent stratification of air. Cultures of hostCultures of P. operculella were maintained in the insectary on White Rose and Russett potato tubers, using techniques developed by Plainer and Oatman (1968). Adult P. operculella were placed in cages which held muslin cloth that had been soaked in potato juice to stimulate oviposition thereon. These u egg cloths" were removed daily and the eggs used to establish subcultures of the parasites or for various experiments. Cultures of parasiteChelonus kellieae and C. phthorimaeae were handled identically throughout these studies. Studies of both species were conducted concurrently in separate spaces with identical conditions and repeated for replication. A culture of C. kellieae has been maintained in the insectary since its release from quarantine in June 1973. The culture of C. phthorimaeae was obtained in 1977 from host material collected from potato plants grown on the University of California's field station at Moreno.The parasite colonies were maintained in wooden cage "emergence units" (41.9 X 41.9 X 35.6 cm) with glass tops, lateral panels of organdy cloth for ventilation, and a detachable section on one side to facilitate manipulation of the material inside the emergence unit without letting the insects escape. White sand was distributed evenly over the bottom of the emergence units for pupation of the larvae. To maintain the culture, female parasites, newly emerged from hosts, were removed daily and placed in a wooden cage "sting unit" (30.5 X 35.6 X 27.9 cm). The sting unit was similar in construction to the emergence unit, except that its top was covered with black cloth to eliminate light. The back organdy panel also was covered with black cloth, except for a 10.2 X 10.2 cm area which permitted light to penetrate. An egg cloth (ca. 10 X 10 cm) with newly oviposited host eggs was fastened to the inside of this lighted area of the sting unit. Female parasites were attracted to this lighted area and, upon contact with the egg cloth, oviposited in the host egg. After a 24-hour exposure, the host egg cloth was removed and placed on punctured tubers on an inverted galvanized wire tray (12 X 12 cm) within the emergence unit. These procedures were repeated periodically, using one emergence unit and one sting unit for each species.When needed, virgin female or male parasites were obtained by isolating cocoons in clear gelatin capsules (size 000) and holding them until the parasite emerged.

The Potato Tuberworm: A Literature Review of Its Biology, Ecology, and Control

“…Other parasitoids like Tachinidae (Incamyia cuzcensis T.T. and Lixophaga diatraeae Towns), and more than 60 Hymenoptera (Braconidae, Encyrtidae, Eulophidae, Ichneumonidae, Mymaridae, Perilampidae, Pteromalidae, Scelionidae, and Trichogrammatidae) have also been described by several authors (Labeyrie 1959;Lloyd and Guido 1963;Jai Rao 1967;Rao 1967;Rao and Ramachandran-Nair 1967;Leong and Oatman 1968;Rao and Nagaraja 1968;Oatman et al 1969;Lloyd 1972;Odebiyi and Oatman 1972;Cruickshank and Ahmed 1973;Callan 1974;Oatman et al 1974;Oatman and Platner 1974;Cardona and Oatman 1975;Chundurwar 1977Chundurwar , 1978Odebiyi and Oatman 1977;Mitchell 1978;Divakar and Pawar 1979;Franzman 1980;Sankaran and Girling 1980;Briese 1981;Oatman 1982, 1987;Powers and Oatman 1984;Izhevskiy 1985;Horne 1990Horne , 1993. Among all parasitoids listed, there are some ecological differences; for instance, while C. desantisi oviposits in the eggs, A. subandinus and O. lepidus prefer young P. operculella larvae (Platner and Oatman 1972a).…”

Studies on the population dynamics of the potato tuber moth (Phthorimaea operculella Zell. (Lep., Gelechiidae) in the Republic of Yemen

“…(Hym. Braconidae) parasitizing the eggs (POWERS and OATMAN 1984). It was therefore of interest to know how many potato tuber moth larvae are parasitized in leaves and tubers.…”

“…The parasitoids Diadegma molliplum and Chelonusphthorimaeae also occur in other countries as antagonists of the potato tuber moth. C. phthorimaeae occurs in southern California (POWERS and OATMAN 1984) and D. molliplum (Diadegma stellenboschense Cameron) as well as Chelonus curvimaculatus Cam. occur in South Africa (WATMOUGH et al 1973;WHITESIDE 1980).…”

“…In addition, in comparison to the potato tuber moth, the life cycle of C. phthovimaeae is much longer at temperatures below 25°C. According to POWERS and OATMAN (1984), at mean temperatures of 21 "C, the potato tuber moth needs 3 5 4 0 days, and C. phthorimaeae between 50-55 days, for the development from egg to adult. The development of D. molliplum is much shorter at all temperatures than that of the potato tuber moth (BROOD-RYK 1971b).…”

Oviposition behavior of wild Zabrotes subfasciatus (Coleoptera, Chrysomelidae) females deprived of the host Phaseolus vulgaris (Fabaceae)

“…According to these authors they make antennation, probably searching an ideal site to carry out oviposition. In parasitoid wasps, antennation has as function to recognize the host and distinguish whether it is parasited, as observed by POWERS & OATMAN (1984) in Chelonuns kellieae (Marsh, 1919) and C. phthorimaeae (Gahan, 1917) andTAGAWA et al (1985) in Apanteles glomeratus (Linnaeus, 1758). This behavior can be due to the presence of odors of the host that orientate the female for oviposition (VISSER, 1986).…”