The Biology of the Parasites of Loxostege sticticalis, L., in North America—Bracon vulgaris (Cress.) (Braconidae, Agathinae)

Abstract

In a previous paper (Simmonds 1946*) the biology of Phytodietus pulcherrimus (Cress.), a parasite of Loxostege sticticalis, L., the sugar-beet web-worm, has been described. This paper will be devoted to the habits and life-history of another important parasite of Loxostege in North America, Bracon vulgaris (Cress.). This species appears to be confined to the American continent, all of the records being from Canada and the U.S.A. It has been reared only from Loxostege sticticalis, L., and L. commixtalis, Wlk. From the former species it has been recorded by Paddock (1912), Swenk (1918), Jones, Hoerner and Corkins (1921), Pepper and Hastings (1941), and Simmonds (1946); from the latter species by Hoerner (1933). During the present work it has been reared from L. sticticalis, material from both Montana and Alberta.

An Insight in the Reproductive Biology of Therophilus javanus (Hymenoptera, Braconidae, and Agathidinae), a Potential Biological Control Agent against the Legume Pod Borer (Lepidoptera, Crambidae)

“…In spite of the uniform size of M. vitrata caterpillars used for parasitization, we did observe a variable number of eggs in T. javanus females, which has been demonstrated to depend on abiotic or biotic factors in the Agathidinae B. vulgaris and A. gibbosa [9,11]. For instance, the number of eggs laid by B. vulgaris varies depending on the size of the wasp female and on temperature at adult emergence, whereas mating is known to decrease egg load in A. gibbosa.…”

“…This minute size and the tear shape of T. javanus eggs correspond to previous descriptions of Agathidinae eggs such as those produced by B. vulgaris (Cress. ), A. pumila, and A. gibbosa [9][10][11]. T. javanus females are synovigenic; that is, they emerge with high numbers of immature eggs and only few mature eggs but continue to produce eggs throughout the adult stage, implying that females can start to oviposit in host caterpillars just after emergence.…”

“…Although Agathidinae have been Psyche studied for taxonomic or phylogeny purposes, the biology of members of this subfamily remains largely unknown. A few biological and quite ancient studies have been conducted on Agathidinae oviposition and larval development [8][9][10][11]. Most studied Agathidinae species oviposit into special organs (nerve ganglia) [12], but some, including T. javanus, place their eggs directly into the host hemocoel [8][9][10].…”

“…Most studied Agathidinae species oviposit into special organs (nerve ganglia) [12], but some, including T. javanus, place their eggs directly into the host hemocoel [8][9][10]. Apart from a few studies, that is, the number of eggs laid by Bracon vulgaris (Hymenoptera: Braconidae) [11], and the number of offspring produced by Agathis gibbosa (Hymenoptera: Braconidae) [9], there is a dearth of data concerning Agathidinae reproductive biology.…”

Revision of the Oriental genera of Agathidinae (Hymenoptera, Braconidae) with an emphasis on Thailand and interactive keys to genera published in three different formats

“…In general they are solitary, attack fi rst-instar Lepidoptera larvae in concealed microhabitats such as leafrolls or stems, and emerge from the last larval instar of the host after it has spun its cocoon. Detailed studies of life history have been conducted for a few species (e.g., Simmonds 1947, Dondale 1954, Odebiyi and Oatman 1972, Janzen et al 1998) and a few have been used in classical biological control eff orts. Currently there are about 50 genera recognized (Sharkey 1992).Th e history of higher classifi cation of the Agathidinae was summarized by Sharkey (1992) who also proposed a tribal-level classifi cation based on groundplan coding.…”