Delayed mating reduces fecundity of blackheaded fireworm, Rhopobota naevana, on cranberry

Abstract

This study examines the effects of delayed mating on two successive generations of blackheaded fireworm, Rhopobota naevana Hübner (Lepidoptera: Tortricidae), a pest of cranberry, Vaccinium macrocarpon Aiton (Ericaceae). The first (spring) generation produces eggs that hatch soon after oviposition, whereas the second (summer) generation produces mostly diapause eggs. Unmated female and male moths were placed together on the first, second, fourth, sixth, or eighth day after emergence. In the first generation, incidence of mating was greatest in the 1‐, 2‐, and 4‐day treatments then declined as female survival decreased. In the second generation, incidence of mating was lowest in the 1‐day treatment and greatest in the 2‐, 4‐, and 6‐day treatments. Most second generation females in the 6‐ and 8‐day treatments survived to mate. The mean oviposition period was 2.6 days for first generation females and 4.1 days for second generation females. Fecundity of singly mated females in both generations declined as age at mating advanced, but the pattern of decline differed between generations. First generation females that were mated on the first or second day laid more eggs than those mated on the fourth, sixth, or eighth day, and the number of infertile eggs increased as age at mating advanced. Fecundity of second generation females declined more gradually and the number of infertile eggs was greatest for females mated on the first, sixth, or eighth day. A consequence of the marked decline in fecundity due to mating delays in the first generation was that mean fecundity of the entire group of first generation females was ca. 13% less than that of the group of second generation females. On cranberry farms, pheromone‐mediated mating disruption can prevent or delay mating of blackheaded fireworm. If the frequency of disrupted (prevented and delayed) matings is similar in the two generations, fewer eggs will be laid in the first generation than in the second.

Female detection of the synthetic sex pheromone contributes to the efficacy of mating disruption of the European grapevine moth, Lobesia botrana

“…The negative effect of extended calling on the number of eggs laid by moths has been demonstrated previously by Harari et al ., while reduced fecundity with female age at mating has been demonstrated for L. botrana by Torres‐Vila et al . and for other species elsewhere . Jones and Aihara‐Sasaki have further suggested a synergetic effect on the decreased number of eggs when mating is delayed, as older females may die before ovipositing because of various mortality factors.…”

When mating disruption does not disrupt mating: fitness consequences of delayed mating in moths

“…However, there are examples of successful mating disrup-tion programs for both univoltine and multivoltine moth species. Delayed mating can differentially affect different generations within bivoltine and multivoltine species (Fitzpatrick, 2006). As well, the multivoltine codling moth, C. pomonella, is effectively controlled with mating disruption in many temperate fruit growing regions (Kehat et al, 1995;Brunner et al, 2002).…”

“…In British Columbia, Canada, each generation of the bivoltine blackheaded fireworm, Rhopobota naevana Hübner (Lepidoptera: Tortricidae), is affected differently by delayed mating (Fitzpatrick, 2006). Assessment of the effect of delayed mating on moth fitness in different families or with different life-history traits, such as voltinism, larval diet breadth, dispersal capacity, female mating strategy, and egg development strategy, will provide more information on how to best implement mating disruption into IPM programs that target different species.…”

“…Assessment of the effect of delayed mating on moth fitness in different families or with different life-history traits, such as voltinism, larval diet breadth, dispersal capacity, female mating strategy, and egg development strategy, will provide more information on how to best implement mating disruption into IPM programs that target different species. Second-generation females primarily produce diapause eggs for overwintering, and this may contribute to the difference in the effect of delayed mating between the two generations (Fitzpatrick, 2006). In British Columbia, Canada, each generation of the bivoltine blackheaded fireworm, Rhopobota naevana Hübner (Lepidoptera: Tortricidae), is affected differently by delayed mating (Fitzpatrick, 2006).…”

Effect of Increased Male and Female Age at Mating on the Reproductive Performance of <I>Cnaphalocrocis medinalis</I> (Crambidae: Lepidoptera)

“…In some situations, mating disruption does not completely inhibit mating because some males may eventually Þnd females if given enough time (Torres-Vila et al 2002, Wenninger andAverill 2006). Nevertheless, several laboratory studies have shown that delayed mating can have a signiÞcantly negative effect on the reproductive performance of lepidopteran pests by decreasing female readiness to mate, and reducing the number of eggs laid and the hatchability (Torres-Vila et al 2002, Michereff et al 2004, Fitzpatrick 2006. Thus, even though mating disruption treatment may not inhibit mating completely, signiÞcant control of the pest population may be achieved through delayed mating (Miller et al 2006).…”