Biological Relationships Between Cardiochiles nigriceps and the Heliothis Complex1

Lewis, W. J.; Brazzel, J. R.

doi:10.1093/jee/59.4.820

Cited by 20 publications

(7 citation statements)

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“…Larvae that died prior to either pupation or parasitoid emergence were dissected as described in Lewis and Brazzel (1966) to check for the presence of parasitoid eggs and larvae. After collecting larvae, we assessed percent of larvae initially set out that were recovered from plants, percent of recovered larvae dying prior to pupation from causes other than parasitism, and percent of recovered larvae parasitized (i.e., a parasitoid either emerged or was detected upon dissection of a dead larva).…”

Section: Experimental Methodsmentioning

confidence: 99%

Behavioral Adaptations Increase the Value of Enemy-Free Space for Heliothis Subflexa, a Specialist Herbivore

Oppenheim

Gould

2002

Evolution

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Abstract. We investigated the importance of specialized behaviors in the use of enemy-free space by comparing the host-use behavior of two closely related moths, Heliothis subflexa Guenee and H. virescens Fabricius. Heliothis subflexa is a specialist on plants in the genus Physalis, whereas H. virescens is an extreme generalist, feeding on plants in at least 14 families. Heliothis subflexa uses the inflated calyx surrounding Physalis fruits as enemy-free space, and field rates of parasitism for H. subflexa on Physalis are much lower than for H. virescens on tobacco and cotton, common hosts found in the same habitat as Physalis. If Physalis' architecture were solely responsible for H. subflexa's low rates of parasitism on Physalis, we predicted that H. virescens larvae experimentally induced to feed on Physalis would experience parasitism rates similar to those of H. subflexa. We found, however, that specialized host-use and hostacceptance behaviors are integral to the use of enemy-free space on Physalis and strongly augment the effects of the structural refuge. In laboratory assays, we found considerable differences between the larval behavior of the specialist, H. subflexa, and the generalist, H. virescens, and these contributed to H. subflexa's superior use of enemy-free space on Physalis. We tested the importance of these behavioral differences in the field by comparing parasitism of H. virescens on Physalis, H. virescens on tobacco, and H. subflexa on Physalis by Cardiochiles nigriceps Vierick, a specialist braconid parasitoid. For H. virescens, a threefold decrease in parasitism occurred when feeding on Physalis (mean parasitism Ϯ SEM ϭ 13 Ϯ 4%) rather than tobacco (43 Ϯ 4%), a difference we attribute to the structural refuge provided by Physalis. However, parasitism of H. virescens on Physalis was more than ten times as great as that of H. subflexa on Physalis (1 Ϯ 4%), supporting the hypothesis that specialized behaviors have a substantial impact on use of Physalis as enemy-free space. Behavioral adaptations may be central to the use of enemy-free space by phytophagous insects and may act as an important selective force in the evolution of dietary specialization. The question of why insect herbivores eat what they do has long intrigued biologists. With the huge variety of edible plants available in the world, why should a herbivore limit itself to one or a few plant species? Yet, the vast majority of phytophagous insects are dietary specialists (Farrell and Mitter 1993;Thompson 1994), feeding on plants from a single genus or a single family (Menken and Roessingh 1998). Less than 10% of all phytophagous insects are generalists, feeding on plants from three or more families (Bernays and Graham 1988). This predominance of specialist feeders suggests that insects with narrow host ranges may enjoy some selective advantage over generalist feeders.The ability to use enemy-free space, defined by Berdegue et al. (1996, p. 203) as ''a discrete moment in evolutionary time where the fitness of the prey, under select...

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Section: Experimental Methodsmentioning

confidence: 99%

Behavioral Adaptations Increase the Value of Enemy-Free Space for Heliothis Subflexa, a Specialist Herbivore

Oppenheim

Gould

2002

Evolution

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“…They were later dissected as described in Lewis and Brazzel (1966) to determine if they were parasitized. For each bag we also recorded the total number of larvae and the identity of each larva as H. subflexa was verified (McElvare 1941).…”

Section: Methodsmentioning

confidence: 99%

The Inflated Calyx of Physalis angulata: A Refuge from Parasitism for Heliothis subflexa

