A sex pheromone isolated from the cuticle and feces of the female house fly attracts the male fly; it has been identified as ( Z )-9-tricosene. Chemical and biological comparisons of the natural and synthesized compounds show that they are identical.

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In memory of Christa L. Hoyt We have examined the effects of RH 5849, a lion-steroidal ecdysteroid mimic, on the growth and development of Plodia inferpuncteila. When R H 5849 was administered in the diet, larval growth was inhibited in a dose-dependent manner, while concentrations of 15 ppm and greater were highly toxic. However, the deleterious effects of RH 5849 could be prevented, except at very high concentrations of RH 5849, by the simultaneous administration of the juvenile hormone mimic methoprene. Larvae simultaneously treated with both hormone mimics continued to grow until they attained a size about three times normal. This growth was accompanied by at least one and sometimes two supernumerary molts, whereas, only an occasional supernumerary molt occurred in larvae treated with methoprene alone. In larvae undergoing supernumerary molts, wing imaginal discs produced a tanned pupal cuticle, but did not evaginate. When wing discs were cultured in vitro, RH 5849 stimulated evagination and chitin synthesis at concentrations of 10 and 1 pM, respectively. Likewise, RH 5849 stimulated GlcNAc uptake and inhibited cellular proliferation in IAL-PID2 cells at similar concentrations. These in vitro effects of RH 5849 also were produced by 20-hydroxyecdysone, but at lower concentrations. We conclude that RH 5849 exhibits molting hormone activity in vivo as well as in vitro. However, the toxicological effects in /? interpunctella result from action on feeding and growth, rather than molting. Thus, RH 5849 represents a new class of IGR, which will have impact on our understanding of endocrine regulation and open up new avenues for pest control.

The first non-steroidal ecdysteroid agonists are dibenzoyl hydrazines and are typified by the compounds designated RH-5849 and RH-5992. The discovery that these compounds mimic 20E in a variety of insect orders, and especially the Lepidoptera, generated great interest from the research and agricultural communities. Such compounds provide important new research tools for physiological, biochemical, and molecular studies. In addition, the potential for application to agricultural pests looks very promising, especially for RH-5992 (tebufenozidej. This review evaluates the evidence o n the specificity of the ecdysteroid-like actions of these materials and considers their application for research and pest management. o 1995 WiIey-Liss, Inc *

: Insect growth regulators (IGRs) have been proposed as agents for the control of insect pests. These compounds disrupt the normal development of insects by mimicking juvenile hormone and the molting hormone, 20-hydroxyecdsyone, or by interfering with chitin synthesis. The e †ectiveness and selectivity of IGRs provide new tools for integrated pest management. The simultaneous advances in the chemistry of IGRs and the ability to study insect tissues in culture, have led to research on the mode of action of IGRs in vitro. Plodia interpunctella and Spodoptera frugiperda have been used to examine the e †ects of IGRs on wing imaginal discs in organ culture, as well as in hormonally responsive cell lines established from wing imaginal discs of these species. Our research has focused on the action of ecdysteroid mimics, chitin synthesis inhibitors and juvenile hormone mimics. The e †ects of the IGRs on chitin synthesis, uptake of amino-sugars, and cellular proliferation were studied in tissue culture. The results demonstrate the e †ectiveness of using organ cultures and hormonally responsive cell lines for investigating IGRs at the cellular and tissue level.1998 Society of Chemical Industry ( Pestic. Sci., 54, 000È000 (1998) Key words : tebufenozide ; methoprene ; fenoxycarb ; chlorÑua-zuron ; diÑubenzuron ; insect growth regulators ; juvenile hormone mimicsThe use of tissue culture techniques to study insect physiology was Ðrst described in a publication on spermatogenesis by Goldschmidt in 1915,1 but, substantial * To whom correspondence should be addressed. E-mail : hoberlander=gainsville.usda.uÑ.edu interest in such techniques was not evident until the 1960s. Even in 1983, Marks pointed out that the "use of organ and cell cultures to study the mode of action of various agricultural and industrial chemicals is a new Ðeld with considerable potentialÏ.2 While there was rapid progress in the utilization of organ cultures for studying the action of insect hormones, particularly ecdysteroids, there was little progress in using established cell lines for this purpose until the 1980s. Most insect cell lines at that time derived from embryonic tissues or the ovariole sheath. Thus, it was difficult to utilize continuous cell lines for studying hormonal e †ects, given the unknown speciÐc source of the cells, and the lack of retention of any specialized properties by the dividing cells. This problem was overcome with establishment of cell lines from wing imaginal discs which retained their ability to respond to ecdysteroid hormones.3,4 Several reviews have focused on the advantages of utilizing cell lines as well as organ cultures for investigating hormonal action in insects.5h7 With increasing use of organ and cell cultures for this purpose, it became apparent that these same systems could be used to study the action of insect growth regulators (IGRs) which either mimic insect hormones or otherwise interfere with developmental processes.Chitin, an essential component of insect cuticle, is central to the structural int...

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We describe a provitellogenic stage, a previously unrecognized stage of follicle development in moths, and show that oocytes begin yolk sphere formation prior to the development of patency by the follicular epithelium. The vitellogenic activities of follicles from pharate adult femalePlodia interpunctella (Hübner) were determined by visualizing the subunits of vitellin (YP1 and YP3) and the follicular epithelium yolk protein (YP2 and YP4) using monospecific antisera to each subunit to immunolabel whole-mounted ovaries or ultrathin sections. At 92 h after pupation, yolk spheres that contained only YP2 began to proliferate in the oocytes. The inter-follicular epithelial cell spaces were closed at 92 h making vitellogenin inaccessible to the oocyte, and consequently, the vitellin subunits were not observed in the yolk spheres. YP2 uptake most likely occurred across the brush border from the follicular epithelial cells to the oocyte at this time. At 105 h, the inter-follicular epithelial cell spaces appeared closed yet trace amounts of labeling for vitellin were observed in the spaces and also in the yolk spheres along with YP2. Equivalent labeling for all four YPs in yolk spheres was finally observed at 112 h after pupation when the follicular epithelium had become patent. These data indicate that the provitellogenic stage is an extended transition period between the previtellogenic and vitellogenic stages that lasts for approximately 13 h, and it is marked at the beginning by YP2 yolk sphere formation in the oocyte and at the end by patency in the follicular epithelium.