Sisterson¹

1999

Ecology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecology. Abstract.Heliothis subflexa and H. virescens are the only known hosts of the parasitoid Cardiochiles nigriceps. H. subflexa, a specialist on plants in the genus Physalis, appears to have a lower parasitism rate compared to the polyphagous H. virescens. Physalis is characterized by producing fruits that are concealed within a paper-like lantern, within which H. subflexa larvae feed. We conducted an experiment to determine whether H. subflexa is protected from parasitism by feeding within the lanterns of Physalis. We compared parasitism rates of wild H. subflexa larvae on normal P. angulata plants to parasitism rates of larvae on plants that had the tips of all the lanterns removed to allow parasitoids access to the larvae. A higher percentage of larvae were parasitized on plants with cut lanterns (48.25%) than uncut lanterns (6.74%). A second experiment was conducted to determine whether volatiles released from cut lanterns influenced the searching of C. nigriceps. This experiment consisted of the two treatments from the previous experiment and a third in which the tips of lanterns were removed and the resulting hole was stapled shut. Cutting plants did not make the plants more attractive to searching parasitoids. We conclude that H. subflexa gains protection from parasitism by feeding within the inflated (;alyx of Physalis.

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“…Other information on C. nigriceps is given on: (a) host finding by Strand & Vinson, 1982;Vinson, 1968Vinson, , 1975Vinson & Lewis, 1965; host acceptance by Hays & Vinson, 1971;Lewis & Brazzel, 1966;Lewis et al, 1967;Lewis & Vinson, 1968a;Lynn & Vinson, 1977;Vinson, 19726, 1974aVinson, 19726, , I977a&b, 1978Vinson & Abies, 1980;Vinson & Guillot, 1972; host suitability by Lewis & Vinson, 1971;Vinson, 1971Vinson, , 1972aVinson & Iwantsch, 1980; morphology by Davies et al, 1986;Edson et al, 1982;Norton & Vinson, 1974a&6;Vinson, 1969;Vinson & Scott, 1974; (e) microbiology by Brooks, 1973;Brooks & Cranford, 1972;Dunbar & Johnson, 1975;Fuxa & Brooks, 1979;Stoltz et al, 1976;Thompson, 1983;Vinson & Scott, 1975; (/) biochemistry by Brewer & Vinson, 1971;Brewer et al, 1973;Dahlman & Vinson, 1975;Guillot et al, 1974;Kahn et al, 1976;Thompson, 1983;Tingle & Mitchell. 1982;Vinson, 19746; insecticides by Fix & Plapp, 1983; teratocytes by Joiner et al, 1973;Vinson & Lewis, 1973;Vinson & Scott, 1974.…”

Section: Biology Of Cardiochiles Nigricepsmentioning

confidence: 99%

Cardiochiles (Hymenoptera: Braconidae), a parasitoid of lepidopterous larvae, in the Sahel of Africa, with a review of the biology and host relationships of the genus

Huddleston

Walker

1988

Bull. Entomol. Res.

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In the ecologically sensitive Sahel of West Africa, two major crop pests, Helicoverpa armigera (Hubner) and Heliocheilus albipunctella (de Joannis), are attacked by Cardiochiles variegatus Szepligeti and C. sahelensis sp. n., respectively. The twelve Cardiochiles species present in the Sahel are revised, and a key is given for their identification. Five of these species (C. calvus sp.n., C. coelofrons sp. n., C. exiguurus sp. n., C. nixoni sp. n. and C. sahelensis sp. n.) are described, and C. striatus Brues is made a synonym of C. punctatus Szepligeti. Host relationships of the genus worldwide are discussed and the host records, principally involving Pyralidae and Noctuidae, collated. The known biology is summarized from the literature on the North American species C. nigriceps Viereck, and a comprehensive bibliography on the genus is given. Abstract

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Biological Relationships Between Cardiochiles nigriceps and the Heliothis Complex1

Cited by 20 publications

References 0 publications

Behavioral Adaptations Increase the Value of Enemy-Free Space for Heliothis Subflexa, a Specialist Herbivore

Behavioral Adaptations Increase the Value of Enemy-Free Space for Heliothis Subflexa, a Specialist Herbivore

The Inflated Calyx of Physalis angulata: A Refuge from Parasitism for Heliothis subflexa

Cardiochiles (Hymenoptera: Braconidae), a parasitoid of lepidopterous larvae, in the Sahel of Africa, with a review of the biology and host relationships of the genus

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